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Sample records for nd-fe-b magnet scrap

  1. Liquid metal extraction of Nd from NdFeB magnet scrap

    SciTech Connect

    Xu, Yanchen

    1999-12-10

    This research involves using molten magnesium (Mg) to remove neodymium (Nd) from NdFeB magnet scrap by diffusion. The results show that liquid metal extraction of Nd may be a viable and inexpensive method for recovering the expensive rare earth element Nd for use in Mg castings.

  2. Selective Leaching Process for Neodymium Recovery from Scrap Nd-Fe-B Magnet

    NASA Astrophysics Data System (ADS)

    Lee, Ching-Hwa; Chen, Yu-Jung; Liao, Ching-Hua; Popuri, Srinivasa R.; Tsai, Shang-Lin; Hung, Chi-En

    2013-12-01

    Neodymium-iron-boron (Nd-Fe-B) magnets were most widely applied to permanent magnetic products in the world due to their high magnetic force. The increasing growth of scrap Nd-Fe-B magnets resulted in disposal problems and the reduction of neodymium (Nd) valuable resources. In this study, we developed a simple hydrometallurgical precipitation process with pH adjustment to separate and recover Nd 100 pct recovery from scrap Nd-Fe-B magnets. Several physical and chemical methods such as demagnetization, grinding, screening, and leaching processes were also adopted to investigate the recovery of Nd and other metals from scrap Nd-Fe-B magnets. The leaching process was carried out with four leaching reagents such as NaOH, HCl, HNO3, and H2SO4. Batch studies were also conducted to optimize the leaching operating conditions with respect to leaching time, concentration of leaching reagent, temperature, and solid/liquid ratio for both HCl and H2SO4 leaching reagents. Nd was successfully separated and recovered with 75.41 wt pct from optimized H2SO4 leaching solution through precipitation. Further, the purity and weight percentage of the obtained Nd product was analyzed using scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) analysis. An X-ray diffraction (XRD) study confirmed the obtained product of Nd was in the form of NdOOH and Nd(OH)3.

  3. Corroded microstructure of HDDR-NdFeB magnetic powders

    NASA Astrophysics Data System (ADS)

    Zhu, L. Y.; Itakura, M.; Tomokiyo, Y.; Kuwano, N.; Machida, K.

    2004-08-01

    The microstructure of corroded HDDR-NdFeB magnetic powders in bonded magnet has been investigated by transmission electron microscopy. Following an exposure time of 300 h at 398 K in air, the HDDR-NdFeB magnetic powders are found covered with an altered layer about 300 nm thick on the surface. The layer is composed of α-Fe grains 5-10 nm in diameter and h-Nd 2O 3 grains smaller than 5 nm. Under the altered layer, corrosion has proceeded along the Nd 2(Fe,Co) 14B grain boundaries to leave a wetting layer composed of a dense mixture of α-Fe and h-Nd 2O 3 phase. The appearance of α-Fe grains in both of the altered layer wetting layer leads to the high magnetic flux loss of the corroded HDDR-NdFeB bonded magnet.

  4. Experimental Investigation and Thermodynamic Modeling of the B2O3-FeO-Fe2O3-Nd2O3 System for Recycling of NdFeB Magnet Scrap

    NASA Astrophysics Data System (ADS)

    Jakobsson, Lars Klemet; Tranell, Gabriella; Jung, In-Ho

    2017-02-01

    NdFeB magnet scrap is an alternative source of neodymium that could have a significantly lower impact on the environment than current mining and extraction processes. Neodymium can be readily oxidized in the presence of oxygen, which makes it easy to recover neodymium in oxide form. Thermochemical data and phase diagrams for neodymium oxide containing systems is, however, very limited. Thermodynamic modeling of the B2O3-FeO-Fe2O3-Nd2O3 system was hence performed to obtain accurate phase diagrams and thermochemical properties of the system. Key phase diagram experiments were also carried out for the FeO-Nd2O3 system in saturation with iron to improve the accuracy of the present modeling. The modified quasichemical model was used to describe the Gibbs energy of the liquid oxide phase. The Gibbs energy functions of the liquid phase and the solids were optimized to reproduce all available and reliable phase diagram data, and thermochemical properties of the system. Finally the optimized database was applied to calculate conditions for selective oxidation of neodymium from NdFeB magnet waste.

  5. Metal Injection Molding (MIM) of NdFeB Magnets

    NASA Astrophysics Data System (ADS)

    Hartwig, T.; Lopes, L.; Wendhausen, P.; Ünal, N.

    2014-07-01

    Due to the increased and unstable prices for Rare Earth elements there are activities to develop alternative hard magnetic materials. Reducing the amount of material necessary to produce complex sintered NdFeB magnets can also help to reduce some of the supply problem. Metal Injection Molding (MIM) is able to produce near net shape parts and can reduce the amount of finishing to achieve final geometry. Although MIM of NdFeB has been patented and published fairly soon after the development of the NdFeB magnets there has never been an industrial production. This could be due to the fact that MIM was very young at that time and hardly developed. Thus, the feasibility of the process needs to be revaluated. This paper presents results of our work on determining the process parameters influencing the magnetic properties of the sintered magnets as well as the shrinkage during processing. The role of binder and powder loading on the alignment of the particles as well as on the carbon and oxygen contamination was examined.

  6. Anisotropic powder from sintered NdFeB magnets by the HDDR processing route

    NASA Astrophysics Data System (ADS)

    Sheridan, R. S.; Sillitoe, R.; Zakotnik, M.; Harris, I. R.; Williams, A. J.

    2012-01-01

    Sintered NdFeB-based scrap magnets were recovered and processed using the HD and HDDR routes. The effects of varying the HDDR processing temperature were investigated (over the range 835-930 °C). The disproportion was carried out with a pressure ramp to a maximum of 1000 mbar hydrogen pressure with a 1 h hold time at each step and the optimum recombination conditions were set at 100 mbar with a 20 min hold time. Anisotropic NdFeB powder was produced in all cases with the best magnetic properties achieved at a processing temperature of 880 °C, producing powder with a remanence of 1.10(±0.02) T and an intrinsic coercivity of 800 (±16) kA m-1 and giving a (BH)max of 129(±2.5) kJ m-3.

  7. Magnetization reversal in melt-quenched NdFeB

    SciTech Connect

    Crew, D.C.; Lewis, L.H.; McCormick, P.G.; Street, R.; Panchanathan, V.

    1999-06-01

    Melt-quenched NdFeB is an important modern permanent magnet material. However there still remains doubt as to the magnetization reversal mechanism which controls coercivity in material prepared by this processing route. To investigate this problem a new technique based on measurements of reversible magnetization along recoil curves has been used. The technique identifies the presence of free domain walls during magnetic reversal. For this study samples of isotropic (MQI), hot pressed (MQII) and die upset (MQIII) melt-quenched NdFeB were examined. The results indicate that in MQI free domain walls are not present during reversal and the reversal mechanism is most likely incoherent rotation of some form. Free domain walls are also not present during reversal in the majority of grains of MQII, even though initial magnetization measurements indicate that the grain size is large enough to support them. In MQIII free domain walls are present during reversal. These results are attributed to the reduced domain wall nucleation field in MQIII compared with MQII and the increased dipolar interactions in MQIII.

  8. Development of extrusion molded Nd-Fe-B magnets

    SciTech Connect

    Sakata, M.; Ikuma, K. ); Watanabe, R.; Iwasa, T.; Miyadera, H.; McAloon, K.

    1993-01-01

    A new manufacturing process for extrusion molded magnets, composed of isotropic Nd-Fe-B powder and Nylon-12, has been developed. This newly developed extrusion molding process has several interesting features. First, the extruded product contains 72% by volume magnetic powder and yields a (BH)[sub max] of 8.0 MGO[sub e]. Second, through the addition of an anti-oxidant, the viscosity of the magnetic powder-nylon compound remains almost constant during molding. Third, by means of a specially cooled outlet, which is separated from the heated die by a thermal insulator, an optimized temperature profile is obtained which yields uniformly smooth extrusion molded magnets. Both long thin-walled magnets and small arc-shaped (kawala) magnets are easily molded by this new process.

  9. Effects of surface modification of Nd-Fe-B powders using parylene C by CVDP method on the properties of anisotropic bonded Nd-Fe-B magnets

    NASA Astrophysics Data System (ADS)

    Ma, Bin; Sun, Aizhi; Lu, Zhenwen; Cheng, Chuan; Xu, Chen

    2016-10-01

    This paper presents effects of surface modification of Nd-Fe-B powders using parylene C by means of chemical vapor deposition polymerization (CVDP) on the properties of anisotropic bonded Nd-Fe-B magnets. It can be well verified from SEM images and EDS analysis that the surface of Nd-Fe-B powder is coated with thin parylene C films. The maximum energy product ((BH)max), degree of alignment (DOA), actual density and corrosion resistance of parylene Nd-Fe-B magnets prepared at room temperature are much higher than that of non-parylene Nd-Fe-B magnets. (BH)max, DOA and actual density of parylene Nd-Fe-B magnets (70 kJ/m3, 0.342, 5.82 g/cm3) prepared at room temperature under 578 MPa are improved by 18.6%, 4.6%, 2.1% and 27.3%, 29.1%, 7.8% compared with non-parylene Nd-Fe-B magnets prepared at 140 °C (59 kJ/m3, 0327, 5.70 g/cm3) and room temperature (55 kJ/m3, 0.265, 5.40 g/cm3), respectively. Additional, the improvement of actual density and the room temperature process also solve problems such as powders' sticking wall, non-uniform powder filling, non-uniform magnetic properties, seriously mould damage, short life cycle of mould and so on, which exists during warm compaction process. Parylene Nd-Fe-B magnets have better corrosion resistance and worse mechanical properties than that of non-parylene Nd-Fe-B magnets. The reason for the improvement of magnetic properties and actual density is the low friction cofficient of parylene C films, which results in lower frictional resistance and better lubricating property of parylene Nd-Fe-B powders.

  10. Magnetic properties and thermal stability of MnBi/NdFeB hybrid bonded magnets

    NASA Astrophysics Data System (ADS)

    Cao, S.; Yue, M.; Yang, Y. X.; Zhang, D. T.; Liu, W. Q.; Zhang, J. X.; Guo, Z. H.; Li, W.

    2011-04-01

    Magnetic properties and thermal stability were investigated for the MnBi/NdFeB (MnBi = 0, 20, 40, 60, 80, and 100 wt.%) bonded hybrid magnets prepared by spark plasma sintering (SPS) technique. Effect of MnBi content on the magnetic properties of the hybrid magnets was studied. With increasing MnBi content, the coercivity of the MnBi/NdFeB hybrid magnets increases rapidly, while the remanence and maximum energy product drops simultaneously. Thermal stability measurement on MnBi magnet, NdFeB magnet, and the hybrid magnet with 20 wt.% MnBi indicates that both the NdFeB magnet and the MnBi/NdFeB hybrid magnet have a negative temperature coefficient of coercivity, while the MnBi magnet has a positive one. The (BH)max of the MnBi/NdFeB magnet (MnBi = 20 wt.%) is 5.71 MGOe at 423 K, which is much higher than 3.67 MGOe of the NdFeB magnet, indicating a remarkable improvement of thermal stability.

  11. Dy-Free Nd-Fe-B Based Permanent Magnets

    NASA Astrophysics Data System (ADS)

    Pathak, Arjun; Khan, Mahmud; Gschneidner, Karl, Jr.; McCallum, Ralph; Pecharsky, Vitalij

    2015-03-01

    Nd2Fe14B based permanent magnets are the current state of the art for high performance magnets. The prototype crystallize in the P42 / mnm tetragonal crystal structure, where the Nd atoms occupy the 4f and 4gsites, Fe atoms occupy six different atomic sites (16k1, 16k2, 8j1, 8j2, 4e, 4c), and B occupies only the 4g site. The leading contribution to the magnetocrystalline anisotropy in Nd2Fe14B energy comes from the Nd ions, which strongly prefer a c-axis alignment at ambient temperature. Nd2Fe14B permanent magnet has excellent magnetic properties at room temperature but has poor high temperature properties (T>400 K). A small amount of Dy (up to 10%) is substituted for Nd in Nd2Fe14B to increase the high temperature performance. Although Dy containing Nd2Fe14B magnets are desired for high temperature applications, the high price and limited supply of Dy urges the development of Dy-free permanent magnets. Here, we discuss the magnetic properties of several Dy-free Nd-Fe-B based nanostructured magnets and propose alternatives for Dy-based Nd2Fe14B permanent magnets for high temperature applications such as electric drive motors and wind turbines. This work was supported by the U.S.DOE, ARPA-E, Rare Earth Alternatives in Critical Technologies for Energy (REACT). The research was performed at the Ames Laboratory which is operated for the U.S. DOE by Iowa State University under contract #DE-AC02-07CH11358.

  12. 3-D laser confocal microscopy study of the oxidation of NdFeB magnets in atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Meakin, J. P.; Speight, J. D.; Sheridan, R. S.; Bradshaw, A.; Harris, I. R.; Williams, A. J.; Walton, A.

    2016-08-01

    Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.- computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to atmospheric conditions prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under atmospheric conditions. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd2O3 and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10-13 cm2/sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth observations at elevated temperatures in the literature. This indicates that the growth of the room temperature oxidation products are likely defect enhanced processes at the NdFeB triple junctions.

  13. Thermal aging of melt-spun NdFeB magnetic powder in hydrogen

    NASA Astrophysics Data System (ADS)

    Pinkerton, Frederick E.; Balogh, Michael P.; Ellison, Nicole; Foto, Aldo; Sechan, Martin; Tessema, Misle M.; Thompson, Margarita P.

    2016-11-01

    High energy product neodymium-iron-boron (NdFeB) magnets are the premier candidate for demanding electrified vehicle traction motor applications. Injection molded (IM) or compression molded (CM) magnets made using NdFeB powders are promising routes to improve motor efficiency, cost, and manufacturability. However, IM and CM NdFeB magnets are susceptible to substantial thermal aging losses at motor operating temperatures when exposed to the automatic transmission fluid (ATF) used as a lubricant and cooling medium. The intrinsic coercivity Hci of NdFeB IM and CM magnets degrades by as much as 18% when aged for 1000 h in ATF at 150 °C, compared to a 3% loss when aged in air. Here we report aging studies of rapidly quenched NdFeB powder in air, ATF, and H2 gas. Expansion of the NdFeB crystal lattice in both ATF and H2 identified hydrogen dissociated from the ATF during aging and diffused into the primary NdFeB phase as the probable cause of the coercivity loss of IM and CM magnets.

  14. Impulse Magnetization of Nd-Fe-B Sintered Magnets for Sensors

    PubMed Central

    Przybylski, Marek; Kapelski, Dariusz; Ślusarek, Barbara; Wiak, Sławomir

    2016-01-01

    Magnetization of large Nd-Fe-B sintered permanent magnets is still challenging. This type of permanent magnet is electrically conductive, so impulse magnetization causes a flow of eddy currents which prevent magnetization of the whole volume of the magnet. The paper deals with the impulse magnetization of sintered Nd-Fe-B permanent magnets and shows a method for the determination of suitable parameters for the supply system. The necessary magnetic field strength for magnetization of the magnet to saturation was determined. The optimal magnetizing fixture supply voltage for magnetization to saturation was determined from simulations in PSpice software, finite element analyses in Maxwell 15 and measurements. Measurements of magnetic induction on the surface of the Nd-Fe-B magnet are also presented to ensure that a magnet with 70 mm diameter and 20 mm in height is fully saturated. PMID:27110783

  15. Impulse Magnetization of Nd-Fe-B Sintered Magnets for Sensors.

    PubMed

    Przybylski, Marek; Kapelski, Dariusz; Ślusarek, Barbara; Wiak, Sławomir

    2016-04-21

    Magnetization of large Nd-Fe-B sintered permanent magnets is still challenging. This type of permanent magnet is electrically conductive, so impulse magnetization causes a flow of eddy currents which prevent magnetization of the whole volume of the magnet. The paper deals with the impulse magnetization of sintered Nd-Fe-B permanent magnets and shows a method for the determination of suitable parameters for the supply system. The necessary magnetic field strength for magnetization of the magnet to saturation was determined. The optimal magnetizing fixture supply voltage for magnetization to saturation was determined from simulations in PSpice software, finite element analyses in Maxwell 15 and measurements. Measurements of magnetic induction on the surface of the Nd-Fe-B magnet are also presented to ensure that a magnet with 70 mm diameter and 20 mm in height is fully saturated.

  16. Protection of NdFeB magnets by corrosion resistance phytic acid conversion film

    NASA Astrophysics Data System (ADS)

    Nan, Haiyang; Zhu, Liqun; Liu, Huicong; Li, Weiping

    2015-11-01

    Phytic acid conversion film was prepared on NdFeB magnets by dipping the NdFeB into phytic acid solution. The morphology, composition, structure and corrosion resistance of the film were systematically investigated. The results showed that the phytic acid film was effective in improving the corrosion resistance of NdFeB magnets. XRD, TEM and FT-IR analyses revealed that the film was amorphous and had a strong peak of phosphate radical (PO43-). The formation mechanism of the film was also explored by XPS and the potential of zero charge (Epzc) measurement at the solution-metal interface.

  17. Direct-write 3D printing of NdFeB bonded magnets

    DOE PAGES

    Compton, Brett Gibson; Kemp, James William; Novikov, Timofei V.; ...

    2016-08-17

    We report a method to fabricate Nd-Fe-B bonded magnets of complex shape via extrusion-based additive manufacturing (AM), also known as 3D-printing. We have successfully formulated a 3D-printable epoxy-based ink for direct-write AM with anisotropic MQA NdFeB magnet particles that can be deposited at room temperature. The new feedstocks contain up to 40 vol.% MQA anisotropic Nd-Fe-B magnet particles, and they are shown to remain uniformly dispersed in the thermoset matrix throughout the deposition process. Ring, bar, and horseshoe-type 3D magnet structures were printed and cured in air at 100°C without degrading the magnetic properties. Lastly, this study provides a newmore » pathway for fabricating Nd-Fe-B bonded magnets with complex geometry at low temperature, and presents new opportunities for fabricating multifunctional hybrid structures and devices.« less

  18. Direct-write 3D printing of NdFeB bonded magnets

    SciTech Connect

    Compton, Brett Gibson; Kemp, James William; Novikov, Timofei V.; Pack, Robert Cody; Nlebedim, Cajetan I.; Duty, Chad Edward; Rios, Orlando; Paranthaman, M. Parans

    2016-08-17

    We report a method to fabricate Nd-Fe-B bonded magnets of complex shape via extrusion-based additive manufacturing (AM), also known as 3D-printing. We have successfully formulated a 3D-printable epoxy-based ink for direct-write AM with anisotropic MQA NdFeB magnet particles that can be deposited at room temperature. The new feedstocks contain up to 40 vol.% MQA anisotropic Nd-Fe-B magnet particles, and they are shown to remain uniformly dispersed in the thermoset matrix throughout the deposition process. Ring, bar, and horseshoe-type 3D magnet structures were printed and cured in air at 100°C without degrading the magnetic properties. Lastly, this study provides a new pathway for fabricating Nd-Fe-B bonded magnets with complex geometry at low temperature, and presents new opportunities for fabricating multifunctional hybrid structures and devices.

  19. Origins of axial inhomogeneity of magnetic performance in hot deformed Nd-Fe-B ring magnets

    NASA Astrophysics Data System (ADS)

    Yin, Wen-Zong; Chen, Ren-Jie; Tang, Xu; Lin, Min; Lee, Don; Yan, Aru

    2012-04-01

    Hot-deformed Nd-Fe-B ring magnets have wide potential applications. These ring magnets, however, exhibit axial inhomogeneity of magnetic performance. In this work, the effects of density, pressure, deformation temperature, deformation rate, and texture on axial magnetic performance were investigated over ring magnets prepared by backward extrusion method. It was demonstrated that the texture accounted for the variation of magnetic performance along axial direction. Microstructures of the ring magnets were examined with SEM, which further revealed two different origins of axial inhomogeneity of magnetic performance. The deformation degree of Nd-Fe-B grains plays a critical role in the performance difference between the top and middle part of ring magnet. But that between the middle and bottom part mainly results from different alignment orientations of platelet Nd-Fe-B grains. It was both deformation degree and alignment orientation that determined the axial texture and consequent magnetic performance of hot-deformed ring magnets.

  20. Multiple magnetic scattering in small-angle neutron scattering of Nd-Fe-B nanocrystalline magnet

    NASA Astrophysics Data System (ADS)

    Ueno, Tetsuro; Saito, Kotaro; Yano, Masao; Ito, Masaaki; Shoji, Tetsuya; Sakuma, Noritsugu; Kato, Akira; Manabe, Akira; Hashimoto, Ai; Gilbert, Elliot P.; Keiderling, Uwe; Ono, Kanta

    2016-06-01

    We have investigated the influence of multiple scattering on the magnetic small-angle neutron scattering (SANS) from a Nd-Fe-B nanocrystalline magnet. We performed sample-thickness- and neutron-wavelength-dependent SANS measurements, and observed the scattering vector dependence of the multiple magnetic scattering. It is revealed that significant multiple scattering exists in the magnetic scattering rather than the nuclear scattering of Nd-Fe-B nanocrystalline magnet. It is considered that the mean free path of the neutrons for magnetic scattering is rather short in Nd-Fe-B magnets. We analysed the SANS data by the phenomenological magnetic correlation model considering the magnetic microstructures and obtained the microstructural parameters.

  1. Multiple magnetic scattering in small-angle neutron scattering of Nd-Fe-B nanocrystalline magnet.

    PubMed

    Ueno, Tetsuro; Saito, Kotaro; Yano, Masao; Ito, Masaaki; Shoji, Tetsuya; Sakuma, Noritsugu; Kato, Akira; Manabe, Akira; Hashimoto, Ai; Gilbert, Elliot P; Keiderling, Uwe; Ono, Kanta

    2016-06-20

    We have investigated the influence of multiple scattering on the magnetic small-angle neutron scattering (SANS) from a Nd-Fe-B nanocrystalline magnet. We performed sample-thickness- and neutron-wavelength-dependent SANS measurements, and observed the scattering vector dependence of the multiple magnetic scattering. It is revealed that significant multiple scattering exists in the magnetic scattering rather than the nuclear scattering of Nd-Fe-B nanocrystalline magnet. It is considered that the mean free path of the neutrons for magnetic scattering is rather short in Nd-Fe-B magnets. We analysed the SANS data by the phenomenological magnetic correlation model considering the magnetic microstructures and obtained the microstructural parameters.

  2. Modeling of magnetic properties of polymer bonded Nd-Fe-B magnets with surface modifications

    NASA Astrophysics Data System (ADS)

    Xiao, Jun; Otaigbe, Joshua U.; Jiles, David C.

    2000-07-01

    The effects of surface modification on the magnetic properties of polymer-bonded Nd-Fe-B magnets have been studied. Two sets of Nd-Fe-B powders, coated and uncoated, were blended and compression molded with polyphenylene sulfide in isotropic form. Their magnetic properties were measured using a Helmholtz coil and a SQUID. The results showed that the effect of the coating significantly improved the irreversible loss in flux and energy product of the polymer-bonded magnets. The results have been interpreted using an isotropic model of hysteresis that takes into account energy losses. The modeling showed that the presence of soft magnetic materials in the Nd-Fe-B powders caused by oxidation reduces the interaction among magnetic particles, however, the coating treatment alters the magnetic properties by increasing the remanence of polymer-bonded magnets via increasing the interparticle coupling coefficient.

  3. Development of High Performance Permanent Magnets Based on Nd-Fe-B System

    NASA Astrophysics Data System (ADS)

    Pourarian, F.

    2000-09-01

    Rare earth iron boron magnets based on Nd2Fe14B type is the most powerful permanent magnets, which have outstanding magnetic properties in the vicinity of room temperature. Production of NdFeB is carried out by two distinctly different processes. These include the conventional powder - sintering process and consolidation of rapidly solidified powders. The latter is used to produce both bonded and anisotropic bulk magnets. NdFeB sintered magnets essentially consist of three basic phases; Nd2Fe14B(Φ) Nd1Fe4B4 phase (η) and Nd-rich phase (n). Therefore, the magnetic properties of the magnets strongly depend on their microstructure. The current focus of NdFeB magnet research and development is on improvement of the magnetic properties such as the magnetic remanence (Br) and intrinsic coercivity (Hci), corrosion resistance and temperature characteristics of sintered magnets and rapidly solidified (melt spinning) magnets. Since the discovery of NdFeB magnets, their performance has been continuously enhanced and the current maximum energy product is achieved to be 444 kJ/m3 (55.8 MGOe). Other processes also have been used for improving microstructure for developing high energy product NdFeB magnets. These processes include: i) mechanical alloying process of metals which uses an inter-diffusional reaction magnet, ii) HDDR process (hydrogenation, disprorportionation, desorption, recombination) of magnet powder, and iii) nanocrystalline composite magnet (exchange-coupled) which are composed of magnetically hard and soft grains. The negative side of the NdFeB magnet is their low corrosion resistance. They are sensitive to attack by both climatic and corrosive environments, resulting in deterioration of the hard magnetic properties of the magnet. In this paper the development of the high-energy product NdFeB based magnets in terms of improved microstructure and magnet processing methods is reviewed.

  4. Assessment of corrosion resistance of Nd-Fe-B magnets by silanization for orthodontic applications

    NASA Astrophysics Data System (ADS)

    Fabiano, F.; Celegato, F.; Giordano, A.; Borsellino, C.; Bonaccorsi, L.; Calabrese, L.; Tiberto, P.; Cordasco, G.; Matarese, G.; Fabiano, V.; Azzerboni, B.

    2014-02-01

    Nd-Fe-B permanent magnets are characterised by excellent magnetic properties. However, being extremely vulnerable to the attack of both climate and corrosive environments, their applications are limited. This paper describes how, at different thicknesses of N-propyl-trimetoxy-silane, the coating affects the magnetic force of nickel plated magnets. We also investigate if the corrosion resistance of silanized Nd-Fe-B magnets increases in mildly corrosive environments by immersing them in a synthetic saliva solution. It was found that the silanization treatment does not affect the strength of the magnetic force and provide an enhancement of the corrosion resistance of the substrate.

  5. Prediction of particle orientation in simple upsetting process of NdFeB magnets

    SciTech Connect

    Chang, Chao-Cheng; Hsiao, Po-Jen; You, Jr-Shiang; Chen, Yen-Ju; Chang, Can-Xun

    2013-12-16

    The magnetic properties of NdFeB magnets are strongly affected by crystallographic texture which is highly associated with particle orientation. This study proposed a method for predicting the particle orientation in the simple upsetting process of NdFeB magnets. The method is based on finite element simulation with flow net analysis. The magnets in a cylindrical form were compressed by two flat dies in a chamber filled with argon at 750°C. Three forming speeds were taken into account in order to obtain flow stress curves used in simulations. The micrographs of the cross sections of the deformed magnets show that the particle deformation significantly increases with the compression. The phenomenon was also predicted by the proposed method. Both simulated and experimental results show that the inhomogeneity of the texture of the NdFeB magnets can be increased by the simple upsetting process. The predicted particle orientations were in a good agreement with those examined in the deformed magnets. The proposed method for predicting particle orientations can also be used in other forming processes of NdFeB magnets.

  6. Modification of the Interface Nanostructure and Magnetic Properties in Nd-Fe-B Thin Films.

    PubMed

    Koike, Kunihiro; Kusano, Takanao; Ogawa, Daisuke; Kobayashi, Keisuke; Kato, Hiroaki; Oogane, Mikihiko; Miyazaki, Takamichi; Ando, Yasuo; Itakura, Masaru

    2016-12-01

    The effects of Nd2Fe14B grain size and Nd coating on the coercivity in sputter-deposited Nd-Fe-B/Nd thin films have been investigated in order to gain an insight into the coercivity mechanism of Nd-Fe-B magnets. Highly textured Nd2Fe14B particles were grown successfully on the MgO(100) single-crystal substrate with the Mo underlayer. As the Nd-Fe-B layer thickness t NFB was decreased from 70 to 5 nm, the coercivity H c increased gradually from 6.5 to 16 kOe. By depositing the Nd overlayer onto these films and post-annealing at 500 °C, the H c value further increased from 17.5 kOe (t NFB=70 nm) to 26.2 kOe (t NFB=5 nm). The amount of H c increase by the combination of the Nd coating and post-annealing was about 10 kOe irrespective of the t NFB value. These results therefore suggest an independence of size and interface effects on the coercivity of Nd-Fe-B magnets.

  7. Application of bonded NdFeB magnet for C-Band circulator component

    NASA Astrophysics Data System (ADS)

    Kristiantoro, T.; Idayanti, N.; Sudrajat, N.; Septiani, A.; Dedi

    2016-11-01

    In this paper bonded NdFeB permanent magnets of the crashed-ribbon type were made as an alternative for circulator magnet to improve their magnetic performance. The fabrication process is also easier than the sintered NdFeB because there had no shrinkage of product (such as sintered barium ferrite magnet), with the others advantages as follows; large freeness of product shapes, high precision of dimension and good corrosion resistance. The dimension of the samples was measured to calculate its bulk densities and the magnetic properties were characterized by Permagraph to obtain values such as; Remanence induction (Br) in kG, Coercivity value (Hcj) in kOe, the Maximum energy product (BH max) in MGOe. Whereas the surface magnetic field strength (B) was observed by the Gauss-meter. The bonded NdFeB permanent magnets revealed 6.39 kG of Br, 6.974 kOe of Hcj and 7.13 MGOe of BHmax. The circulator performance was measured using Vector Network Analyzer (VNA). The optimum values of the circulator measurement at a frequency of 5 GHz show a VSWR value of 1.062 and insertion loss of -0.463 dB. The bonded magnet could be used as component of permanent magnets on the circulator that working on C-Band at a frequency range of 4 GHz - 8 GHz.

  8. Binder Jetting: A Novel NdFeB Bonded Magnet Fabrication Process

    NASA Astrophysics Data System (ADS)

    Paranthaman, M. Parans; Shafer, Christopher S.; Elliott, Amy M.; Siddel, Derek H.; McGuire, Michael A.; Springfield, Robert M.; Martin, Josh; Fredette, Robert; Ormerod, John

    2016-07-01

    The goal of this research is to fabricate near-net-shape isotropic (Nd)2Fe14B-based (NdFeB) bonded magnets using a three dimensional printing process to compete with conventional injection molding techniques used for bonded magnets. Additive manufacturing minimizes the waste of critical materials and allows for the creation of complex shapes and sizes. The binder jetting process works similarly to an inkjet printer. A print-head passes over a bed of NdFeB powder and deposits a polymer binding agent to bind the layer of particles together. The bound powder is then coated with another layer of powder, building the desired shape in successive layers of bonded powder. Upon completion, the green part and surrounding powders are placed in an oven at temperatures between 100°C and 150°C for 4-6 h to cure the binder. After curing, the excess powder can be brushed away to reveal the completed "green" part. Green magnet parts were then infiltrated with a clear urethane resin to achieve the measured density of the magnet of 3.47 g/cm3 close to 46% relative to the NdFeB single crystal density of 7.6 g/cm3. Magnetic measurements indicate that there is no degradation in the magnetic properties. This study provides a new pathway for preparing near-net-shape bonded magnets for various magnetic applications.

  9. Cerium: an unlikely replacement of dysprosium in high performance Nd-Fe-B permanent magnets.

    PubMed

    Pathak, Arjun K; Khan, Mahmud; Gschneidner, Karl A; McCallum, Ralph W; Zhou, Lin; Sun, Kewei; Dennis, Kevin W; Zhou, Chen; Pinkerton, Frederick E; Kramer, Matthew J; Pecharsky, Vitalij K

    2015-04-24

    Replacement of Dy and substitution of Nd in NdFeB-based permanent magnets by Ce, the most abundant and lowest cost rare earth element, is important because Dy and Nd are costly and critical rare earth elements. The Ce, Co co-doped alloys have excellent high-temperature magnetic properties with an intrinsic coercivity being the highest known for T ≥ 453 K.

  10. Coercivity and Grain Boundary Morphology in Nd-Fe-B Sintered Magnets

    NASA Astrophysics Data System (ADS)

    Tsubokawa, Yoshiyuki; Hirosawa, Satoshi; Shimizu, Ryuichi

    1990-12-01

    The microstructure of Nd15Fe77B8 sintered permanent magnets has been investigated under a 400 kV high-resolution transmission electron microscope. With particular concern about the microstructural changes in the Nd-Nd2Fe14B interfaces, the effects of isothermal heat treatment at 870 K have been studied for a more comprehensive understanding of the coercivity-microstructure relationship in the Nd-Fe-B sintered magnets. The atomic-scale steps along the grain boundary can be observed in as-sintered samples. The steps disappear after heat treatment, and very flat interfaces are formed. This atomic-scale alignment at the grain boundary, therefore, is one of the factors affecting the coercivity of Nd-Fe-B sintered magnets.

  11. Backward extruded NdFeB HDDR ring magnets

    NASA Astrophysics Data System (ADS)

    Gutfleisch, O.; Kirchner, A.; Grünberger, W.; Hinz, D.; Schäfer, R.; Schultz, L.; Harris, I. R.; Müller, K. H.

    1998-03-01

    Isotropic, submicron grained Nd 15Fe 77B 8 powder has been prepared by applying the HDDR process. Fully dense isotropic magnets have been produced by hot pressing, textured compacts have been obtained by subsequent die upsetting. Radially oriented ring magnets have been prepared by backward extrusion of the hot pressed compacts. Very encouraging magnetic properties have been achieved, the remanence measured in the radial direction is Br=1.07 T with a coercivity of iHc=575 kA/m. However, a decrease in alignment has been observed in the axial direction of the ring magnet. The effects of deformation temperature and speed have been investigated. Magnetic properties and the physical and magnetic microstructure have been characterised by VSM, SEM and high-resolution Kerr-effect microscopy, the latter showing the formation of interaction domains, which indicate a high degree of texture in a fine grained material, in both the die upset and the backward extruded ring magnet produced from Nd 15Fe 77B 8 HDDR material.

  12. Magnetization reversal mechanism of a sintered Nd-Fe-B magnet with Dy segregation

    SciTech Connect

    Suzuki, Hiroyuki; Satsu, Yuichi; Komuro, Matahiro; Kohashi, Teruo; Motai, Kumi

    2011-04-01

    The magnetization reversal mechanism of a sintered Nd-Fe-B magnet with Dy segregation near grain boundaries (GB) was studied using spin polarized scanning electron spectroscopy and magnetization measurements. More fine magnetic domains near GB were found in the magnet with Dy segregation than in the magnet without treatment. Magnetic modifications near the GB had no effect on the magnetization development. The domain wall motion of a quasihard magnetic component in the magnet with Dy segregation was suppressed in comparison with those in the magnet without treatment; this could also be confirmed in the different behaviors of asymmetry components toward a magnetic field direction between both magnets. From analyzing the probability of rotating magnetization near the GB, the magnetization reversal of the magnet with Dy segregation was more difficult to produce than those of the magnet without treatment.

  13. Magnetic microstructure and magnetic properties of spark plasma sintered NdFeB magnets

    NASA Astrophysics Data System (ADS)

    Huang, Y. L.; Wang, Y.; Hou, Y. H.; Wang, Y. L.; Wu, Y.; Ma, S. C.; Liu, Z. W.; Zeng, D. C.; Tian, Y.; Xia, W. X.; Zhong, Z. C.

    2016-02-01

    Nanocrystalline NdFeB magnets were prepared by spark plasma sintering (SPS) technique using melt-spun ribbons as starting materials. A distinct two-zone structure with coarse grain zone and fine grain zone was formed in the SPSed magnets. Multi-domain particle in coarse grain zone and exchange interaction domain for fine grain zone were observed. Intergranular non-magnetic phase was favorable to improve the coercivity due to the enhancement of domain wall pinning effects and increased exchange-decouple. The remanent polarization of 0.83 T, coercivity of 1516 kA/m, and maximum energy product of 118 kJ/m3 are obtained for an isotropic magnet.

  14. Prediction method of flux loss in anisotropic NdFeB/SmFeN hybrid magnets

    NASA Astrophysics Data System (ADS)

    Fukunaga, Hirotoshi; Murata, Hiroki; Yanai, Takeshi; Nakano, Masaki; Yamashita, Fumitoshi

    2010-05-01

    We systematically evaluated the initial flux loss of anisotropic HDDR-NdFeB/RD-SmFeN hybrid bonded magnets. The measured flux loss values were compared with those obtained by two prediction methods based on our previous proposal. Consequently, it was clarified that the initial flux loss of anisotropic bonded magnets can be predicted from demagnetization curves at room and exposure temperatures of the corresponding hybrid magnets, which suggests that the method proposed previously for isotropic magnets can be also applicable to anisotropic ones.

  15. Strategic coating of NdFeB magnets with Dy to improve the coercivity of permanent magnets

    DOE PAGES

    Ucar, Huseyin; Parker, David S.; Nlebedim, I. C.; ...

    2015-12-25

    Here, we present a method, supported by theoretical analysis, for optimizing the usage of the critical rare earth element dysprosium in Nd2Fe14B (NdFeB)-based permanent magnets. In this method, we use Dy selectively in locations such as magnet edges and faces, where demagnetization factors are most significant, rather than uniformly throughout the bulk sample. A 200 nm thick Dy film was sputtered onto commercial N-38, NdFeB magnets with a thickness of 3 mm and post-annealed at temperatures from 600 - 700 C. Magnets displayed enhanced coercivities after post-annealing. Furthermore, our experimental results indicate as large as a 5 percent increase inmore » the energy product of NdFeB magnets, achieved for a total Dy weight percentage of 0.06 percent, much less than that used in commercial grade Dy-NdFeB magnets. Finally, by assuming all Dy diffused into NdFeB magnets, the improvement in energy product corresponds to a saving of over 1% Dy (critical element). Magnets manufactured using this technique will therefore be higher performing and significantly less expensive than those made presently.« less

  16. Strategic coating of NdFeB magnets with Dy to improve the coercivity of permanent magnets

    SciTech Connect

    Ucar, Huseyin; Parker, David S.; Nlebedim, I. C.; McCallum, R. W.; McCall, S. K.; Parans Paranthaman, M.

    2015-12-25

    Here, we present a method, supported by theoretical analysis, for optimizing the usage of the critical rare earth element dysprosium in Nd2Fe14B (NdFeB)-based permanent magnets. In this method, we use Dy selectively in locations such as magnet edges and faces, where demagnetization factors are most significant, rather than uniformly throughout the bulk sample. A 200 nm thick Dy film was sputtered onto commercial N-38, NdFeB magnets with a thickness of 3 mm and post-annealed at temperatures from 600 - 700 C. Magnets displayed enhanced coercivities after post-annealing. Furthermore, our experimental results indicate as large as a 5 percent increase in the energy product of NdFeB magnets, achieved for a total Dy weight percentage of 0.06 percent, much less than that used in commercial grade Dy-NdFeB magnets. Finally, by assuming all Dy diffused into NdFeB magnets, the improvement in energy product corresponds to a saving of over 1% Dy (critical element). Magnets manufactured using this technique will therefore be higher performing and significantly less expensive than those made presently.

  17. Physical and magnetic properties, microstructure of bonded magnet NdFeB prepared by using synthesis rubber

    NASA Astrophysics Data System (ADS)

    Suprapedi; Sardjono, P.; Muljadi

    2016-11-01

    The magnet permanent has been made by using NdFeB (NQP-B) powder with purity 99.90% and polymer rubber with purity 90%. This research was done to determine the effect of the polymer (rubber) composition as binder in the manufacture of bonded magnet NdFeB on physical properties, microstructure and magnetic properties. Bonded magnets are magnet material made from a mixture of magnetic powder as a filler and the polymer as a matrix material or as binder to bind the magnetic particles. The NdFeB (NQP-B) powder fractions of bonded magnets NdFeB investigated were as follows: a) 97 wt.% of NdFeB (NQP-B) and 3 wt.% of rubber,b) 95wt.% of NdFeB (NQP-B) and 5 wt.% of rubber, c) 93 wt.% of NdFeB (NQP-B) and 7 wt.% of rubber, d) 91 wt.% of NdFeB (NQP-B) and 9 wt.% of rubber. Both raw materials were mixed by using mixer until homogen with total weight about 16 g for each sample, then added 0.3 ml of catalyst and mixed again and put in dies mould and compacted at pressure 30 MPa, then dried for 2 hours at room temperature. The dried samples was characterized such as: bulk density measurement and magnetic properties by using BH-curve permeagraph. The bulk density values of the sample bonded NdFeB magnets using the binder 3% wt. and 5% wt. rubber are respectively 4,70 g/cm3 and 4.88 g/cm3. The result from BH- curve shows that the highest value of remanence (Br = 5.12 kGauss) is at sample with 3% wt. of rubber, but sample with 5% wt. of rubber has lowest value of remanance (Br = 4.40 kGauss). Based on the observation of the SEM photograph shown that the rubber material has been successfully covered the whole surface of the grain and fill some of the voids that are in the grain boundary.

  18. Binder Jetting: A Novel NdFeB Bonded Magnet Fabrication Process

    SciTech Connect

    Paranthaman, M. Parans; Shafer, Christopher S.; Elliott, Amy M.; Siddel, Derek H.; McGuire, Michael A.; Springfield, Robert M.; Martin, Josh; Fredette, Robert; Ormerod, John

    2016-04-05

    Our goal of this research is to fabricate near-net-shape isotropic (Nd)2Fe14B-based (NdFeB) bonded magnets using a three dimensional printing process to compete with conventional injection molding techniques used for bonded magnets. Additive manufacturing minimizes the waste of critical materials and allows for the creation of complex shapes and sizes. The binder jetting process works similarly to an inkjet printer. A print-head passes over a bed of NdFeB powder and deposits a polymer binding agent to bind the layer of particles together. The bound powder is then coated with another layer of powder, building the desired shape in successive layers of bonded powder. Upon completion, the green part and surrounding powders are placed in an oven at temperatures between 100°C and 150°C for 4–6 h to cure the binder. After curing, the excess powder can be brushed away to reveal the completed “green” part. Green magnet parts were then infiltrated with a clear urethane resin to achieve the measured density of the magnet of 3.47 g/cm3 close to 46% relative to the NdFeB single crystal density of 7.6 g/cm3. Magnetic measurements indicate that there is no degradation in the magnetic properties. In conclusion, this study provides a new pathway for preparing near-net-shape bonded magnets for various magnetic applications.

  19. Binder Jetting: A Novel NdFeB Bonded Magnet Fabrication Process

    DOE PAGES

    Paranthaman, M. Parans; Shafer, Christopher S.; Elliott, Amy M.; ...

    2016-04-05

    Our goal of this research is to fabricate near-net-shape isotropic (Nd)2Fe14B-based (NdFeB) bonded magnets using a three dimensional printing process to compete with conventional injection molding techniques used for bonded magnets. Additive manufacturing minimizes the waste of critical materials and allows for the creation of complex shapes and sizes. The binder jetting process works similarly to an inkjet printer. A print-head passes over a bed of NdFeB powder and deposits a polymer binding agent to bind the layer of particles together. The bound powder is then coated with another layer of powder, building the desired shape in successive layers ofmore » bonded powder. Upon completion, the green part and surrounding powders are placed in an oven at temperatures between 100°C and 150°C for 4–6 h to cure the binder. After curing, the excess powder can be brushed away to reveal the completed “green” part. Green magnet parts were then infiltrated with a clear urethane resin to achieve the measured density of the magnet of 3.47 g/cm3 close to 46% relative to the NdFeB single crystal density of 7.6 g/cm3. Magnetic measurements indicate that there is no degradation in the magnetic properties. In conclusion, this study provides a new pathway for preparing near-net-shape bonded magnets for various magnetic applications.« less

  20. Magnetic properties and microstructure of bulk Nd-Fe-B magnets solidified in magnetic field

    NASA Astrophysics Data System (ADS)

    Wang, C.; Lai, Y. S.; Hsieh, C. C.; Chang, W. C.; Chang, H. W.; Sun, A. C.

    2011-04-01

    The Nd-Fe-B bulk magnets with a slab shape of 0.9 × 4 × 15 mm3 were prepared by injection casting into a copper mold. The effects of applying a magnetic field during the casting process on the magnetic properties and microstructure of Nd9.5Fe71.5Ti2.5Zr0.5Cr1B14.5C0.5 alloy have been studied. The results show that the sample cast with magnetic field has a stronger (00L) texture of Nd2Fe14B phase with the c-axis perpendicular to the slab plane than the sample cast without magnetic field. The intensity of the texture weakens from surface to inner region of the bulk magnets. Applying a magnetic field during the casting process is helpful to refine the grain size effectively. As a result, the magnetic properties are improved from Br = 5.8 kG, iHc = 6.5 kOe, and (BH)max = 5.9 MGOe for thesample cast without magnetic field to Br = 6.1 kG, iHc = 10.3 kOe, and (BH)max = 7.3 MGOe for the sample cast with a 3.7 kOe magnetic field.

  1. Big area additive manufacturing of high performance bonded NdFeB magnets

    SciTech Connect

    Li, Ling; Tirado, Angelica; Nlebedim, I. C.; Rios, Orlando; Post, Brian; Kunc, Vlastimil; Lowden, R. R.; Lara-Curzio, Edgar; Fredette, Robert; Ormerod, John; Lograsso, Thomas A.; Paranthaman, M. Parans

    2016-10-31

    Additive manufacturing allows for the production of complex parts with minimum material waste, offering an effective technique for fabricating permanent magnets which frequently involve critical rare earth elements. In this report, we demonstrate a novel method - Big Area Additive Manufacturing (BAAM) - to fabricate isotropic near-net-shape NdFeB bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic NdFeB powder and 35 vol% polyamide (Nylon-12). The density of the final BAAM magnet product reached 4.8 g/cm3, and the room temperature magnetic properties are: intrinsic coercivity Hci = 688.4 kA/m, remanence Br = 0.51 T, and energy product (BH)max = 43.49 kJ/m3 (5.47 MGOe). In addition, tensile tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average failure strain of 4.18%. Scanning electron microscopy images of the fracture surfaces indicate that the failure is primarily related to the debonding of the magnetic particles from the polymer binder. As a result, the present method significantly simplifies manufacturing of near-net-shape bonded magnets, enables efficient use of rare earth elements thus contributing towards enriching the supply of critical materials.

  2. Big area additive manufacturing of high performance bonded NdFeB magnets

    DOE PAGES

    Li, Ling; Tirado, Angelica; Nlebedim, I. C.; ...

    2016-10-31

    Additive manufacturing allows for the production of complex parts with minimum material waste, offering an effective technique for fabricating permanent magnets which frequently involve critical rare earth elements. In this report, we demonstrate a novel method - Big Area Additive Manufacturing (BAAM) - to fabricate isotropic near-net-shape NdFeB bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic NdFeB powder and 35 vol% polyamide (Nylon-12). The density of the final BAAM magnet product reached 4.8 g/cm3, and the room temperature magnetic propertiesmore » are: intrinsic coercivity Hci = 688.4 kA/m, remanence Br = 0.51 T, and energy product (BH)max = 43.49 kJ/m3 (5.47 MGOe). In addition, tensile tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average failure strain of 4.18%. Scanning electron microscopy images of the fracture surfaces indicate that the failure is primarily related to the debonding of the magnetic particles from the polymer binder. As a result, the present method significantly simplifies manufacturing of near-net-shape bonded magnets, enables efficient use of rare earth elements thus contributing towards enriching the supply of critical materials.« less

  3. Big Area Additive Manufacturing of High Performance Bonded NdFeB Magnets

    PubMed Central

    Li, Ling; Tirado, Angelica; Nlebedim, I. C.; Rios, Orlando; Post, Brian; Kunc, Vlastimil; Lowden, R. R.; Lara-Curzio, Edgar; Fredette, Robert; Ormerod, John; Lograsso, Thomas A.; Paranthaman, M. Parans

    2016-01-01

    Additive manufacturing allows for the production of complex parts with minimum material waste, offering an effective technique for fabricating permanent magnets which frequently involve critical rare earth elements. In this report, we demonstrate a novel method - Big Area Additive Manufacturing (BAAM) - to fabricate isotropic near-net-shape NdFeB bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic NdFeB powder and 35 vol% polyamide (Nylon-12). The density of the final BAAM magnet product reached 4.8 g/cm3, and the room temperature magnetic properties are: intrinsic coercivity Hci = 688.4 kA/m, remanence Br = 0.51 T, and energy product (BH)max = 43.49 kJ/m3 (5.47 MGOe). In addition, tensile tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average failure strain of 4.18%. Scanning electron microscopy images of the fracture surfaces indicate that the failure is primarily related to the debonding of the magnetic particles from the polymer binder. The present method significantly simplifies manufacturing of near-net-shape bonded magnets, enables efficient use of rare earth elements thus contributing towards enriching the supply of critical materials. PMID:27796339

  4. Big Area Additive Manufacturing of High Performance Bonded NdFeB Magnets.

    PubMed

    Li, Ling; Tirado, Angelica; Nlebedim, I C; Rios, Orlando; Post, Brian; Kunc, Vlastimil; Lowden, R R; Lara-Curzio, Edgar; Fredette, Robert; Ormerod, John; Lograsso, Thomas A; Paranthaman, M Parans

    2016-10-31

    Additive manufacturing allows for the production of complex parts with minimum material waste, offering an effective technique for fabricating permanent magnets which frequently involve critical rare earth elements. In this report, we demonstrate a novel method - Big Area Additive Manufacturing (BAAM) - to fabricate isotropic near-net-shape NdFeB bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic NdFeB powder and 35 vol% polyamide (Nylon-12). The density of the final BAAM magnet product reached 4.8 g/cm(3), and the room temperature magnetic properties are: intrinsic coercivity Hci = 688.4 kA/m, remanence Br = 0.51 T, and energy product (BH)max = 43.49 kJ/m(3) (5.47 MGOe). In addition, tensile tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average failure strain of 4.18%. Scanning electron microscopy images of the fracture surfaces indicate that the failure is primarily related to the debonding of the magnetic particles from the polymer binder. The present method significantly simplifies manufacturing of near-net-shape bonded magnets, enables efficient use of rare earth elements thus contributing towards enriching the supply of critical materials.

  5. Big Area Additive Manufacturing of High Performance Bonded NdFeB Magnets

    NASA Astrophysics Data System (ADS)

    Li, Ling; Tirado, Angelica; Nlebedim, I. C.; Rios, Orlando; Post, Brian; Kunc, Vlastimil; Lowden, R. R.; Lara-Curzio, Edgar; Fredette, Robert; Ormerod, John; Lograsso, Thomas A.; Paranthaman, M. Parans

    2016-10-01

    Additive manufacturing allows for the production of complex parts with minimum material waste, offering an effective technique for fabricating permanent magnets which frequently involve critical rare earth elements. In this report, we demonstrate a novel method - Big Area Additive Manufacturing (BAAM) - to fabricate isotropic near-net-shape NdFeB bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic NdFeB powder and 35 vol% polyamide (Nylon-12). The density of the final BAAM magnet product reached 4.8 g/cm3, and the room temperature magnetic properties are: intrinsic coercivity Hci = 688.4 kA/m, remanence Br = 0.51 T, and energy product (BH)max = 43.49 kJ/m3 (5.47 MGOe). In addition, tensile tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average failure strain of 4.18%. Scanning electron microscopy images of the fracture surfaces indicate that the failure is primarily related to the debonding of the magnetic particles from the polymer binder. The present method significantly simplifies manufacturing of near-net-shape bonded magnets, enables efficient use of rare earth elements thus contributing towards enriching the supply of critical materials.

  6. Electron holography on remanent magnetization distribution of melt-spun Nd-Fe-B magnets.

    PubMed

    Park, Young-Gil; Shindo, Daisuke

    2004-01-01

    Microstructures and magnetic domain structures of melt-spun Nd-Fe-B permanent magnets were investigated in detail by analytical electron microscopy and electron holography. While the crystal orientation of matrix Nd2Fe14B grains was analyzed by nanobeam electron diffraction, precipitates of a few tens of nanometers at grain boundaries were identified to be alpha-Fe by energy-dispersive X-ray spectroscopy. The detailed magnetization distribution in Nd2Fe14B grains and at their boundaries was visualized by electron holography. Ex situ experimentation with an electromagnet revealed that the domain walls in the demagnetized state and remanent states were pinned at grain boundaries, and Fe precipitates at the grain boundary were situated at the center of the closure domain.

  7. Studies on in situ magnetic alignment of bonded anisotropic Nd-Fe-B alloy powders

    NASA Astrophysics Data System (ADS)

    Nlebedim, I. C.; Ucar, Huseyin; Hatter, Christine B.; McCallum, R. W.; McCall, Scott K.; Kramer, M. J.; Paranthaman, M. Parans

    2017-01-01

    Considerations for achieving high degree of alignment in polymer bonded permanent magnets are presented via the results of a study on in situ magnetic alignment of anisotropic Nd-Fe-B magnet powders. Contributions from effect of the alignment temperature, alignment magnetic field and the properties of the polymer on the hard magnetic properties of the bonded magnet were considered. The thermo-rheological properties of the polymer and the response of the magnet powders to the applied magnetic field indicate that hard magnetic properties were optimized at an alignment temperature just above the melting temperature of the EVA co-polymer. This agrees with an observed correlation between the change in magnetization due to improved magnetic alignment of the anisotropic powders and the change in viscosity of the binder. Manufacturing cost can be minimized by identifying optimum alignment temperatures and magnetic field strengths.

  8. Studies on in situ magnetic alignment of bonded anisotropic Nd-Fe-B alloy powders

    DOE PAGES

    Nlebedim, I. C.; Ucar, Huseyin; Hatter, Christine B.; ...

    2016-08-30

    We presented some considerations for achieving high degree of alignment in polymer bonded permanent magnets via the results of a study on in situ magnetic alignment of anisotropic Nd-Fe-B magnet powders. Contributions from effect of the alignment temperature, alignment magnetic field and the properties of the polymer on the hard magnetic properties of the bonded magnet were considered. Moreover, the thermo-rheological properties of the polymer and the response of the magnet powders to the applied magnetic field indicate that hard magnetic properties were optimized at an alignment temperature just above the melting temperature of the EVA co-polymer. This agrees withmore » an observed correlation between the change in magnetization due to improved magnetic alignment of the anisotropic powders and the change in viscosity of the binder. Finally, manufacturing cost can be minimized by identifying optimum alignment temperatures and magnetic field strengths.« less

  9. Studies on in situ magnetic alignment of bonded anisotropic Nd-Fe-B alloy powders

    SciTech Connect

    Nlebedim, I. C.; Ucar, Huseyin; Hatter, Christine B.; McCallum, R. W.; McCall, Scott K.; Kramer, M. J.; Paranthaman, M. Parans

    2016-08-30

    We presented some considerations for achieving high degree of alignment in polymer bonded permanent magnets via the results of a study on in situ magnetic alignment of anisotropic Nd-Fe-B magnet powders. Contributions from effect of the alignment temperature, alignment magnetic field and the properties of the polymer on the hard magnetic properties of the bonded magnet were considered. Moreover, the thermo-rheological properties of the polymer and the response of the magnet powders to the applied magnetic field indicate that hard magnetic properties were optimized at an alignment temperature just above the melting temperature of the EVA co-polymer. This agrees with an observed correlation between the change in magnetization due to improved magnetic alignment of the anisotropic powders and the change in viscosity of the binder. Finally, manufacturing cost can be minimized by identifying optimum alignment temperatures and magnetic field strengths.

  10. Observation of spin-wave dispersion in Nd-Fe-B magnets using neutron Brillouin scattering

    SciTech Connect

    Ono, K. Inami, N.; Saito, K.; Takeichi, Y.; Kawana, D.; Yokoo, T.; Itoh, S.; Yano, M.; Shoji, T.; Manabe, A.; Kato, A.; Kaneko, Y.

    2014-05-07

    The low-energy spin-wave dispersion in polycrystalline Nd-Fe-B magnets was observed using neutron Brillouin scattering (NBS). Low-energy spin-wave excitations for the lowest acoustic spin-wave mode were clearly observed. From the spin-wave dispersion, we were able to determine the spin-wave stiffness constant D{sub sw} (100.0 ± 4.9 meV.Å{sup 2}) and the exchange stiffness constant A (6.6 ± 0.3 pJ/m)

  11. Microstructure evolution of hot-deformed Nd-Fe-B anisotropic magnets

    SciTech Connect

    Liu, J. Hono, K.; Sepehri-Amin, H.; Ohkubo, T.; Hioki, K.; Hattori, A.

    2014-05-07

    The microstructural evolution of hot-deformed Nd-Fe-B magnets in each stage of hot-deformation process was studied using transmission electron microscopy and three dimensional atom probe (3DAP). The anisotropic growth of initially isotropic grains in rapidly solidified alloy occurs by annealing without pressing. 3DAP analyses showed a higher concentration of rare-earth elements in the intergranular phase parallel to the flat surface of platelet shaped Nd{sub 2}Fe{sub 14}B grains compared to that in the intergranular phase at the side of platelets.

  12. Microstructure evolution of hot-deformed Nd-Fe-B anisotropic magnets

    NASA Astrophysics Data System (ADS)

    Liu, J.; Sepehri-Amin, H.; Ohkubo, T.; Hioki, K.; Hattori, A.; Hono, K.

    2014-05-01

    The microstructural evolution of hot-deformed Nd-Fe-B magnets in each stage of hot-deformation process was studied using transmission electron microscopy and three dimensional atom probe (3DAP). The anisotropic growth of initially isotropic grains in rapidly solidified alloy occurs by annealing without pressing. 3DAP analyses showed a higher concentration of rare-earth elements in the intergranular phase parallel to the flat surface of platelet shaped Nd2Fe14B grains compared to that in the intergranular phase at the side of platelets.

  13. Influence of annealing temperature on the Dy diffusion process in NdFeB magnets

    NASA Astrophysics Data System (ADS)

    Hu, Sheng-qing; Peng, Kun; Chen, Hong

    2017-03-01

    Sintered NdFeB magnets were coated with a layer of Dy metal using electron beam evaporation method and then annealed at various temperatures to investigate the temperature dependence of Dy diffusion process in NdFeB magnets. A Dy-rich phase was observed along the grain boundaries after the grain boundary diffusion process, the diffusion coefficients of various temperatures were obtained, the diffusion coefficients of Dy along the grain boundaries at 800 °C and 900 °C were determined to be 9.8×10-8 cm2 s-1 and 2.4×10-7 cm2 s-1, respectively. The diffusion length depended on the annealing temperature and the maximum diffusion length of approximately 1.8 mm and 3.0 mm can be obtained after annealing at 800 °C and 900 °C for 8 h. Higher diffusion temperature results in the diffusion not only along the grain boundaries but also into grains and then decrease in magnetic properties. The optimum annealing conditions can be determined as 900 °C for 8 h. The coercivity was improved from 1040 kA/m to 1450 kA/m and its magnetization has no significant reduction after the grain boundary diffusion process at the optimum annealing conditions.

  14. Corrosion Resistance Analysis of Sintered NdFeB Magnets Using Ultrasonic-Aided EDM Method

    NASA Astrophysics Data System (ADS)

    Li, L.; Wei, X. T.; Li, Z. Y.; Cheng, X.

    2015-01-01

    Sintered neodymium-iron-boron (NdFeB) permanent magnets are widely used in many fields because of their excellent magnetic property. However, their poor corrosion resistance has been cited as a potential problem that limits their extensive application. This paper presents an experimental investigation into the improvement of surface corrosion resistance with the ultrasonic-aided electrical discharge machining (U-EDM) method. A scanning electron microscope was used to analyze the surface morphology of recast layers formed through the EDM and U-EDM processes. The chemical structure and elements of these recast layers were characterized using x-ray diffraction and energy dispersive spectroscopy. Corrosion resistance was also studied by means of potentiodynamic polarization, electrochemical impedance spectroscopy, and immersion tests in 0.5 mol/L H2SO4 solution. Experimental results show that an amorphous structure was formed in the recast layer during the EDM and U-EDM processes and that this structure could improve the corrosion resistance of sintered NdFeB magnets. Moreover, the corrosion resistance of U-EDM-treated surface was better than that of the EDM-treated surface.

  15. Coercivity enhancement of Nd-Fe-B thin film magnets by Dy buffer and capping layers

    NASA Astrophysics Data System (ADS)

    You, C. Y.; Wang, J. W.; Lu, Z. X.

    2012-04-01

    The Dy layer was inserted into the structure of SiO2/Ti/Nd-Fe-B/Ti as the buffer or capping layer of the Nd-Fe-B layer. The insertions of Dy layers had no significant influence on the film texture with the easy axis mainly perpendicular to the film plane. The film without Dy layer gave the out-of-plane coercivity of 533 kA/m, maximum magnetic energy product (BH)max of 245 kJ/m3. With a Dy buffer layer, the out-of-plane coercivity and (BH)max were increased to 1074 kA/m, 291 kJ/m3 respectively. The film with Dy capping layer had a coercivity of 1035 kA/m and (BH)max of 286 kJ/m3. Microstructure observations showed that the Nd-rich phases were evolved into grain boundaries from triple junctions by a Dy buffer layer deposition, resulting in a well magnetic decoupling of Nd2Fe14B neighboring grains. Through capping a Dy layer, the environment of grain boundaries had been improved and some Dy diffused into Nd2Fe14B phases, which contributed to the enhancement of magnetic performance.

  16. Material flow analysis of NdFeB magnets for Denmark: a comprehensive waste flow sampling and analysis approach.

    PubMed

    Habib, Komal; Schibye, Peter Klausen; Vestbø, Andreas Peter; Dall, Ole; Wenzel, Henrik

    2014-10-21

    Neodymium-iron-boron (NdFeB) magnets have become highly desirable for modern hi-tech applications. These magnets, in general, contain two key rare earth elements (REEs), i.e., neodymium (Nd) and dysprosium (Dy), which are responsible for the very high strength of these magnets, allowing for considerable size and weight reduction in modern applications. This study aims to explore the current and future potential of a secondary supply of neodymium and dysprosium from recycling of NdFeB magnets. For this purpose, material flow analysis (MFA) has been carried out to perform the detailed mapping of stocks and flows of NdFeB magnets in Denmark. A novel element of this study is the value added to the traditionally practiced MFAs at national and/or global levels by complementing them with a comprehensive sampling and elemental analysis of NdFeB magnets, taken out from a sample of 157 different products representing 18 various product types. The results show that the current amount of neodymium and dysprosium in NdFeB magnets present in the Danish waste stream is only 3 and 0.2 Mg, respectively. However, this number is estimated to increase to 175 Mg of neodymium and 11.4 Mg of dysprosium by 2035. Nevertheless, efficient recovery of these elements from a very diverse electronic waste stream remains a logistic and economic challenge.

  17. NdFeB thin anisotropic magnets obtained by hot working process

    NASA Astrophysics Data System (ADS)

    Kim, H. T.; Cho, S. H.; Kim, Y. B.; Ryu, K. S.; Kapustin, G. A.; Kim, H. S.

    2004-05-01

    The current-applied pressure-assisted process has been applied to obtain anisotropic thin NdFeB magnets. The magnetic properties and microstructure of Nd14Fe80B6 and Nd12Dy2Fe73.2Co6.6Ga0.6B5.6 magnets with thickness of millimeter and sub-millimeter scale were investigated. For the thin magnets, the remanence and coercivity are lower than those of the thick magnet in spite of higher thickness reduction ratio due to the poor c-axis texture and abnormal grain growth. The optimized magnetic properties of the thin Nd12Dy2Fe73.2Co6.6Ga0.6B5.6 magnet with thickness of 780μm are Br=12.4kG, iHc=164kOe, and (BH)max=37.1MGOe.

  18. Effect of buffer and interlayer on the adhesion and magnetic properties of anisotropic Nd-Fe-B single and multilayer films

    NASA Astrophysics Data System (ADS)

    Grigoras, M.; Urse, M.; Lupu, N.; Borza, F.; Chiriac, H.

    2015-10-01

    Nd-Fe-B films with good perpendicular magnetic anisotropy were obtained by using a Mo film with the thickness of about 40 nm as buffer layer. Large out-of-plane coercivity (Hc⊥ = 1182 kA/m) and remanent ratio (remanent magnetization/saturation magnetization)⊥ = 0.99 are obtained by the stratification of the Nd-Fe-B magnetic film in three NdFeB(180 nm)/Mo(5 nm) bilayer sequences using Mo as interlayer. Using a Ni film, with a thickness of about 8 nm, alongside with a Mo film of 40 nm as buffer layer improves the adhesion to substrate and keeps the anisotropic hard magnetic performances of the Nd-Fe-B films unchanged. By increasing the total thickness of the Nd-Fe-B magnetic layer from 540 nm to 1620 nm the coercivity measured at high fields increases from about 1350 kA/m for Nd-Fe-B film with 3 NdFeB(180 nm)/Mo(5 nm) sequences to about 1640 kA/m for Nd-Fe-B film with 9 NdFeB(180 nm)/Mo(5 nm) sequences which can be ascribed to a stronger pinning effect as a result of the increased number of NdFeB/Mo interfaces.

  19. Magnetization reversal mechanism of Nd-Fe-B films with perpendicular magnetic anisotropy

    SciTech Connect

    Liu Xiaoxi; Ishida, Go; Morisako, Akimitsu

    2011-04-01

    The microstructure and magnetic properties of Nd-Fe-B films with thicknesses from 100 nm to 3 nm have been investigated. All the films show excellent perpendicular magnetic anisotropy with a squareness ratio of 1 in the perpendicular direction and almost zero coercivity in the in-plane direction. Of particular interest is that the initial magnetization curves sensitively depended on the film thickness. Films thicker than 15 nm show steep initial magnetization curve. Although the films have coercivities larger than 21 kOe, the films can be fully magnetized from the thermally demagnetized state with a field as small as 5 kOe. With the decrease of film thickness to 5 nm, the initial magnetization curve becomes flat. The evolution of initial magnetization curves with film thickness can be understood by the microstructure of the films. Films with thickness of 15 nm show close-packed grains without any intergranular phases. Such microstructures lead to steep initial magnetization curves. On the other hand, when the film thickness decreased to 3 nm, the film thickness became nonuniform. Such microstructure leads to flat initial magnetization curves.

  20. Al-Mn coating electrodeposited from ionic liquid on NdFeB magnet with high hardness and corrosion resistance

    NASA Astrophysics Data System (ADS)

    Ding, Jingjing; Xu, Bajin; Ling, Guoping

    2014-06-01

    Al-Mn coatings were electrodeposited on sintered NdFeB permanent magnet in MnCl2-AlCl3-1-ethyl-3-methylim-idazolium chloride (MnCl2-AlCl3-EMIC) ionic liquid at room temperature. The coatings were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adhesion strength of the coating on NdFeB substrate was evaluated by thermal shock and scratch test. The hardness and corrosion behavior of Al-Mn coating were measured by a Knoop microhardness tester, immersion test and neutral salt spray test respectively. The results showed that the amorphous structure of the deposits was obtained at the current density of 6 mA/cm2, while higher current densities resulted in a mixed structure of amorphous and crystalline. The Al-Mn coating showed excellent adhesion strength on NdFeB substrate with the thermal shock test over 30 cycles and Lc > 80 N. The hardness of Al-Mn coating was up to 5.4 GPa. The amorphous Al-Mn coating showed an anodic sacrificial protection with a low corrosion rate for NdFeB. Meanwhile, the magnetic properties measured by an AMT-4 magnetic measurement device showed that Al-Mn coating did not deteriorate the magnetic property of NdFeB.

  1. Micromagnetic simulations on the grain shape effect in Nd-Fe-B magnets

    NASA Astrophysics Data System (ADS)

    Yi, Min; Gutfleisch, Oliver; Xu, Bai-Xiang

    2016-07-01

    Micromagnetic simulations were performed to study the effect of grain shape and defect layer in Nd-Fe-B magnets. It was found that the coercivity can be increased by a factor of ˜2 by changing the grain shape from the triangular prism to the spheroid. Both the anisotropy field contribution and the shape contribution to the coercivity, and thus also the final coercivity, were found to decrease in the order: spheroid > circular prism > hexagonal prism > square prism > triangular prism. Sputtered columnar grains and hot-deformed platelet grains with a constant volume were also considered. Results show that the coercivity initially increases with the aspect ratio and then nearly saturates above the ratio of ˜4. Simulations of multigrain ensembles showed that depending on the grain shape, compared to the case of single grain, a further decrease of ˜10%-45% in the coercivity is induced by magnetostatic coupling.

  2. Enhanced method of magnetic powder alignment for production of PLP Nd-Fe-B magnets

    NASA Astrophysics Data System (ADS)

    Popov, A. G.; Golovnia, O. A.; Protasov, A. V.

    2017-04-01

    It is demonstrated how the high degree of powder alignment in PLP magnets can be achieved by loading the powder into a container placed in a magnetic field of moderate strength. The strip-cast alloy with a composition of 30.00 Nd, 1.95 Dy, 66.42 Fe, 0.99 B, 0.54 Co, 0.1 Ga (wt%) was subjected to hydrogen decrepitation and then milled in a vibratory mill in toluene to an average particle size of 2.9 μm determined by the FSSS method. The powder was compacted in the magnetic field of 0.2 - 1.2 T to the filling density 2.6 - 3.2×103 kg/m3. It is shown that loading the powder into a container placed in a magnetic field enhances the degree of powder alignment in sintered Nd-Fe-B magnets produced from non-pressed powder. At the filling density less than 3.2×103 kg/m3, the density of magnets is high but insufficient, because of the formation of magnetostatic chains of particles, which impedes the powder compaction. The simulation by the discrete-element method qualitatively proves that the magnetostatic interaction of the chains of particles that are formed in the course of loading in the magnetic field stimulates a decrease in the density of the sintered magnets and its non-uniform distribution over the sample. As a result of the optimization of the parameters of the alignment and compaction of the powder loaded in a magnetic field, PLP magnets with Br ≥1.34 T, Нc ≥950 kA/m, (BH)max ≥340 kJ/m3, and the degree of alignment exceeding 96% were produced.

  3. Use of paired, bonded NdFeB magnets in redox magnetohydrodynamics.

    PubMed

    Arumugam, Prabhu U; Clark, Emily A; Fritsch, Ingrid

    2005-02-15

    Bonded neodymium-iron-boron (NdFeB) permanent magnets in a paired configuration were successfully used to control mass transport in redox-based, magnetohydrodynamics (MHD). Control of fluid flow based on magnetic fields has potential for use in portable lab-on-a-chip (LOAC) and analytical devices. Bonded magnets, composed of magnetic powder and organic binder materials, are less expensive and easier to fabricate and pattern than electromagnets and sintered permanent magnets, which have been previously used in MHD studies on electrochemical systems. The ability to pattern bonded magnets near and around the electrodes is expected to allow for better control over the magnetic field distribution and solution flow. Current was generated at an 800-microm-radius platinum disk electrode in a solution of 0.06 M nitrobenzene and 0.5 M tetra-n-butylammonium hexafluorophosphate in acetonitrile. Increases in limiting current in the presence of the magnetic field, which indicate enhancement in mass transport, for sintered (210+/-14%, N = 4, where B(r) = 1.23 T and magnetic field strength is 0.55 T) and bonded (94+/-8%, N = 4, where B(r) = 0.41 T and magnetic field strength is 0.20 T) magnets, were similar to those obtained using an electromagnet with the same magnetic flux densities. The magnetic field strength and not the magnet type is important in controlling fluid flow, which is encouraging for integration of bonded permanent magnets into LOAC devices.

  4. Thermomagnetic treatment effects on microstructure in Nd-Fe-B type sintered magnets

    NASA Astrophysics Data System (ADS)

    PaigeSmith, Catherine

    Optimizing the microstructure of sintered Nd-Fe-B type magnets has become increasingly important. Sintered magnets are key components to the growing industry of alternative energy, particularly wind turbines and electric car generators. With rising costs and limited supply of rare earth elements, special attention has been dedicated to improving magnetic properties of these magnets through processing rather than compositional modifications. The magnetic property needing the most improvement in Nd-Fe-B type sintered magnets is coercivity. Coercivity dictates the performance of magnets at temperatures still below the demagnetizing threshold temperature. It has been shown that annealing sintered magnets in a magnetic field can enhance coercivity when compared to conventional post-sinter annealing in the absence of a magnetic field. However, little is known about the microstructural changes that occur in sintered magnets as a result of these thermo-magnetic treatments. This work presents themicrostructural characterization of Dy-free and Dy-containing sintered magnets that have undergone annealing in a magnetic field of 9T. Microstructural characterization techniques were used to identify phases, analyze the texture of phases identified, and to study intergranular phases. Microstructural findings were then used to propose a solidification scheme during annealing and connect such findings to magnetic property results, as well as to make suggestions for optimizing the manufacturing process. In addition to the magnetic phase, phases identified in the Dy-free and Dy-containing Nd-Fe-B sintered magnets consisted of Nb-rich precipitates, Nd-rich phases, and phases from the Nd-Fe-Cu ternary system. Nd-Fe-Cu phases included alpha-Nd, NdCu, and the tau (Nd6Fe13Cu). The Nd-rich phases were specifically identified to be NdOx precipitates in an alpha-Nd matrix, and contained an orientation relationship described by (0001)alpha-Nd||(111)NdOx and [112¯0]alpha-Nd||[1¯10]NdO x. This

  5. High-performance nanocrystalline NdFeB magnets by CAPA process

    NASA Astrophysics Data System (ADS)

    Kim, H. T.; Kim, Y. B.; Jeon, J. W.; Jang, I. H.; Kapustin, G. A.; Kim, H. S.

    2006-09-01

    The anisotropic NdFeB magnets were prepared from the melt-spun isotropic powders by CAPA process. The precursor isotropic magnet shows the uniform magnetic properties according to the overall position in the magnet. In the case of the anisotropic magnet, the outer position shows higher remanence and energy product compared to the center position. The magnetic properties of the anisotropic magnet obtained from Nd 14Fe 80B 6 powders are B=15 kG, iH=4.1 kOe and BH=36 MG Oe. In the case of addition of Zn to Nd 14Fe 80B 6 powders, the energy product increased because of the improved coercivity. The magnetic properties of the Zn-added magnet are B=14.5 kG, iH=9.7 kOe and BH=52 MG Oe. The Zn addition is effective to depress Nd 2Fe 14B grain growth of the interparticle regions during plastic deformation.

  6. Grain Texture, Nd Content and Processing Condition Effects on Magnetic Properties of NdFeB Composite Magnets

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoya; Hu, Lianxi; Li, Yuping; Deng, Taiqing

    2013-07-01

    The effects of grain texture, Nd content, processing conditions on magnetic properties and behavior of NdFeB nanocomposite magnet were investigated. The results demonstrate that mechanically activated disproportionation and desorption-recombination combined with plastic deformation process (M-HDDR & D) is an effective way to produce anisotropic NdFeB-type magnet. Magnetic anisotropy significantly enhances the magnetic properties of Nd16Fe76B8 nanocomposite magnet, with the intrinsic coercivity (Hci), magnetic induction (Br), and the energy product (BH)max achieving 0.88 T, 676.8 kA/m, and 135.2 kJ/m3, respectively. Decrease in Nd content improves the remanence but deteriorates the coercivity of NdFeB ternary composites. A low annealing temperature or short annealing time leads to an incomplete recombination, while a high temperature or long annealing time may result in grain overgrowth, and the optimum processing condition is found to be 780°C × 30 min. Pinning mechanism dominates in the magnetic hardening mechanism of Nd16Fe76B8 composites prepared by both complete and incomplete recombination process, and particularly reversal nucleation process is also responsible for the latter case.

  7. Synthesis and magnetic properties of Ta/NdFeB-based composite microwires

    SciTech Connect

    Szary, P. Périgo, E. A.; Michels, A.; Luciu, I.; Duday, D.; Wirtz, T.; Choquet, P.

    2015-05-07

    Magnetic NdFeB-based microwire composites have been prepared by the direct current magnetron sputtering technique in a specifically designed sputtering chamber for thin-film deposition in wire geometry. As substrate wire material, we have employed steel and Ta. Annealing of the substrate wires during the deposition process was performed by ohmic heating through the application of a direct current. Samples were characterized by means of vibrating sample magnetometry (VSM) and scanning electron microscopy. Best properties have been encountered when using Ta wires as core (substrate) material. The VSM data show a dramatic impact of the current applied during the deposition process on the magnetic properties. For higher current values, i.e., higher annealing temperatures, the wires exhibit a reversal process that is typical for a two-phase system. Moreover, an increase of the coercive field (and remanent magnetization) is observed, which is ascribed to a modification of the magnetic phase present in the sample due to the annealing. We find an indication for the formation of a magnetic easy-axis direction which is azimuthally oriented around the wire axis.

  8. Cellular uptake of magnetite nanoparticles enhanced by NdFeB magnets in staggered arrangement

    NASA Astrophysics Data System (ADS)

    Lu, Yi-Ching; Chang, Fan-Yu; Tu, Shu-Ju; Chen, Jyh-Ping; Ma, Yunn-Hwa

    2017-04-01

    Magnetic force may greatly enhance uptake of magnetic nanoparticles (MNPs) by cultured cells; however, the effects of non-uniformity of magnetic field/ magnetic gradient on MNP internalization in culture has not been elucidated. Cellular uptake of polyacrylic acid coated-MNP by LN229 cells was measured with cylindrical NdFeB magnets arranged in a staggered pattern. The magnetic field generated by placing a magnet underneath (H-field) elicited a homogenous distribution of MNPs on the cells in culture; whereas the field without magnet underneath (L-field) resulted in MNP distribution along the edge of the wells. Cell-associated MNP (MNPcell) appeared to be magnetic field- and concentration-dependent. In H-field, MNPcell reached plateau within one hour of exposure to MNP with only one-min application of the magnetic force in the beginning of incubation; continuous presence of the magnet for 2 h did not further increase MNPcell, suggesting that magnetic force-induced uptake may be primarily contributed to enhanced MNP sedimentation. Although MNP distribution was much inhomogeneous in L-field, averaged MNPcell in the L-field may reach as high as 80% of that in H-field during 1-6 h incubation, suggesting high capacity of MNP internalization. In addition, no significant difference was observed in MNPcell analyzed by flow cytometry with the application of H-field of staggered plate vs. filled magnet plate. Therefore, biological variation may dominate MNP internalization even under relatively uniformed magnetic field; whereas non-uniformed magnetic field may serve as a model for tumor targeting with MNPs in vivo.

  9. CRADA/NFE-15-05761 Report: Additive Manufacturing of Isotropic NdFeB Bonded Permanent Magnets

    SciTech Connect

    Paranthaman, M. Parans

    2016-07-18

    The technical objective of this technical collaboration phase I proposal is to fabricate net shape isotropic NdFeB bonded magnets utilizing additive manufacturing technologies at the ORNL MDF. The goal is to form complex shapes of thermoplastic and/or thermoset bonded magnets without expensive tooling and with minimal wasted material. Two additive manufacturing methods; the binder jet process; and big area additive manufacturing (BAAM) were used. Binder jetting produced magnets with the measured density of the magnet of 3.47 g/cm3, close to 46% relative to the NdFeB single crystal density of 7.6 g/cm3 were demonstrated. Magnetic measurements indicate that there is no degradation in the magnetic properties. In addition, BAAM was used to fabricate isotropic near-net-shape NdFeB bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic NdFeB powder and 35 vol% polyamide (Nylon-12). The density of the final BAAM magnet product reached 4.8 g/cm3, and the room temperature magnetic properties are: Intrinsic coercivity Hci = 8.65 kOe, Remanence Br = 5.07 kG, and energy product (BH)max = 5.47 MGOe (43.50 kJ/m3). This study provides a new pathway for preparing near-net shape bonded magnets for various magnetic applications.

  10. First-Principles Study of the Role of Cu in Improving the Coercivity of Nd-Fe-B Permanent Magnets

    NASA Astrophysics Data System (ADS)

    Tatetsu, Y.; Tsuneyuki, S.; Gohda, Y.

    2016-12-01

    We study the magnetic and electronic properties of Cu-doped Nd2 Fe14 B /NdOx systems with first-principles calculations in order to understand the roles of Cu in improving the coercivity of Nd-Fe-B permanent magnets. By analyzing the formation energies of several model systems, we find that Cu prefers to be at the interface. We conclude that the Cu addition to Nd-Fe-B magnets is a practical way of not only increasing the anisotropy of Nd atoms at the interface but also of lessening the magnetic coupling between the Nd and Fe atoms. Particularly, substituting Fe at the interface of the main phase with Cu works effectively in terms of improving the magnetic anisotropy in Nd atoms. This may explain the coercivity improvements reported recently.

  11. Influence of AC external magnetic field on guidance force relaxation between HTS bulk and NdFeB guideway

    NASA Astrophysics Data System (ADS)

    Zhang, Longcai; Wang, Suyu; Wang, Jiasu; Zheng, Jun

    2007-12-01

    Superconducting maglev vehicle is one of the most promising applications of HTS bulks. In such a system, the HTS bulks are always exposed to time-varying external magnetic field, which is generated by the inhomogeneous surface magnetic field of the NdFeB guideway. So it is required to study whether the guidance force of the bulks is influenced by the inhomogeneity. In this paper, we studied the characteristics of the guidance force relaxation between the HTS bulk and the NdFeB guideway by an experiment in which AC external magnetic field generated by an electromagnet was used to simulate the time-varying external magnetic field caused by the inhomogeneity of the guideway. From the experiment results, it was found that the guidance force was decreased with the application of the AC external magnetic field, and the decay increased with the amplitude and was almost independent of the frequency.

  12. Effect of hydriding degree on the microstructure and magnetic properties of sintered NdFeB magnets

    NASA Astrophysics Data System (ADS)

    Guo, Shuai; Liu, Youhao; Chen, Bicheng; Yan, Changjiang; Chen, Renjie; Lee, Don; Yan, Aru

    2012-04-01

    The effects of hydriding degree on the microstructure and magnetic properties of sintered NdFeB magnets have been studied. The degree of crushing depends on the absorption content of hydrogen and affects the magnetic properties of final magnet. Insertion of hydrogen atoms leads to a significant increase of the unit cell volume. And the crush mechanism depends on the internal stress resulting from differences in the expansion rates of the two phases. The remanence of final magnets increases monotonously while the coercivity decreases sharply with the increasing of hydriding degree, attributed to the strip fracture features and the morphology of particles.

  13. The epoxy resin variation effect on microstructure and physical properties to improve bonded NdFeB flux magnetic density

    NASA Astrophysics Data System (ADS)

    Rusnaeni, N.; Sarjono, Priyo; Muljadi; Noer, Nasrudin

    2016-11-01

    NdFeB magnets have been fabricated from a mixture of powder NdFeB (MPQ-B+) and epoxy resins (ER) with a variation of 0% wt, 2% wt, 4% wt and 6% wt. The pellets samples were made by pressing 4 tons of the mixture powder at room temperature before curing at 100°C for 1 hour. The SEM-EDX results showed the microstructure with ER were evenly smeared the NdFeB magnetic particles due to higher percent C and lower transition metals value. Sample with 2% wt epoxy resin was able to achieve the highest density of 5.35 g/cm3 and the highest magnetic flux of 2121 Gauss. The magnetic properties characterization using the permagraph indicates that the sample pellets with 2% wt epoxy resin has a value of remanence (Br) = 4.92 kG, coercivity (Hc) = 7.76 kOe, and energy product (Bhmax) = 4.58 MGOe. Despite low remanence value in the pellet samples, the resistance to demagnetization value was still acceptable.

  14. Investigation of coercivity mechanism in hot deformed Nd-Fe-B permanent magnets by small-angle neutron scattering

    SciTech Connect

    Yano, M. Manabe, A.; Shoji, T.; Kato, A.; Ono, K.; Harada, M.; Kohlbrecher, J.

    2014-05-07

    The magnetic reversal behaviors of single domain sized Nd-Fe-B permanent magnets, with and without isolation between the Nd{sub 2}Fe{sub 14}B grains, was clarified using small-angle neutron scattering (SANS). The SANS patterns obtained arose from changes in the magnetic domains and were analyzed using the Teubner–Stray model, a phenomenological correlation length model, to quantify the periodicity and morphology of the magnetic domains. The results indicated that the magnetic reversal evolved with the magnetic domains that had similar sized grains. The grain isolation enabled us to realize the reversals of single domains.

  15. Magnetic properties and texture of NdFeB magnets fabricated by current-applied-pressure-assisted process

    NASA Astrophysics Data System (ADS)

    Kim, H. T.; Kim, Y. B.; Kim, H. S.

    2001-03-01

    The current-applied-pressure-assisted (CAPA) process has been applied to obtain full dense isotropic and anisotropic NdFeB magnets from melt spun NdFeB alloy (MQP-A). The energy product of isotropic magnets obtained by this process was 120-135 kJ/m 3(15-17 MGOe) and the remanence was 0.8-0.9 T(8-9 kG). These isotropic magnets were deformed with different thickness reduction ratio by CAPA process. The energy product obtained by this procedure was in excess of 320 kJ/m 3(40 MGOe), and the best magnetic properties obtained were B r=1.36 T(13.6 kG) , iH c=868 kA/m(10.9 kOe) and (BH) max=352 kJ/m 3(44.2 MGOe) . The effect of deformation by CAPA process on texture was examined using pole figures. The (1 0 5) texture was dominant up to the thickness reduction ratio of 74%, whereas the (0 0 6) texture was dominant at the thickness reduction ratio of 81%.

  16. The impact of processing parameters on the properties of Zn-bonded Nd-Fe-B magnets

    NASA Astrophysics Data System (ADS)

    Kelhar, Luka; Zavašnik, Janez; McGuiness, Paul; Kobe, Spomenka

    2016-12-01

    We report on the effect of loading factor and pressure on the density and the magnetic properties of Zn-bonded Nd-Fe-B magnets produced by pulsed-electric-current sintering (PECS). The idea behind this study is to fabricate bonded magnets with a metallic binder in order for the bonded magnet to operate at temperatures higher than 180 °C: the current upper-limit for polymer-bonded magnets. These composites are made of hard-magnetic powder in the form of melt-spun ribbons bonded with the low-melting-point metal Zn. The binder additions were varied from 10 to 30 wt%, and pressures of 50 and 500 MPa were applied. The high-pressure mode with 20 wt% Zn resulted in a 24% increase of Jr, compared to the low-pressure mode. The magnetic measurements revealed a maximum remanence of 0.64 T for 10 wt% Zn, while the coercivity is largely unaffected by the processing conditions. The density of the composites was up to 7.0 g/cm3, corresponding to 94% of the theoretical density. Compared to commercial polymer-bonded magnets, the Zn-bonded counterparts exhibit a slightly lower Jr, but the coercivity is retained. We show that there is a minor diffusion of Zn into the Nd-Fe-B, forming a 1 μm thin transition layer, but it does not harm the magnetic properties. These metal-bonded Nd-Fe-B magnets are ideal for use in high-temperature automotive applications like under-the-hood sensors and other magnet-based devices that are close to the engine.

  17. Magnetization processes in two different types of anisotropic, fully dense NdFeB hydrogenation, disproportionation, desorption, and recombination magnets

    NASA Astrophysics Data System (ADS)

    Gutfleisch, O.; Eckert, D.; Schäfer, R.; Müller, K. H.; Panchanathan, V.

    2000-05-01

    Two types of textured, fully dense NdFeB hydrogenation, disproportionation, desorption, and recombination (HDDR) magnets were produced. The first type was produced by hot pressing isotropic HDDR powder followed by die upsetting; the second, by hot pressing prealigned, anisotropic HDDR powder (MQA-T). Studies of the magnetization processes revealed that for isotropic HDDR powder and its hot pressed and die-upset magnets a much larger initial susceptibility is found after thermal demagnetization than after reverse dc-field demagnetization. Prealigned, hot pressed magnets made from MQA-T material showed a different virgin magnetization curve, indicating a unique coercivity mechanism. Interaction domains larger than the average grain size can be observed in both cases by Kerr microscopy, with the MQA-T type showing significantly broader interaction domains.

  18. Commercial-scale recycling of NdFeB-type magnets with grain boundary modification yields products with 'designer properties' that exceed those of starting materials.

    PubMed

    Zakotnik, M; Tudor, C O

    2015-10-01

    NdFeB-type magnets dominate the market for high performance magnetic materials, yet production of 'virgin' magnets via mining is environmentally, financially and energetically costly. Hence, interest is growing in 'magnet to magnet' recycling schemes that offer the potential for cheaper, more environmentally-friendly solutions to the world's growing appetite for rare-earth based magnetic materials. Unfortunately, previously described recycling processes only partially capitalise on this potential, because the methods described to date are limited to 'laboratory scale' or operate only under ideal conditions and result in products that fail to recapture the coercivity of the starting, scrap materials. Herein, we report a commercial scale process (120 kg batches) that completely recovers the properties of the starting scrap magnets. Indeed, 'grain boundary modification', via careful addition of a proprietary mix of blended elements, produces magnets with 'designer properties' that can exceed those of the starting materials and can be closely tailored to meet a wide variety of end-user applications, including high-coercivity (>2000 kA/m), sintered magnets suitable for motor applications.

  19. The influence of carbon and oxygen on the magnetic characteristics of press-less sintered NdFeB magnets

    NASA Astrophysics Data System (ADS)

    Xia, M.; Abrahamsen, A. B.; Bahl, C. R. H.; Veluri, B.; Søegaard, A. I.; Bøjsøe, P.; Millot, S.

    2017-01-01

    The Pressless Process (PLP) was adopted to manufacture NdFeB sintered magnets, where the investigations on carbon and oxygen residues from heptane milling liquid media and graphite crucibles used for sintering were quantified to evaluate the influence on the magnetic characteristics. The carbon and oxygen content in the magnets produced from wet ball milling of strip cast flakes was found to be of the order 104 ppm and 4·104 ppm respectively, which resulted in soft magnetic behavior. However using jet milling the carbon and oxygen concentration were decreased by an order of magnitude resulting in coercivity of up to 829 kA/m. Thus the influence of the carbon from the graphite crucibles is small.

  20. The effect of surface grain reversal on the AC losses of sintered Nd-Fe-B permanent magnets

    NASA Astrophysics Data System (ADS)

    Moore, Martina; Roth, Stefan; Gebert, Annett; Schultz, Ludwig; Gutfleisch, Oliver

    2015-02-01

    Sintered Nd-Fe-B magnets are exposed to AC magnetic fields in many applications, e.g. in permanent magnet electric motors. We have measured the AC losses of sintered Nd-Fe-B magnets in a closed circuit arrangement using AC fields with root mean square-values up to 80 mT (peak amplitude 113 mT) over the frequency range 50 to 1000 Hz. Two magnet grades with different dysprosium content were investigated. Around the remanence point the low grade material (1.7 wt% Dy) showed significant hysteresis losses; whereas the losses in the high grade material (8.9 wt% Dy) were dominated by classical eddy currents. Kerr microscopy images revealed that the hysteresis losses measured for the low grade magnet can be mainly ascribed to grains at the sample surface with multiple domains. This was further confirmed when the high grade material was subsequently exposed to DC and AC magnetic fields. Here a larger number of surface grains with multiple domains are also present once the step in the demagnetization curve attributed to the surface grain reversal is reached and a rise in the measured hysteresis losses is evident. If in the low grade material the operating point is slightly offset from the remanence point, such that zero field is not bypassed, its AC losses can also be fairly well described with classical eddy current theory.

  1. Solidification process in melt spun Nd-Fe-B type magnets

    SciTech Connect

    Li, Changping

    1998-02-23

    A generalized solidification model has been developed based on a systematic investigation on the microstructure of melt spun Nd-Fe-B alloys. Melt spinning was conducted on initial stoichiometric and TiC added Nd2Fe14B (2-14-1) compositions to produce under, optimally and over quenched microstructures. Microstructural characterization was carried out by TEM, SEM, Optical microscopy, XRD, DTA, VSM and DC SQUID techniques. By taking the dendritic breakup during recalescence into consideration, this generalized model has successfully explained the solidification process of the melt spun Nd-Fe-B alloys. Challenging the conventional homogeneous nucleation models, the new model explains the fine and uniform equiaxed 2-14-1 microstructure in optimally quenched ribbons as a result of the breakup of the 2-14-1 dendrites which nucleate heterogeneously from the wheel surface and grow dendritically across the ribbon thickness due to the recalescence. Besides this dendritic breakup feature, the under quenched microstructure is further featured with another growth front starting with the primary solidification of Fe phase near the free side, which results in a coarsely grained microstructure with Fe dendritic inclusions and overall variation in microstructure across the ribbon thickness. In addition, because a epitaxy exists between the Fe phase and the 2-14-1, the so-formed coarse 2-14-1 grains may be textured. C-axis texturing was observed in under quenched ribbons. As a constraint to solidification models in this system, the cause and characteristics of this phenomenon has been studied in detail to test the authors proposed model, and agreement has been found. An extension has also been made to understand the solidification process when TiC is added, which suggests that Ti and C slow down the growth front of both Fe and 2-14-1 phase.

  2. Influence of Segmentation of Ring-Shaped NdFeB Magnets with Parallel Magnetization on Cylindrical Actuators

    PubMed Central

    Eckert, Paulo Roberto; Goltz, Evandro Claiton; Filho, Aly Ferreira Flores

    2014-01-01

    This work analyses the effects of segmentation followed by parallel magnetization of ring-shaped NdFeB permanent magnets used in slotless cylindrical linear actuators. The main purpose of the work is to evaluate the effects of that segmentation on the performance of the actuator and to present a general overview of the influence of parallel magnetization by varying the number of segments and comparing the results with ideal radially magnetized rings. The analysis is first performed by modelling mathematically the radial and circumferential components of magnetization for both radial and parallel magnetizations, followed by an analysis carried out by means of the 3D finite element method. Results obtained from the models are validated by measuring radial and tangential components of magnetic flux distribution in the air gap on a prototype which employs magnet rings with eight segments each with parallel magnetization. The axial force produced by the actuator was also measured and compared with the results obtained from numerical models. Although this analysis focused on a specific topology of cylindrical actuator, the observed effects on the topology could be extended to others in which surface-mounted permanent magnets are employed, including rotating electrical machines. PMID:25051032

  3. Influence of segmentation of ring-shaped NdFeB magnets with parallel magnetization on cylindrical actuators.

    PubMed

    Eckert, Paulo Roberto; Goltz, Evandro Claiton; Flores Filho, Aly Ferreira

    2014-07-21

    This work analyses the effects of segmentation followed by parallel magnetization of ring-shaped NdFeB permanent magnets used in slotless cylindrical linear actuators. The main purpose of the work is to evaluate the effects of that segmentation on the performance of the actuator and to present a general overview of the influence of parallel magnetization by varying the number of segments and comparing the results with ideal radially magnetized rings. The analysis is first performed by modelling mathematically the radial and circumferential components of magnetization for both radial and parallel magnetizations, followed by an analysis carried out by means of the 3D finite element method. Results obtained from the models are validated by measuring radial and tangential components of magnetic flux distribution in the air gap on a prototype which employs magnet rings with eight segments each with parallel magnetization. The axial force produced by the actuator was also measured and compared with the results obtained from numerical models. Although this analysis focused on a specific topology of cylindrical actuator, the observed effects on the topology could be extended to others in which surface-mounted permanent magnets are employed, including rotating electrical machines.

  4. Polydimethylsiloxane films doped with NdFeB powder: magnetic characterization and potential applications in biomedical engineering and microrobotics.

    PubMed

    Iacovacci, V; Lucarini, G; Innocenti, C; Comisso, N; Dario, P; Ricotti, L; Menciassi, A

    2015-12-01

    This work reports the fabrication, magnetic characterization and controlled navigation of film-shaped microrobots consisting of a polydimethylsiloxane-NdFeB powder composite material. The fabrication process relies on spin-coating deposition, powder orientation and permanent magnetization. Films with different powder concentrations (10 %, 30 %, 50 % and 70 % w/w) were fabricated and characterized in terms of magnetic properties and magnetic navigation performances (by exploiting an electromagnet-based platform). Standardized data are provided, thus enabling the exploitation of these composite materials in a wide range of applications, from MEMS/microrobot development to biomedical systems. Finally, the possibility to microfabricate free-standing polymeric structures and the biocompatibility of the proposed composite materials is demonstrated.

  5. Properties of hydrogenation-disproportionation-desorption-recombination NdFeB powders prepared from recycled sintered magnets

    NASA Astrophysics Data System (ADS)

    Périgo, E. A.; da Silva, S. C.; Martin, R. V.; Takiishi, H.; Landgraf, F. J. G.

    2012-04-01

    The effects of the hydrogenation-disproportionation-desorption-recombination (HDDR) processing conditions on the microstructure and magnetic properties of NdFeB powders prepared from recycling sintered N42 grade magnets were evaluated. Temperatures below 840 oC and above 900 oC are deleterious to HDDR powders' properties. The hydrogen pressure, ranging from 60 to 135 kPa, has a major influence on the remanence compared to that on the intrinsic coercivity. The best magnetic properties (Jr = 0.58 T and μ0Hc = 1.15 T) were obtained with Trecomb = 860 °C, PH2 = 135 kPa, and trecomb = 330 s. Such coercivity value corresponds to 93% of the starting material, not achieved yet by optimizing the HDDR process and without using Dy.

  6. Effects of thickness and annealing condition on magnetic properties and thermal stabilities of Ta/Nd/NdFeB/Nd/Ta sandwiched films

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Feng; Zhang, Min-Gang; Zhang, Ke-Wei; Zhang, Hai-Jie; Xu, Xiao-Hong; Chai, Yue-Sheng

    2016-11-01

    Ta/Nd/NdFeB/Nd/Ta sandwiched films are deposited by magnetron sputtering on Si (100) substrates, and subsequently annealed in vacuum at different temperatures for different time. It is found that both the thickness of NdFeB and Nd layer and the annealing condition can affect the magnetic properties of Ta/Nd/NdFeB/Nd/Ta films. Interestingly, the thickness and annealing temperature show the relevant behaviors that can affect the magnetic properties of the film. The high coercivity of 24.1 kOe (1 Oe = 79.5775 A/m) and remanence ratio (remanent magnetization/saturation magnetization) of 0.94 can be obtained in a Ta/Nd(250 nm)/NdFeB(600 nm)/Nd(250 nm)/Ta film annealed for 3 min at 1023 K. In addition, the thermal stability of the film is also linked to the thickness of NdFeB and Nd layer and the annealing temperature as well. The excellent thermal stability can be achieved in a Ta/Nd(250 nm)/NdFeB(600 nm)/Nd(250 nm)/Ta film annealed at 1023 K. Program supported by the National Natural Science Foundation of China (Grant No. 51305290), the Higher Education Technical Innovation Project of Shanxi Province, China (Grant No. 2013133), the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals of Shanxi Province, China (Grant No. 2015003), and the Program for the Key Team of Scientific and Technological Innovation of Shanxi Province, China (Grant No. 2013131009).

  7. Improved room-temperature-selectivity between Nd and Fe in Nd recovery from Nd-Fe-B magnet

    SciTech Connect

    Kataoka, Y.; Kitagawa, J.; Ono, T.; Tsubota, M.

    2015-11-15

    The sustainable society requires the recycling of rare metals. Rare earth Nd is one of rare metals, accompanying huge consumption especially in Nd-Fe-B magnets. Although the wet process using acid is in practical use in the in-plant recycle of sludge, higher selectivity between Nd and Fe at room temperature is desired. We have proposed a pretreatment of corrosion before the dissolution into HCl and the oxalic acid precipitation. The corrosion produces γ-FeOOH and a Nd hydroxide, which have high selectivity for HCl solution at room temperature. Nd can be recovered as Mn{sub 2}O{sub 3}-type Nd{sub 2}O{sub 3}. The estimated recovery-ratio of Nd reaches to 97%.

  8. Improved room-temperature-selectivity between Nd and Fe in Nd recovery from Nd-Fe-B magnet

    NASA Astrophysics Data System (ADS)

    Kataoka, Y.; Ono, T.; Tsubota, M.; Kitagawa, J.

    2015-11-01

    The sustainable society requires the recycling of rare metals. Rare earth Nd is one of rare metals, accompanying huge consumption especially in Nd-Fe-B magnets. Although the wet process using acid is in practical use in the in-plant recycle of sludge, higher selectivity between Nd and Fe at room temperature is desired. We have proposed a pretreatment of corrosion before the dissolution into HCl and the oxalic acid precipitation. The corrosion produces γ-FeOOH and a Nd hydroxide, which have high selectivity for HCl solution at room temperature. Nd can be recovered as Mn2O3-type Nd2O3. The estimated recovery-ratio of Nd reaches to 97%.

  9. Computational micromagnetic investigation of magnetization reversal in Nd-Fe-B nanocomposite magnets

    NASA Astrophysics Data System (ADS)

    David, S.; Kevorkian, B.; Toussaint, J. C.; Givord, D.

    1998-06-01

    As a complement to the experimental analysis of magnetization reversal in a two-phase system, a numerical micromagnetic three-dimensional calculation is developed and tested. It is applied to a set of 64 nanometer-scale hard (Nd2Fe14B) and soft (Fe3B) cubic grains. Calculations reproduce qualitatively the experimentally observed processes and allow the relation between the structure and the coercivity mechanism in nanocomposite hard magnetic materials to be better understood.

  10. Improved HDDR processing route for production of anisotropic powder from sintered NdFeB type magnets

    NASA Astrophysics Data System (ADS)

    Sheridan, R. S.; Williams, A. J.; Harris, I. R.; Walton, A.

    2014-01-01

    The hydrogenation disproportionation desorption recombination (HDDR) process has been investigated as a possible means of producing bonded magnets from used NdFeB-type sintered magnets with compositions, Nd13.4Dy0.8Al0.7Nb0.3Fe78.5B6.3 and Nd12.5Dy1.8Al0.9Nb0.6Co5.0Fe72.8B6.4 (atomic%). It has been shown that by increasing the processing temperature, an increase in the equilibrium pressure for disproportionation and in the overall reaction time was observed. The magnetic properties of the lower Dy content magnet were affected significantly by the change in processing temperature with a peak in properties observed at 880 °C producing magnetic powder with a remanence of 1.08 (±0.02) T, a coercivity of 840 (±17) kA m-1, and a maximum energy product of 175 (±2.5) kJ m-3. Further work on magnets with a significantly higher Dy content has shown that simultaneous processing of sintered magnets with varying compositions can be achieved by increasing the hydrogen pressure, however a range of magnetic properties are produced depending on the initial compositions of the samples in the input feed.

  11. Micro-patterning of NdFeB and SmCo magnet films for integration into micro-electro-mechanical-systems

    NASA Astrophysics Data System (ADS)

    Walther, A.; Marcoux, C.; Desloges, B.; Grechishkin, R.; Givord, D.; Dempsey, N. M.

    2009-03-01

    The integration of high-performance RE-TM (NdFeB and SmCo) hard magnetic films into micro-electro-mechanical-systems (MEMS) requires their patterning at the micron scale. In this paper we report on the applicability of standard micro-fabrication steps (film deposition onto topographically patterned substrates, wet etching and planarization) to the patterning of 5-8 μm thick RE-TM films. While NdFeB comprehensively fills micron-scaled trenches in patterned substrates, SmCo deposits are characterized by poor filling of the trench corners, which poses a problem for further processing by planarization. The magnetic hysteresis loops of both the NdFeB and SmCo patterned films are comparable to those of non-patterned films prepared under the same deposition/annealing conditions. A micron-scaled multipole magnetic field pattern is directly produced by the unidirectional magnetization of the patterned films. NdFeB and SmCo show similar behavior when wet etched in an amorphous state: etch rates of approximately 1.25 μm/min and vertical side walls which may be attributed to a large lateral over-etch of typically 20 μm. Chemical-mechanical-planarization (CMP) produced material removal rates of 0.5-3 μm/min for amorphous NdFeB. Ar ion etching of such films followed by the deposition of a Ta layer prior to film crystallization prevented degradation in magnetic properties compared to non-patterned films.

  12. Improvement of microstructure and magnetic properties of Nd-Fe-B alloys by Nb and Co additions

    NASA Astrophysics Data System (ADS)

    Ahmed, F. M.; Harris, I. R.

    In order to establish the role of niobium on the hydrogenation, disproportionation, desorption and recombination (HDDR) behavior of near-stoichiometric alloys, two alloys: NdI3Fe8OB7 and Nd13Fe78Nb1Co1B7 (at%) were investigated before, during and after the HDDR process. The microstructure of the as-cast Nb-free alloy before employing the HDDR process was found to consist of three phases, the matrix Nd 2Fe 14B (φ) phase, Nd-rich phase and a significant amount of free iron; whereas, the microstructure of the Nb-containing alloy consisted of only the first two phases. The HDDR behavior of the above alloys was characterized using a high-resolution scanning electron microscope (HRSEM). The disproportionation of the Nd 2Fe 14B (φ) matrix phase starts at the Nd-rich/φ phase interface, resulting in the formation of a sub-micron structure consisting of Fe, Fe 2B and Nd-hydride. The disproportionated structures of the Nb-free alloy contained large arms of free iron dendrites, which were retained from the as-cast structures. In the niobium-containing alloy, the recombined grains appear finer and with more rounded shapes in comparison with those of the NdFeB alloy. Promising magnetic properties have been obtained for bonded magnets using the HDDR powder. The magnetic properties, especially the intrinsic coercivity, improved significantly by using ˜1% Nd in excess of the stoichiometric content.

  13. The use of polytetrafluoroethylene in the production of high-density bonded Nd-Fe-B magnets

    NASA Astrophysics Data System (ADS)

    Tattam, C.; Williams, A. J.; Hay, J. N.; Harris, I. R.; Tedstone, S. F.; Ashraf, M. M.

    1994-11-01

    Rotary forging has been used to produce high-density bonded magnets from rapidly quenched Nd-Fe-B based ribbons (MQP-D, of nominal composition 28%Nd-56%Fe-15%Co-1%B (wt%)). Polytetrafluoroehtylene (PTFE), when used as an additive (5%-15% by volume) has been found to act as an effective binder and greatly enhances the forgeability of the MQI, allowing higher forging pressures to be used. Densities of up to 98% of the fully dense composite have been achieved. The forging process can be undertaken in air at room temperature. Magnetically, the compacts are comparable to conventional epoxy resin bonded MQI, with energy products of up to 84 kJ/cu m. Equivalent volume fractions of MQI (approximately 83.5 vol %) have been achieved in the compacts with increased PTFE content due to the displacement of pores by the PTFE. The effect of PTFE content on the mechanical strength of the compacts has been assessed and it has been found that strength increases with increasing PTFE content, consistent with the reduction in porosity.

  14. Inducing magnetic anisotropy and optimized microstructure in rapidly solidified Nd-Fe-B based magnets by thermal gradient, magnetic field and hot deformation

    NASA Astrophysics Data System (ADS)

    Zhao, L. Z.; Li, W.; Wu, X. H.; Hussain, M.; Liu, Z. W.; Zhang, G. Q.; Greneche, J. M.

    2016-10-01

    Direct preparation of Nd-Fe-B alloys by rapid solidification of copper mold casting is a very simple and low cost process for mini-magnets, but these magnets are generally magnetically isotropic. In this work, high coercivity Nd24Co20Fe41B11Al4 rods were produced by injection casting. To induce magnetic anisotropy, temperature gradient, assisted magnetic field, and hot deformation (HD) procedures were employed. As-cast samples showed non-uniform microstructure due to the melt convection. The thermal gradient during solidification led to the formation of radially distributed acicular hard magnetic grains, which gives the magnetic anisotropy. The growth of the oriented grains was confirmed by phase field simulation. A magnetic field up to 1 T applied along the casting direction could not induce significant magnetic anisotropy, but it improved the magnetic properties by reducing the non-uniformity and forming a uniform microstructure. The annealed alloys exhibited high intrinsic coercivity but disappeared anisotropy. HD was demonstrated to be a good approach for inducing magnetic anisotropy and enhanced coercivity by deforming and refining the grains. This work provides an alternative approach for preparing fully dense Nd-rich anisotropic bulk Nd-Fe-B magnets.

  15. Evaluation of the effects of aging in synthetic saliva solution of both commercial and silanized Nd-Fe-B magnets for dental application

    NASA Astrophysics Data System (ADS)

    Fabiano, F.; Puliafito, V.; Calabrese, L.; Borsellino, C.; Bonaccorsi, L. M.; Giordano, A.; Fabiano, V.; Cordasco, G.

    2016-04-01

    Neodymium-iron-boron magnets are able to ensure a magnetic flux with high maximum energy product also at miniaturized size. In the past, due to their marked corrosion in saliva they were unsuccessfully implemented in orthodontic systems. Thereby, we propose a multi-layered organic-inorganic coating able to supply anticorrosion resistance, wear resistance and durability to the whole assembly. We evaluated the influence on the magnetic force of commercial nickel plated and silanized Nd-Fe-B during aging time in synthetic Fusayama saliva. Two magnets based-micromagnetic simulations were performed in order to analyze the magnetic field generated which is linked to the magnetic force. Our key results underline that the proposed hybrid coating does not affect the magnetic force of Nd-Fe-B magnets, moreover, preventing corrosion degradation in aggressive solution. Thus the limiting aspects avoiding the use of Nd-Fe-B magnets for orthodontic and prosthodontic applications can be overcome by using silane agents as surface coating.

  16. Exchange-coupled nanoscale SmCo/NdFeB hybrid magnets

    SciTech Connect

    Wang, Dapeng; Poudyal, Narayan; Rong, Chuanbing; Zhang, Ying; Kramer, Matthew J.; Liu, J. Ping

    2012-05-11

    Nanoscalehybridmagnets containing SmCo5 and Nd2Fe14B hard magnetic phases have been produced via a novel “in-one-pot” processing route. The grain size of the processed bulk composite materials is controlled below 20 nm. The refinement of the nanoscale morphology leads to effective inter-phase exchange coupling that results in single-phase like magnetic properties. Energy product of 14 MGOe was obtained in the isotropic nanocomposite magnets at room temperature. At elevated temperatures, the hybridmagnets have greatly improved thermal stability compared to the Nd2Fe14B single-phase counterpart and have substantially increased magnetization and energy products compared to the single-phase SmCo5 counterpart.

  17. Multifaceted Material Substitution: The Case of NdFeB Magnets, 2010-2015

    NASA Astrophysics Data System (ADS)

    Smith, Braeton J.; Eggert, Roderick G.

    2016-07-01

    Substitution is an important response for material users when faced with disruption to the availability or price of an essential material. In economic terms, substitution refers to the ability of firms to alter their patterns of material use in response to exogenous market shocks. Substitution comes in different forms which vary from situation to situation. This paper uses expert opinion to identify the specific forms of substitution that occurred in permanent magnets, specifically neodymium-iron-boron magnets, following the significant increase in rare earth prices in 2010-2011. The paper provides a framework for understanding the multifaceted nature of substitution and assesses the relative importance of five different types of substitution. Technology-for-element, grade-for-grade, and system-for-system substitution appear to have been more important than element-for-element and magnet-for-magnet substitution. Cost pass-through and absorption were also important responses.

  18. NdFeB Magnets Aligned in a 9-T Superconducting Solenoid (asterisk)

    NASA Astrophysics Data System (ADS)

    Mulcahy, T. M.; Hull, J. R.

    2002-08-01

    Commercial-grade magnet powder (Magnequench UG) was uniaxial die-pressed into cylindrical compacts, while being aligned in the 1-T to 8-T DC field of a superconducting solenoid at Argonne National Laboratory. Then, the compacts were added to normal Magnequench UG production batches for sintering and annealing. The variations in magnet properties for different strengths of alignment fields are reported for 15.88-mm (5/8-in.) diameter compacts made with length-to-diameter (L/D) ratios in the range 3 0.25 and L 1. The best magnets were produced when the powder-filled die was inserted into the active field of the solenoid and then pressed. Improvements in the residual flux density of 8% and in the energy product of 16% were achieved by increasing the alignment field beyond the typical 2-T capabilities of electromagnets. The most improvement was achieved for the compacts with the smallest L/D ratio. The ability to make very strong magnets with small L/D, where self-demagnetization effects during alignment are greatest, would benefit most the production of near-final-shape magnets. Compaction of the magnet powder using a horizontal die and a continuously active superconducting solenoid was not a problem. Although the press was operated in the batch mode for this proof-of-concept study, its design is intended to enable automated production.

  19. Textured NdFeB HDDR magnets produced by die-upsetting and backward extrusion

    NASA Astrophysics Data System (ADS)

    Gutfleisch, O.; Kirchner, A.; Grünberger, W.; Hinz, D.; Nagel, H.; Thompson, P.; Chapman, J. N.; Müller, K. H.; Schultz, L.; Harris, I. R.

    1998-04-01

    The hydrogenation disproportionation desorption recombination (HDDR) process was applied to produce isotropic, submicron 0022-3727/31/7/009/img6 powder in 500 g batches in a specially designed HDDR reactor. The hot pressing characteristics of the material were determined and it was shown that the material has an excellent stability against grain growth. The coercivity of 1000-1080 0022-3727/31/7/009/img7 is almost constant over a hot pressing temperature range of 700-0022-3727/31/7/009/img8, making the material highly suitable for subsequent hot deformation. Die-upset HDDR magnets were prepared in order to study the basic deformation behaviour. A remanence of 1.13 T in the axial direction and a coercivity of 0022-3727/31/7/009/img9 were achieved. Similar properties were obtained for the backward extruded magnets produced at 0022-3727/31/7/009/img10 and only a small decrease in alignment along the axial direction of the ring was found. Grain sizes were very uniform and on the submicron scale. Platelet-shaped grains were observed in the die-upset magnets. The formation of interaction domains, along the axial and radial directions for the die-upset and backward extruded magnets respectively, were established by high-resolution Kerr microscopy. The high degree of texture in the hot deformed HDDR magnets was also confirmed by Lorentz microscopy revealing continuous equispaced domains extending over the entire thinned sample with only small directional variations.

  20. Barkhausen noise in the Random Field Ising Magnet NdFeB

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Silevitch, Daniel; Rosenbaum, Thomas

    2015-03-01

    With the application of a magnetic field transverse to the magnetic easy axis, sintered blocks of the rare-earth ferromagnet Nd2Fe14B form a realization of the Random-Field Ising Model at room temperature. We study domain reversal and avalanche dynamics through an analysis of the Barkhausen noise. Power-law behavior with a cutoff is observed in the avalanche energy spectrum, consistent with theoretical predictions for disordered materials. Two regimes of behavior are found, one at low temperature and high transverse field where the system shows behavior consistent with randomness-dominated dynamics, and a high-temperature, low-transverse-field regime in which thermal fluctuations dominate the dynamics. In the randomness-dominated regime, the critical exponents are consistent with mean-field predictions for heavily disordered system, whereas in the thermal-fluctuation regime, the critical exponents differ substantially from the mean-field predictions.

  1. High performance Nd-Fe-B permanent magnets without critical elements

    DOE PAGES

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Khan, M.; ...

    2016-01-28

    Scanning electron microscopy, and magnetization measurements reveal that as cast (Nd1–xCex)2Fe14B alloys contain significant amounts of α-Fe that can be dramatically reduced by annealing the alloys at 1000 °C for 3 days. The room temperature intrinsic coercivity, Hci, of (Nd0.8Ce0.2)2.2Fe14B melt spun ribbons was found to be 11 kOe, which is ~32 to ~10% higher in comparison to that of Nd2Fe14B (Hci = 8.3 kOe), and (Nd0.8Ce0.2)2.0Fe14B (Hci = 10 kOe), respectively. The substitution of Co for Fe in (Nd0.8Ce0.2)2Fe14–zCozB significantly increases both TC and the maximum energy product, (BH)max. Our study shows that both Co-containing and Co-free Ce-substituted Nd2Fe14Bmore » alloys have excellent magnetic properties at room temperature and above. As a result, the experimental results also demonstrate the potential of Nd-Ce-Fe-TM-B based alloys as alternative to expensive Dy-containing high performance rare earth magnets.« less

  2. Structural and magnetic studies of the nanocrystalline Nd-Fe-B-Nb alloy ribbons

    NASA Astrophysics Data System (ADS)

    Szwaja, M.; Pawlik, K.; Pawlik, P.; Kaszuwara, W.; Wysłocki, J. J.; Gębara, P.

    2013-01-01

    A detailed studies of the phase constitution, microstructure and magnetic properties of the nanocrystalline Nd9.2Fe61.64B21.16Nb8 alloy ribbons, are reported. It was shown that the rapidly solidified ribbons have partially amorphous structure and soft magnetic properties in the as-cast state. The heat treatment at temperatures higher than 923 K led to the growth of the hard magnetic Nd2Fe14B phase and the metastable Nd2Fe23B3 phase. The Mössbauer confirmed that during annealing of the samples at temperature higher than 923 K the paramagnetic Nd1+ɛFe4B4 phase was also formed. The microstructure consisting of mixture of constituent phases was observed with transmission electron microscopy (TEM). Furthermore, with increasing annealing temperature the decrease of the saturation polarization Js was observed. The maximum values of coercivity JHc = 1175 kA/m was obtained for a sample annealed at 1023K. However, annealing at 1003 K resulted in the improvement of remanence polarization Jr = 0.35 T and the maximum energy product (BH)max = 21 kJ/m3.

  3. Preparation and characterization of amorphous SiO2 coatings deposited by mirco-arc oxidation on sintered NdFeB permanent magnets

    NASA Astrophysics Data System (ADS)

    Xu, J. L.; Xiao, Q. F.; Mei, D. D.; Zhong, Z. C.; Tong, Y. X.; Zheng, Y. F.; Li, L.

    2017-03-01

    Amorphous SiO2 coatings were prepared on sintered NdFeB magnets by micro-arc oxidation (MAO) in silicate solution. The surface and cross-sectional morphologies, element and phase composition, corrosion resistance and magnetic properties of the coatings were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and physical properties measurements system (PPMS). The results showed that the surface morphologies of the coatings exhibited the "coral reef" like structure, different from the typical MAO porous structure. With increasing the voltages, the thickness of the coatings increased from 12.72 to 19.90 μm, the content of Si element increased, while the contents of Fe, Nd and P elements decreased. The coatings were mainly composed of amorphous SiO2 and a few amorphous Fe2O3 and Nd2O3. The amorphous SiO2 coatings presented excellent thermal shock resistance, while the thermal shock resistance decreased with increasing the voltages. The corrosion resistance of the coatings increased with increasing the voltages, and it could be enhanced by one order of magnitude compared to the uncoated NdFeB magnets. The MAO coatings slightly decreased the magnetic properties of the NdFeB samples in different degrees.

  4. High performance Nd-Fe-B permanent magnets without critical elements

    SciTech Connect

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Khan, M.; McCallum, R. W.; Pecharsky, V. K.

    2016-01-28

    Scanning electron microscopy, and magnetization measurements reveal that as cast (Nd1–xCex)2Fe14B alloys contain significant amounts of α-Fe that can be dramatically reduced by annealing the alloys at 1000 °C for 3 days. The room temperature intrinsic coercivity, Hci, of (Nd0.8Ce0.2)2.2Fe14B melt spun ribbons was found to be 11 kOe, which is ~32 to ~10% higher in comparison to that of Nd2Fe14B (Hci = 8.3 kOe), and (Nd0.8Ce0.2)2.0Fe14B (Hci = 10 kOe), respectively. The substitution of Co for Fe in (Nd0.8Ce0.2)2Fe14–zCozB significantly increases both TC and the maximum energy product, (BH)max. Our study shows that both Co-containing and Co-free Ce-substituted Nd2Fe14B alloys have excellent magnetic properties at room temperature and above. As a result, the experimental results also demonstrate the potential of Nd-Ce-Fe-TM-B based alloys as alternative to expensive Dy-containing high performance rare earth magnets.

  5. Magnetic and microstructural modification of the Nd-Fe-B sintered magnet by mixed DyF3/DyHx powder doping

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Hoon; Lee, Seong-Rae; Kim, Hyo-Jun; Lee, Min-Woo; Jang, Tae-Suk

    2014-05-01

    We investigated the magnetic and microstructural properties of Nd-Fe-B sintered magnets doped with DyF3, DyHx, and a mixture of DyF3 and DyHx powders. In the DyHx-doped magnet, diffusion of Dy occurs predominantly via grain boundary diffusion. However, the proportion of Dy being diffused by lattice diffusion is increased in the DyF3-doped magnet due to the different influences of F- and H+ ions. The detailed mechanism of the microstructural changes in terms of the diffusional behavior of Dy induced by the DyF3 and DyHx powder doping is discussed. The formation of a Dy-segregated Nd-rich oxide phase (RE-rich, Dy-Nd-O) was suppressed only in the DyF3-doped magnet, and the (00L) alignment of Nd2Fe14B grains in the sintered magnet increased when it was doped with the DyHx powder. We obtained the optimum microstructural and magnetic properties of the Nd-Fe-B sintered magnet through doping with a mixture of DyF3 and DyHx powders, which compensated for the drawbacks of using each powder alone.

  6. Magnetism in grain-boundary phase of a NdFeB sintered magnet studied by spin-polarized scanning electron microscopy

    SciTech Connect

    Kohashi, Teruo Motai, Kumi; Nishiuchi, Takeshi; Hirosawa, Satoshi

    2014-06-09

    The magnetism in the grain-boundary phase of a NdFeB sintered magnet was measured by spin-polarized scanning electron microscopy (spin SEM). A sample magnet was fractured in the ultra-high-vacuum chamber to avoid oxidation, and its magnetizations in the exposed grain-boundary phase on the fracture surface were evaluated through the spin polarization of secondary electrons. Spin-SEM images were taken as the fracture surface was milled gradually by argon ions, and the magnetization in the grain-boundary phase was quantitatively obtained separately from that of the Nd{sub 2}Fe{sub 14}B phase. The obtained magnetization shows that the grain-boundary phase of this magnet has substantial magnetization, which was confirmed to be ferromagnetic.

  7. Magnetization reversal of a Nd-Cu-infiltrated Nd-Fe-B nanocrystalline magnet observed with small-angle neutron scattering

    SciTech Connect

    Saito, Kotaro Ono, Kanta; Ueno, Tetsuro; Yano, Masao; Shoji, Tetsuya; Sakuma, Noritsugu; Manabe, Akira; Kato, Akira; Harada, Masashi; Keiderling, Uwe

    2015-05-07

    The magnetization reversal process of Nd-Fe-B nanocrystalline magnets infiltrated with Nd-Cu alloy was examined using small-angle neutron scattering (SANS). The magnetic-field dependence of SANS intensity revealed a qualitative difference between Nd-Cu-infiltrated samples and as-deformed samples. Insufficient magnetic isolation along the direction perpendicular to the nominal c-axis is expected from comparable SANS intensities for different ranges of q values along this direction. For small q values near the coercivity field, Nd-Cu-infiltrated samples show a noticeable reduction in SANS intensity along the nominal c-axis, which is parallel to the external magnetic field. This indicates less spatial fluctuation of magnetic moments in Nd-Cu-infiltrated samples, owing to magnetically isolated Nd{sub 2}Fe{sub 14}B grains.

  8. A combined experimental and finite element analysis method for the estimation of eddy-current loss in NdFeB magnets.

    PubMed

    Fratila, Radu; Benabou, Abdelkader; Tounzi, Abdelmounaïm; Mipo, Jean-Claude

    2014-05-14

    NdFeB permanent magnets (PMs) are widely used in high performance electrical machines, but their relatively high conductivity subjects them to eddy current losses that can lead to magnetization loss. The Finite Element (FE) method is generally used to quantify the eddy current loss of PMs, but it remains quite difficult to validate the accuracy of the results with complex devices. In this paper, an experimental test device is used in order to extract the eddy current losses that are then compared with those of a 3D FE model.

  9. Effect of Partial Substitution of Neodymium with Praseodymium on the Magnetic and Process Properties of Sintered Magnets of Type NdFeB

    NASA Astrophysics Data System (ADS)

    Dormidontov, N. A.; Dormidontov, A. G.; Lileev, A. S.; Kamynin, A. V.; Lukin, A. A.

    2017-01-01

    The effect of substitution of neodymium with praseodymium in sintered magnets of type NdFeB on their magnetic and process properties in the concentration range of [Pr] = 0 - 13 wt.% is studied. The special features of milling of the alloys, sintering processes and heat treatments in the production of magnets containing praseodymium are discussed. Hysteresis characteristics of B r ≥ 1.2 T, H cJ ≥ 1200 kA/m, H cb ≥ 880 kA/m, H k ≥ 960 kA/m, and BH max ≥ 280 kJ/m3 are obtained for magnets with composition (in wt.%) 33 Nd, 10 Pr, 1.5 (Ti + Al + Cu), 1.3 B, the remainder Fe.

  10. Effect of titania particles on the microstructure and properties of the epoxy resin coatings on sintered NdFeB permanent magnets

    NASA Astrophysics Data System (ADS)

    Xu, J. L.; Huang, Z. X.; Luo, J. M.; Zhong, Z. C.

    2014-04-01

    The nanometer titania particles enhanced epoxy resin composite coatings were prepared on the sintered NdFeB permanent magnets by cathodic electrophoretic deposition. The effects of titania particle concentrations on the microstructure and properties of the epoxy coatings were investigated by surface and cross-sectional morphologies observation, surface roughness and microhardness measurement, H2SO4 solution immersion test, neutral salt spray test and magnetic properties measurement. The results showed that the thickness of epoxy coatings with and without the titania particles addition was about 40 μm. The titania particles could be uniformly dispersed and embedded in the epoxy matrix if the titania particles concentration was lower than 40 g/l. With increasing titania particle concentrations, the number of the particles embedded in the epoxy matrix increased and the surface roughness and microhardness of the composite coatings increased. At the same time, the weight loss of the coated samples immersed in H2SO4 solution decreased and the neutral salt spray time of the coated samples prolonged. It could be concluded that the titania particles did not change the thickness of the epoxy coatings and did not deteriorate the magnetic properties of NdFeB substrates, but could greatly improve the microhardness and corrosion resistance of the epoxy coatings.

  11. Improvement of the thermal stability of sintered Nd-Fe-B magnets by intergranular addition of Dy{sub 82.3}Co{sub 17.7}

    SciTech Connect

    Zhang, Xiaofeng; Guo, Shuai; Yan, Changjiang; Cai, Lingwen; Chen, Renjie; Yan, Aru; Lee, Don

    2014-05-07

    In this study, microstructure and magnetic properties of sintered Nd-Fe-B magnets with addition of Dy{sub 82.3}Co{sub 17.7} (wt. %) were investigated. By adding a small amount of Dy{sub 82.3}Co{sub 17.7}, the coercivity is improved greatly, and the irreversible loss is decreased sharply. The increase of Curie temperature suggests that Co atoms have entered into the 2:14:1 main phase. Microstructural analysis indicates that a well-developed core-shell structure was formed in the magnets with the addition of Dy{sub 82.3}Co{sub 17.7}. The improvement of magnetic properties can be attributed to the microstructural modification and the intrinsic properties' improvement.

  12. Magnetic Properties Improvement of Die-upset Nd-Fe-B Magnets by Dy-Cu Press Injection and Subsequent Heat Treatment

    PubMed Central

    Wang, Zexuan; Ju, Jinyun; Wang, Jinzhi; Yin, Wenzong; Chen, Renjie; Li, Ming; Jin, Chaoxiang; Tang, Xu; Lee, Don; Yan, Aru

    2016-01-01

    Ultrafine-grained die-upset Nd-Fe-B magnets are of importance because they provide a wide researching space to redesign the textured structures. Here is presented a route to obtain a new die-upset magnet with substantially improved magnetic properties. After experiencing the optimized heat treatment, both the coercivity and remanent magnetization of the Dy-Cu press injected magnets increased substantially in comparison with those of the annealed reference magnets, which is distinct from the reported experimental results on heavy rare-earth diffusion. To study the mechanism, we analyzed the texture evolution in high-temperature annealed die-upset magnets, which had significant impact on the improvement of remanent magnetization. On basis of the results, we find that the new structures are strongly interlinked with the initial structures. With injecting Dy-Cu eutectic alloy, an optimized initial microstructure was achieved in the near-surface diffused regions, which made preparations for the subsequent texture improvement. Besides, the Dy gradient distribution of near-surface regions of the Dy-Cu press injected magnets was also investigated. By controlling the initial microstructure and subsequent diffusion process, a higher performance magnet is expected to be obtained. PMID:27922060

  13. Magnetic Properties Improvement of Die-upset Nd-Fe-B Magnets by Dy-Cu Press Injection and Subsequent Heat Treatment.

    PubMed

    Wang, Zexuan; Ju, Jinyun; Wang, Jinzhi; Yin, Wenzong; Chen, Renjie; Li, Ming; Jin, Chaoxiang; Tang, Xu; Lee, Don; Yan, Aru

    2016-12-06

    Ultrafine-grained die-upset Nd-Fe-B magnets are of importance because they provide a wide researching space to redesign the textured structures. Here is presented a route to obtain a new die-upset magnet with substantially improved magnetic properties. After experiencing the optimized heat treatment, both the coercivity and remanent magnetization of the Dy-Cu press injected magnets increased substantially in comparison with those of the annealed reference magnets, which is distinct from the reported experimental results on heavy rare-earth diffusion. To study the mechanism, we analyzed the texture evolution in high-temperature annealed die-upset magnets, which had significant impact on the improvement of remanent magnetization. On basis of the results, we find that the new structures are strongly interlinked with the initial structures. With injecting Dy-Cu eutectic alloy, an optimized initial microstructure was achieved in the near-surface diffused regions, which made preparations for the subsequent texture improvement. Besides, the Dy gradient distribution of near-surface regions of the Dy-Cu press injected magnets was also investigated. By controlling the initial microstructure and subsequent diffusion process, a higher performance magnet is expected to be obtained.

  14. Magnetic Properties Improvement of Die-upset Nd-Fe-B Magnets by Dy-Cu Press Injection and Subsequent Heat Treatment

    NASA Astrophysics Data System (ADS)

    Wang, Zexuan; Ju, Jinyun; Wang, Jinzhi; Yin, Wenzong; Chen, Renjie; Li, Ming; Jin, Chaoxiang; Tang, Xu; Lee, Don; Yan, Aru

    2016-12-01

    Ultrafine-grained die-upset Nd-Fe-B magnets are of importance because they provide a wide researching space to redesign the textured structures. Here is presented a route to obtain a new die-upset magnet with substantially improved magnetic properties. After experiencing the optimized heat treatment, both the coercivity and remanent magnetization of the Dy-Cu press injected magnets increased substantially in comparison with those of the annealed reference magnets, which is distinct from the reported experimental results on heavy rare-earth diffusion. To study the mechanism, we analyzed the texture evolution in high-temperature annealed die-upset magnets, which had significant impact on the improvement of remanent magnetization. On basis of the results, we find that the new structures are strongly interlinked with the initial structures. With injecting Dy-Cu eutectic alloy, an optimized initial microstructure was achieved in the near-surface diffused regions, which made preparations for the subsequent texture improvement. Besides, the Dy gradient distribution of near-surface regions of the Dy-Cu press injected magnets was also investigated. By controlling the initial microstructure and subsequent diffusion process, a higher performance magnet is expected to be obtained.

  15. Low temperature diffusion process using rare earth-Cu eutectic alloys for hot-deformed Nd-Fe-B bulk magnets

    SciTech Connect

    Akiya, T. Sepehri-Amin, H.; Ohkubo, T.; Liu, J.; Hono, K.; Hioki, K.; Hattori, A.

    2014-05-07

    The low temperature grain boundary diffusion process using RE{sub 70}Cu{sub 30} (RE = Pr, Nd) eutectic alloy powders was applied to sintered and hot-deformed Nd-Fe-B bulk magnets. Although only marginal coercivity increase was observed in sintered magnets, a substantial enhancement in coercivity was observed when the process was applied to hot-deformed anisotropic bulk magnets. Using Pr{sub 70}Cu{sub 30} eutectic alloy as a diffusion source, the coercivity was enhanced from 1.65 T to 2.56 T. The hot-deformed sample expanded along c-axis direction only after the diffusion process as RE rich intergranular layers parallel to the broad surface of the Nd{sub 2}Fe{sub 14}B are thickened in the c-axis direction.

  16. TEM studies of the effects of Zr additions on some HDDR-processed, high boron, NdFeB-type powders and hot-pressed magnets

    NASA Astrophysics Data System (ADS)

    Yi, G.; Chapman, J. N.; Brown, D. N.; Harris, I. R.

    2000-10-01

    The transmission electron microscope has been used to study the physical and magnetic microstructures of two HDDR-processed NdFeB-type alloys, one without Zr and the other containing 1.1 at% Zr. Studies were made of the as-produced powders and the solids produced following hot-pressing at 900°C. In the HDDR powders, the principal effects of adding Zr were to reduce the average grain size by ≈ {1}/{3} and made the grain size distribution more uniform. In the hot-pressed samples, the effect of Zr was more dramatic in that grain growth was very significantly reduced. Zr-containing phases were identified and a simple model, due to Zener, used to provide a plausible explanation of how the small amount of Zr present could stabilise the grain size to ≈0.5 μm. The microstructural results correlated well with measured magnetic properties.

  17. Improvement in coercivity, thermal stability, and corrosion resistance of sintered Nd-Fe-B magnets with Dy80Ga20 intergranular addition

    NASA Astrophysics Data System (ADS)

    Zhou, Beibei; Li, Xiangbin; Cao, Xuejing; Yan, Gaolin; Yan, Aru

    2016-11-01

    To investigate the coercivity, corrosion resistance, and thermal stability of Nd-Fe-B magnets, their properties were investigated at room and high temperature before and after doping with Dy80Ga20 (at.%) powder. The coercivity of the magnets increased from the undoped value of 12.72 kOe to a doped value of 21.44 kOe. A micro-structural analysis indicates that a well-developed core-shell structure forms in the magnets doped with Dy80Ga20 powder. The improvement in magnetic properties is believed to be related to the refined and uniform matrix grains, continuous grain boundaries, and a hardened (Nd, Dy)2Fe14B shell surrounding the matrix grains. Additionally, the doped magnets exhibit an obvious improvement in thermal stability. For the magnets with added Dy80Ga20 powder, the temperature coefficients of remanence (α) and coercivity (β) increased to -0.106% °C-1 and -0.60% °C-1 over the range 20-100 °C, compared to temperature coefficients of -0.117% °C-1 (α) and -0.74% °C-1 (β) in the regular magnets without Dy80Ga20 powder. The irreversible loss of magnetic flux (Hirr) was investigated at different temperatures. After being exposed to 150 °C for 2 h, the Hirr of magnets with 4 wt.% Dy80Ga20 decreased by ˜95% compared to that of the undoped magnets. The enhanced temperature coefficients and Hirr indicate improved thermal stability in the doped Nd-Fe-B magnets. The intergranular addition of Dy80Ga20 also improved the corrosion resistance of the magnets because of the enhanced intergranular phase. In a corrosive atmosphere for 96 h, the mass loss of the sintered magnets with 4 wt.% Dy80Ga20 was 2.68 mg/cm2, less than 10% of that suffered by the undoped magnets (28.1 mg/cm2). Project supported by the Ministry of Science and Technology of China (Grant Nos. 2014DFB50130 and 2011CB612304) and the National Natural Science Foundation of China (Grant Nos. 51172168 and 51072139).

  18. Magnetic properties and coercivity mechanism of isotropic HDDR NdFeB bonded magnets with Co and Dy addition

    NASA Astrophysics Data System (ADS)

    Chen, W.; Gao, R. W.; Zhu, M. G.; Pan, W.; Li, W.; Li, X. M.; Han, G. B.; Feng, W. C.; Wang, B.

    2003-04-01

    Isotropic NdDyFeCoB bonded magnets with high coercivity of 1.59 MA/m and low temperature coefficient of remanence of -0.056%/ K (in the temperature range 298-428 K) were prepared successfully by controlling the HDDR process and adjusting the compositions. The influence of Co and Dy additions on the magnetic properties and the magnetization reversal process in magnet was investigated. The high coercivity in (Nd 0.8Dy 0.2) 13(Fe 0.875Co 0.125) 81B 6 HDDR magnet can be attributed to its unique microstructure and the enhancement of anisotropy field of 2:14:1 phase by substitution of Nd by Dy.

  19. A Simple, Nearly 2D Explosively Shocked NdFeB(52) Permanent Magnet and a Comparison to a Cale Calculation Suggesting the Mechanism for Magnetic Flux Release and Subsequent EMF Pulse

    DTIC Science & Technology

    2011-06-01

    these simulations the MHD was turned off. Only the effect of the HE generated shock wave heating was being examined. The following series of images are...A SIMPLE, NEARLY 2D EXPLOSIVELY SHOCKED NdFeB(52) PERMANENT MAGNET AND A COMPARISON TO A CALE CALCULATION SUGGESTING THE MECHANISM FOR MAGNETIC...phenomenon of the generation of pulsed electrical energy realized from the shocking of modern strong permanent Ferro magnets. The Care’n Co., together

  20. Microstructure and magnetic properties of backward extruded NdFeB ring magnets by the CAPA process

    NASA Astrophysics Data System (ADS)

    Kim, Hyoung-Tae; Kim, Yoon-Bae

    2004-06-01

    The inhomogeneity in microstructure and magnetic properties of a ring magnet prepared by backward extrusion with a current-applied pressure-assisted process has been investigated. The initial part (top part) of a ring magnet prepared by back extrusion shows a high coercivity which is comparable to the raw powder. It exhibits isotropic characteristics along the three orthogonal directions probably due to small deformation. The last part (bottom part) of the ring magnet has a a low coercivity with large grains because high current flows through the pressurized punches during the whole deformation process as to increase the temperature and grain growth. The middle part is under an appropriate deformation with short time exposure at high temperature, therefore it maintains a relatively high remanent polarization with high coercivity.

  1. International comparison of the properties of NdFeB permanent magnets measured using an electromagnet and a pulsed field magnetometer

    NASA Astrophysics Data System (ADS)

    Hall, Michael

    2013-08-01

    An IEC TC 68 comparison on the measurement of the magnetic properties of permanent magnets was completed in 2011. Measurements were performed on 6 NdFeB magnets with intrinsic coercivities ranging from 1000 to 2600 kA/m by 8 institutes based in China, Japan, Italy, Belgium, Germany and the UK. Many versions of a Pulsed Field Magnetometer (PFM) that can determine the full BH curve in as little as 100 ms have been developed during the last 2 decades. By comparing measurements made using an internationally accepted electromagnet method and pulsed methods, the influence of the dynamic effects of the latter could be investigated and established. For the quantities remanence, B r , magnetic flux density coercivity, H cB and energy product, BH max the measurements agree within the combined uncertainties. For the intrinsic coercivity, H cJ , the dependence of the measurement of this quantity on the speed at which the magnetic field is reversed was found to be significant with the largest changes in value occurring as a DC measurement condition is approached.

  2. Coercivity of the Nd-Fe-B hot-deformed magnets diffusion-processed with low melting temperature glass forming alloys

    NASA Astrophysics Data System (ADS)

    Seelam, U. M. R.; Liu, Lihua; Akiya, T.; Sepehri-Amin, H.; Ohkubo, T.; Sakuma, N.; Yano, M.; Kato, A.; Hono, K.

    2016-08-01

    Nd- and Pr-based alloys with bulk glass forming ability and low melting temperatures, Nd60Al10Ni10Cu20 and Pr60Al10Ni10Cu20, were used for grain boundary diffusion process to enhance the coercivity of hot-deformed magnets. The coercivity increment was proportional to the weight gain after the diffusion process. For the sample with 64% weight gain, the coercivity increased up to 2.8 T, which is the highest value for bulk Nd-Fe-B magnets that do not contain heavy rare-earth elements, Dy or Tb. Approximately half of the intergranular regions were amorphous and the remaining regions were crystalline. Magnetic isolation of the Nd2Fe14B grains by the Nd-rich amorphous/crystalline intergranular phases is attributed to the large coercivity enhancement. The coercivity does not change after the crystallization of the intergranular phase, indicating that the coercivity is not influenced by the strain at the interface with the crystalline intergranular phase.

  3. Crystal structure and magnetic properties of Nd2Fe14B powder prepared by using high energy milling from elements metal Nd,Fe,B powders

    NASA Astrophysics Data System (ADS)

    Ramlan; Muljadi; Sardjono, P.; Gulo, F.; Setiabudidaya, D.

    2016-11-01

    The Nd2Fe14B powder has been made by using High Energy Milling (HEM) from mixed metal powders Iron (Fe), Neodymium (Nd) and Boron (B). The Nd, Fe and B powders were mixed according stoichiometric composition (atomic ratio Nd:Fe:B = 2: 14: 1) and milled and milling time was varied in 10, 20, and 40 hours by using HEM. Toluene liquid was used as milling media to protect of metal powders from oxygen. The measurement result of x- ray diffraction show that the optimum Nd2Fe14B phase already formed about 69,46% after milling 40 hours with crystallite size about 25.64 nm. The magnetic properties of milled powders were measured by using VSM at room temperature. The highest value of magnetic properties are obtained at powder milled in 40 hours, at this condition, it is obtained Ms = 122 emu/g, Mr = 81 emu/g, Hc = 5.54 kOe and BHmax = 11.01 MGOe.

  4. Improving sintered NdFeB permanent magnets by powder compaction in a 9 T superconducting solenoid

    NASA Astrophysics Data System (ADS)

    Mulcahy, T. M.; Hull, J. R.; Rozendaal, E.; Wise, J. H.; Turner, L. R.

    2003-05-01

    Commercial-grade magnet powder (Magnequench UG) was axial die pressed in the 76.2 mm warm bore of a 9 T superconducting solenoid. Otherwise, processing was performed as part of normal factory operations. This pressing was done to improve the alignment of the anisotropic single-crystal particles of the compact and, thus, the remanent magnetization of the sintered cylindrical permanent magnets (12.7 mm diameter). Although the press was operated in batch mode for this proof-of-concept study, its design enables automated production. Improvements of up to 8% in magnetization and 16% in energy products were obtained, as the alignment field H was increased above the 2 T maximum field of electromagnets used in industry. The greatest improvements were obtained for magnets with the smallest length-to-diameter ratios, L/D<0.5. The production of quality magnets in this near-final-shape size range is currently being pursued by industry to eliminate expensive machining steps. To understand the potential for 2-8 T alignment fields to overcome the distortions created in the otherwise uniform field by the self-field of short compacts, electromagnetic code (Opera) calculations were made. A simple material model was used to predict the distortions. The trends in the predicted field-line inclinations, with L/D and H, compare to trends in the improvement of the magnetic properties.

  5. Nd2Fe17 nanograins effect on the coercivity of HDDR NdFeB magnets with low boron content

    NASA Astrophysics Data System (ADS)

    Sun, Ai-Zhi; Wu, Shen; Xu, Wen-Huan; Wang, Jin; Zhang, Qian; Zhai, Fu-Qiang; Volinsky, Alex A.

    2012-03-01

    Relationships between the coercivity of hydrogenation disproportionation desorption recombination (HDDR) Nd12.5Fe81.5- x Co6B x bonded magnets and boron content were investigated. Nd2Fe17 phase with planar magnetic anisotropy is present in the microstructure when x= 4at%-5.88at%, which does not reduce the coercivity of the bonded magnets. High-resolution transmission electron microscopy (TEM) images show that Nd2Fe17 phase exists in the form of nanocrystals in the Nd2Fe14B matrix. There is an exchange-coupling interaction between the two phases so that the coercivity of HDDR Nd12.5Fe81.5- x Co6B x bonded magnets is hardly reduced with a decrease in boron content.

  6. Large-scale micromagnetic simulation of Nd-Fe-B sintered magnets with Dy-rich shell structures

    NASA Astrophysics Data System (ADS)

    Oikawa, T.; Yokota, H.; Ohkubo, T.; Hono, K.

    2016-05-01

    Large-scale micromagnetic simulations have been performed using the energy minimization method on a model with structural features similar to those of Dy grain boundary diffusion (GBD)-processed sintered magnets. Coercivity increases as a linear function of the anisotropy field of the Dy-rich shell, which is independent of Dy composition in the core as long as the shell thickness is greater than about 15 nm. This result shows that the Dy contained in the initial sintered magnets prior to the GBD process is not essential for enhancing coercivity. Magnetization reversal patterns indicate that coercivity is strongly influenced by domain wall pinning at the grain boundary. This observation is found to be consistent with the one-dimensional pinning theory.

  7. Normal and abnormal grain growth in fine-grained Nd-Fe-B sintered magnets prepared from He jet milled powders

    NASA Astrophysics Data System (ADS)

    Bittner, F.; Woodcock, T. G.; Schultz, L.; Schwöbel, C.; Gutfleisch, O.; Zickler, G. A.; Fidler, J.; Üstüner, K.; Katter, M.

    2017-03-01

    Fine-grained, heavy rare earth free Nd-Fe-B sintered magnets were prepared from He jet milled powders with an average particle size of 1.5 μm by low temperature sintering at 920 °C or 980 °C. A coercivity of >1600 kA/m was achieved for an average grain size of 1.68 μm. Transmission electron microscopy showed that the distribution and composition of intergranular and grain boundary junction phases was similar to that in conventionally processed magnets. Microstructural analysis on different length scales revealed the occurrence of abnormal grain growth, which is unexpected for sintering temperatures below 1000 °C. A larger area fraction of abnormal grains was observed in the sample sintered at 920 °C compared to that sintered at 980 °C. Microtexture investigation showed a better crystallographic alignment of the abnormal grains compared to the fine-grained matrix, which is explained by a size dependent alignment of the powder particles during magnetic field alignment prior to sintering. Slightly larger particles in the initial powder show a better alignment and will act as nucleation sites for abnormal grain growth. Magneto-optical Kerr investigations confirmed the lower switching field of the abnormal grains compared to the fine-grained matrix. The demagnetisation curve of the sample sintered at 920 °C showed reduced rectangularity and this was attributed to a cooperative effect of the larger fraction of abnormal grains with low switching field and, as a minor effect, a reduced degree of crystallographic texture in this sample compared to the material sintered at 980 °C, which did not show the reduced rectangularity of the demagnetisation curve.

  8. Coercivity enhancement of sintered Nd-Fe-B magnets by chemical bath deposition of TbCl{sub 3}

    SciTech Connect

    Guo, Shuai Zhang, Xiaofeng; Ding, Guangfei; Chen, Renjie; Yan, Aru; Lee, Don

    2014-05-07

    The chemical bath deposition (CBD) and the grain boundary diffusion method were combined to diffuse the heavy rare earth for obtain the thick magnets with high coercivity and low heavy rare earth. The jet mill powders were soaked into the alcohol solution of 0.2 wt. % TbCl{sub 3}. A thin layer of TbCl{sub 3} was wrapped to the surface of (PrNd){sub 2}Fe{sub 14}B powder particles. The coercivity of magnet is increased from 11.89 kOe to 14.72 kOe without significant reduction of remanence after grain boundary diffusion in the sintering and the annealing processes. The temperature coefficients of the remanence and the coercivity are improved by the substitution of PrNd by Tb in the surface of grains. The highly accelerated temperature/humidity stress test (HAST) results indicate that the CBD magnet has poor corrosion resistance, attributing to the present of Cl atoms in the grain boundaries.

  9. Unsupervised Data Mining in nanoscale X-ray Spectro-Microscopic Study of NdFeB Magnet

    PubMed Central

    Duan, Xiaoyue; Yang, Feifei; Antono, Erin; Yang, Wenge; Pianetta, Piero; Ermon, Stefano; Mehta, Apurva; Liu, Yijin

    2016-01-01

    Novel developments in X-ray based spectro-microscopic characterization techniques have increased the rate of acquisition of spatially resolved spectroscopic data by several orders of magnitude over what was possible a few years ago. This accelerated data acquisition, with high spatial resolution at nanoscale and sensitivity to subtle differences in chemistry and atomic structure, provides a unique opportunity to investigate hierarchically complex and structurally heterogeneous systems found in functional devices and materials systems. However, handling and analyzing the large volume data generated poses significant challenges. Here we apply an unsupervised data-mining algorithm known as DBSCAN to study a rare-earth element based permanent magnet material, Nd2Fe14B. We are able to reduce a large spectro-microscopic dataset of over 300,000 spectra to 3, preserving much of the underlying information. Scientists can easily and quickly analyze in detail three characteristic spectra. Our approach can rapidly provide a concise representation of a large and complex dataset to materials scientists and chemists. For example, it shows that the surface of common Nd2Fe14B magnet is chemically and structurally very different from the bulk, suggesting a possible surface alteration effect possibly due to the corrosion, which could affect the material’s overall properties. PMID:27680388

  10. Unsupervised Data Mining in nanoscale X-ray Spectro-Microscopic Study of NdFeB Magnet.

    PubMed

    Duan, Xiaoyue; Yang, Feifei; Antono, Erin; Yang, Wenge; Pianetta, Piero; Ermon, Stefano; Mehta, Apurva; Liu, Yijin

    2016-09-29

    Novel developments in X-ray based spectro-microscopic characterization techniques have increased the rate of acquisition of spatially resolved spectroscopic data by several orders of magnitude over what was possible a few years ago. This accelerated data acquisition, with high spatial resolution at nanoscale and sensitivity to subtle differences in chemistry and atomic structure, provides a unique opportunity to investigate hierarchically complex and structurally heterogeneous systems found in functional devices and materials systems. However, handling and analyzing the large volume data generated poses significant challenges. Here we apply an unsupervised data-mining algorithm known as DBSCAN to study a rare-earth element based permanent magnet material, Nd2Fe14B. We are able to reduce a large spectro-microscopic dataset of over 300,000 spectra to 3, preserving much of the underlying information. Scientists can easily and quickly analyze in detail three characteristic spectra. Our approach can rapidly provide a concise representation of a large and complex dataset to materials scientists and chemists. For example, it shows that the surface of common Nd2Fe14B magnet is chemically and structurally very different from the bulk, suggesting a possible surface alteration effect possibly due to the corrosion, which could affect the material's overall properties.

  11. Unsupervised data mining in nanoscale x-ray spectro-microscopic study of NdFeB magnet

    DOE PAGES

    Duan, Xiaoyue; Yang, Feifei; Antono, Erin; ...

    2016-09-29

    Novel developments in X-ray based spectro-microscopic characterization techniques have increased the rate of acquisition of spatially resolved spectroscopic data by several orders of magnitude over what was possible a few years ago. This accelerated data acquisition, with high spatial resolution at nanoscale and sensitivity to subtle differences in chemistry and atomic structure, provides a unique opportunity to investigate hierarchically complex and structurally heterogeneous systems found in functional devices and materials systems. However, handling and analyzing the large volume data generated poses significant challenges. Here we apply an unsupervised data-mining algorithm known as DBSCAN to study a rare-earth element based permanentmore » magnet material, Nd2Fe14B. We are able to reduce a large spectro-microscopic dataset of over 300,000 spectra to 3, preserving much of the underlying information. Scientists can easily and quickly analyze in detail three characteristic spectra. Our approach can rapidly provide a concise representation of a large and complex dataset to materials scientists and chemists. For instance, it shows that the surface of common Nd2Fe14B magnet is chemically and structurally very different from the bulk, suggesting a possible surface alteration effect possibly due to the corrosion, which could affect the material’s overall properties.« less

  12. Unsupervised Data Mining in nanoscale X-ray Spectro-Microscopic Study of NdFeB Magnet

    NASA Astrophysics Data System (ADS)

    Duan, Xiaoyue; Yang, Feifei; Antono, Erin; Yang, Wenge; Pianetta, Piero; Ermon, Stefano; Mehta, Apurva; Liu, Yijin

    2016-09-01

    Novel developments in X-ray based spectro-microscopic characterization techniques have increased the rate of acquisition of spatially resolved spectroscopic data by several orders of magnitude over what was possible a few years ago. This accelerated data acquisition, with high spatial resolution at nanoscale and sensitivity to subtle differences in chemistry and atomic structure, provides a unique opportunity to investigate hierarchically complex and structurally heterogeneous systems found in functional devices and materials systems. However, handling and analyzing the large volume data generated poses significant challenges. Here we apply an unsupervised data-mining algorithm known as DBSCAN to study a rare-earth element based permanent magnet material, Nd2Fe14B. We are able to reduce a large spectro-microscopic dataset of over 300,000 spectra to 3, preserving much of the underlying information. Scientists can easily and quickly analyze in detail three characteristic spectra. Our approach can rapidly provide a concise representation of a large and complex dataset to materials scientists and chemists. For example, it shows that the surface of common Nd2Fe14B magnet is chemically and structurally very different from the bulk, suggesting a possible surface alteration effect possibly due to the corrosion, which could affect the material’s overall properties.

  13. Unsupervised data mining in nanoscale x-ray spectro-microscopic study of NdFeB magnet

    SciTech Connect

    Duan, Xiaoyue; Yang, Feifei; Antono, Erin; Yang, Wenge; Pianetta, Piero; Ermon, Stefano; Mehta, Apurva; Liu, Yijin

    2016-09-29

    Novel developments in X-ray based spectro-microscopic characterization techniques have increased the rate of acquisition of spatially resolved spectroscopic data by several orders of magnitude over what was possible a few years ago. This accelerated data acquisition, with high spatial resolution at nanoscale and sensitivity to subtle differences in chemistry and atomic structure, provides a unique opportunity to investigate hierarchically complex and structurally heterogeneous systems found in functional devices and materials systems. However, handling and analyzing the large volume data generated poses significant challenges. Here we apply an unsupervised data-mining algorithm known as DBSCAN to study a rare-earth element based permanent magnet material, Nd2Fe14B. We are able to reduce a large spectro-microscopic dataset of over 300,000 spectra to 3, preserving much of the underlying information. Scientists can easily and quickly analyze in detail three characteristic spectra. Our approach can rapidly provide a concise representation of a large and complex dataset to materials scientists and chemists. For instance, it shows that the surface of common Nd2Fe14B magnet is chemically and structurally very different from the bulk, suggesting a possible surface alteration effect possibly due to the corrosion, which could affect the material’s overall properties.

  14. Electrophoretic deposition of graphene oxide as a corrosion inhibitor for sintered NdFeB

    NASA Astrophysics Data System (ADS)

    He, Wenting; Zhu, Liqun; Chen, Haining; Nan, Haiyang; Li, Weiping; Liu, Huicong; Wang, Yan

    2013-08-01

    Graphene oxide (GO) was deposited uniformly on the surface of permanent magnet material NdFeB by electrophoretic deposition (EPD). Electrophoretic deposited graphene oxide (EPD-GO) coating was reduced partially after EPD process, owing to the removal of oxygen functional groups. And EPD-GO coating showed excellent adhesion to the NdFeB matrix. According to the results of electrochemical tests, the decrease in corrosion current density and the positive shift in corrosion potential have both demonstrated that EPD-GO coating served as a corrosion inhibitor, protecting NdFeB from NaCl aqueous solution.

  15. Dependence of the magnetic properties on the alignment magnetic field for NdFeB bonded magnets made from anisotropic HDDR powders

    NASA Astrophysics Data System (ADS)

    Gao, R. W.; Zhang, J. C.; Zhang, D. H.; Dai, Y. Y.; Meng, X. H.; Wang, Z. M.; Zhang, Y. J.; Liu, H. Q.

    1999-01-01

    The dependence of the hard magnetic properties on the alignment magnetic field for Nd(Fe,Co)B bonded magnets made from anisotropic HDDR powders is studied. The experimental results demonstrate that addition of a little Ga can induce a strong magnetic anisotropy in the HDDR magnetic powders. The application of an alignment magnetic field while the powders are bonded can increase the remanence, the coercivity and the maximum energy product in different degrees and the hard magnetic properties of the magnet are obviously improved with increasing alignment field.

  16. On the energy losses of hot worked Nd-Fe-B magnets and ferrites in a small alternating magnetic field perpendicular to a bias field

    SciTech Connect

    Staa, F. von; Hempel, K.A.; Artz, H.

    1995-11-01

    Torsion pendulum magnetometer measurements on ferrites and on neodymium-iron-boron permanent magnets are presented. The damping of the oscillation of the pendulum leads to information on the magnetic energy losses of the magnets in a small alternating magnetic field applied perpendicular to a bias field. The origin of the energy absorption is explained by the magnetization reversal of single-domain particles. It is shown experimentally that the energy absorption mechanism requires the ferromagnetic order of the sample, and that the magnetic field strength of maximal energy absorption coincides with the effective anisotropy field strength.

  17. Effect of sintering conditions on the magnetic and microstructural properties of Nd-Fe-B sintered magnets doped with DyF(3) powders.

    PubMed

    Park, Song-E; Kim, Tae-Hoon; Lee, Seong-Rae; Namkung, Seok; Jang, Tae-Suk

    2012-04-01

    The microstructural and magnetic property changes of DyF(3)-doped (Nd(26.06), Dy(6.51))-Fe(bal) -B(0.97)-M(2.39) (wt. %) (M = Cu, Al, Co, and Nb) sintered magnets as functions of the sintering conditions were studied. The sintering conditions for the optimum core-shell microstructure were determined. When the magnets were sintered at 1050 °C for 4 h, a coercivity of 35.1 kOe was obtained without sacrificing the remanence. When the magnets were doped with DyF(3), the formation of the RE-rich phase (Nd-Dy-O) was effectively suppressed and, hence, saving the Dy. In addition, the formation of a cubic-NdOF triple-junction phase (TJP) improves the interface uniformity and enhances the coercivity.

  18. Direct observation of ferromagnetism in grain boundary phase of Nd-Fe-B sintered magnet using soft x-ray magnetic circular dichroism

    SciTech Connect

    Nakamura, T.; Yasui, A.; Kotani, Y.; Iwai, H.; Akiya, T.; Ohkubo, T.; Hono, K.; Hirosawa, S.; Gohda, Y.

    2014-11-17

    We have investigated the magnetism of the grain boundary (GB) phase in a Nd{sub 14.0}Fe{sub 79.7}Cu{sub 0.1}B{sub 6.2} sintered magnet using soft x-ray magnetic circular dichroism (XMCD) at the Fe L{sub 2,3}-edges. Soft XMCD spectra were measured from the fractured surface that was confirmed to be covered with a thin GB phase by Auger electron spectroscopy. The magnetic moment of Fe in the GB phase was estimated to be m{sub GB}=1.4 μ{sub B} at 30 °C using the sum rule analysis for XMCD spectra, which is 60% of that of Fe in the Nd{sub 2}Fe{sub 14}B compound. The temperature dependence of m{sub GB} evaluated with reference to Fe in the Nd{sub 2}Fe{sub 14}B phase indicated that the Curie temperature of the GB phase is more than 50 °C lower compared to that of Nd{sub 2}Fe{sub 14}B.

  19. Temperature properties of the alignment dependence of coercive force decrease ratio and the angular dependence of coercive force in Nd-Fe-B sintered magnets

    NASA Astrophysics Data System (ADS)

    Matsuura, Yutaka; Kitai, Nobuyuki; Ishii, Rintaro; Natsumeda, Mitsutoshi; Hoshijima, Jun; Kuniyoshi, Futoshi

    2016-01-01

    The temperature dependence of the coercive force decrease ratio for aligned magnets was investigated from room temperature (296 K) to 473 K. The temperature properties of the angular dependence of the coercive force were also measured from room temperature to 413 K, for comparison against the coercive force decrease ratio. From the temperature dependence of the coercive force decrease ratio of magnets with different alignment, it was found that the coercive force decrease ratio decreased as temperature increased until becoming close to the calculation results that were obtained from the Gaussian distribution for Nd2Fe14B grain alignment and from the postulation that every grain follows the Kondorskii law or the 1/cos θ law. When we compared the angle of the magnetization reverse area obtained from these calculation results and the angle of the reverse magnetization area calculated from the experimental data of the coercive force decrease ratio, it was found that this latter expanded to 30° for Nd13.48B5.76Co0.55Febal. having 0.95 alignment, at room temperature, from 14° that was the calculated angle obtained from the Gaussian distribution and the Kondorskii law. The angular dependence of coercive force of this magnet at room temperature agrees well with the calculation, when σ=31°, which is 30° for the reversed magnetization area, is applied as the standard deviation of Nd2Fe14B grain alignment distribution. For Nd12.75Dy0.84B5.81Co0.55Febal. with 0.96 for alignment, the reverse magnetization area also expanded to 36° and agreed well with the calculation result applied σ=44°, which has 36° for the reverse magnetization area. It was also found that, as temperature increased, the angle of the reverse magnetization area obtained from the experimental data shrunk towards the calculated angle. When we apply these results to the temperature properties of the angular dependence of the coercive force, it seems that the calculated angular dependence of the

  20. A high-resolution field-emission-gun, scanning electron microscope investigation of anisotropic hydrogen decrepitation in Nd-Fe-B-based sintered magnets

    NASA Astrophysics Data System (ADS)

    Soderznik, Marko; McGuiness, Paul; Zuzek-Rozman, Kristina; Škulj, Irena; Yan, Gaolin; Kobe, Spomenka

    2010-05-01

    In this investigation commercial magnets based on (Nd,Dy)14(Fe,Co)79B7 were prepared by a conventional powder-metallurgy route with a degree of alignment equal to ˜90% and then exposed to hydrogen at a pressure of 1 bar. The magnets, in the form of cylinders, were observed to decrepitate exclusively from the ends. High-resolution electron microscopy was able to identify the presence of crack formation within the Nd2Fe14B grains, with the cracks running parallel to the c axis of these grains. Based on the concentration profile for hydrogen in a rare-earth transition-metal material, it is clear that the presence of hydrogen-induced cracks running perpendicular to the ends of the magnet provides for a much more rapidly progressing hydrogen front in this direction than from the sides of the magnet. This results in the magnet exhibiting a macroscopic tendency to decrepitate from the poles of the magnet toward the center. This combination of microstructural modification via particle alignment as part of the sintering process and direct observation via high-resolution electron microscopy has led to a satisfying explanation for the anisotropic hydrogen-decrepitation effect.

  1. Segregation phenomena in Nd-Fe-B nanoparticles

    NASA Astrophysics Data System (ADS)

    Schmidt, F.; Pohl, D.; Schultz, L.; Rellinghaus, B.

    2015-04-01

    We report on the phase stability and phase formation of Nd-Fe-B nanoparticles from the gas phase in the size range from 10 to 25 nm. Particular attention is paid to the question, if the intermetallic Nd2Fe_{14}B phase also forms in free particles with a few nanometers in size that grow without contact to any solid or liquid matrix in a low pressure Ar atmosphere. The paper also addresses the possible influence of segregation phenomena that go along with the phase formation and the effect of (rapid) thermal annealing on the structure and phase stability of the particles. Aberration-corrected transmission electron microscopy in combination with spectroscopic methods was used to determine the local atomic structure and the chemical composition of the particles. Unheated particles are found to be mainly amorphous, while the rapidly optically annealed particles are crystalline. In both cases, we observe an enrichment of Nd in the shell of the particles and a Fe enrichment in the core. This segregation of Nd toward the particles' surface is more pronounced in heated particles, which form a clear core-shell structure with a Fe core surrounded by a Nd2O3 shell. This finding is attributed to the comparably small surface energy and the higher affinity of Nd to oxygen as compared to Fe. A simple model is introduced and used in order to estimate these surface energies. These estimations support the experimentally observed segregation phenomena. It is further found that B prefers the vicinity of Fe over that of Nd atoms, which as a consequence leads to a B enrichment in the Fe-rich parts of the particles. Magnetic measurements show a soft magnetic behavior for both, unheated and heated Nd-Fe-B nanoparticles.

  2. Life cycle inventory of the production of rare earths and the subsequent production of NdFeB rare earth permanent magnets.

    PubMed

    Sprecher, Benjamin; Xiao, Yanping; Walton, Allan; Speight, John; Harris, Rex; Kleijn, Rene; Visser, Geert; Kramer, Gert Jan

    2014-04-01

    Neodymium is one of the more critical rare earth elements with respect to current availability and is most often used in high performance magnets. In this paper, we compare the virgin production route of these magnets with two hypothetical recycling processes in terms of environmental impact. The first recycling process looks at manual dismantling of computer hard disk drives (HDDs) combined with a novel hydrogen based recycling process. The second process assumes HDDs are shredded. Our life cycle assessment is based both on up to date literature and on our own experimental data. Because the production process of neodymium oxide is generic to all rare earths, we also report the life cycle inventory data for the production of rare earth oxides separately. We conclude that recycling of neodymium, especially via manual dismantling, is preferable to primary production, with some environmental indicators showing an order of magnitude improvement. The choice of recycling technology is also important with respect to resource recovery. While manual disassembly allows in principle for all magnetic material to be recovered, shredding leads to very low recovery rates (<10%).

  3. Recycling as a strategy against rare earth element criticality: a systemic evaluation of the potential yield of NdFeB magnet recycling.

    PubMed

    Rademaker, Jelle H; Kleijn, René; Yang, Yongxiang

    2013-09-17

    End-of-life recycling is promoted by OECD countries as a promising strategy in the current global supply crisis surrounding rare earth elements (REEs) so that dependence on China, the dominant supplier, can be decreased. So far the feasibility and potential yield of REE recycling has not been systematically evaluated. This paper estimates the annual waste flows of neodymium and dysprosium from permanent magnets, the main deployment of these critical REEs, during the 2011-2030 period. The estimates focus on three key permanent magnet waste flows: wind turbines, hybrid and electric vehicles, and hard disk drives (HDDs) in personal computers (PCs). This is a good indication of the end-of-life recycling of neodymium and dysprosium maximum potential yield. Results show that for some time to come, waste flows from permanent magnets will remain small relative to the rapidly growing global REE demand. Policymakers therefore need to be aware that during the next decade recycling is unlikely to substantially contribute to global REE supply security. In the long term, waste flows will increase sharply and will meet a substantial part of the total demand for these metals. Future REE recycling efforts should, therefore, focus on the development of recycling technology and infrastructure.

  4. Influence of bath PH value on microstructure and corrosion resistance of phosphate chemical conversion coating on sintered Nd-Fe-B permanent magnets

    NASA Astrophysics Data System (ADS)

    Ding, Xia; Xue, Long-fei; Wang, Xiu-chun; Ding, Kai-hong; Cui, Sheng-li; Sun, Yong-cong; Li, Mu-sen

    2016-10-01

    The effect of bath PH value on formation, microstructure and corrosion resistance of the phosphate chemical conversion (PCC) coatings as well as the effect on the magnetic property of the magnets is investigated in this paper. The results show that the coating mass and thickness increase with the decrease of the bath PH value. Scanning electron microscopy observation demonstrates that the PCC coatings are in a blocky structure with different grain size. Transmission electron microscope and X-ray diffractometer tests reveal the coatings are polycomponent and are mainly composed of neodymium phosphate hydrate and praseodymium phosphate hydrate. The electrochemical analysis and static immersion corrosion test show the corrosion resistance of the PCC coatings prepared at bath PH value of 0.52 is worst. Afterwards the corrosion resistance increases first and then decreases with the increasing of the bath PH values. The magnetic properties of all the samples with PCC treatment are decreased. The biggest loss is occurred when the bath PH value is 0.52. Taken together, the optimum PH range of 1.00-1.50 for the phosphate solution has been determined.

  5. Corrosion resistance of sintered NdFeB coated with SiC/Al bilayer thin films by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Huang, Yiqin; Li, Heqin; Zuo, Min; Tao, Lei; Wang, Wei; Zhang, Jing; Tang, Qiong; Bai, Peiwen

    2016-07-01

    The poor corrosion resistance of sintered NdFeB imposes a great challenge in industrial applications. In this work, the SiC/Al bilayer thin films with the thickness of 510 nm were deposited on sintered NdFeB by magnetron sputtering to improve the corrosion resistance. A 100 nm Al buffer film was used to reduce the internal stress between SiC and NdFeB and improve the surface roughness of the SiC thin film. The morphologies and structures of SiC/Al bilayer thin films and SiC monolayer film were investigated with FESEM, AFM and X-ray diffraction. The corrosion behaviors of sintered NdFeB coated with SiC monolayer film and SiC/Al bilayer thin films were analyzed by polarization curves. The magnetic properties were measured with an ultra-high coercivity permanent magnet pulse tester. The results show that the surface of SiC/Al bilayer thin films is more compact and uniform than that of SiC monolayer film. The corrosion current densities of SiC/Al bilayer films coated on NdFeB in acid, alkali and salt solutions are much lower than that of SiC monolayer film. The SiC/Al bilayer thin films have little influence to the magnetic properties of NdFeB.

  6. Performance enhancement of NdFeB nanoflakes prepared by surfactant-assisted ball milling at low temperature by using different surfactants

    NASA Astrophysics Data System (ADS)

    An, Xiaoxin; Jin, Kunpeng; Wang, Fang; Fang, Qiuli; Du, Juan; Xia, Weixing; Yan, Aru; Liu, J. Ping; Zhang, Jian

    2017-02-01

    Hard magnetic NdFeB submicron and nanoflakes were successfully prepared by surfactant-assisted ball milling at room temperature (SABMRT) and low temperature (SABMLT) by using oleic acid (OA), oleylamine (OLA) and trioctylamine (TOA) as surfactant, respectively. Among the surfactants used, OA and OLA have similar effects on the morphology of the NdFeB nanoflakes milled at both room and low temperature. In the case of TOA, irregular micron-sized particles and submirco/nanoflakes were obtained for the NdFeB powders prepared by SABMRT and SABMLT, respectively. Samples prepared by SABMLT show better crystallinity and better degree of grain alignment than that prepared by SABMRT with the same surfactant. Comparing with the samples milled at RT, higher coercivity and larger remanence ratio were achieved in the NdFeB samples prepared at LT. The amounts of residual surfactants in final NdFeB powders were also calculated, which reveals that the final NdFeB powders milled at LT possess lower amount of residual surfactants than those milled at RT. It was found that lowering milling temperature of SABM would be a promising way for fabricating permanent magnetic materials with better hard magnetic properties.

  7. Superferrimagnetism in hard Nd-Fe-B thick films, an original concept for coercivity enhancement

    NASA Astrophysics Data System (ADS)

    Akdogan, O.; Dobrynin, A.; Le Roy, D.; Dempsey, N. M.; Givord, D.

    2014-05-01

    In a number of applications (automotive, wind generators), RFeB magnets are parts of systems which operate at temperatures in the range of 160 °C-180 °C. At these high temperatures, coercivity is preserved by substituting Dy atoms for a part of the Nd ones. The enhanced coercivity obtained may be associated to the high magnetocrystalline anisotropy of Dy atoms, which diffuse into the R2Fe14B phase. The introduction of Dy, however, induces a reduction in the remanent magnetization. Furthermore, Dy is an expensive and strategic material. In this study, we explore a radically different approach to coercivity. A magnetic layer is deposited at the surface of the hard grains, this layer being exchange coupled to the main hard phase in a way that its magnetization is antiparallel to it. Under an applied field that tends to reverse the main phase magnetization, the surface layer, the magnetization of which is along the field, works against reversal. This is the concept of superferrimagnetism. In order to test its impact on the coercivity of real systems, magnetically hard thick films of NdFeB have been sandwiched between thin layers of Gd/Fe, which were transformed to GdFe2 upon annealing. Coercivity enhancement was achieved compared to a reference NdFeB single layer.

  8. Corrosion properties of aluminium coatings deposited on sintered NdFeB by ion-beam-assisted deposition

    NASA Astrophysics Data System (ADS)

    Mao, Shoudong; Yang, Hengxiu; Li, Jinlong; Huang, Feng; Song, Zhenlun

    2011-04-01

    Pure Al coatings were deposited by direct current (DC) magnetron sputtering to protect sintered NdFeB magnets. The effects of Ar+ ion-beam-assisted deposition (IBAD) on the structure and the corrosion behaviour of Al coatings were investigated. The Al coating prepared by DC magnetron sputtering with IBAD (IBAD-Al-coating) had fewer voids than the coating without IBAD (Al-coating). The corrosion behaviour of the Al-coated NdFeB specimens was investigated by potentiodynamic polarisation, a neutral salt spray (NSS) test, and electrochemical impedance spectroscopy (EIS). The pitting corrosion of the Al coatings always began at the voids of the grain boundaries. Bombardment by the Ar+ ion-beams effectively improved the corrosion resistance of the IBAD-Al-coating.

  9. Observation of Pseudopartial Grain Boundary Wetting in the NdFeB-Based Alloy

    NASA Astrophysics Data System (ADS)

    Straumal, B. B.; Mazilkin, A. A.; Protasova, S. G.; Schütz, G.; Straumal, A. B.; Baretzky, B.

    2016-08-01

    The NdFeB-based alloys were invented in 1980s and remain the best-known hard magnetic alloys. In order to reach the optimum magnetic properties, the grains of hard magnetic Nd2Fe14B phase have to be isolated from one another by the (possibly thin) layers of a non-ferromagnetic Nd-rich phase. In this work, we observe that the few-nanometer-thin layers of the Nd-rich phase appear between Nd2Fe14B grains due to the pseudopartial grain boundary (GB) wetting. Namely, some Nd2Fe14B/Nd2Fe14B GBs are not completely wetted by the Nd-rich melt and have the high contact angle with the liquid phase and, nevertheless, contain the 2-4-nm-thin uniform Nd-rich layer.

  10. Effect of niobium on the HDDR behaviour of near-stoichiometric NdFeB alloys

    NASA Astrophysics Data System (ADS)

    Ahmed, F. M.; Ataie, A.; Williams, A. J.; Harris, I. R.

    1996-05-01

    The HDDR behaviours of Nd11.8Fe81.3Nb1B5.9, Nd11.8Fe80.3Nb2B5.9 (at%) alloys were studied using a high resolution scanning electron microscope (HRSEM) in order to relate the initial, intermediate and final microstructures, to that of NdFeB-type alloys without additions. The disproportionation of the Nd2Fe14B (φ) matrix phase starts at the grain boundary and at the interface of the Nb26Fe32B42/φ phases, resulting in the formation of a submicron structure consisting of Fe, Fe2B and Nd-hydride. The HDDR process proved to be a very rapid and efficient method of homogenising the as-cast alloys. Promising magnetic properties have been obtained for bonded magnets using the HDDR powder.

  11. EXAFS determination of Hf localization in HDDR Nd Fe B Hf alloys

    NASA Astrophysics Data System (ADS)

    Torres, C. E. Rodríguez; Fernández van Raap, M. B.; Sánchez, F. H.; Pasquevich, A. F.

    2005-05-01

    The local structure around Hf in Nd 15.78Fe 76.3-xHf xB 7.8 ( x=0.1 and 0.2) submitted to conventional and solid hydrogenation-disproportionation-desorption-recombination (HDDR) sequence was studied by extended X-ray absorption fine structure (EXAFS) in order to understand the relation between the presence of Hf and magnetic anisotropy found only in solid-HDDR samples. EXAFS results show that Hf is not in the Nd 2Fe 14B structure but incorporated into a local atomic arrangement (HfB ClNa-type) which is the same for as-cast, solid and conventional HDDR samples. It is concluded that the magnetic anisotropy induced by Hf addition to NdFeB alloys must be related to microstructural features.

  12. Influence of melt convection on the microstructure of levitated and undercooled Nd-Fe-B alloys

    NASA Astrophysics Data System (ADS)

    Filip, O.; Hermann, R.; Gerbeth, G.; Priede, J.; Shatrov, V.; Gueth, A.; Schultz, L.

    2004-05-01

    The influence of melt rotation on the microstructure formation of Nd-Fe-B alloys, mainly the volume fraction and grain size of the α-Fe phase, is investigated using the electromagnetic levitation technique. Molten droplets were subjected to a strong rotation during levitation and compared to fixed samples without rotation. Additionally, experiments have been carried out where sealed samples were subjected to a well-defined forced rotation. A distinct reduction of the α-Fe volume fraction in samples with strong rotation was observed by measuring the magnetic moment. The melt flow in a levitated droplet is studied numerically under the additional effect of a global sample rotation which may give a strong suppression of internal motions.

  13. Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction

    SciTech Connect

    Kim, Daejin; Powell, Lawrence E.; Delmau, Lætitia H.; Peterson, Eric S.; Herchenroeder, Jim; Bhave, Ramesh R.

    2015-06-24

    In this paper, the rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acid solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. Finally, the resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.

  14. Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction

    DOE PAGES

    Kim, Daejin; Powell, Lawrence E.; Delmau, Lætitia H.; ...

    2015-06-24

    In this paper, the rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acidmore » solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. Finally, the resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.« less

  15. Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction.

    PubMed

    Kim, Daejin; Powell, Lawrence E; Delmau, Lætitia H; Peterson, Eric S; Herchenroeder, Jim; Bhave, Ramesh R

    2015-08-18

    The rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acid solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. The resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.

  16. Two-phase high-performance Nd-Fe-B powders prepared by mechanical milling

    NASA Astrophysics Data System (ADS)

    Neu, V.; Schultz, L.

    2001-08-01

    Nanocrystalline two-phase NdFeB+α-Fe material was prepared by milling techniques and subsequent heat treatment. These isotropic exchange-coupled powders show excellent hard magnetic properties with enhanced remanences up to 1.20 T and energy densities (BH)max around 150 kJ/m3. The performance is based on (i) the use of grain refining additions, (ii) partial substitution of Fe by Co and (iii) the use of pre-melted master alloys. The distribution of Co among the hard and soft magnetic phases upon milling and annealing is studied via Curie temperature measurements up to 10 at. % Co substitution. The effect of Co on the intrinsic properties is estimated and clarifies the extrinsic magnetic behavior. An overview of samples prepared with different milling techniques and compositions is presented. It summarizes the above listed, three different approaches to improve the magnetic performance together with the influence of the phase ratio of hard and soft magnetic phases.

  17. Rare earth-transition metal scrap treatment method

    DOEpatents

    Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.; Jones, L.L.; Lincoln, L.P.

    1992-02-11

    Rare earth-transition metal (e.g. iron) scrap (e.g. Nd-Fe-B scrap) is melted to reduce the levels of tramp oxygen and nitrogen impurities therein. The tramp impurities are reduced in the melt by virtue of the reaction of the tramp impurities and the rare earth to form dross on the melt. The purified melt is separated from the dross for reuse. The oxygen and nitrogen of the melt are reduced to levels acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. 3 figs.

  18. Rare earth-transition metal scrap treatment method

    DOEpatents

    Schmidt, Frederick A.; Peterson, David T.; Wheelock, John T.; Jones, Lawrence L.; Lincoln, Lanny P.

    1992-02-11

    Rare earth-transition metal (e.g. iron) scrap (e.g. Nd-Fe-B scrap) is melted to reduce the levels of tramp oxygen and nitrogen impurities therein. The tramp impurities are reduced in the melt by virtue of the reaction of the tramp impurities and the rare earth to form dross on the melt. The purified melt is separated from the dross for reuse. The oxygen and nitrogen of the melt are reduced to levels acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets.

  19. Method for treating rare earth-transition metal scrap

    DOEpatents

    Schmidt, Frederick A.; Peterson, David T.; Wheelock, John T.; Jones, Lawrence L.

    1992-12-29

    Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a prefused, rare earth fluoride-bearing flux of CaF.sub.2, CaCl.sub.2 or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy.

  20. Method for treating rare earth-transition metal scrap

    DOEpatents

    Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.; Jones, L.L.

    1992-12-29

    Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a rare earth fluoride-bearing flux of CaF[sub 2], CaCl[sub 2] or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy. 3 figs.

  1. Quantitative laser atom probe analyses of hydrogenation-disproportionated Nd-Fe-B powders.

    PubMed

    Sepehri-Amin, H; Ohkubo, T; Nishiuchi, T; Hirosawa, S; Hono, K

    2011-05-01

    We report a successful atom probe tomography of hydrides in hydrogenation-disproportionated Nd-Fe-B powder using a green femtosecond laser. The atom probe specimens were prepared from one particle of powder using the focused ion beam lift-out method. The atom probe tomography taken from an α-Fe/NdH(2) structure suggested that B and Ga (trace added element) were partitioned in the NdH(2) phase. The hydrogen concentration of 64 at% determined from the atom probe analysis was in excellent agreement with the stoichiometry of the NdH(2) phase.

  2. ECR plasma-assisted PVD deposition of α-Fe thin film on melt-spun Nd-Fe-B alloys

    NASA Astrophysics Data System (ADS)

    Fedorchenko, V. D.; Bovda, A. M.; Bovda, V. A.; Chen, C. H.; Chebotarev, V. V.; Garkusha, I. E.; Liu, S.; Medvedev, A. V.; Tereshin, V. I.

    2008-03-01

    The paper deals with plasma-assisted PVD of α-Fe thin film onto the melt-spun Nd-Fe-B-Co ribbons. The parameters of the plasma created by a planar rectangular ECR plasma source with a multipolar magnetic field and a double-slot antenna were as follows: electron density up to 1×1010 cm-3, electron temperature ˜22 eV, the current density of ion flow to grounded disk-substrate was equal to ˜0.5 mA/cm2 at the gas flow of 1 sccm, the microwave power was up to 300W. After degreasing and ultrasonic washing of Nd-Fe-B-Co ribbons, follow by ion etching, the deposition process was realized at a pulsed voltage bias of -1000 V with frequency 100 Hz, total current on the target 240 mA, current density 2.9 mA/cm2. The deposition rate of 0.0083 μm/min was achieved. The process continued for 2 hour. It was found that the magnetic melt-spun ribbons were homogeneously coated with the α-Fe film having a typical thickness of 1 μm.

  3. Effect of Nb and Cu on the crystallization behavior of under-stoichiometric Nd-Fe-B alloys

    NASA Astrophysics Data System (ADS)

    Salazar, D.; Martín-Cid, A.; Madugundo, R.; Garitaonandia, J. S.; Barandiaran, J. M.; Hadjipanayis, G. C.

    2017-01-01

    In this work, we present a complete study of the influence of Nb and Cu addition on the crystallization behavior of Nd-lean Nd-Fe-B melt-spun alloys. Alloys with compositions Nd10-x-y Fe84B6Nb x Cu y (x  =  1, y  =  0 and x  =  0.5, y  =  0.5) were melt-spun at different wheel speeds (15-40 m s-1) to obtain samples in amorphous, highly disordered and nanocrystalline structures. The crystallization process, induced by different heat treatments, was studied by means of differential thermal analysis and x-ray powder thermodiffraction. Magnetic properties of as-made and heat-treated ribbons were measured by magnetometry. The as-made amorphous samples showed a crystallization to the 2:14:1 hard magnetic phase at T 1 ~ 350 °C. Doping with Nb results in an increase of T 1, and addition of Cu lowers T 1. This behavior is explained in terms of an inhibition of grain growth by Nb and a nucleation enhancement by Cu additions. During the crystallization process, a secondary phase (identified as a bcc-Fe-rich phase) is formed. The amount of such a phase increases with the annealing temperature. Coercivity increases upon annealing reaching maxima at 700-750 °C. This can be explained in terms of competition between the two phases formed: the 2:14:1 hard phase and the soft bcc-Fe-rich phase. The highest coercivity of the Nd-lean samples is observed when the microstructure is appropriate and both phases are exchange-coupled.

  4. Study of Sintered Magnets of the Nd-Fe-B Type

    DTIC Science & Technology

    1989-02-01

    availability is much greater if iron is used instead of cobalt, and neodymium instead of the samarium . (Later perhaps also Pr, Ce and/or La.) The first...alloying additions included cobalt as a partial substituent for iron to raise the Curie temperature, dysprosium and erbium substitutions for some of the... nitrogen (LN) temperature, -196’C, to see what effect the onset of the spin reorientation in the 2-14-1 main phase (at about -150 0C) has on the

  5. A comparison of the micromagnetic and microstructural properties of four NdFeB-type materials processed by the HDDR route

    NASA Astrophysics Data System (ADS)

    Thompson, P.; Gutfleisch, O.; Chapman, J. N.; Harris, I. R.

    1999-07-01

    Transmission electron microscopy has been used to study the physical and magnetic microstructures of thinned sections of four different NdFeB-type alloys. Three of the materials were prepared by the solid-HDDR process and differed in that one was a simple ternary alloy, another contained Co & Ga additions and a third was appreciably richer in Nd than stoichiometric Nd 2Fe 14B 1. For the fourth material HDDR powder had been hot-pressed into a fully dense compact prior to die-upsetting. Isotropic grains with a mean size ≈300 nm were found for the first three materials whilst the die-upset material had an average grain size of ≈300×700 nm 2. All materials other than the simple ternary alloy showed strong alignment of the c-axis, the clustering of grains with similar alignment being most pronounced in the sample with Co & Ga additions. The sample with the largest region of alignment was the die-upset material, the c-axis orientation being approximately parallel to the pressing direction throughout. It was in this sample that magnetic alignment was found to be most extensive, the domains lying parallel to the mean c-axis across the whole of the visible area. Significant magnetic alignment was also found in the sample with Co & Ga whilst the Nd-rich material had relatively small areas of magnetic alignment. In the three samples with good crystallographic alignment local variations in domain wall orientation between neighbouring grains within an aligned region showed maximum variations that corresponded with the angular spread of spots in the selected area diffraction patterns.

  6. Photopatternable NdFeB polymer micromagnets for microfluidics and microrobotics applications

    NASA Astrophysics Data System (ADS)

    Li, Hui; Flynn, Tyler J.; Nation, Joshua C.; Kershaw, Joe; Stephens, L. Scott; Trinkle, Christine A.

    2013-06-01

    Microscale sensors and transducers based on magnetic forces can be used to provide wireless, contamination-free interaction with micro- and nanoenvironments. However, integration of magnetic components with typical microfabrication processes can be challenging. Here we show the creation and characterization of polymer micromagnets that can be utilized in microelectromechanical systems (MEMS), microfluidics, microassembly and microrobotics applications. These magnets can be patterned using standard UV lithography, are inexpensive to manufacture, and require limited equipment to produce. We demonstrate the creation of polymer micromagnets with 3 µm feature resolution and greater than 10:1 aspect ratio, the controlled movement of freestanding structures using contact-free applied magnetic fields, and the fabrication of novel ‘hybrid’ magnetic microstructures with controlled heterogeneity of magnetic properties.

  7. Rapid sintering of anisotropic, nanograined Nd-Fe-B by flash-spark plasma sintering

    NASA Astrophysics Data System (ADS)

    Castle, Elinor; Sheridan, Richard; Grasso, Salvatore; Walton, Allan; Reece, Mike

    2016-11-01

    A Spark Plasma Sintering (SPS) furnace was used to Flash-Sinter (FS) Nd-Fe-Dy-Co-B-Ga melt spun permanent magnetic material. During the 10 s "Flash" process (heating rate 2660 K min-1), sample sintering (to theoretical density) and deformation (54% height reduction) occurred. This produced texturing and significant magnetic anisotropy, comparable to conventional die-upset magnets; yet with much greater coercivities (>1600 kA m-1) due to the nanoscale characteristics of the plate-like sintered grains. These preliminary results suggest that Flash-SPS could provide a new processing route for the mass production of highly anisotropic, nanocrystalline magnetic materials with high coercivity.

  8. The development of microstructure during hydrogenation-disproportionation-desorption-recombination treatment of sintered neodymium-iron-boron-type magnets

    NASA Astrophysics Data System (ADS)

    Sheridan, R. S.; Harris, I. R.; Walton, A.

    2016-03-01

    The hydrogen absorption and desorption characteristics of the hydrogenation disproportionation desorption and recombination (HDDR) process on scrap sintered neodymium-iron-boron (NdFeB) type magnets have been investigated. At each stage of the process, the microstructural changes have been studied using high resolution scanning electron microscopy. It was found that the disproportionation reaction initiates at grain boundaries and triple points and then propagates towards the centre of the matrix grains. This process was accelerated at particle surfaces and at free surfaces produced by any cracks in the powder particles. However, the recombination reaction appeared to initiate randomly throughout the particles with no apparent preference for particle surfaces or internal cracks. During the hydrogenation of the grain boundaries and triple junctions, the disproportionation reaction was, however, affected by the much higher oxygen content of the sintered NdFeB compared with that of the as-cast NdFeB alloys. Throughout the entire HDDR reaction the oxidised triple junctions (from the sintered structure) remained unreacted and hence, remained in their original form in the fine recombined microstructure. This resulted in a very significant reduction in the proportion of cavitation in the final microstructure and this could lend to improved consolidation in the recycled magnets.

  9. Collision-Free Structure Using Thin-Film Magnet For Electrostatic Energy Harvester

    NASA Astrophysics Data System (ADS)

    Yoshii, S.; Yamaguchi, K.; Fujita, T.; Kanda, K.; Maenaka, K.

    2016-11-01

    This paper proposes collision-free structure using NdFeB thin-film magnet for vibration energy harvesters. By using stripe shaped NdFeB magnet array on the Si MEMS structure, we finally obtained 3 mN of magnetic repulsive force on 8 × 8 mm2 specimen with 40 μm air-gap.

  10. Ultrahigh coercivity and core-shell microstructure achieved in oriented Nd-Fe-B thin films diffusion-processed with Dy-based alloys

    NASA Astrophysics Data System (ADS)

    Zhang, Tongbo; Zhou, Xiaoqian; Yu, Dedong; Fu, Yanqing; Li, Guojian; Cui, Weibin; Wang, Qiang

    2017-01-01

    Ultrahigh ambient coercivities of 4 T were achieved in Nd-Fe-B benchmark thin film with coercivity of 1.06 T by diffusion-processing with Dy, Dy70Cu30 and Dy80Ag20 alloy layer. High texture and good squareness were obtained. In triple-junction regions, Dy element was found to be immiscible with Nd element. Microstructure observation indicated the typical gradient elementary distribution. Unambiguous core/shell microstructure was characterized by transition electron microscopy. Due to the enhanced ambient coercivity, the coercivity temperature stability was also substantially increased.

  11. Utilizing the magnetic fraction of raw refuse with shredded automobile scrap in cupola gray iron

    SciTech Connect

    Spironello, V.R.; Mahan, W.M.

    1980-01-01

    The Bureau of Mines is involved in research directed toward the utilization of municipal solid waste. One of the primary objectives is the recycling of the magnetic fraction of municipal solid waste (raw refuse). This is consistent with one of the Bureau's goals, which is to minimize the requirements for mineral commodities by maximizing metals recovery from secondary domestic resources. In this investigation, cupola trials were made using combinations of refuse scrap with shredded automobile scrap under basic and acid slag practices. Furnace operating information and the behavior of alloying and tramp elements were obtained. The research showed that it is possible to utilize up to 60% refuse scrap in the cupola under basic practice and 30% under acid practice. Aluminum in refuse scrap, present in bimetallic cans, increased the recoveries of silicon and manganese charged to the cupola. Increased use of refuse scrap provided iron of lower sulfur. The alumina resulting from oxidation increased the slag volume. The aluminum and tin contents of the iron increased with increasing levels of refuse scrap in the charge. Lead was not a problem with respect to contamination of the iron. In basic practice, operation of the cupola was satisfactory since all slags were adequately fluid. In acid practice, operation became troublesome above the 45% level. Under both practices, the cupola iron melting rate decreased. Particulates in scrubber water and stack condensate samples contained lead, zinc, and tin, and the dust load increased. The tensile and transverse strengths of the iron produced under both practices are reported.

  12. Spin Structures of Textured and Isotropic Nd-Fe-B-Based Nanocomposites: Evidence for Correlated Crystallographic and Spin Textures

    NASA Astrophysics Data System (ADS)

    Michels, A.; Weber, R.; Titov, I.; Mettus, D.; Périgo, É. A.; Peral, I.; Vallcorba, O.; Kohlbrecher, J.; Suzuki, K.; Ito, M.; Kato, A.; Yano, M.

    2017-02-01

    We report the results of a comparative study of the magnetic microstructure of textured and isotropic Nd2Fe14B /α -Fe nanocomposites using magnetometry, transmission electron microscopy, synchrotron x-ray diffraction, and, in particular, magnetic small-angle neutron scattering (SANS). Analysis of the magnetic neutron data of the textured specimen and computation of the correlation function of the spin-misalignment SANS cross section suggests the existence of inhomogeneously magnetized regions on an intraparticle nanometer length scale, about 40-50 nm in the remanent state. Possible origins for this spin disorder are discussed: it may originate in thin-grain-boundary layers (where the material parameters are different than in the Nd2Fe14B grains), or it may reflect the presence of crystal defects (introduced via hot pressing), or the dispersion in the orientation distribution of the magnetocrystalline anisotropy axes of the Nd2Fe14B grains. X-ray powder diffraction data reveal a crystallographic texture in the direction perpendicular to the pressing direction—a finding which might be related to the presence of a texture in the magnetization distribution, as inferred from the magnetic SANS data.

  13. Preparation of Nd-Fe-B by nitrate-citrate auto-combustion followed by the reduction-diffusion process

    NASA Astrophysics Data System (ADS)

    Ma, Hao Xuan; Kim, Chang Woo; Kim, Dong Soo; Jeong, Ji Hun; Kim, In Ho; Kang, Young Soo

    2015-04-01

    The Nd2Fe14B alloy has been successfully synthesized by nitrate-citrate auto-combustion followed by the reduction and diffusion process with low energy consumption. H3BO3, Fe(NO3)3.9H2O, and Nd(NO3)3.6H2O were used as precursors and citric acid was used as the chelating ligand of metal ions. Ammonia water was used to adjust pH to 7. CaH2 was used as a reducing agent for the reduction and diffusion process. NdFeO3 and Fe2O3 were produced during auto-combustion of gel. The combustion process of the gel was investigated by TGA/DTA curve measurements. The phase compositions were studied by XRD measurements. The differences of the overall morphology and magnetic properties were measured by SEM, TEM and vibrating sample magnetometry (VSM) at 300 K. The comparison of the magnetic properties of the reduced samples between the pellet type and the random powder type was done with VSM and it showed better magnetic properties of the pellet type Nd2Fe14B. Making a compact pellet type sample for reduction is more efficient for solid reduction and phase transition for higher coercivity.The Nd2Fe14B alloy has been successfully synthesized by nitrate-citrate auto-combustion followed by the reduction and diffusion process with low energy consumption. H3BO3, Fe(NO3)3.9H2O, and Nd(NO3)3.6H2O were used as precursors and citric acid was used as the chelating ligand of metal ions. Ammonia water was used to adjust pH to 7. CaH2 was used as a reducing agent for the reduction and diffusion process. NdFeO3 and Fe2O3 were produced during auto-combustion of gel. The combustion process of the gel was investigated by TGA/DTA curve measurements. The phase compositions were studied by XRD measurements. The differences of the overall morphology and magnetic properties were measured by SEM, TEM and vibrating sample magnetometry (VSM) at 300 K. The comparison of the magnetic properties of the reduced samples between the pellet type and the random powder type was done with VSM and it showed better

  14. Preparation of Nd-Fe-B by nitrate-citrate auto-combustion followed by the reduction-diffusion process.

    PubMed

    Ma, Hao Xuan; Kim, Chang Woo; Kim, Dong Soo; Jeong, Ji Hun; Kim, In Ho; Kang, Young Soo

    2015-05-07

    The Nd2Fe14B alloy has been successfully synthesized by nitrate-citrate auto-combustion followed by the reduction and diffusion process with low energy consumption. H3BO3, Fe(NO3)3·9H2O, and Nd(NO3)3·6H2O were used as precursors and citric acid was used as the chelating ligand of metal ions. Ammonia water was used to adjust pH to 7. CaH2 was used as a reducing agent for the reduction and diffusion process. NdFeO3 and Fe2O3 were produced during auto-combustion of gel. The combustion process of the gel was investigated by TGA/DTA curve measurements. The phase compositions were studied by XRD measurements. The differences of the overall morphology and magnetic properties were measured by SEM, TEM and vibrating sample magnetometry (VSM) at 300 K. The comparison of the magnetic properties of the reduced samples between the pellet type and the random powder type was done with VSM and it showed better magnetic properties of the pellet type Nd2Fe14B. Making a compact pellet type sample for reduction is more efficient for solid reduction and phase transition for higher coercivity.

  15. Scanning Electron Microscope-Cathodoluminescence Analysis of Rare-Earth Elements in Magnets.

    PubMed

    Imashuku, Susumu; Wagatsuma, Kazuaki; Kawai, Jun

    2016-02-01

    Scanning electron microscope-cathodoluminescence (SEM-CL) analysis was performed for neodymium-iron-boron (NdFeB) and samarium-cobalt (Sm-Co) magnets to analyze the rare-earth elements present in the magnets. We examined the advantages of SEM-CL analysis over conventional analytical methods such as SEM-energy-dispersive X-ray (EDX) spectroscopy and SEM-wavelength-dispersive X-ray (WDX) spectroscopy for elemental analysis of rare-earth elements in NdFeB magnets. Luminescence spectra of chloride compounds of elements in the magnets were measured by the SEM-CL method. Chloride compounds were obtained by the dropwise addition of hydrochloric acid on the magnets followed by drying in vacuum. Neodymium, praseodymium, terbium, and dysprosium were separately detected in the NdFeB magnets, and samarium was detected in the Sm-Co magnet by the SEM-CL method. In contrast, it was difficult to distinguish terbium and dysprosium in the NdFeB magnet with a dysprosium concentration of 1.05 wt% by conventional SEM-EDX analysis. Terbium with a concentration of 0.02 wt% in an NdFeB magnet was detected by SEM-CL analysis, but not by conventional SEM-WDX analysis. SEM-CL analysis is advantageous over conventional SEM-EDX and SEM-WDX analyses for detecting trace rare-earth elements in NdFeB magnets, particularly dysprosium and terbium.

  16. Recycling of rare earth metals from rare earth-transition metal alloy scrap by liquid metal extraction

    DOEpatents

    Ellis, T.W.; Schmidt, F.A.

    1995-08-01

    A method is described for treating rare earth metal-bearing scrap, waste or other material (e.g. Nd--Fe--B or Dy--Tb--Fe scrap) to recover the rare earth metal comprising melting the rare earth metal-bearing material, melting a Group IIA metal extractant, such as Mg, Ca, or Ba, in which the rare earth is soluble in the molten state, and contacting the melted material and melted extractant at a temperature and for a time effective to extract the rare earth from the melted material into the melted extractant. The rare earth metal is separated from the extractant metal by vacuum sublimation or distillation. 2 figs.

  17. Recycling of rare earth metals from rare earth-transition metal alloy scrap by liquid metal extraction

    DOEpatents

    Ellis, Timothy W.; Schmidt, Frederick A.

    1995-08-01

    Method of treating rare earth metal-bearing scrap, waste or other material (e.g. Nd--Fe--B or Dy--Tb--Fe scrap) to recover the rare earth metal comprising melting the rare earth metal-bearing material, melting a Group IIA metal extractant, such as Mg, Ca, or Ba, in which the rare earth is soluble in the molten state, and contacting the melted material and melted extractant at a temperature and for a time effective to extract the rare earth from the melted material into the melted extractant. The rare earth metal is separated from the extractant metal by vacuum sublimation or distillation.

  18. SCRAP STEEL AND FOUNDRY SCRAP IRON, USED AS THE PRIMARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SCRAP STEEL AND FOUNDRY SCRAP IRON, USED AS THE PRIMARY METAL SOURCES, ARE STORED IN THESE BINS AND LIFTED TO SCALES BY AN ELECTRIC MAGNET. - Southern Ductile Casting Company, Melting, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  19. Anisotropy and microstructure of rare earth permanent magnet materials

    NASA Astrophysics Data System (ADS)

    Fidler, J.; Groessinger, R.; Kirchmayr, H.; Skalicky, P.

    1984-06-01

    Recently a new family of hard magnetic materials based on Nd-Fe-B was developed. With these compounds permanent magnets with energy products up to 40 MGOe were produced. The greater abundance of Nd combined with the low price for Fe are a hope for producing high qualitative, low cost magnets in the future. Therefore large scale applications are proposed for Nd-Fe-B magnetic. The aim of the scientific part of the present report will be the investigation of the low temperature physical properties of this new family of compounds.

  20. Cryogenic Permanent Magnet Undulators

    SciTech Connect

    Chavanne, J.; Lebec, G.; Penel, C.; Revol, F.; Kitegi, C.

    2010-06-23

    For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm{sub 2}Co{sub 17} or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulator above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.

  1. A new approach to fabricate Nd2Fe14B/α-Fe nanocomposite precursors by selective removal of Nd from Nd-Fe-B powders

    NASA Astrophysics Data System (ADS)

    Nie, Junwu; Du, Juan; Liu, Jingjing; Yin, Wenzong; Zhang, Jian; Yan, Aru

    2012-01-01

    A facile method based on α-Fe self-supply was developed to get exchange coupling Nd2Fe14B/α-Fe nanocomposites. A small amount of neodymium was removed from the Nd2Fe14B compound in Nd-rich melt-spun powders by chemical treatment with NH4Cl and CH3COOH acid solution and α-Fe remained. Full dense anisotropic Nd2Fe14B/α-Fe magnets were prepared via hot pressing and hot deformation techniques using the as-prepared powders. The evolution of composition and phase was investigated. The best energy product (BH)max of the Nd2Fe14B/α-Fe magnets was 47.5 MG Oe, 5% higher than that of a single-phase Nd2Fe14B magnet. The α-Fe phase, which was precipitated on the edge of the Nd2Fe14B particle, contributed to the exchange coupling effect and the enhancement of remanence (Br). This method can be applied as a new strategy to prepare next generation nanocomposite magnets with good magnetic properties.

  2. Dysprosium-free melt-spun permanent magnets.

    PubMed

    Brown, D N; Wu, Z; He, F; Miller, D J; Herchenroeder, J W

    2014-02-12

    Melt-spun NdFeB powders can be formed into a number of different types of permanent magnet for a variety of applications in electronics, automotive and clean technology industries. The melt-spinning process produces flake powder with a fine uniform array of nanoscale Nd2Fe14B grains. These powders can be net-shape formed into isotropic polymer-bonded magnets or hot formed into fully dense magnets. This paper discusses the influence of heavy rare earth elements and microstructure on the magnetic performance, thermal stability and material cost of NdFeB magnets. Evidence indicates that melt-spun nanocrystalline NdFeB magnets are less dependent on heavy rare earth elements for high-temperature performance than the alternative coarser-grained sintered NdFeB magnets. In particular, hot-pressed melt-spun magnets are an attractive low-cost solution for applications that require thermal stability up to 175-200 °C.

  3. Barkhausen noise from sintered permanent magnets

    SciTech Connect

    Cuntze, G.; Brendel, H.; Hubert, A.

    1996-09-01

    The authors introduce the well known Barkhausen technique as a tool for investigation of reversal processes in hard magnetic nucleation-type material. First results of the experiments show the occurrence of correlated grain switching not to be neglectible in the samples of sintered Nd-Fe-B as the volume fraction of multiple Barkhausen jumps reaches 50% near coercivity.

  4. Interference of neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators: an in vitro study.

    PubMed

    Ryf, Salome; Wolber, Thomas; Duru, Firat; Luechinger, Roger

    2008-01-01

    Permanent magnets may interfere with the function of cardiac pacemakers and implantable cardioverter-defibrillators (ICDs). Neodymium-iron-boron (NdFeB) magnets have become widely available in recent years and are incorporated in various articles of daily life. We conducted an in-vitro study to evaluate the ability of NdFeB magnets for home and office use to cause interference with cardiac pacemakers and ICDs. The magnetic fields of ten NdFeB magnets of different size and shape were measured at increasing distances beginning from the surface until a field-strength (B-field) value of 0.5 mT was reached. Furthermore, for each magnet the distance was determined at which a sample pacemaker switched from magnet mode to normal mode. Depending on the size and remanence of individual magnets, a B-field value of 0.5 mT was found at distances ranging from 1.5 cm to 30 cm and a value of 1 mT at distances from 1 cm to 22 cm. The pacemaker behavior was influenced at distances from 1 cm to 24 cm. NdFeB magnets for home and office use may cause interference with cardiac pacemakers and ICDs at distances up to 24 centimeters. Patient education and product declarations should include information about the risk associated with these magnets.

  5. Permanent magnet design methodology

    NASA Technical Reports Server (NTRS)

    Leupold, Herbert A.

    1991-01-01

    Design techniques developed for the exploitation of high energy magnetically rigid materials such as Sm-Co and Nd-Fe-B have resulted in a revolution in kind rather than in degree in the design of a variety of electron guidance structures for ballistic and aerospace applications. Salient examples are listed. Several prototype models were developed. These structures are discussed in some detail: permanent magnet solenoids, transverse field sources, periodic structures, and very high field structures.

  6. Modifying bone scaffold architecture in vivo with permanent magnets to facilitate fixation of magnetic scaffolds.

    PubMed

    Panseri, S; Russo, A; Sartori, M; Giavaresi, G; Sandri, M; Fini, M; Maltarello, M C; Shelyakova, T; Ortolani, A; Visani, A; Dediu, V; Tampieri, A; Marcacci, M

    2013-10-01

    The fundamental elements of tissue regeneration are cells, biochemical signals and the three-dimensional microenvironment. In the described approach, biomineralized-collagen biomaterial functions as a scaffold and provides biochemical stimuli for tissue regeneration. In addition superparamagnetic nanoparticles were used to magnetize the biomaterials with direct nucleation on collagen fibres or impregnation techniques. Minimally invasive surgery was performed on 12 rabbits to implant cylindrical NdFeB magnets in close proximity to magnetic scaffolds within the lateral condyles of the distal femoral epiphyses. Under this static magnetic field we demonstrated, for the first time in vivo, that the ability to modify the scaffold architecture could influence tissue regeneration obtaining a well-ordered tissue. Moreover, the association between NdFeB magnet and magnetic scaffolds represents a potential technique to ensure scaffold fixation avoiding micromotion at the tissue/biomaterial interface.

  7. Current status and recent topics of rare-earth permanent magnets

    NASA Astrophysics Data System (ADS)

    Sugimoto, S.

    2011-02-01

    After the development of Nd-Fe-B magnets, rare-earth magnets are now essential components in many fields of technology, because of their ability to provide a strong magnetic flux. There are two, well-established techniques for the manufacture of rare earth magnets: powder metallurgy is used to obtain high-performance, anisotropic, fully dense magnet bodies; and the melt-spinning or HDDR (hydrogenation, disproportionation, desorption and recombination) process is widely used to produce magnet powders for bonded magnets. In the industry of sintered Nd-Fe-B magnets, the total amount of production has increased and their dominant application has been changed to motors. In particular, their use for motors in hybrid cars is one of the most attractive applications. Bonded magnets have also been used for small motors, and the studies of nanocomposite and Sm-Fe-N magnets have become widespread. This paper reviews the current status and future trend in the research of permanent magnets.

  8. Measurement of the Magnet Blocks for SSRF Insertion Devices

    SciTech Connect

    He Yongzhou; Zhang Jidong; Zhou Qiaogen; Qian Zhenmei; Li Yang

    2010-06-23

    Two in-vacuum undulators IVU25s and one elliptically polarized undulator EPU100 have been developed for SSRF. Two IVU25s with the same hybrid design contain about 640 Sm{sub 2}Co{sub 17} magnet blocks and the dimension of blocks is 65 Wx25 Hx9 D. The EPU100 of the APPLE-II type contains about 690 NdFeB magnet blocks with the dimension of 35 Wx35 Hx25 D. This paper describes the magnetic measurements of these magnet blocks with the Helmholtz coil measurement system for IVU25 magnet blocks and the Hall probe measurement system for EPU100 magnet blocks. The measured maximum magnetic moment deviation and the maximum angle deviation are less than {+-}1.0% and 1.1 deg. respectively both for Sm{sub 2}Co{sub 17} blocks and NdFeB blocks and satisfy the specifications of undulators.

  9. Recovery of nonferrous metals from scrap automobiles by magnetic fluid levitation.

    NASA Technical Reports Server (NTRS)

    Mir, L.; Simard, C.; Grana, D.

    1973-01-01

    Ferrofluids are colloidal dispersions of subdomain magnetic solids in carrier liquids. In the presence of a non-homogeneous magnetic field, ferrofluids exert a pressure on immersed nonmagnetic objects in the opposite sense of the field gradient. This pressure force can, when opposite to gravity, levitate objects of higher density than the ferrofluid. This levitation technique can be used to separate solids according to density. Its application to the separation of nonferrous metals from shredded automobiles has been demonstrated on a prototype of a full-scale separator. Its use to recover nonferrous metals from municipal solid wastes also seems practical.

  10. Method for forming permanent magnets with different polarities for use in microelectromechanical devices

    DOEpatents

    Roesler, Alexander W.; Christenson, Todd R.

    2007-04-24

    Methods are provided for forming a plurality of permanent magnets with two different north-south magnetic pole alignments for use in microelectromechanical (MEM) devices. These methods are based on initially magnetizing the permanent magnets all in the same direction, and then utilizing a combination of heating and a magnetic field to switch the polarity of a portion of the permanent magnets while not switching the remaining permanent magnets. The permanent magnets, in some instances, can all have the same rare-earth composition (e.g. NdFeB) or can be formed of two different rare-earth materials (e.g. NdFeB and SmCo). The methods can be used to form a plurality of permanent magnets side-by-side on or within a substrate with an alternating polarity, or to form a two-dimensional array of permanent magnets in which the polarity of every other row of the array is alternated.

  11. Enduring Attraction: America’s Dependence On and Need to Secure Its Supply of Permanent Magnets

    DTIC Science & Technology

    2012-10-01

    refined metals neodymium and samarium, are key components in the manufacture of miniature high temperature resistant permanent magnets. These magnets...indispensable. Consequently, rare-earth permanent magnets comprise the widest use of REEs.12 Neodymium and Samarium Neodymium and samarium are only...military applications. Similarly, neodymium - iron-boron (NdFeB) magnets are incredibly strong—the most powerful commercial magnet available. Compared to

  12. Electromagnetic braking revisited with a magnetic point dipole model

    NASA Astrophysics Data System (ADS)

    Land, Sara; McGuire, Patrick; Bumb, Nikhil; Mann, Brian P.; Yellen, Benjamin B.

    2016-04-01

    A theoretical model is developed to predict the trajectory of magnetized spheres falling through a copper pipe. The derive magnetic point dipole model agrees well with the experimental trajectories for NdFeB spherical magnets of varying diameter, which are embedded inside 3D printed shells with fixed outer dimensions. This demonstration of electrodynamic phenomena and Lenz's law serves as a good laboratory exercise for physics, electromagnetics, and dynamics classes at the undergraduate level.

  13. Thermal stability of sintered and bonded rare-earth magnets

    NASA Astrophysics Data System (ADS)

    Kato, Yoshio

    1999-04-01

    One of most important issues of magnets for automobiles is thermal stability. The aim of the present work is to make clear the available temperature limit of sintered and bonded magnets for automobile applications. Thermal stability was determined by the critical temperature of 3% irreversible flux loss (T-3%φ) under thermal cycles. For instance, the T-3%φ of sintered NdFeB magnets (Pc=0.5) with the intrinsic coercivity of 1600, 1920, and 2240 kA/m, were 393, 423, and 453 K, respectively. On the other hand, the T-3%φ of HDDR-NdFeB (HcJ=960 kA/m) and SmFeN (HcJ=560 kA/m) bonded magnets (Pc=2) were about 353 K.

  14. Magnetizing of permanent magnets using HTS bulk magnets

    NASA Astrophysics Data System (ADS)

    Oka, Tetsuo; Muraya, Tomoki; Kawasaki, Nobutaka; Fukui, Satoshi; Ogawa, Jun; Sato, Takao; Terasawa, Toshihisa

    2012-01-01

    A demagnetized Nd-Fe-B permanent magnet was scanned just above the magnetic pole which contains the HTS bulk magnet generating a magnetic field of 3.27 T. The magnet sample was subsequently found to be fully magnetized in the open space of the static magnetic fields. We examined the magnetic field distributions when the magnetic poles were scanned twice to activate the magnet plate inversely with various overlap distances between the tracks of the bulk magnet. The magnetic field of the "rewritten" magnet reached the values of the magnetically saturated region of the material, showing steep gradients at the border of each magnetic pole. As a replacement for conventional pulse field magnetizing methods, this technique is proposed to expand the degree of freedom in the design of electromagnetic devices, and is proposed as a novel practical method for magnetizing rare-earth magnets, which have excellent magnetic performance and require intense fields of more than 3 T to be activated.

  15. Hot Isostatically Pressed Sm(2)(TM)17 Magnets.

    DTIC Science & Technology

    1985-04-01

    SUB. GR. HIP - hot isostatic pressing Stepped aging treatment Samarium - transition metal magnets f Samarium , Copper, Iron, Zirconium, Cobalt magnets 1...5 ptaI2 TABLE OF CONTENTS Section Page INTRODUCTION...............................................1 2 EXPERIMENTAL METHODS ...values of BR and Hci of the Nd-Fe-B type materials, however, have precluded their use in several critical applications such as in microwave devices and

  16. Method of making permanent magnets

    DOEpatents

    McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

    1993-09-07

    A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles. Wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties. 13 figures.

  17. Method of making permanent magnets

    DOEpatents

    McCallum, R. William; Dennis, Kevin W.; Lograsso, Barbara K.; Anderson, Iver E.

    1993-09-07

    A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties.

  18. Additive Manufacturing of Near-net Shaped Permanent Magnets

    SciTech Connect

    Paranthaman, M. Parans; Sridharan, Niyanth; List, Fred A.; Babu, S. S.; Dehoff, Ryan R.; Constantinides, Steve

    2016-07-26

    The technical objective of this technical collaboration phase I proposal is to fabricate near net-shaped permanent magnets using alloy powders utilizing direct metal deposition technologies at the ORNL MDF. Direct Manufacturing using the POM laser system was used to consolidate Nd2Fe14B (NdFeB) magnet powders into near net-shape parts efficiently and with virtually no wasted material as part of the feasibility study. We fabricated builds based on spherical NdFeB magnet particles. The results show that despite the ability to fabricate highly reactive materials in the laser deposition process, the magnetic coercivity and remanence of the NdFeB hard magnets is significantly reduced. X-ray powder diffraction in conjunction with electron microscopy showed that the material experienced a primary Nd2Fe17Bx solidification due to the undercooling effect (>60K). Consequently the presence of alpha iron phase resulted in deterioration of the build properties. Further optimization of the processing parameters is needed to maintain the Nd2Fe14B phase during fabrication.

  19. Nanocrystalline (Pr,Dy)-(Fe,Co)-Zr-Ti-B magnets produced directly by rapid solidification

    NASA Astrophysics Data System (ADS)

    Pawlik, P.; Pawlik, K.; Davies, H. A.; Wysłocki, J. J.; Kaszuwara, W.

    2009-01-01

    Hard magnetic thick ribbon samples of a series of Pr9-xDyxFe60Co13Zr1+yTi3-yB14 alloys (where x=0;1 and y=0;1) (having average thicknesses tr of~ 140 µm) were produced directly by the melt-spinning technique under an Ar atmosphere. The phase constitution of the samples in the as-cast state was determined by X-ray diffractomety and Mössbauer spectroscopy. Hysteresis loops measurements at room temperature indicated very good hard magnetic properties for the alloys, which the coercivity attaining a maximum values of 1.58 MA/m. This is comparable with the coercivities of commercial NdFeB magnets based on melt spun ribbon and with those for nanocrystalline Nd-Fe-B magnets produces by other processes such as mechanical alloying or HDDR.

  20. Anisotropy and Microstructure of Rare Earth Permanent Magnet Materials.

    DTIC Science & Technology

    1986-01-01

    ideal uniaxial 60 crystal as well as their first and second derivative. 3. Orientation between H and M for the case that 61 H lies approximately in the...the powder particles may be single crystals or may be polycrystalline. In some cases the agglomeration of individual particles must be taken into...structural characteritic does not play an important role in the case of optimally sintered Nd-Fe-B magnets. The compacting parameters (die-pressing or

  1. Nanocrystalline high performance permanent magnets

    NASA Astrophysics Data System (ADS)

    Gutfleisch, O.; Bollero, A.; Handstein, A.; Hinz, D.; Kirchner, A.; Yan, A.; Müller, K.-H.; Schultz, L.

    2002-04-01

    Recent developments in nanocrystalline rare earth-transition metal magnets are reviewed and emphasis is placed on research work at IFW Dresden. Principal synthesis methods include high energy ball milling, melt spinning and hydrogen assisted methods such as reactive milling and hydrogenation-disproportionation-desorption-recombination. These techniques are applied to NdFeB-, PrFeB- and SmCo-type systems with the aim to produce high remanence magnets with high coercivity. Concepts of maximizing the energy density in nanostructured magnets by either inducing a texture via anisotropic HDDR or hot deformation or enhancing the remanence via magnetic exchange coupling are evaluated.

  2. Precise measurement of magnetization characteristics in high pulsed field

    NASA Astrophysics Data System (ADS)

    Nakahata, Y.; Borkowski, B.; Shimoji, H.; Yamada, K.; Todaka, T.; Enokizono, M.

    2012-04-01

    Permanent magnets, especially Nd-Fe-B magnets, are very important engineering elements that are widely used in many applications. The detailed design of electrical and electronic equipment using permanent magnets requires the precise measurement of magnetization characteristics. High pulsed magnetic fields can be used to measure the magnetization characteristics of permanent magnets in the easy and hard magnetization directions. Errors influencing the measurements stem from the relationship between the tested material, pick-up sensor configuration, and excitation coil. We present an analysis of the effect of the sensor construction on the accuracy of the measurements of the material's magnetic properties. We investigated the coaxial and series types sensor configurations.

  3. Preparation and characterization of polymeric composite permanent magnet Nd2Fe14B

    NASA Astrophysics Data System (ADS)

    Muljadi, Sardjono, Priyo; Suprapedi

    2016-03-01

    Preparation of polymeric composite magnets using isotropic NdFeB powder and polymeric materials (epoxy resin and latex rubber) have been investigated in this work. Isotropic powder NdFeB was crushed mechanically by hand mortar and sieved until passing 400 mesh. Epoxy Resin / latex rubber with the isotropic powder NdFeB were manually mixed for 20 minutes to achieve a good (homogeneous) mixture. Amount of polymeric materials were 5, 10, 15, and 20 % wt. from the mass of magnetic powder NdFeB. The mixtures were moulded in cylindrical die with a diameter of 10 mm by cold pressing under a force of three tons, then all samples were cured at temperature 100oC for two hours by using drying oven. The cured samples were measured bulk density by archimedes method, and all samples were magnetized by impulse magnetizer. The surface magnetic field strength (FS) was measure by Gaussmeter, other magnetic properties (remanence Br, coercivity Hc and energy product BHmax) were measured by permeagraph. The measured properties for all samples are as follows : the optimum value of bulk density are 5.21 g/cm3 for samples with 5 % wt. epoxy resin and 5.03 g/cm3 for samples with 10 % wt. latex rubber. The sample with 5 % wt. epoxy resin has FS=2400 Gauss, Br=0.558 T, Hc=6.77 kOe, and BHmax=7.28 MGOe; also the sample with 10 % wt. latex rubber has FS=1750 Gauss, Br=0.402 T, Hc=5.14 kOe, and BHmax=4.38 MGOe.

  4. Corrosion Protection of Nd-Fe Magnets via Phophatization, Silanization and Electrostatic Spraying with Organic Resin Composite Coatings

    NASA Astrophysics Data System (ADS)

    Ding, Xia; Li, Jingjie; Li, Musen; Ge, Shengsong; Wang, Xiuchun; Ding, Kaihong; Cui, Shengli; Sun, Yongcong

    2014-09-01

    Nd-Fe-B permanent magnets possess excellent properties. However, they are highly sensitive to the attack of corrosive environment. The aim of this work is to improve the corrosion resistance of the magnets by phosphatization, silanization, and electrostatic spraying with organic resin composite coatings. Field emission scanning electron microscope (FE-SEM) and energy dispersive spectrometer (EDS) tests showed that uniform phosphate conversion coatings and spray layers were formed on the surface of the Nd-Fe-B magnets. Neutral salt spray tests exhibited that, after treated by either phosphating, silanization or electrostatic spraying, the protectiveness of Nd-Fe-B alloys was apparently increased. And corrosion performance of magnets treated with silane only was slightly inferior to those of phosphatized ones. However, significant improvement in corrosion protection was achieved after two-step treatments, i.e. by top-coating spray layer with phosphate or silane films underneath. Grid test indicated that the phosphate and silane coating were strongly attached to the substrate while silane film was slightly weaker than the phosphate-treated ones. Magnetic property analysis revealed phosphatization, silanization, and electrostatic spraying caused decrease in magnetism, but silanization had the relatively smaller effect.

  5. Design and optimization of arrays of neodymium iron boron-based magnets for magnetic tweezers applications

    SciTech Connect

    Zacchia, Nicholas A.; Valentine, Megan T.

    2015-05-15

    We present the design methodology for arrays of neodymium iron boron (NdFeB)-based magnets for use in magnetic tweezers devices. Using finite element analysis (FEA), we optimized the geometry of the NdFeB magnet as well as the geometry of iron yokes designed to focus the magnetic fields toward the sample plane. Together, the magnets and yokes form a magnetic array which is the basis of the magnetic tweezers device. By systematically varying 15 distinct shape parameters, we determined those features that maximize the magnitude of the magnetic field gradient as well as the length scale over which the magnetic force operates. Additionally, we demonstrated that magnetic saturation of the yoke material leads to intrinsic limitations in any geometric design. Using this approach, we generated a compact and light-weight magnetic tweezers device that produces a high field gradient at the image plane in order to apply large forces to magnetic beads. We then fabricated the optimized yoke and validated the FEA by experimentally mapping the magnetic field of the device. The optimization data and iterative FEA approach outlined here will enable the streamlined design and construction of specialized instrumentation for force-sensitive microscopy.

  6. Design and optimization of arrays of neodymium iron boron-based magnets for magnetic tweezers applications

    NASA Astrophysics Data System (ADS)

    Zacchia, Nicholas A.; Valentine, Megan T.

    2015-05-01

    We present the design methodology for arrays of neodymium iron boron (NdFeB)-based magnets for use in magnetic tweezers devices. Using finite element analysis (FEA), we optimized the geometry of the NdFeB magnet as well as the geometry of iron yokes designed to focus the magnetic fields toward the sample plane. Together, the magnets and yokes form a magnetic array which is the basis of the magnetic tweezers device. By systematically varying 15 distinct shape parameters, we determined those features that maximize the magnitude of the magnetic field gradient as well as the length scale over which the magnetic force operates. Additionally, we demonstrated that magnetic saturation of the yoke material leads to intrinsic limitations in any geometric design. Using this approach, we generated a compact and light-weight magnetic tweezers device that produces a high field gradient at the image plane in order to apply large forces to magnetic beads. We then fabricated the optimized yoke and validated the FEA by experimentally mapping the magnetic field of the device. The optimization data and iterative FEA approach outlined here will enable the streamlined design and construction of specialized instrumentation for force-sensitive microscopy.

  7. CRADA/NFE-15-05779 Report: Fabrication of Large Area Printable Composite Magnets

    SciTech Connect

    Paranthaman, M. Parans

    2016-09-29

    The technical objective of this technical collaboration phase I proposal was to fabricate large area NdFeB composite magnets at the Oak Ridge National Laboratory Manufacturing Demonstration Facility (ORNL MDF). The goal was to distribute domestically produced isotropic and highly anisotropic high energy density magnetic particles throughout the composite structure in order to enable site specific placement of magnetic phases and minimize the generated waste associated with permanent magnet manufacturing. Big area additive manufacturing (BAAM) and magnet composite fabrication methods were used in this study. BAAM was used to fabricate 65 vol % isotropic MQP NdFeB magnets in nylon polymer matrix. BAAM magnet cylinder was sliced to two magnetic arc-shaped braces. The density of the small BAAM magnet pieces reached 4.1 g/cm3, and the room temperature magnetic properties are: Intrinsic coercivity Hci = 8.8 kOe, Remanence Br = 4.2 kG, and energy product (BH)max = 3.7 MGOe. Also, 1.5” x 1.5” composite magnets with anisotropic MQA NdFeB magnet in a resin were also fabricated under magnetic field. The unaligned sample had a density of 3.75 g/cm3. However, aligned sample possessed a density of 4.27 g/cm3. The magnetic properties didn’t degrade during this process. This study provides a pathway for preparing composite magnets for various magnetic applications.

  8. Towards high-performance permanent magnets without rare earths.

    PubMed

    Kuz'min, M D; Skokov, K P; Jian, H; Radulov, I; Gutfleisch, O

    2014-02-12

    Achieving a very strong magnetic anisotropy in a 3d material is a difficult, but not an impossible task. It is difficult because there is no general recipe (necessary condition) for a strong anisotropy in a band magnet. Several strategies can be pursued in this situation. One of them is to re-examine the less studied 3d compounds, somewhat neglected since the discovery of the Nd-Fe-B magnets 30 years ago. As an example, a single crystal of (Fe0.7Co0.3)2B has been investigated in this work.

  9. Scrap tire recycling

    SciTech Connect

    Lula, J.W.; Bohnert, G.W.

    1997-03-01

    As the automobile tire technology has grown and met the need for safer and more durable tires, stronger reinforcement and more chemically resistant rubber compounds have made recycling tires more difficult. In an effort to resolve this problem, techniques and equipment were developed to grind tires into small pieces, and new markets were sought to utilize the crumb rubber product streams from ground tires. Industrial combustion processes were modified to accept scrap tires as fuel. These efforts have been beneficial, steadily increasing the percentage of scrap tires recycled to about 10% in 1985, and reaching 72% in 1995. By the end of 1997, fully 100% of tires generated in the U.S. are expected to be recycled.

  10. The steel scrap age.

    PubMed

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-02

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  11. Contaminated nickel scrap processing

    SciTech Connect

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs.

  12. De Magnete et Meteorite: Cosmically Motivated Materials

    SciTech Connect

    Lewis, LH; Pinkerton, FE; Bordeaux, N; Mubarok, A; Poirier, E; Goldstein, JI; Skomski, R; Barmak, K

    2014-01-01

    Meteorites, likely the oldest source of magnetic material known to mankind, are attracting renewed interest in the science and engineering community. Worldwide focus is on tetrataenite, a uniaxial ferromagnetic compound with the tetragonal L1(0) crystal structure comprised of nominally equiatomic Fe-Ni that is found naturally in meteorites subjected to extraordinarily slow cooling rates, as low as 0.3 K per million years. Here, the favorable permanent magnetic properties of bulk tetrataenite derived from the meteorite NWA 6259 are quantified. The measured magnetization approaches that of Nd-Fe-B (1.42 T) and is coupled with substantial anisotropy (1.0-1.3 MJ/m(3)) that implies the prospect for realization of technologically useful coercivity. A highly robust temperature dependence of the technical magnetic properties at an elevated temperature (20-200 degrees C) is confirmed, with a measured temperature coefficient of coercivity of -0.005%/ K, over one hundred times smaller than that of Nd-Fe-B in the same temperature range. These results quantify the extrinsic magnetic behavior of chemically ordered tetrataenite and are technologically and industrially significant in the current context of global supply chain limitations of rare-earth metals required for present-day high-performance permanent magnets that enable operation of a myriad of advanced devices and machines.

  13. Issues in recycling galvanized scrap

    SciTech Connect

    Koros, P.J.; Hellickson, D.A.; Dudek, F.J.

    1995-02-10

    The quality of the steel used for most galvanizing (and tinplate) applications makes scrap derived from their production and use a premier solid charge material for steelmaking. In 1989 the AISI created a Task Force to define the issues and to recommend technologically and economically sound approaches to assure continued, unhindered recyclability of the growing volume of galvanized scrap. The AISI program addressed the treatment of full-sized industrial bales of scrap. The current, on-going MRI (US)--Argonne National Laboratory program is focused on ``loose`` scrap from industrial and post-consumer sources. Results from these programs, issues of scrap management from source to steel melting, the choices for handling zinc in iron and steelmaking and the benefits/costs for removal of zinc (and lead) from scrap prior to melting in BOF and foundry operations are reviewed in this paper.

  14. Bonded permanent magnets: Current status and future opportunities (invited)

    NASA Astrophysics Data System (ADS)

    Ormerod, John; Constantinides, Steve

    1997-04-01

    Permanent magnets play a vital role in modern society as a component in a wide range of devices utilized by many industries and consumers. In 1995, the world production of permanent magnets was estimated to be valued at 3.6 billion and growing at an annual rate of 12%. Bonded permanent magnets are the fastest growing segment of this market. Bonded magnet technology enables a wide variety of magnetic powders to be combined with several polymer and binder systems to produce magnetic components utilizing several processing options. In this article, we review the development of bonded magnet technology. The major classes of magnetic powders, binder systems, and processing technologies are described. Recent developments in magnetic material grades, e.g., anisotropic NdFeB, rare earth lean NdFeB, SmFe(N,C) are outlined. The current status of processing and binder options aimed at increasing the upper application temperature limit of these materials is highlighted. Finally, the improvements and future opportunities for bonded magnets are discussed.

  15. Equipment for shredding rubber scrap

    SciTech Connect

    Rozhkov, V.F.; Golikov, V.N.; Kurglov, V.I.; Cherepkova, R.V.

    1987-07-01

    The authors describe a range of machines developed for shredding rubber scrap and discarded rubber articles into crumbs. Technical characteristics of the machine for shredding vulcanized pressed-rubber parts, used rubber articles and scrap from the shoe industry are presented. A machine for shredding rubber scrap from plants making rubber products and from the shoe industry is shown, as is one for producing rubber crumbs from the scrap during the roughing of tires. Another machine is examined which cuts tires with metallic cords.

  16. A transportable magnetic resonance imaging system for in situ measurements of living trees: the Tree Hugger.

    PubMed

    Jones, M; Aptaker, P S; Cox, J; Gardiner, B A; McDonald, P J

    2012-05-01

    This paper presents the design of the 'Tree Hugger', an open access, transportable, 1.1 MHz (1)H nuclear magnetic resonance imaging system for the in situ analysis of living trees in the forest. A unique construction employing NdFeB blocks embedded in a reinforced carbon fibre frame is used to achieve access up to 210 mm and to allow the magnet to be transported. The magnet weighs 55 kg. The feasibility of imaging living trees in situ using the 'Tree Hugger' is demonstrated. Correlations are drawn between NMR/MRI measurements and other indicators such as relative humidity, soil moisture and net solar radiation.

  17. High speed electric motors based on high performance novel soft magnets

    NASA Astrophysics Data System (ADS)

    Silveyra, J. M.; Leary, A. M.; DeGeorge, V.; Simizu, S.; McHenry, M. E.

    2014-05-01

    Novel Co-based soft magnetic materials are presented as a potential substitute for electrical steels in high speed motors for current industry applications. The low losses, high permeabilities, and good mechanical strength of these materials enable application in high rotational speed induction machines. Here, we present a finite element analysis of Parallel Path Magnetic Technology rotating motors constructed with both silicon steel and Co-based nanocomposite. The later achieved a 70% size reduction and an 83% reduction on NdFeB magnet volume with respect to a similar Si-steel design.

  18. Composite elastic magnet films with hard magnetic feature

    NASA Astrophysics Data System (ADS)

    Wang, Weisong; Yao, Zhongmei; Chen, Jackie C.; Fang, Ji

    2004-10-01

    Hard magnetic materials with high remnant magnetic moment, Mr, have unique advantages that can achieve bi-directional (push-pull) movement in an external magnetic field. This paper presents the results on the fabrication and testing of novel composite elastic permanent magnet films. The microsize hard barium ferrite powder, NdFeB powder, and different silicone elastomers have been used to fabricate various large elongation hard magnetic films. Three different fabrication methods, screen-coating processing, moulding processing and squeegee-coating processing, have been investigated, and the squeegee-coating process was proven to be the most successful method. The uniform composite elastic permanent magnet films range from 40 µm to 216 µm in thickness have been successfully fabricated. These films were then magnetized in the thickness direction after fabrication. They exhibited permanent magnet behaviour; for instance, the film (0.640 mm3 in volume) made of polydimethyl siloxane (PDMS) and hard barium ferrite powders is measured to give a coercive force, Hc, of 3.24 × 105 A m-1 and Mr of 1.023 × 10-5 A m2, and the film (0.504 mm3 in volume) made of PDMS and NdFeB powders gives 1.55 × 105 A m-1 Hc and 8.081 × 10-5 A m2 Mr. These composite elastic permanent magnet films' mechanical properties, like Young's modulus and deflection force, have been evaluated. To validate the films' Young's modulus, a finite-element computer simulation (ANSYS®) is used and one film is chosen whose Young's modulus (16.60 MPa) is confirmed by the simulation results with ANSYS®. The large elongation composite elastic permanent magnet film provides an excellent diaphragm material, which plays an important role in the micropump or valve. The movement of the 126 µm thick film with 4.5 mm diameter made of PDMS and NdFeB powders has been tested in a 0.21 Tesla external magnetic field. It was proven to have large deflection of 125 µm.

  19. Sink-float ferrofluid separator applicable to full scale nonferrous scrap separation

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Design and performance of a ferrofluid levitation separator for recovering nonferrous metals from shredded automobiles are reported. The scrap separator uses an electromagnet to generate a region of constant density within a pool of ferrofluid held between the magnetic poles; a saturated kerosene base ferrofluid as able to float all common industrial metals of interest. Conveyors move the scrap into the ferrofluid for separation according to density. Results of scrap mixture separation studies establish the technical feasibility of relatively pure aluminum alloy and zinc alloy fractions from shredded automobile scrap by this ferrofluid levitation process. Economic projections indicate profitable operation for shredders handling more than 300 cars per day.

  20. The performance of bonded magnets used in the treatment of anterior open bite.

    PubMed

    Noar, J H; Shell, N; Hunt, N P

    1996-05-01

    This investigation examined the magnetic flux and repulsive force of neodymium-iron-boron (Nd-Fe-B) magnets based on Nd2Fe14B with acrylic coatings in different orientations. The flux was measured with a Hall probe and the force measured by electronic scales with the magnets mounted on a laboratory jack. Results show that there were no magnetic losses after embedding the magnets in acrylic bite-blocks, although there were significant flux losses when the magnet blocks were directly heated. The alignment of the magnets over each other was of the utmost importance and significantly affected the repulsive force between the magnets. When the magnets were mounted in an articulator to simulate jaw movement, the force levels between the magnets was further reduced as a result of the effects of the rotation of the articulator. It is concluded that Nd-Fe-B type magnets embedded in acrylic can be used to give predictable repulsive forces in the mouth. The dramatic reduction in force levels when the magnets are not in optimal alignment, however, makes their effectiveness in aiding intrusion of teeth doubtful.

  1. The ALPHA Magnetic Spectrometer

    NASA Astrophysics Data System (ADS)

    Viertel, G. M.; Capell, M.

    1998-12-01

    The ALPHA Magnetic Spectrometer (AMS) will be the first large magnetic spectrometer in space. It is scheduled to be installed on the future International Space Station ALPHA (ISSA) in the year 2002 to perform measurements of the charged particle composition to answer fundamental questions in particle physics and astrophysics. Before installation on ISSA, AMS will fly on the shuttle DISCOVERY for a period of 10 days starting in May 1998. This will enable AMS to perform a test of the apparatus and first measurements. The AMS detector has five major components: A permanent NdFeB magnet, six planes of Silicon double-sided microstrip detectors, a plastic scintillator time of flight hodoscope, a plastic scintillator anticoincidence counter and an Aerogel Cherenkov threshold counter. In addition, there are electronics, support infrastructure and interfaces.

  2. A magnetic filter with permanent magnets on the basis of rare earths

    NASA Astrophysics Data System (ADS)

    Žežulka, Václav; Straka, Pavel; Mucha, Pavel

    2004-01-01

    The article presents the development and construction of a magnetic filter based on the HGMS principle with permanent magnets. It is aimed especially at the assembly of the magnetic circuit using magnets from the material NdFeB. The way of the construction of large magnetic blocks, their magnetization and assembly are described. Further, it contains the measured values of magnetic induction in the middle of the air gap as a function of the width of this gap and of the height of the magnetic blocks in question, as well as the corresponding graphic representation. The high values of the magnetic induction obtained together with favourable price are sufficient reasons for the employment of this type of magnetic circuit in various applications.

  3. Small axial flux motor with permanent magnet excitation and etched airgap winding

    NASA Astrophysics Data System (ADS)

    Hamitsch, R.; Belmans, R.; Stephan, R.

    1994-03-01

    Disc-type motors with sintered Nd-Fe-B magnets benefit from the high remanence and near-ideal loop shape of the hard, magnetic material. Consequent advantages include a high torque for a given motor size and improved efficiency. Special airgap windings manufactured as multilayer etched windings contribute to flat package motors and to low torque harmonics. Different back iron designs were examined. For the operation of the brushless dc motor instead the classical hall sensors, small magnetoresistive sensors can be used effectively for rotor position sensing.

  4. Die-upset Pr-Fe-B-type magnets from melt-spun ribbons

    SciTech Connect

    Fuerst, C.D.; Brewer, E.G.; Mishra, R.K. ); Zhu, Y.; Welch, D.O. )

    1994-04-15

    In order to optimize the magnetic properties of die-upset Pr-Fe-B magnets, we have systematically altered alloy compositions, including partial substitution of cobalt and neodymium, and low-level additions of gallium. In general, the remanences of Pr-Fe-B die-upset magnets were lower by [similar to]1 kG, and coercivities were higher by [similar to]4 kOe, than analogous Nd-Fe-B magnets. The microstructure of the Pr-Fe-B die-upset magnets was similar to Nd-Fe-B magnets. Both systems are two phase, consisting of oriented flat platelet-shaped grains of 2-14-1 separated by a rare earth-rich intergranular phase. The intergranular phase is thicker for the Pr-Fe-B magnets, resulting in enhanced magnetic domain wall pinning and increased coercivity. Even higher coercivities were obtained with small amounts of cobalt substitution ([le]5 at. % of the transition metal) and by very low-level additions of gallium ([le]0.5 at. %). The largest remanence ([ital B][sub [ital r

  5. A basic study of a triangular magnet chain for locomotion control

    NASA Astrophysics Data System (ADS)

    Kim, Sung Hoon; Hashi, Shuichiro; Ishiyama, Kazushi

    2011-04-01

    This paper introduces a theoretical (magnetic and robotic) and experimental study of a robotic locomotion principle utilizing a triangular artificial magnetic chain with a rotating magnetic field for biomedical applications. A three-axis Helmholtz coil system with external controller (joystick) controls the moving direction of the proposed magnet chain according to changes of the plane of the rotating magnetic field. The proposed magnet chain consists of three NdFeB magnets, and its magnetic property depends on dipoles interaction. Also, motion dynamics bring about a magnetic torque analyzed by robotics. A total magnetic moment on the triangular magnet chain provides magnetic torque in the rotating magnetic field, and a geometric property produces a stable movement for robotic locomotion.

  6. Neodymium as the main feature of permanent magnets from hard disk drives (HDDs).

    PubMed

    München, Daniel Dotto; Veit, Hugo Marcelo

    2017-03-01

    As a way to manage neodymium-iron-boron (NdFeB) magnets wasted in end-of-life hard disk drives (HDDs), a waste characterization is needed prior to a recycling process. Due to their magnetic properties, NdFeB magnets are essential in technological applications nowadays, thus causing an increase in the industrial demand for rare earth metals. However, these metals have a short supply, since they are difficult to obtain from ores, creating a critical market. In this work, a study of the characterization of sintered neodymium-iron-boron magnets was undertaken by qualitatively and quantitatively uncovering the neodymium recovery potential from this type of electronic waste. From the collection and disassembly of hard disk drives, in which the magnet represents less than 3% of the total weight, an efficient demagnetization process was proceeded at 320°C. Then, the magnet was ground and screened for an X-ray diffraction (XRD) analysis, which showed the Nd2Fe14B tetragonal phase as the dominant constituent of the sample. An analysis was also carried out in a scanning electron microscope (SEM) and an inductively coupled plasma optical emission spectrometer (ICP-OES), where the magnet composition showed 21.5wt% of neodymium and 65.1wt% of iron, among other chemicals. This Nd content is higher than the one found in Nd ores, enhancing the recyclability and the importance of waste management.

  7. Micromagnet structures for magnetic positioning and alignment

    NASA Astrophysics Data System (ADS)

    Zanini, L. F.; Osman, O.; Frenea-Robin, M.; Haddour, N.; Dempsey, N. M.; Reyne, G.; Dumas-Bouchiat, F.

    2012-04-01

    High performance hard magnetic films (NdFeB, SmCo) have been patterned at the micron scale using thermo-magnetic patterning. Both out-of-plane and in-plane magnetized structures have been prepared. These micromagnet arrays have been used for the precise positioning and alignment of superparamagnetic nano- and microparticles. The specific spatial arrangement achieved is shown to depend on both the particle size and the size and orientation of the micromagnets. These micromagnet arrays were used to trap cells magnetically functionalized by endocytosis of 100 nm superparamagnetic particles. These simple, compact, and autonomous structures, which need neither an external magnetic field source nor a power supply, have much potential for use in a wide range of biological applications.

  8. NATO East-West Workshop on Magnetic Materials for Power Applications

    DTIC Science & Technology

    2001-08-01

    the 450-600°C range in developing of coercivity. Both the role of surface of the Nd2Fe14B grains and the intergranular regions are analysed...parameters of the Nd2Fe14B phase vary unmonotonously with annealing temperature. After analysis of the hydrogen concentration in as-cast Nd-Fe-B alloys...sintered and heat treated magnets the effect of hydrogen in Nd2Fe14B and intergranular Nd-rich phases is discussed. The study of model alloys of Fe-Nd

  9. Magnetic performance of DEVU25.20h undulator at IDDL, DAVV,India

    NASA Astrophysics Data System (ADS)

    Mishra, G.; Gehlot, Mona; Sharma, Geetanjali; Khullar, Roma

    2016-10-01

    In this paper, we describe the design development and magnetic performance of a prototype DEVU25.20h, variable gap hybrid undulator at IDD laboratory, DAVV, Indore, India. The undulator is NdFeB based hybrid undulator with twenty five period and 20 mm each period length. Low cost M35 grade cobalt steel is used as the pole material of the undulator. The abc coefficients of the new pole material is prescribed and the measured performance and characteristics of the undulator is evaluated using RADIA. The detailed design parameters and performance indicators are summarized in Table 1 and Table 2 respectively.

  10. Zero Rare-Earth Magnet Integrated Starter-Generator Development for Military Vehicle Applications

    DTIC Science & Technology

    2013-08-14

    generation is expected to reach and exceed 100kW. • Many electric machines capable of (≥ 100kW) output power rely on rare-earth elements such Nd, Sm , Dy...Steel • 1940’s – Alnico • 1950’s – Ferrite • 1960’s – Alnico 9 • 1960’s – SmCo − First RE PM’s • 1980’s – NdFeB • 2007 – LaCo Ferrite ...LaCo Ferrite Developmental Materials Zero Rare-Earth Ferrite Alnico Developmental Materials UNCLASSIFIED UNCLASSIFIED Permanent Magnet

  11. 7 CFR 29.6022 - Leaf scrap.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap...

  12. Managing potentially radioactive scrap metal

    SciTech Connect

    2002-11-19

    The National Council on Radiation Protection and Measurements published NCRP Report No. 141 on November 19, 2002. Contract DE-FG02-98CH10945 provided the sole support for this report titled ''Managing Potentially Radioactive Scrap Metal.'' Some preliminary work supported by the U.S. Environmental Protection Agency that led to an NCRP Letter Report provided some background information for this work. NCRP Report No. 141 provides recommendations on the methodologies and techniques available to the United States for disposing of radioactive, contaminated scrap metals.

  13. Creation of transcatheter aortopulmonary and cavopulmonary shunts using magnetic catheters: feasibility study in swine.

    PubMed

    Levi, Daniel S; Danon, Saar; Gordon, Brent; Virdone, Nicky; Vinuela, Fernando; Shah, Sanjay; Carman, Greg; Moore, John W

    2009-05-01

    Surgical shunts are the basic form of palliation for many types of congenital heart disease. The Glenn shunt (superior cavopulmonary connection) and central shunt (aortopulmonary connection) represent surgical interventions that could potentially be accomplished by transcatheter techniques. We sought to investigate the efficacy of using neodymium iron boron (NdFeB) magnetic catheters to create transcatheter cavopulmonary and aortopulmonary shunts. NdFeB magnets were machined and integrated into catheters. "Target" catheters were placed in the pulmonary arteries (PAs), and radiofrequency "perforation" catheters were placed in either the descending aorta (DAo) for central shunts or the superior vena cava (SVC) for Glenn shunts. The magnet technique or "balloon target" method was used to pass wires from the DAo or the SVC into the PA. Aortopulmonary and cavopulmonary connections were then created using Atrium iCAST covered stents. Magnet catheters were used to perforate the left pulmonary artery from the DAo, thereby establishing a transcatheter central shunt. Given the orientation of the vasculature, magnetic catheters could not be used for SVC-to-PA connections; however, perforation from the SVC to the right pulmonary artery was accomplished with a trans-septal needle and balloon target. Transcatheter Glenn or central shunts were successfully created in four swine.

  14. Reduction in Current Consumption of Small DC Motor with Rare-Earth Flexible Bonded Magnets Prepared by Powder Compacting Press and Hot Rolling

    NASA Astrophysics Data System (ADS)

    Yamashita, Fumitoshi; Watanabe, Akihiko; Fukunaga, Hirotoshi

    The usage of high-performance rare-earth magnets is one of the key technologies in the development of efficient small motors. Ring-shaped melt-spun Nd-Fe-B bonded magnets, prepared using a powder compacting press and/or injection molding, are generally used in typical applications to small efficient motors. For exploiting the maximum characteristics according to the variety of magnetic powder, however, the preparation method of the magnet, the magnet form, and the motor design needs to be changed for high-productivity as well as for improving total performance, including the magnetic properties of bonded magnets. This paper reports recent achievements in new preparation processes for rare-earth bonded magnets and small motors using new materials other than Nd-Fe-B melt-spun powder. This paper especially focuses on the method for maximally exploiting certain rare-earth magnetic powders . Furthermore, reduction in the current consumption of the small DC motor using the developed technique is reported.

  15. New permanent magnets; manganese compounds.

    PubMed

    Coey, J M D

    2014-02-12

    The exponential growth of maximum energy product that prevailed in the 20th century has stalled, leaving a market dominated by two permanent magnet materials, Nd2Fe14B and Ba(Sr)Fe12O19, for which the maximum theoretical energy products differ by an order of magnitude (515 kJ m(-3) and 45 kJ m(-3), respectively). Rather than seeking to improve on optimized Nd-Fe-B, it is suggested that some research efforts should be devoted to developing appropriately priced alternatives with energy products in the range 100-300 kJ m(-3). The prospects for Mn-based hard magnetic materials are discussed, based on known Mn-based compounds with the tetragonal L10 or D022 structure or the hexagonal B81 structure.

  16. A magnetically driven PDMS peristaltic micropump.

    PubMed

    Pan, Tingrui; Kai, Eleanor; Stay, Matthew; Barocas, Victor; Ziaie, Babak

    2004-01-01

    We present a robust low-cost PDMS peristaltic micropump with magnetic drive. The fabrication process is based on the soft molding and bonding of three PDMS layers. A base layer incorporates the microchannel while a middle layer contains the actuation membrane. The top layer encapsulates three small permanent magnetic rods (Ni-plated-NdFeB) in three small chambers. A small DC motor (6 mm in diameter and 15 mm in length) with three permanent magnets stagger-mounted on its shaft is used to pull down and actuate the membrane-mounted magnets to generate a peristaltic waveform. A maximum pumping rate of about 24 muL/min at the speed of 1700 rpm with power consumption of 11 mW was demonstrated. A preliminary numerical analysis of the peristaltic pump was performed, which showed the characteristic membrane deflection and fluid flow of pumping.

  17. Magnetic and viscoelastic response of elastomers with hard magnetic filler

    NASA Astrophysics Data System (ADS)

    Kramarenko, E. Yu; Chertovich, A. V.; Stepanov, G. V.; Semisalova, A. S.; Makarova, L. A.; Perov, N. S.; Khokhlov, A. R.

    2015-03-01

    Magnetic elastomers (MEs) based on a silicone matrix and magnetically hard NdFeB particles have been synthesized and their magnetic and viscoelastic properties have been studied depending on the size and concentration of magnetic particles and the magnetizing field. It has been shown that magnetic particles can rotate in soft polymer matrix under applied magnetic field, this fact leading to some features in both magnetic and viscoelastic properties. In the maximum magnetic field used magnetization of MEs with smaller particles is larger while the coercivity is smaller due to higher mobility of the particles within the polymer matrix. Viscoelastic behavior is characterized by long relaxation times due to restructuring of the magnetic filler under the influence of an applied mechanical force and magnetic interactions. The storage and loss moduli of magnetically hard elastomers grow significantly with magnetizing field. The magnetic response of the magnetized samples depends on the mutual orientation of the external magnetic field and the internal sample magnetization. Due to the particle rotation within the polymer matrix, the loss factor increases abruptly when the magnetic field is turned on in the opposite direction to the sample magnetization, further decreasing with time. Moduli versus field dependences have minimum at non-zero field and are characterized by a high asymmetry with respect to the field direction.

  18. The use of a neodymium-iron-boron magnet device for positioning a multi-stranded wire retainer in lingual retention--a pilot study in humans.

    PubMed

    Hahn, Wolfram; Fricke, Julia; Fricke-Zech, Susanne; Zapf, Antonia; Gruber, Rudolf; Sadat-Khonsari, Reza

    2008-10-01

    The aim of this study was to evaluate the time requirement of a newly developed device made of neodymium-iron-boron (NdFeB) magnets for positioning a multi-stranded, canine-to-canine retainer during bonding compared with dental floss and a transfer tray. Forty-five patients aged between 12 and 33 years (26 male, 19 female) previously treated with fixed appliances were enrolled in the study. The patients were randomly allocated to three groups (15 per group). For each group a mandibular canine-to-canine retainer of 0.018 inch Dentaflex multi-stranded wire (Dentaurum) was prefabricated for each patient on a cast. The bonding procedure was identical, except for the method of positioning the wire during adhesive fixation: group A dental floss, group B a small prefabricated transfer tray of dental resin and group C the NdFeB magnet device. For each group, the time required for the complete bonding process was measured. Kruskal-Wallis and Wilcoxon-Mann-Whitney tests were used for group and pairwise comparisons, respectively. The three methods required statistically significant different times (P < 0.001). The Wilcoxon-Mann-Whitney test revealed that wire positioning with the magnet device was significantly faster [4.98 minutes; standard deviation (SD) 0.68 minutes] than with dental floss (7.65 minutes, SD 1.14 minutes; P = 0.0001) or with transfer tray (5.75 minutes, SD 0.57 minutes; P = 0.001). The NdFeB magnet device is a timesaving appliance for positioning a multi-stranded, canine-to-canine retainer during bonding when compared with dental floss and an individually prefabricated transfer tray.

  19. High Value Scrap Tire Recycle

    SciTech Connect

    Bauman, B. D.

    2003-02-01

    The objectives of this project were to further develop and scale-up a novel technology for reuse of scrap tire rubber, to identify and develop end uses for the technology (products), and to characterize the technology's energy savings and environmental impact.

  20. Inverted Linear Halbach Array for Separation of Magnetic Nanoparticles.

    PubMed

    Ijiri, Y; Poudel, C; Williams, P S; Moore, L R; Orita, T; Zborowski, M

    2013-07-01

    A linear array of Nd-Fe-B magnets has been designed and constructed in an inverted Halbach configuration for use in separating magnetic nanoparticles. The array provides a large region of relatively low magnetic field, yet high magnetic field gradient in agreement with finite element modeling calculations. The magnet assembly has been combined with a flow channel for magnetic nanoparticle suspensions, such that for an appropriate distance away from the assembly, nanoparticles of higher moment aggregate and accumulate against the channel wall, with lower moment nanoparticles flowing unaffected. The device is demonstrated for iron oxide nanoparticles with diameters of ~ 5 and 20 nm. In comparison to other approaches, the inverted Halbach array is more amenable to modeling and to scaling up to preparative quantities of particles.

  1. Inverted Linear Halbach Array for Separation of Magnetic Nanoparticles

    PubMed Central

    Ijiri, Y.; Poudel, C.; Williams, P.S.; Moore, L.R.; Orita, T.; Zborowski, M.

    2014-01-01

    A linear array of Nd-Fe-B magnets has been designed and constructed in an inverted Halbach configuration for use in separating magnetic nanoparticles. The array provides a large region of relatively low magnetic field, yet high magnetic field gradient in agreement with finite element modeling calculations. The magnet assembly has been combined with a flow channel for magnetic nanoparticle suspensions, such that for an appropriate distance away from the assembly, nanoparticles of higher moment aggregate and accumulate against the channel wall, with lower moment nanoparticles flowing unaffected. The device is demonstrated for iron oxide nanoparticles with diameters of ~ 5 and 20 nm. In comparison to other approaches, the inverted Halbach array is more amenable to modeling and to scaling up to preparative quantities of particles. PMID:25382864

  2. Determining the structure-mechanics relationships of dense microtubule networks with confocal microscopy and magnetic tweezers-based microrheology.

    PubMed

    Yang, Yali; Valentine, Megan T

    2013-01-01

    The microtubule (MT) cytoskeleton is essential in maintaining the shape, strength, and organization of cells. Its spatiotemporal organization is fundamental for numerous dynamic biological processes, and mechanical stress within the MT cytoskeleton provides an important signaling mechanism in mitosis and neural development. This raises important questions about the relationships between structure and mechanics in complex MT structures. In vitro, reconstituted cytoskeletal networks provide a minimal model of cell mechanics while also providing a testing ground for the fundamental polymer physics of stiff polymer gels. Here, we describe our development and implementation of a broad tool kit to study structure-mechanics relationships in reconstituted MT networks, including protocols for the assembly of entangled and cross-linked MT networks, fluorescence imaging, microstructure characterization, construction and calibration of magnetic tweezers devices, and mechanical data collection and analysis. In particular, we present the design and assembly of three neodymium iron boron (NdFeB)-based magnetic tweezers devices optimized for use with MT networks: (1) high-force magnetic tweezers devices that enable the application of nano-Newton forces and possible meso- to macroscale materials characterization; (2) ring-shaped NdFeB-based magnetic tweezers devices that enable oscillatory microrheology measurements; and (3) portable magnetic tweezers devices that enable direct visualization of microscale deformation in soft materials under applied force.

  3. Determination of magnetic anisotropy of magnetically hard materials

    SciTech Connect

    Richter, H.J. )

    1990-03-15

    The determination of the first-order anisotropy field strength using the torsion pendulum method is described. Since the applied field need not necessarily be in the range of the anisotropy field, this method is particularly useful for characterizing modern permanent magnet materials which have a very high uniaxial anisotropy. The method requires oriented samples. Measurements were made on polycrystalline samples of NdFeB, SmCo, and barium ferrite. The method is described and error sources are discussed. It is pointed out that the torsion pendulum method is closely related to reversible transverse susceptibility measurements. It is shown both experimentally and theoretically, that using susceptibility measurements similar results can be obtained. The susceptibility method is, however, not applicable to conducting materials at present.

  4. Determination of magnetic anisotropy of magnetically hard materials

    NASA Astrophysics Data System (ADS)

    Richter, H. J.

    1990-03-01

    The determination of the first-order anisotropy field strength using the torsion pendulum method is described. Since the applied field need not necessarily be in the range of the anisotropy field, this method is particularly useful for characterizing modern permanent magnet materials which have a very high uniaxial anisotropy. The method requires oriented samples. Measurements were made on polycrystalline samples of NdFeB, SmCo, and barium ferrite. The method is described and error sources are discussed. It is pointed out that the torsion pendulum method is closely related to reversible transverse susceptibility measurements. It is shown both experimentally and theoretically, that using susceptibility measurements similar results can be obtained. The susceptibility method is, however, not applicable to conducting materials at present.

  5. The Rare Earth Magnet Industry and Rare Earth Price in China

    NASA Astrophysics Data System (ADS)

    Ding, Kaihong

    2014-07-01

    In the past four years, the price of rare earth metal fluctuates sharply for many reasons. Currently, it has become more stable and more reasonable. This presentation is focused on the effect about the rare earth metal price. Some motor manufacturers have shifted from rare earth permanent magnet to ferrite magnet. Many motor manufacturers changed the design for the motor cooling system to make the motor function at a lower temperature. Thus the consumption of Dy can be markedly reduced. As for manufacturer of NdFeB magnet, we are also trying to optimize our process to reduce to dependence of HREE such as Dy and Tb. HS process have been introduced to solve the problem. With more and more people focusing and engaging on the REE industry, the price of REE will be more transparent without too many fluctuations. China is considering the problems of balancing the environment, energy sources, and labor sources. The application field about NdFeB such as wind turbine generator, HEV/EV, FA /OA is flourishing.

  6. Quantum Hall effect in epitaxial graphene with permanent magnets

    PubMed Central

    Parmentier, F. D.; Cazimajou, T.; Sekine, Y.; Hibino, H.; Irie, H.; Glattli, D. C.; Kumada, N.; Roulleau, P.

    2016-01-01

    We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors v = ±2, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications. PMID:27922114

  7. Quantum Hall effect in epitaxial graphene with permanent magnets.

    PubMed

    Parmentier, F D; Cazimajou, T; Sekine, Y; Hibino, H; Irie, H; Glattli, D C; Kumada, N; Roulleau, P

    2016-12-06

    We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors v = ±2, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications.

  8. Variable-field permanent magnet quadrupole for the SSC

    SciTech Connect

    Barlow, D.B.; Kraus, R.H. Jr.; Martinez, R.P.; Meyer, R.E.

    1993-10-01

    A set of compact variable-field permanent-magnet quadrupoles have been designed, fabricated, and tested for use In the SSC linac matching section. The quadrupoles have 24 mm-diameter apertures and 40 mm-long poles. The hybrid (permanent-magnet and iron) design, uses a fixed core of magnet material (NdFeB) and iron (C-1006) surrounded by a rotating ring of the same magnet material and iron. The quadrupole gradient-length product can be smoothly varied from a minimum of 0.7 T up to a maximum, of 4.3 T by a 90{degrees} rotation of the outer ring of iron and magnet material.

  9. Quantum Hall effect in epitaxial graphene with permanent magnets

    NASA Astrophysics Data System (ADS)

    Parmentier, F. D.; Cazimajou, T.; Sekine, Y.; Hibino, H.; Irie, H.; Glattli, D. C.; Kumada, N.; Roulleau, P.

    2016-12-01

    We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors v = ±2, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications.

  10. A magnetically driven PDMS micropump with microball valves.

    PubMed

    McDonald, Scott; Pan, Tingrui; Ziaie, Babak

    2004-01-01

    We present a novel robust PDMS membrane micropump with two one-way microball valves for biomedical applications. The actuating membrane is driven by magnetic force of two miniature permanent magnets. The micropump consists of two PDMS layers, one holding the microball valves and actuating chamber and the second holding the top magnet and covering the chamber and microvalves. A simple approach is used to fabricate a high performance microball valve using an embedded Teflon/sup trade mark/ microtube. A small DC motor (6mm in diameter and 15mm in length) with two permanent magnetic discs (NdFeB) mounted on its shaft is used to actuate the membrane-mounted magnet. This configuration yields a large pumping rate with very low power consumption. Maximum pumping rate of 260muL/min was achieved at the input power of 21mW, the highest pumping rate reported in the literature for micropumps at such power consumption.

  11. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... destruction, by using command, of all military scrap and scrap metal from lands suitable for cultivation...

  12. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... destruction, by using command, of all military scrap and scrap metal from lands suitable for cultivation...

  13. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... destruction, by using command, of all military scrap and scrap metal from lands suitable for cultivation...

  14. Magnetic viscosity studies in hard magnetic materials

    SciTech Connect

    Singleton, E.W.; Hadjipanayis, G.C. )

    1990-05-01

    The magnetic viscosity behavior has been studied in several hard magnets with different magnetization reversal mechanisms including barium ferrite powders, Cu-Mn-Al, ferrite magnets, Nd-Fe-B, and SmCo{sub 5}, Sm{sub 2}(Co,Fe,Cu,Zr){sub 17}. The measurements were made with a vibrating sample magnetometer for times up to 60 s and a SQUID magnetometer for longer times in the range of 60--2300 s. For most of the samples the magnetization was found to vary logarithmically with time. The field and temperature dependence of the magnetic viscosity coefficient {ital S} was studied. Here, {ital S} was found to vary with the applied field and it usually peaked around the coercive field {ital H}{sub {ital c}}. The measured values of {ital S}{sub max} at 10 K range from 0.004 to 1.853 emu/g for Cu-Mn-Al and Sm{sub 2}(Co,Fe,Cu,Zr){sub 17}, respectively. The magnetic viscosity coefficient was used together with the magnetic susceptibility to determine the activation volume.

  15. Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Hashi, S.; Ishiyama, K.

    2011-01-01

    This paper presents a centrifugal force based magnetic micro-pump for the pumping of blood. Most blood pumps are driven by an electrical motor with wired control. To develop a wireless and battery-free blood pump, the proposed pump is controlled by external rotating magnetic fields with a synchronized impeller. Synchronization occurs because the rotor is divided into multi-stage impeller parts and NdFeB permanent magnet. Finally, liquid is discharged by the centrifugal force of multi-stage impeller. The proposed pump length is 30 mm long and19 mm in diameter which much smaller than currently pumps; however, its pumping ability satisfies the requirement for a blood pump. The maximum pressure is 120 mmHg and the maximum flow rate is 5000ml/min at 100 Hz. The advantage of the proposed pump is that the general mechanical problems of a normal blood pump are eliminated by the proposed driving mechanism.

  16. Developments in radioactive scrap monitoring

    SciTech Connect

    Bellian, J.G.

    1997-12-31

    Over the past ten years there have been major developments in radiation monitoring systems used for detecting shielded radioactive sources in scrap metal. The extent of the problem and industry`s awareness of the problem have both grown significantly during that time. The multimillion dollar expenses associated with decontamination after a source passes into the melt and the potential health hazard to employees and the public have added further impetus to the development of monitoring systems. Early attempts at scrap monitoring could detect some radiation, but testing with real life situations showed them to be virtually incapable of detecting shielded sources of radioactivity in incoming vehicles. More sophisticated detector technology and the development of advanced software made useful by more powerful microprocessors led to successive generations of monitoring systems with order-of-magnitude improvement in detection capability. The next generation includes larger detectors and more complex algorithms offering further improvement in truck and rail car monitoring. Complete solutions require monitoring at additional locations within the site, such as the charge bucket and conveyor lines, and at the scrap processor`s site.

  17. Non-invasive modulation of somatosensory evoked potentials by the application of static magnetic fields over the primary and supplementary motor cortices

    PubMed Central

    Kirimoto, Hikari; Asao, Akihiko; Tamaki, Hiroyuki; Onishi, Hideaki

    2016-01-01

    This study was performed to investigate the possibility of non-invasive modulation of SEPs by the application of transcranial static magnetic field stimulation (tSMS) over the primary motor cortex (M1) and supplementary motor cortex (SMA), and to measure the strength of the NdFeB magnetic field by using a gaussmeter. An NdFeB magnet or a non-magnetic stainless steel cylinder (for sham stimulation) was settled on the scalp over M1 and SMA of 14 subjects for periods of 15 min. SEPs following right median nerve stimulation were recorded before and immediately after, 5 min after, and 10 min after tSMS from sites C3′ and F3. Amplitudes of the N33 component of SEPs at C3′ significantly decreased immediately after tSMS over M1 by up to 20%. However, tSMS over the SMA did not affect the amplitude of any of the SEP components. At a distance of 2–3 cm (rough depth of the cortex), magnetic field strength was in the range of 110–190 mT. Our results that tSMS over M1 can reduce the amplitude of SEPs are consistent with those of low-frequency repeated TMS and cathodal tDCS studies. Therefore, tSMS could be a useful tool for modulating cortical somatosensory processing. PMID:27698365

  18. Non-invasive modulation of somatosensory evoked potentials by the application of static magnetic fields over the primary and supplementary motor cortices.

    PubMed

    Kirimoto, Hikari; Asao, Akihiko; Tamaki, Hiroyuki; Onishi, Hideaki

    2016-10-04

    This study was performed to investigate the possibility of non-invasive modulation of SEPs by the application of transcranial static magnetic field stimulation (tSMS) over the primary motor cortex (M1) and supplementary motor cortex (SMA), and to measure the strength of the NdFeB magnetic field by using a gaussmeter. An NdFeB magnet or a non-magnetic stainless steel cylinder (for sham stimulation) was settled on the scalp over M1 and SMA of 14 subjects for periods of 15 min. SEPs following right median nerve stimulation were recorded before and immediately after, 5 min after, and 10 min after tSMS from sites C3' and F3. Amplitudes of the N33 component of SEPs at C3' significantly decreased immediately after tSMS over M1 by up to 20%. However, tSMS over the SMA did not affect the amplitude of any of the SEP components. At a distance of 2-3 cm (rough depth of the cortex), magnetic field strength was in the range of 110-190 mT. Our results that tSMS over M1 can reduce the amplitude of SEPs are consistent with those of low-frequency repeated TMS and cathodal tDCS studies. Therefore, tSMS could be a useful tool for modulating cortical somatosensory processing.

  19. Using injection molding and reversible bonding for easy fabrication of magnetic cell trapping and sorting devices

    NASA Astrophysics Data System (ADS)

    Royet, David; Hériveaux, Yoann; Marchalot, Julien; Scorretti, Riccardo; Dias, André; Dempsey, Nora M.; Bonfim, Marlio; Simonet, Pascal; Frénéa-Robin, Marie

    2017-04-01

    Magnetism and microfluidics are two key elements for the development of inexpensive and reliable tools dedicated to high-throughput biological analysis and providing a large panel of applications in domains ranging from fundamental biology to medical diagnostics. In this work, we introduce a simple protocol, relying on injection molding and reversible bonding for fabrication of magnetic cell trapping and sorting devices using only standard soft-lithography equipment. Magnetic strips or grids made of Polydimethylsiloxane (PDMS) doped with hard (NdFeB) or soft (carbonyl iron) magnetic powders were integrated at the bottom of whole PDMS chips. Preliminary results show the effective deviation/trapping of magnetic beads or magnetically-labeled bacteria as the sample flows through the microchannel, proving the potential of this rapid prototyping approach for easy fabrication of magnetic cell sorters.

  20. Removal of copper from ferrous scrap

    DOEpatents

    Blander, M.; Sinha, S.N.

    1990-05-15

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  1. Removal of copper from ferrous scrap

    DOEpatents

    Blander, M.; Sinha, S.N.

    1987-07-30

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  2. Removal of copper from ferrous scrap

    DOEpatents

    Blander, Milton; Sinha, Shome N.

    1990-01-01

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  3. Management of MSW in Spain and recovery of packaging steel scrap.

    PubMed

    Tayibi, Hanan; Peña, Carmen; López, Félix A; López-Delgado, Aurora

    2007-01-01

    Packaging steel is more advantageously recovered and recycled than other packaging material due to its magnetic properties. The steel used for packaging is of high quality, and post-consumer waste therefore produces high-grade ferrous scrap. Recycling is thus an important issue for reducing raw material consumption, including iron ore, coal and energy. Household refuse management consists of collection/disposal, transport, and processing and treatment - incineration and composting being the most widely used methods in Spain. Total Spanish MSW production exceeds 21 million tons per year, of which 28.1% and 6.2% are treated in compost and incineration plants, respectively. This paper presents a comprehensive study of incineration and compost plants in Spain, including a review of the different processes and technologies employed and the characteristics and quality of the recovered ferrous scrap. Of the total amount of packaging steel scrap recovered from MSW, 38% comes from compost plants and 14% from incineration plants. Ferrous scrap from incineration plants presents a high degree of chemical alteration as a consequence of the thermal process to which the MSW is subjected, particularly the conditions in which the slag is cooled, and accordingly its quality diminishes. Fragmentation and magnetic separation processes produce an enhancement of the scrap quality. Ferrous scrap from compost plants has a high tin content, which negatively affects its recycling. Cleaning and detinning processes are required prior to recycling.

  4. Fernald scrap metal recycling and beneficial reuse

    SciTech Connect

    Motl, G.P.; Burns, D.D.

    1993-10-01

    The Fernald site, formerly the Feed Materials Production Facility, produced uranium metal products to meet defense production requirements for the Department of Energy from 1953 to 1989. In this report is is described how the Fernald scrap metal project has demonstrated that contractor capabilities can be used successfully to recycle large quantities of Department of Energy scrap metal. The project has proven that the {open_quotes}beneficial reuse{close_quotes} concept makes excellent economic sense when a market for recycled products can be identified. Topics covered in this report include the scrap metal pile history, the procurement strategy, scrap metal processing, and a discussion of lessons learned.

  5. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J. ); Morgan, W.A.; Kellner, A.W.; Harrison, J. )

    1992-01-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  6. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.; Kellner, A.W.; Harrison, J.

    1992-08-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  7. Synthesis of magnetic nanofibers using femtosecond laser material processing in air

    PubMed Central

    2011-01-01

    In this study, we report formation of weblike fibrous nanostructure and nanoparticles of magnetic neodymium-iron-boron (NdFeB) via femtosecond laser radiation at MHz pulse repetition frequency in air at atmospheric pressure. Scanning electron microscopy (SEM) analysis revealed that the nanostructure is formed due to aggregation of polycrystalline nanoparticles of the respective constituent materials. The nanofibers diameter varies between 30 and 70 nm and they are mixed with nanoparticles. The effect of pulse to pulse separation rate on the size of the magnetic fibrous structure and the magnetic strength was reported. X-ray diffraction (XRD) analysis revealed metallic and oxide phases in the nanostructure. The growth of magnetic nanostructure is highly recommended for the applications of magnetic devices like biosensors and the results suggest that the pulsed-laser method is a promising technique for growing nanocrystalline magnetic nanofibers and nanoparticles for biomedical applications. PMID:21711890

  8. Magnetic levitation and its application for education devices based on YBCO bulk superconductors

    NASA Astrophysics Data System (ADS)

    Yang, W. M.; Chao, X. X.; Guo, F. X.; Li, J. W.; Chen, S. L.

    2013-10-01

    A small superconducting maglev propeller system, a small spacecraft model suspending and moving around a terrestrial globe, several small maglev vehicle models and a magnetic circuit converter have been designed and constructed. The track was paved by NdFeB magnets, the arrangement of the magnets made us easy to get a uniform distribution of magnetic field along the length direction of the track and a high magnetic field gradient in the lateral direction. When the YBCO bulks mounted inside the vehicle models or spacecraft model was field cooled to LN2 temperature at a certain distance away from the track, they could be automatically floating over and moving along the track without any obvious friction. The models can be used as experimental or demonstration devices for the magnetic levitation applications.

  9. Magnetic levitation in the analysis of foods and water.

    PubMed

    Mirica, Katherine A; Phillips, Scott T; Mace, Charles R; Whitesides, George M

    2010-06-09

    This paper describes a method and a sensor that use magnetic levitation (MagLev) to characterize samples of food and water on the basis of measurements of density. The sensor comprises two permanent NdFeB magnets positioned on top of each other in a configuration with like poles facing and a container filled with a solution of paramagnetic ions. Measurements of density are obtained by suspending a diamagnetic object in the container filled with the paramagnetic fluid, placing the container between the magnets, and measuring the vertical position of the suspended object. MagLev was used to estimate the salinity of water, to compare a variety of vegetable oils on the basis of the ratio of polyunsaturated fat to monounsaturated fat, to compare the contents of fat in milk, cheese, and peanut butter, and to determine the density of grains.

  10. Management of scrap computer recycling in Taiwan.

    PubMed

    Lee, C H; Chang, S L; Wang, K M; Wen, L C

    2000-04-28

    It is estimated that approximately 300,000 scrap personal computers are generated each year in Taiwan [S.-L. Chang, A Study on the Scrap Computer Treatment Cost, Environment Protection Administration of Taiwan, December 1998 (in Chinese)]. The disposal of such a huge number of scrap computers presents a difficult task for the island due to the scarcity of landfills and incineration facilities available locally. Also, the hazardous materials contained (i.e., phosphor coatings of cathode ray tubes (CRTs), batteries, polychlorinated biphenyl capacitors, mercury-containing parts, liquid crystal display, high-lead content CRT funnel glass, and plastic containing flame-retardant bromine, etc.) in the scrap computers may seriously pollute the environment if they are not properly disposed of. Therefore, the EPA of Taiwan declared scrap personal computers the producer's recycling responsibility as of July 1997. Under this decree, the manufacturers, importers and sellers of personal computers have to properly recover and recycle the scrapped computers which they originally sell. On June 1, 1998, a producer responsibility recycling program for scrap computers was officially implemented in Taiwan. Under this program, consumers can bring their unwanted personal computers to the designated collection points and receive reward money. Currently, only six computer items are mandated to be recycled in this recycling program. They are notebooks, monitors, hard disks, power supplies, printed circuit boards and main frame shells. This article outlines the current scrap computer recycling system in Taiwan.

  11. One-Step Synthesis and Magnetic Phase Transformation of Ln-TM-B Alloy by Chemical Reduction.

    PubMed

    Kim, Chang Woo; Kim, Young Hwan; Cha, Hyun Gil; Lee, Don Keun; Kang, Young Soo

    2007-04-11

    Binary and ternary intermetallic alloy systems are of interest for a variety of academic and technological applications. Despite recent advances in synthesizing binary alloy, there are very few reports of ternary alloy related to lanthanide series. The purpose of this work is to contribute to ternary alloy systems such as lanthanide-transition metal-boron with a simple chemical method and analysis of its magnetic behavior. Ternary Nd-Fe-B amorphous alloy was successfully synthesized with borohydride. The magnetic behavior in the process of formation of ternary Nd-Fe-B alloy and Nd2Fe14B from amorphous phase alloy is reported. Compared with the synthesis of a transition metal, the existence of a lanthanide ion makes aggregates-like particles with a diameter of 2 nm possible in the formation of a nanosphere, which is a significantly important result in terms of acceleration of the reduction-diffusion reaction for the formation of ternary alloy. In the process of reduction and diffusion, the Nd phase is diffused into the Fe-based phase, and then the ternary Nd2Fe14B intermetallic compound is fabricated.

  12. Magnetic properties, microstructure and corrosion behavior of (Pr,nd)12.6Fe81.3B6.1-type sintered magnets doped with (Pr,nd)30Fe62Ga8

    NASA Astrophysics Data System (ADS)

    Ni, Junjie; Zhang, Zhenyu; Liu, Ying; Jia, Zhengfeng; Huang, Baoxu; Yin, Yibin

    2016-10-01

    NdFeB sintered magnets with (Pr,Nd)30Fe62Ga8 were prepared by a binary powder blending method and their magnetic properties, microstructure and corrosion behavior were investigated. Addition of 3 wt% (Pr,Nd)30Fe62Ga8 was found to be the most effective for improving (BH)max and iHc of the magnets. The increase in both magnetic parameters was related to the alteration in microstructure. However, in other samples the occurrence of micropore and the aggregation of intergranular phases harmed the magnetic properties. Such disadvantageous microstructure features also caused higher corrosion current density, thus decreasing the corrosion resistance of the sample with higher additive content. In addition, the Ga-containing intergranular phases that are more stable than the (Pr,Nd)-rich phase formed in the additive doped magnets, leading to better corrosion resistance of the 3 wt% additives doped sample in comparison with the contrastive sample.

  13. 7 CFR 29.3157 - Scrap (S Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.3157 Section 29.3157 Agriculture... INSPECTION Standards Grades § 29.3157 Scrap (S Group). A by-product of unstemmed and stemmed tobacco. Scrap... stemmeries. Grades Grade names and specifications S Scrap. Loose, tangled, whole, or broken unstemmed...

  14. 7 CFR 29.2441 - Scrap (S Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.2441 Section 29.2441 Agriculture... INSPECTION Standards Grades § 29.2441 Scrap (S Group). A byproduct of unstemmed and stemmed tobacco. Scrap... stemmeries. U.S. grade Grade name and specifications S Scrap. Tangled, whole, or broken unstemmed leaves,...

  15. 7 CFR 29.3652 - Scrap (S Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.3652 Section 29.3652 Agriculture... INSPECTION Standards Grades § 29.3652 Scrap (S Group). A byproduct of stemmed and unstemmed tobacco. Scrap... stemmeries. Grades Grade name and specifications S Scrap. Loose, tangled, whole, or broken unstemmed...

  16. 7 CFR 29.2666 - Scrap (S Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.2666 Section 29.2666 Agriculture... INSPECTION Standards Grades § 29.2666 Scrap (S Group). A byproduct of unstemmed and stemmed tobacco. Scrap... stemmeries. Grades Grade names and specifications S Scrap. Tangled, whole, or broken unstemmed leaves, or...

  17. 7 CFR 29.1169 - Scrap (S Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.1169 Section 29.1169 Agriculture... INSPECTION Standards Grades § 29.1169 Scrap (S Group). A byproduct of stemmed and unstemmed tobacco. Scrap... stemmeries. Grade, Grade Name and Specifications S—Scrap. Loose, whole, or broken unstemmed leaves; or...

  18. A study on the recycling of scrap integrated circuits by leaching.

    PubMed

    Lee, Ching-Hwa; Tang, Li-Wen; Popuri, Srinivasa R

    2011-07-01

    In order to minimize the problem of pollution and to conserve limited natural resources, a method to recover the valuable metals such as gold, silver and copper) present in the scrap integrated circuits (ICs) was developed in the present study. Roasting, grinding, screening, magnetic separation, melting and leaching were adopted to investigate the efficiency of recovery of gold, silver and copper from scrap ICs. The collected scrap IC samples were roasted at 850 °C to destroy their plastic resin sealing material, followed by screening and magnetic separation to separate the metals from the resin residue. The non-ferrous materials (0.840 mm) were mainly composed of copper and could be melted into a copper alloy. Non-ferrous materials containing gold (860.05 ppm), silver (1323.12 ppm) and copper (37259.7 ppm) (size less than 50 mesh) were recovered 100% by a leaching process and thiourea was used as a leaching reagent.

  19. Magnetic field simulation of wiggler on LUCX accelerator facility using Radia

    NASA Astrophysics Data System (ADS)

    Sutygina, Y. N.; Harisova, A. E.; Shkitov, D. A.

    2016-11-01

    A flat wiggler consisting of NdFeB permanent magnets was installed on a compact linear electron accelerator LUCX (KEK) in Japan. After installing the wiggler on LUCX, the experiments on the generation of undulator radiation (UR) in the terahertz wavelength range is planned. To perform the detailed calculations and optimization of UR characteristics, it is necessary to know the parameters of the magnetic field generated in the wiggler. In this paper extended simulation results of wiggler magnetic field over the entire volume between the poles are presented. The obtained in the Radia simulation magnetic field is compared with the field calculated by another code, which is based on the finite element method.

  20. Magnetic forces and magnetized biomaterials provide dynamic flux information during bone regeneration.

    PubMed

    Russo, Alessandro; Bianchi, Michele; Sartori, Maria; Parrilli, Annapaola; Panseri, Silvia; Ortolani, Alessandro; Sandri, Monica; Boi, Marco; Salter, Donald M; Maltarello, Maria Cristina; Giavaresi, Gianluca; Fini, Milena; Dediu, Valentin; Tampieri, Anna; Marcacci, Maurilio

    2016-03-01

    The fascinating prospect to direct tissue regeneration by magnetic activation has been recently explored. In this study we investigate the possibility to boost bone regeneration in an experimental defect in rabbit femoral condyle by combining static magnetic fields and magnetic biomaterials. NdFeB permanent magnets are implanted close to biomimetic collagen/hydroxyapatite resorbable scaffolds magnetized according to two different protocols . Permanent magnet only or non-magnetic scaffolds are used as controls. Bone tissue regeneration is evaluated at 12 weeks from surgery from a histological, histomorphometric and biomechanical point of view. The reorganization of the magnetized collagen fibers under the effect of the static magnetic field generated by the permanent magnet produces a highly-peculiar bone pattern, with highly-interconnected trabeculae orthogonally oriented with respect to the magnetic field lines. In contrast, only partial defect healing is achieved within the control groups. We ascribe the peculiar bone regeneration to the transfer of micro-environmental information, mediated by collagen fibrils magnetized by magnetic nanoparticles, under the effect of the static magnetic field. These results open new perspectives on the possibility to improve implant fixation and control the morphology and maturity of regenerated bone providing "in site" forces by synergically combining static magnetic fields and biomaterials.

  1. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    EPA Science Inventory

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  2. Management options for recycling radioactive scrap metals

    SciTech Connect

    Dehmel, J.C.; MacKinney, J.; Bartlett, J.

    1997-02-01

    The feasibility and advantages of recycling radioactive scrap metals (RSM) have yet to be assessed, given the unique technical, regulatory, safety, and cost-benefit issues that have already been raised by a concerned recycling industry. As is known, this industry has been repeatedly involved with the accidental recycling of radioactive sources and, in some cases, with costly consequences. If recycling were deemed to be a viable option, it might have to be implemented with regulatory monitoring and controls. Its implementation may have to consider various and complex issues and address the requirements and concerns of distinctly different industries. There are three basic options for the recycling of such scraps. They are: (1) recycling through the existing network of metal-scrap dealers and brokers, (2) recycling directly and only with specific steelmills, or (3) recycling through regional processing centers. Under the first option, scrap dealers and brokers would receive material from RSM generators and determine at which steelmills such scraps would be recycled. For the second option, RSM generators would deal directly with selected steelmills under specific agreements. For the third option, generators would ship scraps only to regional centers for processing and shipment to participating steelmills. This paper addresses the potential advantages of each option, identifies the types of arrangements that would need to be secured among all parties, and attempts to assess the receptivity of the recycling industry to each option.

  3. New avenues to efficient chemical synthesis of exchange coupled hard/soft nanocomposite magnet.

    PubMed

    Lee, Don Keun; Cha, Hyun Gil; Kim, Young Hwan; Kim, Chang Woo; Ji, Eun Sun; Kang, Young Soo

    2009-07-01

    Nd-Fe-B ultrafine amorphous alloy particles were prepared by reaction of metal ions with borohydride in aqueous solution. Monodispersed Fe nanoparticles were synthesized under an argon atmosphere via thermal decomposition of Fe(2+)-oleate2. Exchange coupled Nd2Fe14B/Fe nanocomposite magnets have been prepared by self-assembly using surfactant. The crystal structure of the synthesized nanoparticles was identified by using X-ray powder diffraction (XRD). The size and shape of nanoparticles were obtained by transmission electron microscope (TEM). Thermogravimetry using a microbalance with magnetic field gradient positioned below the sample was used for the measurement of a thermomagnetic analysis (TMA) curve showing the downward magnetic force versus temperature.

  4. Spherical, rolling magnet generators for passive energy harvesting from human motion

    NASA Astrophysics Data System (ADS)

    Bowers, Benjamin J.; Arnold, David P.

    2009-09-01

    In this work, non-resonant, vibrational energy harvester architectures intended for human-motion energy scavenging are researched. The basic design employs a spherical, unidirectionally magnetized permanent magnet (NdFeB) ball that is allowed to move arbitrarily in a spherical cavity wrapped with copper coil windings. As the ball rotates and translates within the cage, the time-varying magnetic flux induces a voltage in the coil according to Faraday's Law. Devices ranging from 1.5 cm3 to 4 cm3 in size were tested under human activity scenarios—held in the user's hand or placed in the user's pocket while walking (4 km h-1) and running (14.5 km h-1). These harvesters have demonstrated rms voltages ranging from ~80 mV to 700 mV and time-averaged power densities up to 0.5 mW cm-3.

  5. Note: Enhanced energy harvesting from low-frequency magnetic fields utilizing magneto-mechano-electric composite tuning-fork.

    PubMed

    Yang, Aichao; Li, Ping; Wen, Yumei; Yang, Chao; Wang, Decai; Zhang, Feng; Zhang, Jiajia

    2015-06-01

    A magnetic-field energy harvester using a low-frequency magneto-mechano-electric (MME) composite tuning-fork is proposed. This MME composite tuning-fork consists of a copper tuning fork with piezoelectric Pb(Zr(1-x)Ti(x))O3 (PZT) plates bonded near its fixed end and with NdFeB magnets attached at its free ends. Due to the resonance coupling between fork prongs, the MME composite tuning-fork owns strong vibration and high Q value. Experimental results show that the proposed magnetic-field energy harvester using the MME composite tuning-fork exhibits approximately 4 times larger maximum output voltage and 7.2 times higher maximum power than the conventional magnetic-field energy harvester using the MME composite cantilever.

  6. Tessellated permanent magnet circuits for flow-through, open gradient separations of weakly magnetic materials

    NASA Astrophysics Data System (ADS)

    Moore, Lee R.; Williams, P. Stephen; Chalmers, Jeffrey J.; Zborowski, Maciej

    2017-04-01

    Emerging microfluidic-based cell assays favor label-free red blood cell (RBC) depletion. Magnetic separation of RBC is possible because of the paramagnetism of deoxygenated hemoglobin but the process is slow for open-gradient field configurations. In order to increase the throughput, periodic arrangements of the unit magnets were considered, consisting of commercially available Nd-Fe-B permanent magnets and soft steel flux return pieces. The magnet design is uniquely suitable for multiplexing by magnet tessellation, here meaning the tiling of the magnet assembly cross-sectional plane by periodic repetition of the magnet and the flow channel shapes. The periodic pattern of magnet magnetizations allows a reduction of the magnetic material per channel with minimal distortion of the field cylindrical symmetry inside the magnet apertures. A number of such magnet patterns are investigated for separator performance, size and economy with the goal of designing an open-gradient magnetic separator capable of reducing the RBC number concentration a hundred-fold in 1 mL whole blood per hour.

  7. Rare-earth free permanent magnets and permanent magnet synchronous motors

    NASA Astrophysics Data System (ADS)

    Park, Jihoon

    In this dissertation, basic and applied research programs are engaged that range from the fundamental magnetism and magnetic properties of ferro- and ferrimagnetic materials to the design and fabrication of rare earth (RE) free permanent and soft magnetic materials for an interior permanent magnet synchronous motor (IPMSM) (i.e., motor for electric vehicles and plug-in electric vehicles) and heat assisted magnetic recording media (HAMR) with 4 Tb/in 2 information storage applications. The applied research program emphasizes the design and synthesis of new RE-free permanent magnetic materials and magnetic exchange coupled core(hard)-shell(soft) particles to achieve a high maximum energy product [(BH) max], and the design of an advanced IPMSM based on RE free permanent magnets. The electronic structures of hard magnetic materials such as Mn-Al, Mn-Bi, Mn-Bi-X, Fe-Pt, Fe-Pt-X, SrFe12O19, and SrFe12 O19-X (X = transition elements) and soft magnetic materials such as nanocrystalline and Mn-B were calculated based on the density functional theory (DFT), and their exchange coupled magnetic properties with soft magnets were designed according to the size and shape of the particles. The calculated magnetic and electronic properties were used to obtain the temperature dependence of saturation magnetization Ms(T) and anisotropy constant K(T) within the mean field theory. Thereby, the temperature dependence of the maximum energy product [(BH)max(T)] is calculated using the calculated Ms(T) and K(T). The experimental approaches were based on chemical and ceramic processes to synthesize hard and soft magnetic materials. Prior to synthesis, material design parameters were optimized by first-principles calculations and micromagnetic simulations. Lastly, performance of RE-free MnAl, MnBi, SrFe12O19 , and Alnico IPMSMs, designed with the finite element method (FEM), at 23 and 200 °C were evaluated and compared to a RE Nd Fe B IPMSM. The performance parameters include torque

  8. The Production and Characterization of Near Stoichiometric NdFeB-Type HDDR Powder

    SciTech Connect

    Shaaban, A.

    2010-03-11

    A study of the processing of HDDR powder with the composition Nd{sub 12.7}Fe{sub 81.3}B{sub 6.0} and Nd{sub 12.2}Fe{sub 81.2}B{sub 5.9}Zr{sub 0.1} have been undertaken. The homogenized alloys were disproportionated at 850 deg. C for 30 minutes and employing a range of recombination temperatures from 790 deg. C to 920 deg. C. The optimum recombination temperature in the HDDR treatment was found to be 880 deg. C. Zr-addition appears to inhibit grain growth during the treatment process.

  9. The Production and Characterization of Near Stoichiometric NdFeB-Type HDDR Powder

    NASA Astrophysics Data System (ADS)

    Shaaban, A.

    2010-03-01

    A study of the processing of HDDR powder with the composition Nd12.7Fe81.3B6.0 and Nd12.2Fe81.2B5.9Zr0.1 have been undertaken. The homogenized alloys were disproportionated at 850° C for 30 minutes and employing a range of recombination temperatures from 790° C to 920° C. The optimum recombination temperature in the HDDR treatment was found to be 880° C. Zr-addition appears to inhibit grain growth during the treatment process.

  10. Monitoring fluid evolution in an Engineered Barrier System using NEO-magnets

    NASA Astrophysics Data System (ADS)

    Rigonat, N.; Butler, I. B.

    2015-12-01

    Long-term monitoring of the evolution of the engineered barrier system (EBS) of a Geological Disposal Facility (GDF) is important for establishing the safety case for deep disposal of the UK inventory of high level radioactive waste. With a view to developing techniques for remote fluid monitoring using magnetic properties, we have examined the correlation between the corrosion properties of NEO-magnets and related changes in the magnetic properties of the alloy with fluid chemistry and crystal-chemical changes of the Na-bentonite matrix. Batch experiments comprised fragments of NEO-magnets with deionised water, saline and alkaline solution both in the presence and absence of MX-80 bentonite, and were performed in sealed vessels for durations of up to 5 months at 70°C. This study combined PXRD, thermomagnetic and hysteresis analysis to demonstrate how progressive hydrogenation of the main magnetic phase led to a maximum loss of remanence and coercitivity and increasing Curie temperature in the samples reacted with deionised water with the samples reacted in saline and alkaline solutions showing smaller changes. Semi-quantitative analysis allowed comparison of the Curie temperatures with crystal-chemical parameters. This reveals a clear positive correlation of increasing lattice parameters a and c (and cell volume) with mean hydrogens per unit formula and the Curie temperature of the product NdFeB hydrides. Precipitation of Nd and Fe hydrides/oxyhydroxides is also demonstated by the PXRD data. A crucial role is played by the transformations occurring to the smectite matrix, in particular by the cation exchange in the interlayer, which causes precipitation of highly charged K- and Ca-smectites. This study demonstrates how NEO-magnets are capable of detecting water saturation in the EBS, and that the NdFeB corrosion properties are strongly controlled by the initial fluid composition and presence / absence of the bentonite matrix.

  11. Life on magnets: stem cell networking on micro-magnet arrays.

    PubMed

    Zablotskii, Vitalii; Dejneka, Alexandr; Kubinová, Šárka; Le-Roy, Damien; Dumas-Bouchiat, Frédéric; Givord, Dominique; Dempsey, Nora M; Syková, Eva

    2013-01-01

    Interactions between a micro-magnet array and living cells may guide the establishment of cell networks due to the cellular response to a magnetic field. To manipulate mesenchymal stem cells free of magnetic nanoparticles by a high magnetic field gradient, we used high quality micro-patterned NdFeB films around which the stray field's value and direction drastically change across the cell body. Such micro-magnet arrays coated with parylene produce high magnetic field gradients that affect the cells in two main ways: i) causing cell migration and adherence to a covered magnetic surface and ii) elongating the cells in the directions parallel to the edges of the micro-magnet. To explain these effects, three putative mechanisms that incorporate both physical and biological factors influencing the cells are suggested. It is shown that the static high magnetic field gradient generated by the micro-magnet arrays are capable of assisting cell migration to those areas with the strongest magnetic field gradient, thereby allowing the build up of tunable interconnected stem cell networks, which is an elegant route for tissue engineering and regenerative medicine.

  12. Development of hybrid bearing system with thrust superconducting magnetic bearing and radial active electromagnetic bearing

    NASA Astrophysics Data System (ADS)

    Nicolsky, R.; Pereira, A. S.; de Andrade, R.; David, D. F. B.; Santisteban, J. A.; Stephan, R. M.; Ripper, A.; Gawalek, W.; Habisreuther, T.; Strasser, T.

    A superconducting/electromagnetic hybrid bearing system is currently under development and test. This system consists of a thrust superconducting magnetic bearing and a double radial active electromagnetic bearing/motor devices. The thrust bearing has been designed using NdFeB permanent magnets levitating on a set of superconducting monoliths of YBCO, prepared by top seeded melt texturing technique, which supports the weight of the rotor. The bearing/motor devices were conceived as 4-pole 2-phase induction machine using stator windings for delivering torque and radial positioning simultaneously. Using this superconducting axial bearing and the active bearings for the rotor radial positioning, a fully levitating vertical-shaft inductive machine has been tested. The tests were successful in reaching a controlled levitation up to 6,300 rpm.

  13. Electroextraction of boron from boron carbide scrap

    SciTech Connect

    Jain, Ashish; Anthonysamy, S.; Ghosh, C.; Ravindran, T.R.; Divakar, R.; Mohandas, E.

    2013-10-15

    Studies were carried out to extract elemental boron from boron carbide scrap. The physicochemical nature of boron obtained through this process was examined by characterizing its chemical purity, specific surface area, size distribution of particles and X-ray crystallite size. The microstructural characteristics of the extracted boron powder were analyzed by using scanning electron microscopy and transmission electron microscopy. Raman spectroscopic examination of boron powder was also carried out to determine its crystalline form. Oxygen and carbon were found to be the major impurities in boron. Boron powder of purity ∼ 92 wt. % could be produced by the electroextraction process developed in this study. Optimized method could be used for the recovery of enriched boron ({sup 10}B > 20 at. %) from boron carbide scrap generated during the production of boron carbide. - Highlights: • Recovery of {sup 10}B from nuclear grade boron carbide scrap • Development of process flow sheet • Physicochemical characterization of electroextracted boron • Microscopic examination of electroextracted boron.

  14. Characterization of shredded television scrap and implications for materials recovery.

    PubMed

    Cui, Jirang; Forssberg, Eric

    2007-01-01

    Characterization of TV scrap was carried out by using a variety of methods, such as chemical analysis, particle size and shape analysis, liberation degree analysis, thermogravimetric analysis, sink-float test, and IR spectrometry. A comparison of TV scrap, personal computer scrap, and printed circuit board scrap shows that the content of non-ferrous metals and precious metals in TV scrap is much lower than that in personal computer scrap or printed circuit board scrap. It is expected that recycling of TV scrap will not be cost-effective by utilizing conventional manual disassembly. The result of particle shape analysis indicates that the non-ferrous metal particles in TV scrap formed as a variety of shapes; it is much more heterogeneous than that of plastics and printed circuit boards. Furthermore, the separability of TV scrap using density-based techniques was evaluated by the sink-float test. The result demonstrates that a high recovery of copper could be obtained by using an effective gravity separation process. Identification of plastics shows that the major plastic in TV scrap is high impact polystyrene. Gravity separation of plastics may encounter some challenges in separation of plastics from TV scrap because of specific density variations.

  15. The Scrap Map: An Environmental Publication for Grades K-6.

    ERIC Educational Resources Information Center

    Institute of Scrap Recycling Industries, Inc., Washington, DC.

    This document contains materials for a 10-day teaching unit on solid waste recycling for grades K-6. Included are: (1) "The Scrap Map," which shows recycling cycles for metals and paper, and a cryptic word puzzle; (2) three pamphlets on recycling paper, nonferrous scrap metals, and scrap iron and steel; (3) a list of the chapters of the Institute…

  16. 48 CFR 245.607-70 - Scrap warranty.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... not made directly with the Government. (d) If the scrap is resold to a second buyer, the first buyer shall obtain a scrap warranty from the second buyer. Upon receipt of the second buyer's scrap warranty, the Government will release the first buyer from liability under the original warranty....

  17. 7 CFR 29.6131 - Scrap (S Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.6131 Section 29.6131 Agriculture... INSPECTION Standards Grades § 29.6131 Scrap (S Group). A byproduct of unstemmed and stemmed tobacco. Scrap... stemmeries. U.S. grades Grade names and specifications S Loose, tangled, whole, or broken unstemmed...

  18. 49 CFR 173.218 - Fish meal or fish scrap.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Fish meal or fish scrap. 173.218 Section 173.218... Fish meal or fish scrap. (a) Except as provided in Column (7) of the HMT in § 172.101 of this subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized...

  19. Permanent magnet electron beam ion source/trap systems with bakeable magnets for improved operation conditions.

    PubMed

    Schmidt, M; Zschornack, G; Kentsch, U; Ritter, E

    2014-02-01

    The magnetic system of a Dresden electron beam ion source (EBIS) generating the necessary magnetic field with a new type of permanent magnet made of high energy density NdFeB-type material operable at temperatures above 100 °C has been investigated and tested. The employment of such kind of magnets provides simplified operation without the time-consuming installation and de-installation procedures of the magnets for the necessary baking of the ion source after commissioning and maintenance work. Furthermore, with the use of a new magnetization technique the geometrical filling factor of the magnetic Dresden EBIS design could be increased to a filling factor of 100% leading to an axial magnetic field strength of approximately 0.5 T exceeding the old design by 20%. Simulations using the finite element method software Field Precision and their results compared with measurements are presented as well. It could be shown that several baking cycles at temperatures higher than 100 °C did not change the magnetic properties of the setup.

  20. Permanent magnet electron beam ion source/trap systems with bakeable magnets for improved operation conditions

    SciTech Connect

    Schmidt, M.; Zschornack, G.; Kentsch, U.; Ritter, E.

    2014-02-15

    The magnetic system of a Dresden electron beam ion source (EBIS) generating the necessary magnetic field with a new type of permanent magnet made of high energy density NdFeB-type material operable at temperatures above 100 °C has been investigated and tested. The employment of such kind of magnets provides simplified operation without the time-consuming installation and de-installation procedures of the magnets for the necessary baking of the ion source after commissioning and maintenance work. Furthermore, with the use of a new magnetization technique the geometrical filling factor of the magnetic Dresden EBIS design could be increased to a filling factor of 100% leading to an axial magnetic field strength of approximately 0.5 T exceeding the old design by 20%. Simulations using the finite element method software Field Precision and their results compared with measurements are presented as well. It could be shown that several baking cycles at temperatures higher than 100 °C did not change the magnetic properties of the setup.

  1. China’s Rare Earth Policies: Economic Statecraft or Interdependence?

    DTIC Science & Technology

    2012-12-01

    Ministry of Land and Resources MOC Ministry of Commerce NdFeB Neodymium Iron Boron NDRC National Development and Reform...SmCo) and neodymium iron boron (NdFeB). NdFeB magnets, known to be the world’s strongest permanent magnets, monopolize rare earth magnet usage in...that there will likely be shortages of other light rare earths and many heavy rare earths (i.e., dysprosium, terbium, neodymium , europium and erbium

  2. The continuing problem of radioactive metal scrap

    SciTech Connect

    Yusko, J.G.; Lubenau, J.O.

    1995-12-31

    Metal scrap found to contain radioactive materials continues to challenge regulatory agencies as discoveries of this unwanted constituent increase. And while efforts are made to prevent the exposure of personnel at metal manufacturing mills and scrap yards when radioactivity is discovered in a shipment of metal scrap, this has not stemmed the number of discoveries. Sources and devices continue to be found, leading to difficulties in the disposal of the radioactive materials, especially with the closure of licensed LLRW facilities to non-compact state members. Naturally-occurring radioactive materials continue to be found, principally as surface contaminants of metals for recycling. And although NORM contamination does not generally pose a threat to the health and safety of personnel at metal mills and scrap yards, there is no consensus about the disposition of NORM-contaminated metal. The changing of trade barriers (such as the North American Free Trade Agreement) also factors into the problem, as materials cross international boundaries and enter the recycling stream. The efforts of entities such as Conference committees, federal regulatory agencies (e.g., NRC, EPA, DOT), state radiation control agencies and the affected industries will be presented and discussed.

  3. Catalytic extraction processing of contaminated scrap metal

    SciTech Connect

    Griffin, T.P.; Johnston, J.E.

    1994-12-31

    The contract was conceived to establish the commercial capability of Catalytic Extraction Processing (CEP) to treat contaminated scrap metal in the DOE inventory. In so doing, Molten Metal Technology, Inc. (MMT), pursued the following objectives: demonstration of the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal can be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP will concentrate the radionuclides in a dense vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP will convert hazardous organics to valuable industrial gases, which can be used as feed gases for chemical synthesis or as an energy source; recovery volatile heavy metals--that CEP`s off-gas treatment system will capture volatile heavy metals, such as mercury and lead; and establish that CEP is economical for processing contaminated scrap metal in the DOE inventory--that CEP is a more cost-effective and, complete treatment and recycling technology than competing technologies for processing contaminated scrap. The process and its performance are described.

  4. EMISSIONS FROM BURNING CABINET MAKING SCRAPS

    EPA Science Inventory

    The report gives results of an initial determination of differences in missions when burning ordinary cordwood compared to kitchen cabinet making scraps. he tests were performed in an instrumented woodstove testing laboratory on a stove that simulated units observed in use at a k...

  5. Vitrification for stability of scrap and residue

    SciTech Connect

    Forsberg, C.W.

    1996-05-01

    A conference breakout discussion was held on the subject of vitrification for stabilization of plutonium scrap and residue. This was one of four such sessions held within the vitrification workshop for participants to discuss specific subjects in further detail. The questions and issues were defined by the participants.

  6. Changes in the topography of cellular components in pea root statocytes exposed to high gradient magnetic fields

    NASA Astrophysics Data System (ADS)

    Belyavskaya, Ninel A.; Polishchuk, Olexandr V.; Kondrachuk, Alexander V.

    2005-08-01

    High-gradient magnetic field (HGMF) is one of methods, by which gravitropism in plants is studied. The aim of our study was elucidation of HGMF effects on topography of cellular components in root statocytes of 4- day Pisum sativum L. seedlings in comparison to gravistimulation. Under gravistimulation during 5, 30 and 60 min seedlings were rotated 45o; magnetostimulation was carried out along gap between two NdFeB magnets (0.7 T). Morphometric measurements were made from images of whole statocytes, for upper, middle and lower thirds of cells, and proximal and distal halves of cells. Morphometric analysis revealed that HGMF resulted in the redistribution of all cellular components in statocytes. The correlation in the amyloplast distribution between gravistimulation and magnetostimulation was established.

  7. Influence of a large amount of Co substitution on the magnetic properties of NdFeCoGaB magnets (abstract)

    NASA Astrophysics Data System (ADS)

    Tsutai, A.; Sakai, I.; Sahashi, M.; Inomata, K.

    1990-05-01

    We have found that a NdFeCoGaB sintered magnet containing 30 at. % Co still shows high coercive force in spite of such a large amount of Co substitution. The Curie temperature of the magnet is higher than that of the ternary NdFeB magnet by 280 °C. As a result, the following magnetic properties have been attained for Nd14.5Fe46Co30Ga1B8.5: Tc=590 °C, Br =11.7 kG, Hci =14.3 kOe, and (BH)max=32 MG Oe. Furthermore, in this magnet there exists an additional phase, Nd1(FeCoGa)4B1 with Ce1Co4B1 structure, which, as far as authors know, has not been reported to exist in the NdFeB-based magnets. In this study we investigated the magnetic properties and microstructure of Nd14.5Fe76-xCoxGa1B8.5 (x=16-50) sintered magnets. The high coercive force can be obtained in the Co-content region from 16 to 30 at. %. In particular, the magnet with 30 at. % Co shows coercive force as high as 14.3 kOe. However, further substitution of Co drastically deteriorates the magnetic properties. The coercive force of the magnet with 50 at. % Co is less than 1 kOe. From the metallographical point of view, the above-mentioned Nd1(FeCoGa)4B1 phase is not observed in the magnets containing less than 30 at. % Co. This phase abruptly appears in the magnet with 30 at. % Co and its amount increases with increasing Co content. The strongest x-ray-diffraction peak observed in the magnet with 50 at. % Co comes from the Nd1(FeCoGa)4B1 phase. The demagnetization-curve measurements suggest that reverse magnetic domains are nucleated in the Nd1(FeCoGa)4B1 phase at a low reverse magnetic field. It is noteworthy that the magnet with 30 at. % Co maintains the high coercive force in spite of the existence of such a soft magnetic phase. Details will be discussed in the coming session.

  8. Using magnetic levitation to distinguish atomic-level differences in chemical composition of polymers, and to monitor chemical reactions on solid supports.

    PubMed

    Mirica, Katherine A; Phillips, Scott T; Shevkoplyas, Sergey S; Whitesides, George M

    2008-12-31

    This communication describes a density-based method that uses magnetic levitation for monitoring solid-supported reactions and for distinguishing differences in chemical composition of polymers. The method is simple, rapid, and inexpensive and is similar to thin-layer chromatography (TLC; for solution-phase chemistry) in its potential for monitoring reactions in solid-phase chemistry. The technique involves levitating a sample of beads (taken from a reaction mixture) in a cuvette containing a paramagnetic solution (e.g., GdCl(3) dissolved in H(2)O) positioned between two NdFeB magnets. The vertical position at which the beads levitate corresponds to the density of the beads and correlates with the progress of a chemical reaction on a solid support. The method is particularly useful for monitoring the kinetics of reactions occurring on polymer beads.

  9. Evaluation of radioactive scrap metal recycling

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

    1995-12-01

    This report evaluates the human health risks and environmental and socio-political impacts of options for recycling radioactive scrap metal (RSM) or disposing of and replacing it. Argonne National Laboratory (ANL) is assisting the US Department of Energy (DOE), Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, in assessing the implications of RSM management alternatives. This study is intended to support the DOE contribution to a study of metal recycling being conducted by the Task Group on Recycling and Reuse of the Organization for Economic Cooperation and Development. The focus is on evaluating the justification for the practice of recycling RSM, and the case of iron and steel scrap is used as an example in assessing the impacts. To conduct the evaluation, a considerable set of data was compiled and developed. Much of this information is included in this document to provide a source book of information.

  10. Lincoln Co. Scrap Metal, Crab Orchard, Kentucky

    EPA Pesticide Factsheets

    The City of Crab Orchard, KY (population less than 1,000) received a $200,000 EPA Brownfields cleanup grant in 2010 to cleanup up the Lincoln County ScrapMetal property. The site, a former scrap metal recycler and general junkyard, was located in the middle of downtown. The city has experienced a dramatic decline in growth over the past few years. The abandoned two-acre site is located in the city’s center, directly across the street from City Hall. It is the largest property on Main Street. The property was an eyesore, and posed potential health risks to area residents, and deterred investment. Its blighted status did little to help the commercial and private properties that surround it. The site was also home to a dilapidated building that once served as the Odd Fellows meeting hall.

  11. Radioactivity in the scrap metal industry

    SciTech Connect

    Cox, J.

    1997-12-31

    This paper discusses problems from the presence of radiation in scrap metal. The source of the radiation is typically radiography cameras, radiation therapy machines, radioactive gauge devices, transportation containers, or NORM scale on equipment from the minerals industry. Since 1983 there have been 46 reported cases of radioactive contamination of metal production facilities. The resulting decontamination, disposal, and downtime has cost some companies over 20 million dollars. The activity normally enters mills with the scrap feed metal. In the process of melting it can then contaminate the metal products, melt shop equipment, baghouse, employees, and environment. The paper discusses the sources of this contamination, the typical detection methods, the problems in detection, the issues of responsibility after detection, the health risks, and practical and regulatory differences between radioactivity from sources vs NORM.

  12. Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

    NASA Astrophysics Data System (ADS)

    Katebi, Samira; Esmaeili, Abolghasem; Ghaedi, Kamran

    2016-03-01

    Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer.

  13. Process for removing cadmium from scrap metal

    SciTech Connect

    Kronberg, J.W.

    1994-01-01

    A process for the recovery of a metal, in particular, cadmium contained in scrap, in a stable form. The process comprises the steps of mixing the cadmium-containing scrap with an ammonium carbonate solution, preferably at least a stoichiometric amount of ammonium carbonate, and/or free ammonia, and an oxidizing agent to form a first mixture so that the cadmium will react with the ammonium carbonate to form a water-soluble ammine complex; evaporating the first mixture so that ammine complex dissociates from the first mixture leaving carbonate ions to react with the cadmium and form a second mixture that includes cadmium carbonate; optionally adding water to the second mixture to form a third mixture; adjusting the pH of the third mixture to the acid range whereby the cadmium carbonate will dissolve; and adding at least a stoichiometric amount of sulfide, preferably in the form of hydrogen sulfide or an aqueous ammonium sulfide solution, to the third mixture to precipitate cadmium sulfide. This mixture of sulfide is then preferably digested by heating to facilitate precipitation of large particles of cadmium sulfide. The scrap may be divided by shredding or breaking up to exposure additional surface area. Finally, the precipitated cadmium sulfide can be mixed with glass formers and vitrified for permanent disposal.

  14. Process for removing cadmium from scrap metal

    DOEpatents

    Kronberg, J.W.

    1995-04-11

    A process is described for the recovery of a metal, in particular, cadmium contained in scrap, in a stable form. The process comprises the steps of mixing the cadmium-containing scrap with an ammonium carbonate solution, preferably at least a stoichiometric amount of ammonium carbonate, and/or free ammonia, and an oxidizing agent to form a first mixture so that the cadmium will react with the ammonium carbonate to form a water-soluble ammine complex; evaporating the first mixture so that ammine complex dissociates from the first mixture leaving carbonate ions to react with the cadmium and form a second mixture that includes cadmium carbonate; optionally adding water to the second mixture to form a third mixture; adjusting the pH of the third mixture to the acid range whereby the cadmium carbonate will dissolve; and adding at least a stoichiometric amount of sulfide, preferably in the form of hydrogen sulfide or an aqueous ammonium sulfide solution, to the third mixture to precipitate cadmium sulfide. This mixture of sulfide is then preferably digested by heating to facilitate precipitation of large particles of cadmium sulfide. The scrap may be divided by shredding or breaking up to expose additional surface area. Finally, the precipitated cadmium sulfide can be mixed with glass formers and vitrified for permanent disposal. 2 figures.

  15. Study on characteristics of high temperature superconducting magnetic thrust bearing for 25 kW h flywheel

    NASA Astrophysics Data System (ADS)

    Nagaya, S.; Kashima, N.; Minami, M.; Kawashima, H.; Unisuga, S.; Kakiuchi, Y.; Ishigaki, H.

    2001-09-01

    An axial air gap type thrust bearing of the outer diameter of 620 mm for 25 kW h flywheel which combined with the permanent magnet of Nd-Fe-B and 10 pieces of high temperature YBaCuO superconductors of the diameter of 150 mm directly cooled by the refrigerator was fabricated, and its performance tests were conducted. Load capacity which could support a planned rotor weight of 8.2 kN was confirmed, and also the stiffness of the radial direction and the axial direction were measured in case of several initial cooling conditions. Spring and damping coefficients in zero field cooling were also measured in the tapping test, and it was found that axial spring coefficients were about 10 times as large as radial spring coefficients, though damping coefficients were almost the same.

  16. Uniform magnetization reversal in dual main-phase (Ce,Nd)2Fe14B sintered magnets with inhomogeneous microstructure

    NASA Astrophysics Data System (ADS)

    Zhang, Le-le; Li, Zhu-bai; Zhang, Xue-feng; Ma, Qiang; Liu, Yan-li; Li, Yong-feng; Zhao, Qian

    2017-02-01

    The element distribution and the magnetic properties were investigated in (Ce,Nd)-Fe-B sintered magnets prepared by mixing Nd13.5Fe80B6.5 and Ce9Nd4.5Fe80B6.5 powders with different mass ratios. Two main phases exist, but element diffusion is evident, and the chemical composition of the main phase is widely different from that of the master alloy. The Ce element tends to be expelled from the Ce-rich Re2Fe14B phase. Compared with the Ce-rich main phase, the Nd-rich Re2Fe14B phase is more stable in structure. Although the microstructure is inhomogeneous and the magnetocrystalline anisotropy is variable, the magnetization reversal is uniform in these dual main-phase magnets, which should ascribe to the existence of the exchange coupling, and magnetization reversal undergoes the nucleation of the reversed domain in irreversible magnetization. It is expected to further improve the coercivity by optimizing the distribution of the Nd-rich main phase in preparing the resource-saving (Ce,Nd)2Fe14B sintered magnets.

  17. The influence of low temperature on gamma-ray irradiated permanent magnets.

    PubMed

    Han, Young Chul; Cha, Hyun Gil; Kim, Chang Woo; Ji, Eun Sun; Kim, Young Hwan; Kang, Dong In; Kang, Young Soo

    2009-12-01

    The temperature effect on the magnetic property of gamma-ray irradiated Nd-Fe-B and Sr-Ferrite magnets has been investigated. When the permanent magnets are exposed to gamma-ray, it's magnetic and other related properties are declined with degree of dose. The decreased magnetic property by gamma-ray irradiation at low temperature is similar with the result of magnet at high temperature. The temperature effect on the gamma-ray irradiation at exposed moment is also regarded as one of the important parameters for the reduced magnetic properties. The gamma-irradiation at low temperature was carried out at 195 K, and the changed properties of two kinds of magnets before and after gamma-irradiation were comparatively studied. The increased demagnetization of the magnets were studied by Hall probe. And changed Curie temperature and micro-crystal structure of each permanent magnet by gamma-ray irradiation has been also studied. Moreover the strong and broad single line shape of ESR signal in the resonance magnetic field is attributed to unpaired electron of Fe2+ in the sample by the effect of gamma-ray irradiation.

  18. Economic feasibility of radioactive scrap steel recycling

    SciTech Connect

    Balhiser, R.; Rosholt, D.; Nichols, F.

    1995-12-31

    The goal of MSE`s Radioactive Scrap Steel (RSS) Recycle Program is to develop practical methods for recycling RSS into useful product. This paper provides interim information about ongoing feasibility investigations that are scheduled for completion by September 1995. The project approach, major issues, and cost projections are outlined. Current information indicates that a cost effective RSS Recycling Facility can be designed, built, and in operation by 1999. The RSS team believes that high quality steel plate can be made from RSS at a conversion cost of $1500 per ton or less.

  19. Magnetic separation of general solid particles realised by a permanent magnet

    NASA Astrophysics Data System (ADS)

    Hisayoshi, K.; Uyeda, C.; Terada, K.

    2016-12-01

    Most existing solids are categorised as diamagnetic or weak paramagnetic materials. The possibility of magnetic motion has not been intensively considered for these materials. Here, we demonstrate for the first time that ensembles of heterogeneous particles (diamagnetic bismuth, diamond and graphite particles, as well as two paramagnetic olivines) can be dynamically separated into five fractions by the low field produced by neodymium (NdFeB) magnets during short-duration microgravity (μg). This result is in contrast to the generally accepted notion that ordinary solid materials are magnetically inert. The materials of the separated particles are identified by their magnetic susceptibility (χ), which is determined from the translating velocity. The potential of this approach as an analytical technique is comparable to that of chromatography separation because the extraction of new solid phases from a heterogeneous grain ensemble will lead to important discoveries about inorganic materials. The method is applicable for the separation of the precious samples such as lunar soils and/or the Hayabusa particles recovered from the asteroids, because even micron-order grains can be thoroughly separated without sample-loss.

  20. Magnetic separation of general solid particles realised by a permanent magnet

    PubMed Central

    Hisayoshi, K.; Uyeda, C.; Terada, K.

    2016-01-01

    Most existing solids are categorised as diamagnetic or weak paramagnetic materials. The possibility of magnetic motion has not been intensively considered for these materials. Here, we demonstrate for the first time that ensembles of heterogeneous particles (diamagnetic bismuth, diamond and graphite particles, as well as two paramagnetic olivines) can be dynamically separated into five fractions by the low field produced by neodymium (NdFeB) magnets during short-duration microgravity (μg). This result is in contrast to the generally accepted notion that ordinary solid materials are magnetically inert. The materials of the separated particles are identified by their magnetic susceptibility (χ), which is determined from the translating velocity. The potential of this approach as an analytical technique is comparable to that of chromatography separation because the extraction of new solid phases from a heterogeneous grain ensemble will lead to important discoveries about inorganic materials. The method is applicable for the separation of the precious samples such as lunar soils and/or the Hayabusa particles recovered from the asteroids, because even micron-order grains can be thoroughly separated without sample-loss. PMID:27929081

  1. 46 CFR Sec. 12 - Disposition of removed equipment and scrap.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Disposition of removed equipment and scrap. Sec. 12... CONTRACT-NSA-LUMPSUMREP Sec. 12 Disposition of removed equipment and scrap. (a) Article 8 of the NSA-LUMPSUMREP Contract provides that any ship equipment, fuel, lube oil, supplies, stores, furniture,...

  2. 91. VIEW NORTHWEST OF SCRAP HOUSE AND CAST HOUSE, BUILDINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. VIEW NORTHWEST OF SCRAP HOUSE AND CAST HOUSE, BUILDINGS 101 AND 72; BUILDING 101 IN THE CENTER OF THE PHOTOGRAPH HOUSED SCRAP METAL CLEANING AND PROCESSING FACILITIES; BUILDING 72 AT RIGHT CENTER HOUSED MELTING FURNACES AND CONTINUOUS CASTING MACHINERY - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

  3. Alternatives to Rare Earth Permanent Magnets for Energy Harvesting Applications

    NASA Astrophysics Data System (ADS)

    Khazdozian, Helena; Hadimani, Ravi; Jiles, David

    Direct-drive permanent magnet generators (DDPMGs) offer increased reliability and efficiency over the more commonly used geared doubly-fed induction generator, yet are only employed in less than 1 percent of utility scale wind turbines in the U.S. One major barrier to increased deployment of DDPMGs in the U.S. wind industry is NdFeB permanent magnets (PMs), which contain critical rare earth elements Nd and Dy. To allow for the use of rare earth free PMs, the magnetic loading, defined as the average magnetic flux density over the rotor surface, must be maintained. Halbach cylinders are employed in 3.5kW Halbach PMGs (HPMGs) of varying slot-to-pole ratio to concentrate the magnetic flux output by a lower energy density PM over the rotor surface. We found that for high pole and slot number, the increase in magnetic loading is sufficient to allow for the use of strontium iron oxide hard ferrite PMs and achieved rated performance. Joule losses in the stator windings were found to increase for the hard ferrite PMs due to increased inductance in the stator windings. However, for scaling of the HPMG designs to 3MW, rated performance and high efficiency were achieved, demonstrating the potential for elimination for rare earth PMs in commercial scale wind turbines. This work was supported by the National Science Foundation under Grant No. 1069283 and a Barbara and James Palmer Endowment at Iowa State University.

  4. MAGNETIC STRUCTURE AND MAGNETIC IMAGING OF RE{sub 2}Fe{sub 14}B (RE=Nd,Pr) PERMANENT MAGNETS

    SciTech Connect

    ZHU,Y.; VOLKOV,V.V.

    2000-04-20

    This chapter aims to review the magnetic structures observed in the RE{sub 2}Fe{sub 14}B (RE = Nd, Pr) system using various TEM magnetic imaging techniques. The authors focus on studies of die-upset Nd-based permanent magnets conducted mainly at Brookhaven National Laboratory in the past several years. Investigations on Nd-Fe-B sintered magnets and single crystals, as well as Pr-Fe-B die-upset magnets also will be covered. In Sec.2 and Sec.3 they review the microstructure, including grain alignment and secondary phases of the materials, and grain boundary structure and composition of the intergranular phase. Sec.4 is devoted to the domain structure, such as the width of domain and domain wall and domain-wall energy. Monte Carlo simulation of the effects of demagnetization fields will be presented in Sec.5. In-situ experiments on the dynamic behavior of domain reorientation as a function of temperature, pinning, grain boundary nucleation related to coercivity under various fields are described in Sec.6. Finally, in Sec.7 the correlation between microstructure and properties are discussed.

  5. Economic feasibility of recycling radioactive scrap steel

    SciTech Connect

    Balhiser, B.C.; Rosholt, D.L.; Nichols, F.A.

    1995-12-31

    Radioactive scrap metal has traditionally been disposed of by burial in low-level waste repositories, an option that will become increasingly unattractive if burial costs rise as projected. This paper will examine recycling opportunities that may arise from two divergent economic trends: (1) escalating burial costs, and (2) historically flat product costs from state-of-the-art metal recycle operations. Emphasis will be placed on recycling the radioactive scrap steel (RSS) that will arise from D&D of Government and commercial nuclear facilities in the western United States. An effort is underway to compare processes for recycling RSS at least cost to the generator, least impact to the environment, and minimum worker exposure to radionuclide hazards. An experienced industry team with expertise in radioactive metals recycling, commercial steel recycling, and state-of-the-art metal recycle facilities design has been assembled under subcontract for this purpose. Methods for evaluating process options to arrive at an optimized solution will be discussed in the paper. An analysis of burial versus recycle costs for RSS will also be presented.

  6. High temperature superconducting axial field magnetic coupler: realization and test

    NASA Astrophysics Data System (ADS)

    Belguerras, L.; Mezani, S.; Lubin, T.; Lévêque, J.; Rezzoug, A.

    2015-09-01

    Contactless torque transmission through a large airgap is required in some industrial applications in which hermetic isolation is necessary. This torque transmission usually uses magnetic couplers, whose dimension strongly depends on the airgap flux density. The use of high temperature superconducting (HTS) coils to create a strong magnetic field may constitute a solution to reduce the size of the coupler. It is also possible to use this coupler to replace a torque tube in transmitting the torque produced by a HTS motor to its load. This paper presents the detailed construction and tests of an axial field HTS magnetic coupler. Pancake coils have been manufactured from BSCCO tape and used in one rotor of the coupler. The second rotor is mainly composed of NdFeB permanent magnets. Several tests have been carried out showing that the constructed coupler is working properly. A 3D finite element (FE) model of the studied coupler has been developed. Airgap magnetic field and torque measurements have been carried out and compared to the FE results. It has been shown that the measured and the computed quantities are in satisfactory agreement.

  7. Measuring densities of solids and liquids using magnetic levitation: fundamentals.

    PubMed

    Mirica, Katherine A; Shevkoplyas, Sergey S; Phillips, Scott T; Gupta, Malancha; Whitesides, George M

    2009-07-29

    This paper describes an analytical system that uses magnetic levitation to measure densities of solids and water-immiscible organic liquids with accuracies ranging from +/-0.0002 to +/-0.02 g/cm(3), depending on the type of experiment. The technique is compatible with densities of 0.8-3 g/cm(3) and is applicable to samples with volumes of 1 pL to 1 mL; the samples can be either spherical or irregular in shape. The method employs two permanent NdFeB magnets positioned with like poles facing one another--with the axis between the poles aligned with the gravitational field--and a container filled with paramagnetic medium (e.g., MnCl(2) dissolved in water) placed between these magnets. Density measurements are obtained by placing the sample into the container and measuring the position of the sample relative to the bottom magnet. The balance of magnetic and gravitational forces determines the vertical position of the sample within the device; knowing this position makes it possible to calculate the density of the sample.

  8. Dense arrays of cobalt nanorods as rare-earth free permanent magnets.

    PubMed

    Anagnostopoulou, E; Grindi, B; Lacroix, L-M; Ott, F; Panagiotopoulos, I; Viau, G

    2016-02-21

    We demonstrate in this paper the feasibility to elaborate rare-earth free permanent magnets based on cobalt nanorods assemblies with energy product (BH)max exceeding 150 kJ m(-3). The cobalt rods were prepared by the polyol process and assembled from wet suspensions under a magnetic field. Magnetization loops of dense assemblies with remanence to a saturation of 0.99 and squareness of 0.96 were measured. The almost perfect M(H) loop squareness together with electron microscopy and small angle neutron scattering demonstrate the excellent alignment of the rods within the assemblies. The magnetic volume fraction was carefully measured by coupling magnetic and thermogravimetric analysis and found in the range from 45 to 55%, depending on the rod diameter and the alignment procedure. This allowed a quantitative assessment of the (BH)max values. The highest (BH)max of 165 kJ m(-3) was obtained for a sample combining a high magnetic volume fraction and a very large M(H) loop squareness. This study shows that this bottom-up approach is very promising to get new hard magnetic materials that can compete in the permanent magnet panorama and fill the gap between the ferrites and the NdFeB magnets.

  9. Replacement and Original Magnet Engineering Options (ROMEOs): A European Seventh Framework Project to Develop Advanced Permanent Magnets Without, or with Reduced Use of, Critical Raw Materials

    NASA Astrophysics Data System (ADS)

    Mcguiness, P.; Akdogan, O.; Asali, A.; Bance, S.; Bittner, F.; Coey, J. M. D.; Dempsey, N. M.; Fidler, J.; Givord, D.; Gutfleisch, O.; Katter, M.; Le Roy, D.; Sanvito, S.; Schrefl, T.; Schultz, L.; Schwöbl, C.; Soderžnik, M.; Šturm, S.; Tozman, P.; Üstüner, K.; Venkatesan, M.; Woodcock, T. G.; Žagar, K.; Kobe, S.

    2015-06-01

    The rare-earth crisis, which peaked in the summer of 2011 with the prices of both light and heavy rare earths soaring to unprecedented levels, brought about the widespread realization that the long-term availability and price stability of rare earths could not be guaranteed. This triggered a rapid response from manufacturers involved in rare earths, as well as governments and national and international funding agencies. In the case of rare-earth-containing permanent magnets, three possibilities were given quick and serious consideration: (I) increased recycling of devices containing rare earths; (II) the search for new, mineable, rare-earth resources beyond those in China; and (III) the development of high-energy-product permanent magnets with little or no rare-earth content used in their manufacture. The Replacement and Original Magnet Engineering Options (ROMEO) project addresses the latter challenge using a two-pronged approach. With its basis on work packages that include materials modeling and advanced characterization, the ROMEO project is an attempt to develop a new class of novel permanent magnets that are free of rare earths. Furthermore, the project aims to minimize rare-earth content, particularly heavy-rare-earth (HRE) content, as much as possible in Nd-Fe-B-type magnets. Success has been achieved on both fronts. In terms of new, rare-earth-free magnets, a Heusler alloy database of 236,945 compounds has been narrowed down to approximately 20 new compounds. Of these compounds, Co2MnTi is expected to be a ferromagnet with a high Curie temperature and a high magnetic moment. Regarding the reduction in the amount of rare earths, and more specifically HREs, major progress is seen in electrophoretic deposition as a method for accurately positioning the HRE on the surface prior to its diffusion into the microstructure. This locally increases the coercivity of the rather small Nd-Fe-B-type magnet, thereby substantially reducing the dependence on the HREs Dy and

  10. 40 CFR 63.10885 - What are my management practices for metallic scrap and mercury switches?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metallic scrap and mercury switches? 63.10885 Section 63.10885 Protection of Environment ENVIRONMENTAL... Affected Sources § 63.10885 What are my management practices for metallic scrap and mercury switches? (a... free liquids. (b) Mercury requirements. For scrap containing motor vehicle scrap, you must procure...

  11. SCRAP BEING FED INTO HARRIS TGS200 BALER. BLOCKS OF COMPACTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SCRAP BEING FED INTO HARRIS TGS-200 BALER. BLOCKS OF COMPACTED SCRAP, CALLED "CABBAGES", ARE MELTED DOWN IN THE CAST SHOP,ALONG WITH RAW METAL AND ALLOYS. BALED SCRAP MELTS MORE RAPIDLY THAN LOOSE SCRAP. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  12. 40 CFR 63.10885 - What are my management practices for metallic scrap and mercury switches?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... metallic scrap and mercury switches? 63.10885 Section 63.10885 Protection of Environment ENVIRONMENTAL... Affected Sources § 63.10885 What are my management practices for metallic scrap and mercury switches? (a... free liquids. (b) Mercury requirements. For scrap containing motor vehicle scrap, you must procure...

  13. 40 CFR 63.10885 - What are my management practices for metallic scrap and mercury switches?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... metallic scrap and mercury switches? 63.10885 Section 63.10885 Protection of Environment ENVIRONMENTAL... Affected Sources § 63.10885 What are my management practices for metallic scrap and mercury switches? (a... free liquids. (b) Mercury requirements. For scrap containing motor vehicle scrap, you must procure...

  14. Feasibility of re-melting NORM-contaminated scrap metal

    SciTech Connect

    Winters, S. J.; Smith, K. P.

    1999-10-26

    Naturally occurring radioactive materials (NORM) sometimes accumulate inside pieces of equipment associated with oil and gas production and processing activities. Typically, the NORM accumulates when radium that is present in solution in produced water precipitates out in scale and sludge deposits. Scrap equipment containing residual quantities of these NORM-bearing scales and sludges can present a waste management problem if the radium concentrations exceed regulatory limits or activate the alarms on radiation screening devices installed at most scrap metal recycling facilities. Although NORM-contaminated scrap metal currently is not disposed of by re-melting, this form of recycling could present a viable disposition option for this waste stream. Studies indicate that re-melting NORM-contaminated scrap metal is a viable recycling option from a risk-based perspective. However, a myriad of economic, regulatory, and policy issues have caused the recyclers to turn away virtually all radioactive scrap metal. Until these issues can be resolved, re-melting of the petroleum industry's NORM-impacted scrap metal is unlikely to be a widespread practice. This paper summarizes the issues associated with re-melting radioactive scrap so that the petroleum industry and its regulators will understand the obstacles. This paper was prepared as part of a report being prepared by the Interstate Oil and Gas Compact Commission's NORM Subcommittee.

  15. MAGNETIC IMAGING OF NANOCOMPOSITE MAGNETS

    SciTech Connect

    VOLKOV,V.V.ZHU,Y.

    2003-08-03

    . The fraction of large particles (of size 250 nm) is less then 57% of total amount of particles (Fig.1c, arrowed). Our new imaging technique allows visualization of domain structure in nanomagnets (Fig.3) in color code. Both projected magnetization and magnetic flux maps (Fig.3) reconstructed using Lorentz phase microscopy suggest a complex domain structure with an average domain size about 100x(100{approx}200) nm{sup 2} in a non-magnetized state. Large particles of darker contrast (of size {ge}50 nm, presumably {alpha}-Fe precipitates) or clusters of such particles act as effective concentrators for magnetic flux in nanocomposite matrix. The measured relative local-flux concentration by factor of 1.28 agrees well with theoretical ratio B{sub sat}({alpha}-Fe)/B{sub sat}(Nd{sub 2}Fe{sub 14}B)=1.31, strongly suggesting clustering of {alpha}-Fe particles that may have a detrimental effect on nanomagnet coercivity. Other smaller {alpha}-Fe particles (< 25 nm) do not disturb flux distribution, hence, they are magnetically coupled to Nd-Fe-B matrix grains as it was postulated by spring-exchange mechanism for nanocomposite magnets.

  16. Release of Radioactive Scrap Metal/Scrap Metal (RSM/SM) at Nevada Test Site (NTS)

    SciTech Connect

    Not Available

    1993-07-01

    Reynolds Electrical and Engineering Company, Inc. (REECo) is the prime contractor to the US Department of Energy (DOE) in providing service and support for NTS operations. Mercury Base Camp is the main control point for the many forward areas at NTS, which covers 1,350 square miles. The forward areas are where above-ground and underground nuclear tests have been performed over the last 41 years. No metal (or other material) is returned to Mercury without first being tested for radioactivity. No radioactive metals are allowed to reenter Mercury from the forward areas, other than testing equipment. RAMATROL is the monitor check point. They check material in various ways, including swipe tests, and have a large assortment of equipment for testing. Scrap metal is also checked to address Resource Conservation and Recovery Act concerns. After addressing these issues, the scrap metals are categorized. Federal Property Management Regulations (FPMR) are followed by REECo. The nonradioactive scrap material is sold through the GSA on a scheduled basis. Radioactive scrap metal are presently held in forward areas where they were used. REECo has gained approval of their Nevada Test Site Defense Waste Acceptance Criteria, Certification, and Transfer Requirements, NVO-325 application, which will allow disposal on site, when RSM is declared a waste. The guideline that REECo uses for release limits is DOE Order 5480.11, Radiation Protection for Occupational Works, Attachment 2, Surface Radioactivity Guides, of this order, give release limits for radioactive materials. However, the removal of radioactive materials from NTS require approval by DOE Nevada Operations Office (DOE/NV) on a case-by-case basis. Requirements to consider before removal are found in DOE Order 5820.2A, Radioactive Waste Management.

  17. 3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer

    NASA Astrophysics Data System (ADS)

    Huber, C.; Abert, C.; Bruckner, F.; Groenefeld, M.; Muthsam, O.; Schuschnigg, S.; Sirak, K.; Thanhoffer, R.; Teliban, I.; Vogler, C.; Windl, R.; Suess, D.

    2016-10-01

    3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup, a measurement resolution of 0.05 mm along the z-axes is achievable. The effectiveness of our calibration method is shown. With our setup, we are able to print polymer bonded magnetic systems with the freedom of having a specific complex shape with locally tailored magnetic properties. The 3D scanning setup is easy to mount, and with our calibration method we are able to get accurate measuring results of the stray field.

  18. Smart damper using the combination of magnetic friction and pre-compressed rubber springs

    NASA Astrophysics Data System (ADS)

    Choi, Eunsoo; Choi, Gyuchan; Kim, Hong-Taek; Youn, Heejung

    2015-09-01

    This paper proposes a new concept of a smart damper using the combination of magnetic friction and rubber springs. The magnet provides energy dissipation, and the rubber springs with precompression contribute to increasing the recentering capacity of the damper. To verify their performance, dynamic tests of magnet frictional dampers and precompressed rubber springs were conducted. For this purpose, hexahedron neodymium (NdFeB) magnets and polyurethane rubber cylinders were used. In the dynamic tests, the loading frequency was varied from 0.1 to 2.0 Hz. The magnets showed almost perfect rectangular behavior in the force-deformation curve, and the frictional coefficient of the magnets was estimated through averaging and regression. The rubber springs were tested with and without precompression. The rubber springs showed different loading path from the second cycle and residual deformation that was not recovered immediately. The rubber springs showed greater rigid force with increasing precompression. Finally, this paper discusses the combination of rigid-elastic behavior and friction to generate 'flag-shaped' behavior for a smart damper and suggests how to combine magnets and rubber springs to obtain flag-shaped behavior. The performance of the magnets and precompressed rubber springs was verified through analytical models.

  19. Characteristic Analysis and Trial Manufacture of Permanent-Magnetic Type Linear Generator

    NASA Astrophysics Data System (ADS)

    Takahara, Kenji; Ohsaki, Shingo; Itoh, Yuzo; Ohyama, Kazuhiro; Kawaguchi, Hideki

    This paper describes design and trial manufacture of the linear generator, which can convert any mechanical vibration of an automobile to electric energy. A mover, which includes permanent magnets, is linearly driven through a stator, by vibrations. Nd Fe-B magnets in the mover are placed as same magnetic poles face mutually, in order to make the change of magnetic flux in the coils of the stator. The coils are placed in the stator with same intervals of magnets. The coils are wound for the reverse to the next coil and they are connected series all. A magnetic material case covers the stator makes the magnetic flax is extended through the case and decrease canceling the flux in the coils of the stator. Numerical simulations calculated distribution of the magnetic field, electromotive force and driven power of the mover in order to determine the size of the linear generator. The linear generator and an experimental apparatus were produced on the basis of the simulation, and its performance was tested by experiments. The produced linear generator was confirmed to be useful as an onboard auxiliary power supply.

  20. Scrap uranium recycling via electron beam melting

    SciTech Connect

    McKoon, R.

    1993-11-01

    A program is underway at the Lawrence Livermore National Laboratory (LLNL) to recycle scrap uranium metal. Currently, much of the material from forging and machining processes is considered radioactive waste and is disposed of by oxidation and encapsulation at significant cost. In the recycling process, uranium and uranium alloys in various forms will be processed by electron beam melting and continuously cast into ingots meeting applicable specifications for virgin material. Existing vacuum processing facilities at LLNL are in compliance with all current federal and state environmental, safety and health regulations for the electron beam melting and vaporization of uranium metal. One of these facilities has been retrofitted with an auxiliary electron beam gun system, water-cooled hearth, crucible and ingot puller to create an electron beam melt furnace. In this furnace, basic process R&D on uranium recycling will be performed with the goal of eventual transfer of this technology to a production facility.

  1. Radioactive scrap metal decontamination technology assessment report

    SciTech Connect

    Buckentin, J.M.; Damkroger, B.K.; Schlienger, M.E.

    1996-04-01

    Within the DOE complex there exists a tremendous quantity of radioactive scrap metal. As an example, it is estimated that within the gaseous diffusion plants there exists in excess of 700,000 tons of contaminated stainless steel. At present, valuable material is being disposed of when it could be converted into a high quality product. Liquid metal processing represents a true recycling opportunity for this material. By applying the primary production processes towards the material`s decontamination and re-use, the value of the strategic resource is maintained while drastically reducing the volume of material in need of burial. Potential processes for the liquid metal decontamination of radioactively contaminated metal are discussed and contrasted. Opportunities and technology development issues are identified and discussed. The processes compared are: surface decontamination; size reduction, packaging and burial; melting technologies; electric arc melting; plasma arc centrifugal treatment; air induction melting; vacuum induction melting; and vacuum induction melting and electroslag remelting.

  2. Economic feasibility of radioactive scrap steel recycling

    SciTech Connect

    Nichols, F.; Balhiser, R.; Rosholt, D.

    1995-12-31

    In the past, government and commercial nuclear operators treated radioactive scrap steel (RSS) as a liability and disposed of it by burial; this was an accepted and economical solution at that time. Today, environmental concerns about burial are changing the waste disposal picture by (a) causing burial costs to soar rapidly, (b) creating pressure to close existing burial sites, and (c) making it difficult and expensive to open and operate burial facilities. To exacerbate the problem, planned dismantling of nuclear facilities will substantially increase volumes of RSS {open_quotes}waste{close_quotes} over the next 30 yr. This report describes a project with the intention of integrating the current commercial mini-mill approach of recycling uncontaminated steel with radiological controls to design a system that can process contaminated metals at prices significantly below the current processors or burial costs.

  3. Update on Recovering Lead From Scrap Batteries

    NASA Astrophysics Data System (ADS)

    Cole, E. R.; Lee, A. Y.; Paulson, D. L.

    1985-02-01

    Previous work at the Bureau of Mines Rolla Research Center, U.S. Department of the Interior, resulted in successful development of a bench-scale, combination electrorefining-electrowinning method for recycling lead from scrap batteries by using waste fluosilicic acid (H2SiF6) as electrolyte.1,2 This paper describes larger scale experiments. Prior attempts to electrowin lead failed because large quantities of insoluble lead dioxide were deposited on the anodes at the expense of lead deposition on the cathodes. A major breakthrough was achieved with the discovery that lead dioxide formation at the anodes is prevented by adding a small amount of phosphorus to the electrolyte. The amount of PbO2 formed on the anodes during lead electrowinning was less than 1% of the total lead deposited on the cathodes. This work recently won the prestigious IR·100 award as one of the 100 most significant technological advances of 1984.

  4. Side mounted EMS for aluminium scrap melters

    SciTech Connect

    Eidem, M.; Tallbaeck, G.; Hanley, P.J.

    1996-10-01

    Normally the electromagnetic stirrer (EMS) is placed below the furnace. However it has recently been found that the EMS can also be placed at the side of the furnace, still giving good stirring. This makes it possible to install EMS on most existing furnaces. The side-mounted EMS is compared with the standard bottom-mounted stirrer with respect to installation, melting time and flow pattern in the melt. The major conclusion is that a side-mounted EMS is practical and will give about as good a performance as the bottom-mounted. Melting time estimates are based upon 3-D fluid flow and heat transfer predictions in combination with a simplified scrap melting theory. Predicted melting times are in fair agreement with operational data for mechanically stirred and electromagnetically bottom stirred furnaces.

  5. Performance outlook of the SCRAP receiver

    NASA Astrophysics Data System (ADS)

    Lubkoll, Matti; von Backström, Theodor W.; Harms, Thomas M.

    2016-05-01

    A combined cycle (CC) concentrating solar power (CSP) plant provides significant potential to achieve an efficiency increase and an electricity cost reduction compared to current single-cycle plants. A CC CSP system requires a receiver technology capable of effectively transferring heat from concentrated solar irradiation to a pressurized air stream of a gas turbine. The small number of pressurized air receivers demonstrated to date have practical limitations, when operating at high temperatures and pressures. As yet, a robust, scalable and efficient system has to be developed and commercialized. A novel receiver system, the Spiky Central Receiver Air Pre-heater (SCRAP) concept has been proposed to comply with these requirements. The SCRAP system is conceived as a solution for an efficient and robust pressurized air receiver that could be implemented in CC CSP concepts or standalone solar Brayton cycles without a bottoming Rankine cycle. The presented work expands on previous publications on the thermal modeling of the receiver system. Based on the analysis of a single heat transfer element (spike), predictions for its thermal performance can be made. To this end the existing thermal model was improved by heat transfer characteristics for the jet impingement region of the spike tip as well as heat transfer models simulating the interaction with ambient. While the jet impingement cooling effect was simulated employing a commercial CFD code, the ambient heat transfer model was based on simplifying assumptions in order to employ empirical and analytical equations. The thermal efficiency of a spike under design conditions (flux 1.0 MW/m2, air outlet temperature just below 800 °C) was calculated at approximately 80 %, where convective heat losses account for 16.2 % of the absorbed radiation and radiative heat losses for a lower 2.9 %. This effect is due to peak surface temperatures occurring at the root of the spikes. It can thus be concluded that the geometric

  6. Superconducting Solenoid and Press for Permanent Magnet Fabrication

    NASA Astrophysics Data System (ADS)

    Mulcahy, T. M.; Hull, J. R.

    2002-08-01

    For the first time, a superconducting solenoid (SCM) was used to increase the remnant magnetization of sintered NdFeB permanent magnets (PMs). In particular, improved magnetic alignment of commercial-grade PM powder was achieved, as it was axial die pressed into 12.7-mm diameter cylindrical compacts in the 76.2-mm warm bore of a 9-T SCM. The press used to compact the powder is unique and was specifically designed for use with the SCM. Although the press was operated in the batch mode for this proof of concept study, its design is intended to enable automated production. In operation, a simple die and punch set made of nonmagnetic materials was filled with powder and loaded into a nonmagnetic press tube. The cantilevered press tube was inserted horizontally, on a carrier manually advanced along a track, into the SCM. The robustness of the mechanical components and the SCM, in its liquid helium dewar, were specifically designed to allow for insertion and extraction of the magnetic powder and compacts, while operating at 9 T.

  7. Paramagnetic ionic liquids for measurements of density using magnetic levitation.

    PubMed

    Bwambok, David K; Thuo, Martin M; Atkinson, Manza B J; Mirica, Katherine A; Shapiro, Nathan D; Whitesides, George M

    2013-09-03

    Paramagnetic ionic liquids (PILs) provide new capabilities to measurements of density using magnetic levitation (MagLev). In a typical measurement, a diamagnetic object of unknown density is placed in a container containing a PIL. The container is placed between two magnets (typically NdFeB, oriented with like poles facing). The density of the diamagnetic object can be determined by measuring its position in the magnetic field along the vertical axis (levitation height, h), either as an absolute value or relative to internal standards of known density. For density measurements by MagLev, PILs have three advantages over solutions of paramagnetic salts in aqueous or organic solutions: (i) negligible vapor pressures; (ii) low melting points; (iii) high thermal stabilities. In addition, the densities, magnetic susceptibilities, glass transition temperatures, thermal decomposition temperatures, viscosities, and hydrophobicities of PILs can be tuned over broad ranges by choosing the cation-anion pair. The low melting points and high thermal stabilities of PILs provide large liquidus windows for density measurements. This paper demonstrates applications and advantages of PILs in density-based analyses using MagLev.

  8. Contaminated scrap metal management on the Oak Ridge Reservation

    SciTech Connect

    Hayden, H.W.; Stephenson, M.J.; Bailey, J.K.; Weir, J.R.; Gilbert, W.C.

    1993-09-01

    Large quantities of scrap metal are accumulating at the various Department of Energy (DOE) installations across the country as a result of ongoing DOE programs and missions in concert with present day waste management practices. DOE Oak Ridge alone is presently storing around 500,000 tons of scrap metal. The local generation rate, currently estimated at 1,400 tons/yr, is expected to increase sharply over the next couple of years as numerous environmental restoration and decommissioning programs gain momentum. Projections show that 775,000 tons of scrap metal could be generated at the K-25 Site over the next ten years. The Y-12 Plant and Oak Ridge National Laboratory (ORNL) have similar potentials. The history of scrap metal management at Oak Ridge and future challenges and opportunities are discussed.

  9. Analysis of disposition alternatives for radioactively contaminated scrap metal

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

    1997-01-01

    Millions of tonnes of slightly radioactive, scrap iron and steel, stainless steel, and copper are likely to become available as nuclear and other facilities and equipment are withdrawn from service. Disposition of this material is an international policy issue under consideration currently. The major alternatives for managing this material are to either develop a regulatory process for decontamination and recycling that will safeguard human health or to dispose of the scrap and replace the metal stocks. To evaluate the alternatives, we estimate quantities of scrap arising from nuclear power plant decommissioning, evaluate potential price impacts of recycling on regional markets, and assess the health and environmental impacts of the management alternatives. We conclude that decontaminating and recycling the scrap is the superior alternative.

  10. Method for forming consumable electrodes from metallic chip scraps

    DOEpatents

    Girshov, Vladimir Leonidovich; Podpalkin, Arcady Munjyvich; Treschevskiy, Arnold Nikolayevich; Abramov, Alexey Alexandrovich

    2005-10-11

    The method relates to metallurgical recycling of waste products, preferably titanium alloys chips scrap. Accordingly after crushing and cleaning, the chip scrap is subjected to vacuum-thermal degassing (VTD); the chip scrap is pressed into briquettes; the briquettes are placed into a mould allowing sufficient remaining space for the addition of molten metal alloy; the mould is pre-heated before filling with the molten metal alloy; the mould remaining space is filled with molten metal alloy. After cooling, the electrode is removed from the mould. The method provides a means for 100% use of chip scrap in producing consumable electrodes having increased mechanical strength and reduced interstitial impurities content leading to improved secondary cast alloys.

  11. Effect of impurities in industrial salts on aluminum scrap melting

    SciTech Connect

    Ye, J.; Sahai, Y.; Revet, A.

    1996-10-01

    Aluminum scrap such as Used Beverage Containers (UBC) is melted under a protective molten salt cover. An appropriate salt protects metal from oxidation, promotes coalescence of molten droplets, and separates clean metal from the oxide contamination. Generally, the salt compositions for aluminum scrap recycling are based on equimolar mixtures of NaCl and KCl. A small amount of fluoride is also added in the salt. In the past, laboratory research at universities and industrial laboratories have been limited to pure salts. However, the industrial salts have impurities such as sulfates and other insoluble materials. These impurities have a pronounced effect on the efficiency of the scrap remelting process. In this paper, the role of impurities in industrial salts in terms of their chemical interactions with the metal are summarized. The efficiency of different industrial grade salts containing varying amounts of sulfates and other insoluble impurities for scrap recycling is compared.

  12. 49 CFR 173.218 - Fish meal or fish scrap.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized for...) Polyethylene-lined burlap or paper bag; (4) Cargo tank; (5) Portable tank; (6) Rail car; or (7)...

  13. 49 CFR 173.218 - Fish meal or fish scrap.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized for...) Polyethylene-lined burlap or paper bag; (4) Cargo tank; (5) Portable tank; (6) Rail car; or (7)...

  14. 49 CFR 173.218 - Fish meal or fish scrap.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized for transportation by vessel only when packaged as follows: (1) Burlap (jute) bag; (2) Multi-wall paper bag;...

  15. 19. 1500 CUBIC FEET CAPACITY SCRAP STEEL CHARGING BOX ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. 1500 CUBIC FEET CAPACITY SCRAP STEEL CHARGING BOX ON THE CHARGING AISLE OF THE BOP SHOP LOOKING NORTHWEST. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  16. Hybrid Nanocrystalline Permanent Magnets for Beam Focusing in High Energy Accelerators

    SciTech Connect

    Liu, Sam; Shen, Yuhui

    2005-07-12

    In this DoE 2004 STTR Phase I research project, bulk hybrid nanograin Nd2Fe14B/Sm2(Co,Fe)17 magnets with MHc = 14.2 kOe and (BH)max = 27.3 MGOe were successfully synthesized. In addition, bulk nanograin PrCo5 magnets with MHc over 15 kOe and bulk hybrid anisotropic nanocomposite Pr2(Fe,Co)14B/Pr(Co,Fe)5 and Pr2(Fe,Co)14B/Pr2(Co,Fe)17 magnets with (BH)max of 28 to 35 MGOe were synthesized. These efforts were guided by the novel model of coercivity mechanism in nanograin magnetic materials and through the use of the innovative rapid RF inductive hot compaction process. With further R&D, a new class of permanent magnets that have the same level of magnetic performance as the mainstream sintered Nd-Fe-B magnets with (BH)max = 35 to 45 MGOe and much improved thermal stability will be developed.

  17. The Inductrack Approach to Magnetic Levitation

    SciTech Connect

    Post, R.F.; Ryutov, D.D.

    2000-04-19

    Concepts developed during research on passive magnetic bearing systems at the Lawrence Livermore National Laboratory gave rise to a new approach to magnetic levitation, the Inductrack. A passive induced-current system employing permanent magnets on the moving vehicle, the Inductrack maximizes levitation forces by a combination of two elements. First, the permanent magnets on the vehicle are arranged in a ''Halbach array,'' a magnet configuration that optimally produces a periodic magnetic field below the array, while canceling the field above the array. Second, the track is made up of close-packed shorted electrical circuits. These circuits couple optimally to the magnetic field of the Halbach array. As a result, levitating forces of order 40 metric tonnes per square meter of Halbach array can be generated, using NdFeB magnets whose weight is a few percent of the levitated weight. Being an induced-current system, the levitation requires motion of the vehicle above a low transition speed. For maglev applications this speed is a few kilometers per hour, walking speed. At rest or in the station auxiliary wheels are needed. The Inductrack is thus fail-safe, that is, drive system failure would only result in the vehicle slowing down and finally settling on its auxiliary wheels. On the basis of theoretical analyses a small model vehicle and a 20-meter-long track was built and tested at speeds of order 12 meters per second. A second model, designed to achieve 10-g acceleration levels and much higher speeds, is under construction under NASA sponsorship, en route to the design of maglev-based launchers for rockets. Some of the presently perceived practical problems of implementing full-scale maglev systems based on the Inductrack concept will be discussed.

  18. Permanent magnet desktop magnetic resonance imaging system with microfabricated multiturn gradient coils for microflow imaging in capillary tubes.

    PubMed

    Sahebjavaher, Ramin S; Walus, Konrad; Stoeber, Boris

    2010-02-01

    A prototype for a desktop high-resolution magnetic resonance imaging (MRI) velocimetry instrument to characterize flow fields in a capillary tube is demonstrated. This inexpensive compact system is achieved with a 0.6 T permanent magnetic configuration (Larmor frequency of 25 MHz) and temperature compensation using off-the-shelf NdFeB permanent magnets. A triaxial gradient module with microfabricated copper coils using a lithographic fabrication process has been developed. This gradient module is capable of generating fast-switching gradients (<100 micros) with amplitudes up to 1.7 T/m using custom made current amplifiers, and was optimized for microflow imaging. The radio frequency probe is integrated with the gradient module and is driven by custom electronics. A two-dimensional (2D) cross-sectional static image of the inside of a capillary tube with an inner diameter of 1.67 mm is acquired at an in-plane spatial resolution of better than 40 microm. Time-of-flight flow measurements were also obtained using this MRI system to measure the velocity profile of water flowing at average velocities of above 50 mm/s. The flow profile for slower flow velocities was obtained using phase-encoded techniques, which provides quantitative velocity information in 2D.

  19. Novel microwave assisted chemical synthesis of Nd₂Fe₁₄B hard magnetic nanoparticles.

    PubMed

    Swaminathan, Viswanathan; Deheri, Pratap Kumar; Bhame, Shekhar Dnyaneswar; Ramanujan, Raju Vijayaraghavan

    2013-04-07

    The high coercivity and excellent energy product of Nd2Fe14B hard magnets have led to a large number of high value added industrial applications. Chemical synthesis of Nd2Fe14B nanoparticles is challenging due to the large reduction potential of Nd(3+) and the high tendency for Nd2Fe14B oxidation. We report the novel synthesis of Nd2Fe14B nanoparticles by a microwave assisted combustion process. The process consisted of Nd-Fe-B mixed oxide preparation by microwave assisted combustion, followed by the reduction of the mixed oxide by CaH2. This combustion process is fast, energy efficient and offers facile elemental substitution. The coercivity of the resulting powders was ∼8.0 kOe and the saturation magnetization was ∼40 emu g(-1). After removal of CaO by washing, saturation magnetization increased and an energy product of 3.57 MGOe was obtained. A range of magnetic properties was obtained by varying the microwave power, reduction temperature and Nd to Fe ratio. A transition from soft to exchange coupled to hard magnetic properties was obtained by varying the composition of NdxFe1-xB8 (x varies from 7% to 40%). This synthesis procedure offers an inexpensive and facile platform to produce exchange coupled hard magnets.

  20. A high-damping magnetorheological elastomer with bi-directional magnetic-control modulus for potential application in seismology

    NASA Astrophysics Data System (ADS)

    Yu, Miao; Qi, Song; Fu, Jie; Zhu, Mi

    2015-09-01

    A high-damping magnetorheological elastomer (MRE) with bi-directional magnetic-control modulus is developed. This MRE was synthesized by filling NdFeB particles into polyurethane (PU)/ epoxy (EP) interpenetrating network (IPN) structure. The anisotropic samples were prepared in a permanent magnetic field and magnetized in an electromagnetic field of 1 T. Dynamic mechanical responses of the MRE to applied magnetic fields are investigated through magneto-rheometer, and morphology of MREs is observed via scanning electron microscope (SEM). Test result indicates that when the test field orientation is parallel to that of the sample's magnetization, the shear modulus of sample increases. On the other hand, when the orientation is opposite to that of the sample's magnetization, shear modulus decreases. In addition, this PU/EP IPN matrix based MRE has a high-damping property, with high loss factor and can be controlled by applying magnetic field. It is expected that the high damping property and the ability of bi-directional magnetic-control modulus of this MRE offer promising advantages in seismologic application.

  1. Shimming with permanent magnets for the x-ray detector in a hybrid x-ray/ MR system.

    PubMed

    Wen, Zhifei; Fahrig, Rebecca; Williams, Scott T; Pelc, Norbert J

    2008-09-01

    In this x-ray/MR hybrid system an x-ray flat panel detector is placed under the patient cradle, close to the MR volume of interest (VOI), where the magnetic field strength is approximately 0.5 T. Immersed in this strong field, several electronic components inside the detector become magnetized and create an additional magnetic field that is superimposed on the original field of the MR scanner. Even after linear shimming, the field homogeneity of the MR scanner remains disrupted by the detector. The authors characterize the field due to the detector with the field of two magnetic dipoles and further show that two sets of permanent magnets (NdFeB) can withstand the main magnetic field and compensate for the nonlinear components of the additional field. The ideal number of magnets and their locations are calculated based on a field map measured with the detector in place. Experimental results demonstrate great promise for this technique, which may be useful in many settings where devices with magnetic components need to be placed inside or close to an MR scanner.

  2. A high-damping magnetorheological elastomer with bi-directional magnetic-control modulus for potential application in seismology

    SciTech Connect

    Yu, Miao Qi, Song; Fu, Jie; Zhu, Mi

    2015-09-14

    A high-damping magnetorheological elastomer (MRE) with bi-directional magnetic-control modulus is developed. This MRE was synthesized by filling NdFeB particles into polyurethane (PU)/ epoxy (EP) interpenetrating network (IPN) structure. The anisotropic samples were prepared in a permanent magnetic field and magnetized in an electromagnetic field of 1 T. Dynamic mechanical responses of the MRE to applied magnetic fields are investigated through magneto-rheometer, and morphology of MREs is observed via scanning electron microscope (SEM). Test result indicates that when the test field orientation is parallel to that of the sample's magnetization, the shear modulus of sample increases. On the other hand, when the orientation is opposite to that of the sample's magnetization, shear modulus decreases. In addition, this PU/EP IPN matrix based MRE has a high-damping property, with high loss factor and can be controlled by applying magnetic field. It is expected that the high damping property and the ability of bi-directional magnetic-control modulus of this MRE offer promising advantages in seismologic application.

  3. Enhanced coercivity thermal stability realized in Nd-Fe-B thin films diffusion-processed by Nd-Co alloys

    NASA Astrophysics Data System (ADS)

    Zhong, Hui; Fu, Yanqing; Li, Guojian; Liu, Tie; Cui, Weibin; Liu, Wei; Zhang, Zhidong; Wang, Qiang

    2017-03-01

    A proposed Nd2Fe14B-core/Nd2(Fe, Co)14B-shell microstructure was realized by diffusion-processing textured Nd14Fe77B9 single-layer film with Nd100-xCox (x=10, 20 and 40) alloys to improve the coercivity thermal stability. The ambient coercivity was increased from around 1 T in single-layer film to nearly 2 T in diffusion-processed films, which was due to the Nd-rich grain boundaries as seen from transmission electron microscopy (TEM) images. The coercivity thermal stability was improved by the core/shell microstructure because Nd-rich grain boundaries provided the high ambient coercivity and Co-rich shell provided the improved coercivity stability.

  4. Scrap metals industry perspective on radioactive materials.

    PubMed

    Turner, Ray

    2006-11-01

    With more than 80 reported/confirmed accidental melts worldwide since 1983 and still counting, potential contamination by radioactive materials remains as a major concern among recycled scrap and steel companies. Some of these events were catastrophic and have cost the industry millions of dollars in business and, at the same time, resulted in declining consumer confidence. It is also known that more events with confirmed radioactive contamination have occurred that involve mining of old steel slag and skull dumps. Consequently, the steel industry has since undergone massive changes that incurred unprecedented expenses through the installation of radiation monitoring systems in hopes of preventing another accidental melt. Despite such extraordinary efforts, accidental melts continue to occur and plague the industry. One recent reported/confirmed event occurred in the Republic of China in 2004, causing the usual lengthy shutdown for expensive decontamination efforts before the steel mill could resume operations. With this perspective in mind, the metal industry has a long-standing opposition to the release of radioactive materials of any kind to commerce for fear of contamination and the potential consequences.

  5. Catalytic extraction processing of contaminated scrap metal

    SciTech Connect

    Griffin, T.P.; Johnston, J.E.; Payea, B.M.

    1995-10-01

    The U.S. Department of Energy issued a Planned Research and Development Announcement (PRDA) in 1993, with the objective of identifying unique technologies which could be applied to the most hazardous waste streams at DOE sites. The combination of radioactive contamination with additional contamination by hazardous constituents such as those identified by the Resource Conservation and Recovery Act (RCRA) pose an especially challenging problem. Traditional remediation technologies are increasingly becoming less acceptable to stakeholders and regulators because of the risks they pose to public health and safety. Desirable recycling technologies were described by the DOE as: (1) easily installed, operated, and maintained; (2) exhibiting superior environmental performance; (3) protective of worker and public health and safety; (4) readily acceptable to a wide spectrum of evaluators; and (5) economically feasible. Molten Metal Technology, Inc. (MMT) was awarded a contract as a result of the PRDA initiative to demonstrate the applicability of Catalytic Extraction Processing (CEP), MMT`s proprietary elemental recycling technology, to DOE`s inventory of low level mixed waste. This includes DOE`s inventory of radioactively- and RCRA-contaminated scrap metal and other waste forms expected to be generated by the decontamination and decommissioning (D&D) of DOE sites.

  6. Scrap metal management issues associated with naturally occurring radioactive material

    SciTech Connect

    Smith, K.P.; Blunt, D.L.

    1995-08-01

    Certain industrial processes sometimes generate waste by-products that contain naturally occurring radioactive material (NORM) at elevated concentrations. Some industries, including the water treatment, geothermal energy, and petroleum industries, generate scrap metal that may be contaminated with NORM wastes. Of these three industries, the petroleum industry probably generates the largest quantity of NORM-contaminated equipment, conservatively estimated at 170,000 tons per year. Equipment may become contaminated when NORM-containing scale or sludge accumulates inside water-handling equipment. The primary radionuclides of concern in these NORM wastes are radium-226 and radium-228. NORM-contaminated equipment generated by the petroleum industry currently is managed several ways. Some equipment is routinely decontaminated for reuse; other equipment becomes scrap metal and may be disposed of by burial at a licensed landfill, encapsulation inside the wellbore of an abandoned well, or shipment overseas for smelting. In view of the increased regulatory activities addressing NORM, the economic burden of managing NORM-contaminated wastes, including radioactive scrap metal, is likely to continue to grow. Efforts to develop a cost-effective strategy for managing radioactive scrap metal should focus on identifying the least expensive disposition options that provide adequate protection of human health and the environment. Specifically, efforts should focus on better characterizing the quantity of radioactive scrap available for recycle or reuse, the radioactivity concentration levels, and the potential risks associated with different disposal options.

  7. Radiation survey of aircraft and heavy machinery scrap.

    PubMed

    Idriss, Hajo; Salih, Isam; Gumaa, Elsadig; Yassin, Abbas; Yousif, E H; Abdel Hamid, Saad Eldeen M; Sam, A K

    2012-12-01

    This study was conducted primarily to survey aircraft and heavy machinery at 30 locations within Khartoum State using handheld radiation survey meters to detect and identify any radiation sources that might be present and to estimate radiation dose levels. The survey has resulted in detection of 16 sealed sources of (90)Sr and one of (226)Ra in aircraft scrap. Of course, (90)Sr sources are used in military aircraft as temperature sensors while (226)Ra is used for indicating fuel levels. These sources were found intact without spreading radioactivity contamination; however, none was detected in heavy machine scrap. The levels of radiation dose measured at 0.1m from the source fall within the range of 25.1-40.2 μSv/h with an average value of 33.52 ± 4.06 μSv/h. These orphan sources have been separated from the scrap, tested for possible leakage, conditioned and stored in waste management facility. The result of this study has revealed without doubt that the scrap constitute a serious source of public exposure and highlights the importance of legislation making radiation monitoring of scrap in the country mandatory before it is sold to metal industry for reprocessing.

  8. Radiological Assessment of Releasing Scrap Metal from Nuclear Facilities

    SciTech Connect

    N. Naraine; C. Conklin; R. Anigstein

    2000-06-04

    Large quantities of scrap metal are generated during the extensive worldwide decontamination and decommissioning of nuclear facilities and, to a lesser extent, during the normal operations of these facilities. To evaluate the radiological impacts of releasing potentially contaminated metals to the general environment, the U.S. Environmental Protection Agency (EPA) performed an exhaustive analysis of the release and recycling of carbon steel scrap. Further assessments were performed of the clearance and recycling of aluminum and copper scrap. The aim of the analyses was to calculate the annual dose and the lifetime risk of cancer to the reasonably maximally exposed (RME) individual, normalized to the specific activity of a given radioactive contaminant in the scrap, from 1 yr of exposure. These results, presented as a set of tables that list the normalized doses and risks to the RME individual for each of 40 radionuclides that are potential contaminants of the three metals, can be used to assess the potential health effects of releasing scrap with a given level of contamination. This report describes the analysis and gives a summary of the results.

  9. Y-12 old salvage yard scrap metal characterization study

    SciTech Connect

    Anderson, L.M.; Melton, S.G.; Shaw, S.S.

    1993-11-01

    The purpose of the Y-12 Old Salvage Yard scrap metal Characterization Study is to make conservative estimates of the quantities of total uranium and the wt % {sup 235}U contained in scrap metal. The original project scope included estimates of thorium, but due to the insignificant quantities found in the yards, thorium was excluded from further analysis. Metal in three of the four Y-12 scrap metal yards were characterized. The scrap metal yard east of the PIDAS fence is managed by the Environmental Restoration Program and therefore was not included in this study. For all Y-12 Plant scrap metal shipments, Waste Transportation, Storage, and Disposal (WTSD) personnel must complete a Request for Authorization to Ship Nuclear Materials, UCN-16409, which requires the grams of total uranium, the wt % {sup 235}U, and the grams of {sup 235}U contained in the shipment. This information is necessary to ensure compliance with Department of Transportation regulations, as well as to ensure that the receiving facility is adhering to its operating license. This characterization study was designed to provide a technical basis for determining these necessary radioactive quantities.

  10. The fate of sulfur during rapid pyrolysis of scrap tires.

    PubMed

    Hu, Hongyun; Fang, Yuan; Liu, Huan; Yu, Ren; Luo, Guangqian; Liu, Wenqiang; Li, Aijun; Yao, Hong

    2014-02-01

    The fate of sulfur during rapid pyrolysis of scrap tires at temperatures from 673 to 1073K was investigated. Sulfur was predominant in the forms of thiophenic and inorganic sulfides in raw scrap tires. In the pyrolysis process, sulfur in organic forms was unstable and decomposed, leading to the sulfur release into tar and gases. At 673 and 773K, a considerable amount of sulfur was distributed in tar. Temperature increasing from 773 to 973K promoted tar decomposition and facilitated sulfur release into gases. At 1073K, the interactions between volatiles and char stimulated the formation of high-molecular-weight sulfur-containing compounds. After pyrolysis, almost half of the total content of sulfur in raw scrap tires still remained in the char and was mostly in the form of sulfides. Moreover, at temperatures higher than 873K, part of sulfur in the char was immobilized in the sulfates. In the pyrolysis gases, H2S was the main sulfur-containing gas. Increasing temperature stimulated the decomposition of organic polymers in scrap tires and more H2S was formed. Besides H2S, other sulfur-containing gases such as CH3SH, COS and SO2 were produced during the rapid pyrolysis of scrap tires.

  11. An overview of recycling and treatment of scrap computers.

    PubMed

    Lee, Ching-Hwa; Chang, Chang-Tang; Fan, Kuo-Shuh; Chang, Tien-Chin

    2004-10-18

    In order to recover valuable materials and to minimize the adverse effects of hazardous materials contained in scrap computers, a dismantling practice is commonly adopted to treat scrap computers. By using the dismantling process, both useful and hazardous materials can be manually separated and retrieved. On the basis of the properties of the retrieved materials, they can be sent to appropriate facilities for further recycling or treatment. Among the retrieved materials, the treatment of hazardous materials from cathode ray tubes (CRT) and printed circuit boards with integrated circuits have drawn considerable attention, thus implying that the proper treatment of such materials can greatly assure the successful recycling of scrap computers. For this reason, this study reviews the available technologies which can be applied to treat and recycle cathode ray tube components and printed circuit boards with integrated circuits. Actual recycling data from a scrap computer recycling plant located in Taiwan are also introduced. The data show that this recycling plant can recover 94.75 wt. % and 45.99 wt. % of useful materials from the main machines (i.e., CPU, power supplier, fan, IC boards, DVD drive, CD drive, hard disk, soft disk, shell casing, etc.) and monitors of scrap computers, respectively.

  12. Feasibility analysis of recycling radioactive scrap steel

    SciTech Connect

    Nichols, F.; Balhiser, B.; Cignetti, N.

    1995-09-01

    The purpose of this study is to: (1) establish a conceptual design that integrates commercial steel mill technology with radioactive scrap metal (RSM) processing to produce carbon and stainless steel sheet and plate at a grade suitable for fabricating into radioactive waste containers; (2) determine the economic feasibility of building a micro-mill in the Western US to process 30,000 tons of RSM per year from both DOE and the nuclear utilities; and (3) provide recommendations for implementation. For purposes of defining the project, it is divided into phases: economic feasibility and conceptual design; preliminary design; detail design; construction; and operation. This study comprises the bulk of Phase 1. It is divided into four sections. Section 1 provides the reader with a complete overview extracting pertinent data, recommendations and conclusions from the remainder of the report. Section 2 defines the variables that impact the design requirements. These data form the baseline to create a preliminary conceptual design that is technically sound, economically viable, and capitalizes on economies of scale. Priorities governing the design activities are: (1) minimizing worker exposure to radionuclide hazards, (2) maximizing worker safety, (3) minimizing environmental contamination, (4) minimizing secondary wastes, and (5) establishing engineering controls to insure that the plant will be granted a license in the state selected for operation. Section 3 provides details of the preliminary conceptual design that was selected. The cost of project construction is estimated and the personnel needed to support the steel-making operation and radiological and environmental control are identified. Section 4 identifies the operational costs and supports the economic feasibility analysis. A detailed discussion of the resulting conclusions and recommendations is included in this section.

  13. Iron/iron oxide core/shell nanoparticles for magnetic targeting MRI and near-infrared photothermal therapy.

    PubMed

    Zhou, Zhiguo; Sun, Yanan; Shen, Jinchao; Wei, Jie; Yu, Chao; Kong, Bin; Liu, Wei; Yang, Hong; Yang, Shiping; Wang, Wei

    2014-08-01

    The development of photothermal agents (PTAs) with good stability, low toxicity, highly targeting ability and photothermal conversion efficiency is an essential pre-requisite to near-infrared photothermal therapy (PTT) in vivo. Herein, we report the readily available PEGylated Fe@Fe3O4 NPs, which possess triple functional properties in one entity - targeting, PTT, and imaging. Compared to Au nanorods, they exhibit comparable photothermal conversion efficiency (∼20%), and much higher photothermal stability. They also show a high magnetization value and transverse relaxivity (∼156 mm(-1) s(-1)), which should be applied for magnetic targeting MRI. With the Nd-Fe-B magnet (0.5 T) beside the tumour for 12 h on the xenograft HeLa tumour model, PEGylated Fe@Fe3O4 NPs exhibit an obvious accumulation. In tumour, the intensity of MRI signal is ∼ three folds and the increased temperature is ∼ two times than those without magnetic targeting, indicating the good magnetic targeting ability. Notably, the intrinsic high photothermal conversion efficiency and selective magnetic targeting effect of the NPs in tumour play synergistically in highly efficient ablation of cancer cells in vitro and in vivo.

  14. [Scrap metal and ionizing radiation hazard: prevention and protection].

    PubMed

    Giugni, U

    2012-01-01

    The numerous accidents occurred in companies that melt scrap metals have shown that the hazard caused by the presence of radioactive materials--or 'orphan sources'--may have serious consequences on standard production, with great economic and social damage. Italian Legislative Decree No. 100/11 establishes the skills required for the safe management of scrap metals in the whole production cycle, thus requiring the involvement of experts in radiation protection. The paper details the procedures that shall be implemented in the companies that melt scrap metals. Said procedures involve several professional roles: managers, department heads and occupational physicians. The paper describes the general characteristics of the instruments used, staff training programs and the experience gained in 15 years of activity.

  15. Scrap tire recycling: Promising high value applications. Final report

    SciTech Connect

    Bauman, B.D.; Leskovyansky, P.J.; Drela, H.

    1993-11-01

    Surface modification of scrap tire rubber (rubber particles treated with chlorine gas) show promise for ameliorating the scrap tire problem (the treated rubber can be used as a component in high- performance, expensive polymer systems). The process has been proven in Phase I. Phase II covers market/applications, process development (Forberg-design mixer reactor was chosen), plant design, capital cost estimate, economics environmental/safety/health, and energy impact. Almost of the small amount of chlorine is consumed. The capital costs for a rubber particle treatment facility are attractive, being at least two orders of magnitude less than that of facilities for making new polymer materials. Large volume markets using treated rubber are needed. The amount of scrap rubber available is small compared to the polymers available for replacement. 7 tabs, 16 figs.

  16. Preliminary evaluation of electrowinning for nickel scrap processing

    SciTech Connect

    Brown, G.M.; Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Wilson, D.F.

    1996-12-01

    Purification of the 70,000 to 245,000 tons of diffusion plant nickel scrap permit its use in a variety of DOE and, with establishment of de minimus standards, foreign and domestic industrial applications. Nickel recycle would also substantially decrease DOE legacy wastes. This report presents data on electrolytes and separations which could be used in electrolytic purification of radiologically contaminated nickel scrap from first generation diffusion plants. Potentiometric scans and plating tests indicate that both industrial electrolytes, buffered nickel sulfate-sodium chloride and nickel chloride, provide good current densities. Electrolytes which contain ammonium thiocyanate or ammonium chloride also perform well. Nickel does not plate appreciably from nitrate solutions because the nitrate was preferentially reduced to nitrite. Solvent extractions of cobalt, a common contaminant in commercial nickel, and pertechnate, a radiological contaminant expected in DOE nickel scrap, are also successful.

  17. Super-paramagnetic nanoparticles synthesis in a thermal plasma reactor assisted by magnetic bottle

    NASA Astrophysics Data System (ADS)

    Cartaya, R.; Puerta, J.; Martín, P.

    2015-03-01

    The present work is a study of the synthesis of super-paramagnetic particles. A preliminary study based on thermodynamic diagrams of Gibbs free energy minimization, was performed with the CSIRO Thermochemical System. In this way, the synthesis of magnetite nanoparticles from precursor powder of ore iron in a thermal reactor, was performed. Then the process was simulated mathematically using magnetohydrodynamic and kinetic equations, in order to predict the synthesis process. A cylindrical reactor assisted by magnetic mirrors was used. The peak intensity of 0.1 tesla (1000 Gauss) was measured at the end of the solenoid. A PlazjetTM 105/15 thermal plasma torch was used. The precursor powder was iron oxide and the plasma gas, nitrogen. The magnetite powder was magnetized whit rare-earth super-magnets, alloy of neodymium-iron boron (NdFeB) grade N-42. The synthesized nanoparticles diameters was measured with a scanning electron microscope LECO and the permanent magnetization with a YOKOGAWA gauss meter, model 325i. Our experimental results show that it is possible the synthesis of super-paramagnetic nanoparticles in thermal plasma reactors.

  18. Design, fabrication, and characterization of a valveless magnetic travelling-wave micropump

    NASA Astrophysics Data System (ADS)

    Yu, Huawei; Ye, Weixiang; Zhang, Wei; Yue, Zhao; Liu, Guohua

    2015-06-01

    In this paper, we propose a valveless magnetic micropump for lab-on-a-chip and microfluidic applications. The micropump, based on polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA), consists primarily of a saw-toothed microchannel, two substrates, and two integrated NdFeB permanent magnetic arrays. The travelling wave beneath the top wall of the elastic microchannel can be induced by the proper magnetic pole orientation arrangement of these magnetic arrays, and the liquid particles are then transported along with the travelling wave in the microchannel. Appropriate geometry of the saw-toothed microchannel was also studied for optimizing the performance of the micropump. Experimental characterization of the micropump has been performed in terms of the frequency response of the flow rate and backpressure. The results demonstrate that this micropump is capable of reliably generating a maximum flow rate of 342.4 μL min-1 and operating against a high backpressure of 1.67 kPa.

  19. Detection of a magnetic bead by hybrid nanodevices using scanning gate microscopy

    NASA Astrophysics Data System (ADS)

    Corte-León, H.; Krzysteczko, P.; Marchi, F.; Motte, J.-F.; Manzin, A.; Schumacher, H. W.; Antonov, V.; Kazakova, O.

    2016-05-01

    Hybrid ferromagnetic(Py)/non-magnetic metal(Au) junctions with a width of 400 nm are studied by magnetotransport measurements, magnetic scanning gate microscopy (SGM) with a magnetic bead (MB) attached to the probe, and micromagnetic simulations. In the transverse geometry, the devices demonstrate a characteristic magnetoresistive behavior that depends on the direction of the in plane magnetic field, with minimum/maximum variation when the field is applied parallel/perpendicular to the Py wire. The SGM is performed with a NdFeB bead of 1.6 μm diameter attached to the scanning probe. Our results demonstrate that the hybrid junction can be used to detect this type of MB. A rough approximation of the sensing volume of the junction has the shape of elliptical cylinder with the volume of ˜1.51 μm3. Micromagnetic simulations coupled to a magnetotransport model including anisotropic magnetoresistance and planar Hall effects are in good agreement with the experimental findings, enabling the interpretation of the SGM images.

  20. Radioactive Material in Scrap Metal | RadTown USA | US EPA

    EPA Pesticide Factsheets

    2016-05-18

    Sometimes radioactive materials are disposed of improperly and end up in scrap metal yards. You will probably never come into contact with contaminated scrap metal. If you think you have found contaminated scrap metal, do not touch it. Immediately contact your state radiation control office.

  1. 29 CFR 570.128 - Loading of certain scrap paper balers and paper box compactors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Loading of certain scrap paper balers and paper box... Amended Exemptions § 570.128 Loading of certain scrap paper balers and paper box compactors. (a) Section... 16- and 17-year-olds to load, but not operate or unload, certain power-driven scrap paper balers...

  2. 41 CFR 109-27.5107 - Recovery of silver from used hypo solution and scrap film.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... used hypo solution and scrap film. 109-27.5107 Section 109-27.5107 Public Contracts and Property... § 109-27.5107 Recovery of silver from used hypo solution and scrap film. The requirements for the recovery of silver from used hypo solution and scrap film are contained in § 109-45.1003 of this chapter....

  3. 41 CFR 109-27.5107 - Recovery of silver from used hypo solution and scrap film.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... used hypo solution and scrap film. 109-27.5107 Section 109-27.5107 Public Contracts and Property... § 109-27.5107 Recovery of silver from used hypo solution and scrap film. The requirements for the recovery of silver from used hypo solution and scrap film are contained in § 109-45.1003 of this chapter....

  4. 41 CFR 109-27.5107 - Recovery of silver from used hypo solution and scrap film.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... used hypo solution and scrap film. 109-27.5107 Section 109-27.5107 Public Contracts and Property... § 109-27.5107 Recovery of silver from used hypo solution and scrap film. The requirements for the recovery of silver from used hypo solution and scrap film are contained in § 109-45.1003 of this chapter....

  5. 41 CFR 109-27.5107 - Recovery of silver from used hypo solution and scrap film.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... used hypo solution and scrap film. 109-27.5107 Section 109-27.5107 Public Contracts and Property... § 109-27.5107 Recovery of silver from used hypo solution and scrap film. The requirements for the recovery of silver from used hypo solution and scrap film are contained in § 109-45.1003 of this chapter....

  6. 41 CFR 109-27.5107 - Recovery of silver from used hypo solution and scrap film.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... used hypo solution and scrap film. 109-27.5107 Section 109-27.5107 Public Contracts and Property... § 109-27.5107 Recovery of silver from used hypo solution and scrap film. The requirements for the recovery of silver from used hypo solution and scrap film are contained in § 109-45.1003 of this chapter....

  7. 40 CFR 63.10685 - What are the requirements for the control of contaminants from scrap?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... paragraph (b)(3) of this section. (b) Mercury requirements. For scrap containing motor vehicle scrap, you... plan for mercury switches. You must comply with the requirements in paragraphs (b)(1)(i) through (v) of this section. (i) You must include a requirement in your scrap specifications for removal of...

  8. 40 CFR 63.10685 - What are the requirements for the control of contaminants from scrap?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... paragraph (b)(3) of this section. (b) Mercury requirements. For scrap containing motor vehicle scrap, you... plan for mercury switches. You must comply with the requirements in paragraphs (b)(1)(i) through (v) of this section. (i) You must include a requirement in your scrap specifications for removal of...

  9. Advanced technologies for decontamination and conversion of scrap metal

    SciTech Connect

    Muth, T.R.; Shasteen, K.E.; Liby, A.L.

    1995-10-01

    The Department of Energy (DOE) accumulated large quantities of radioactive scrap metal (RSM) through historic maintenance activities. The Decontamination and Decommissioning (D&D) of major sites formerly engaged in production of nuclear materials and manufacture of nuclear weapons will generate additional quantities of RSM, as much as 3 million tons of such metal according to a recent study. The recycling of RSM is quickly becoming appreciated as a key strategy in DOE`s cleanup of contaminated sites and facilities. The work described here has focused on recycle of the concentrated and high-value contaminated scrap metal resource that will arise from cleanup of DOE`s gaseous diffusion plants.

  10. A novel all-in-one magnetic pump and power harvester design for bio-medical applications

    NASA Astrophysics Data System (ADS)

    Kim, Sung Hoon; Shin, Jaewon; Hashi, Shuichiro; Ishiyama, Kazushi

    2011-03-01

    This paper presents a magnetic centrifugal pump with a magnetic power harvester (all-in-one system) for medical applications. The proposed pump is driven by an external rotating magnetic field. To produce pressure and electrical power, an all-in-one device consisting of a pump and a power harvester was designed. It consists of a multi-stage impeller, a disc type NdFeB permanent magnet, and a fixed wound coil on the pump case. The rotation of the rotor creates a continuous flow of liquid through the pump, with a pressure head, and an electrical power is generated in the wound coil because of the rotating magnetic field. The maximum flow rate and pressure are 5000 ml min-1 and 16 kPa, respectively, at 100 Hz. These results meet the requirements of an artificial heart assistance blood pump. Under these operating conditions, the harvested voltage can reach a maximum of 8.2 Vp-p. With this configuration and control method, wireless and battery-free operation is possible, which is required in the medical field. Moreover, the power harvester can monitor the pump conditions without additional electrical power and can provide electrical power to other implanted electrical devices. The performances of the pump and power harvester were verified in a laboratory experiment. Overall, the proposed system acts as a pump and a power harvester that is fully wireless and battery-free.

  11. A magnetic-piezoelectric smart material-structure utilizing magnetic force interaction to optimize the sensitivity of current sensing

    NASA Astrophysics Data System (ADS)

    Yeh, Po-Chen; Chung, Tien-Kan; Lai, Chen-Hung; Wang, Chieh-Min

    2016-01-01

    This paper presents a magnetic-piezoelectric smart material-structure using a novel magnetic-force-interaction approach to optimize the sensitivity of conventional piezoelectric current sensing technologies. The smart material-structure comprises a CuBe-alloy cantilever beam, a piezoelectric PZT sheet clamped to the fixed end of the beam, and an NdFeB permanent magnet mounted on the free end of the beam. When the smart material-structure is placed close to an AC conductor, the magnet on the beam of the smart structure experiences an alternating magnetic attractive and repulsive force produced by the conductor. Thus, the beam vibrates and subsequently generates a strain in the PZT sheet. The strain produces a voltage output because of the piezoelectric effect. The magnetic force interaction is specifically enhanced through the optimization approach (i.e., achieved by using SQUID and machining method to reorient the magnetization to different directions to maximize the magnetic force interaction). After optimizing, the beam's vibration amplitude is significantly enlarged and, consequently, the voltage output is substantially increased. The experimental results indicated that the smart material-structure optimized by the proposed approach produced a voltage output of 4.01 Vrms with a sensitivity of 501 m Vrms/A when it was placed close to a conductor with a current of 8 A at 60 Hz. The optimized voltage output and sensitivity of the proposed smart structure were approximately 316 % higher than those (1.27 Vrms with 159 m Vrms/A) of representative piezoelectric-based current sensing technologies presented in other studies. These improvements can significantly enable the development of more self-powered wireless current sensing applications in the future.

  12. Results of chemical decontamination of DOE`s uranium-enrichment scrap metal

    SciTech Connect

    Levesque, R.G.

    1997-02-01

    The CORPEX{reg_sign} Nuclear Decontamination Processes were used to decontaminate representative scrap metal specimens obtained from the existing scrap metal piles located at the Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio. In September 1995, under contract to Lockheed Martin Energy Systems, MELE Associates, Inc. performed the on-site decontamination demonstration. The decontamination demonstration proved that significant amounts of the existing DOE scrap metal can be decontaminated to levels where the scrap metal could be economically released by DOE for beneficial reuse. This simple and environmentally friendly process can be used as an alternative, or in addition to, smelting radiologically contaminated scrap metal.

  13. Innovative technologies for recycling contaminated concrete and scrap metal

    SciTech Connect

    Bossart, S.J.; Moore, J.

    1993-09-01

    Decontamination and decommissioning of US DOE`s surplus facilities will generate enormous quantities of concrete and scrap metal. A solicitation was issued, seeking innovative technologies for recycling and reusing these materials. Eight proposals were selected for award. If successfully developed, these technologies will enable DOE to clean its facilities by 2019.

  14. Assessment of recycling or disposal alternatives for radioactive scrap metal

    SciTech Connect

    Murphie, W.E.; Lilly, M.J. III; Nieves, L.A.; Chen, S.Y.

    1993-11-01

    The US Department of Energy, Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, is participating with the Organization for Economic Cooperation and Development in providing analytical support for evaluation of management alternatives for radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing environmental and societal implications of recycling and/or disposal process alternatives. This effort includes development of inventory estimates for contaminated metals; investigation of scrap metal market structure, processes, and trends; assessment of radiological and nonradiological effects of recycling; and investigation of social and political factors that are likely to either facilitate or constrain recycling opportunities. In addition, the option of scrap metal disposal is being assessed, especially with regard to the environmental and health impacts of replacing these metals if they are withdrawn from use. This paper focuses on the radiological risk assessment and dose estimate sensitivity analysis. A {open_quotes}tiered{close_quotes} concept for release categories, with and without use restrictions, is being developed. Within the tiers, different release limits may be indicated for specific groupings of radionuclides. Depending on the spectrum of radionuclides that are present and the level of residual activity after decontamination and/or smelting, the scrap may be released for unrestricted public use or for specified public uses, or it may be recycled within the nuclear industry. The conservatism of baseline dose estimates is examined, and both more realistic parameter values and protective measures for workers are suggested.

  15. 46 CFR 148.265 - Fish meal or fish scrap.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... written certification stating— (1) The total weight of the shipment; (2) The moisture content of the material; (3) The fat content of the material; (4) The type of antioxidant and its concentration in the... a maximum of 15 percent fat by weight. (c) At the time of production, fish meal or fish scrap...

  16. 46 CFR 148.265 - Fish meal or fish scrap.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... written certification stating— (1) The total weight of the shipment; (2) The moisture content of the material; (3) The fat content of the material; (4) The type of antioxidant and its concentration in the... a maximum of 15 percent fat by weight. (c) At the time of production, fish meal or fish scrap...

  17. 46 CFR 148.265 - Fish meal or fish scrap.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... written certification stating— (1) The total weight of the shipment; (2) The moisture content of the material; (3) The fat content of the material; (4) The type of antioxidant and its concentration in the... a maximum of 15 percent fat by weight. (c) At the time of production, fish meal or fish scrap...

  18. 46 CFR 148.265 - Fish meal or fish scrap.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... written certification stating— (1) The total weight of the shipment; (2) The moisture content of the material; (3) The fat content of the material; (4) The type of antioxidant and its concentration in the... a maximum of 15 percent fat by weight. (c) At the time of production, fish meal or fish scrap...

  19. 21. Scrapping In Dry Dock #4. Naval Shipyard Philadelphia. February ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Scrapping In Dry Dock #4. Naval Shipyard Philadelphia. February 18, 1946. Original Photograph In Collection of National Archives, Mid-Atlantic Regional Records Center, Philadelphia. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Dry Dock No. 4, Broad Street south of Government Avenue, Philadelphia, Philadelphia County, PA

  20. Scrap tires: Black gold or fool`s gold?

    SciTech Connect

    Glaz, S.

    1995-10-01

    Three years ago, a US EPA report estimated there were between 2 and 3 billion tires stockpiled in the US. Currently, according to the Scrap Tire Management Council (STMC, Washington, DC), the number of stockpiled tires totals 850 million. However, this reduction is not due to federal or state legislation; simply, the number was overestimated. Whatever the actual number, scrap tire mounds have been large enough to prompt 34 states to developed scrap tire funding programs aimed at eliminating the stockpiling of the some 250 million tires generated per year, while gradually eliminating the tires already stockpiled. However, of the 34 states, only Illinois, Oregon, Florida, Wisconsin, and Minnesota, are aggressively tackling the problem. In each of these five cases, state officials claim, the only viable way to reduce large quantities of tires quickly is through energy reuse, and, like any other disposal method, it costs money. To compensate for the costs of elimination, states are developing funding for scrap tire reduction programs by placing fees on tire disposal, tire purchase, or vehicle title transfer and registration.

  1. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Clearance of military scrap. 644.522 Section 644.522 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

  2. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Clearance of military scrap. 644.522 Section 644.522 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

  3. 48 CFR 45.606 - Contractor scrap procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CONTRACT MANAGEMENT GOVERNMENT PROPERTY Reporting, Reutilization, and Disposal 45.606 Contractor scrap... proper disposition and are properly documented in the contractor's property management procedures. (b... precious or strategic metals; or (6) That is dangerous to public health or safety. (c) Absent...

  4. 48 CFR 45.606 - Contractor scrap procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CONTRACT MANAGEMENT GOVERNMENT PROPERTY Reporting, Reutilization, and Disposal 45.606 Contractor scrap... proper disposition and are properly documented in the contractor's property management procedures. (b... precious or strategic metals; or (6) That is dangerous to public health or safety. (c) Absent...

  5. BRONZE FOUNDRY SCRAP STORED IN THE BINS TO THE RIGHT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BRONZE FOUNDRY SCRAP STORED IN THE BINS TO THE RIGHT ARE LOADED INTO THE BOTTOM DROPPING CHARGE BUCKET IN THE BACKGROUND BEFORE BEING CHARGED INTO ONE OF THE ELECTRIC ARC FURNACES. - Stockham Pipe & Fittings Company, Brass Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  6. [Optimum of polysaccharide distillation on scrap Cordyceps militaris medium].

    PubMed

    Ren, Shu-Yu; Zhao, Chun-Yan; Song, Hui-Yi; Zhao, Hao-Lu; Sun, Jun-De

    2008-03-01

    A mass of scrap Cordyceps militaris solid culture medium could not be utilized better. In this test, using orthogonal design the optimal technique parmeter of extracting polysaccharide was 80 degrees C, two times, in twenty times of water, and 120 minutes each time. Temperature was the most important factor. The referenced data could be provided to depurative production of Cordyceps militaris and resource utilization.

  7. INTERIOR VIEW, LOOKING NORTH, TOWARDS CUPOLA WHERE SCRAP METAL AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW, LOOKING NORTH, TOWARDS CUPOLA WHERE SCRAP METAL AND OTHER COMPONENTS ARE MELTED TO CREATE DUCTILE IRON. BRIGHT FLASH IN BACKGROUND RESULTS FROM MOLTEN METAL (DUCTILE IRON) BEING POURED FROM CUPOLA INTO TRANSFER LADLE - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

  8. Recycling of Al-Si die casting scraps for solar Si feedstock

    NASA Astrophysics Data System (ADS)

    Seo, Kum-Hee; Jeon, Je-Beom; Youn, Ji-Won; Kim, Suk Jun; Kim, Ki-Young

    2016-05-01

    Recycling of aluminum die-casting scraps for solar-grade silicon (SOG-Si) feedstock was performed successfully. 3 N purity Si was extracted from A383 die-casting scrap by using the combined process of solvent refining and an advanced centrifugal separation technique. The efficiency of separating Si from scrap alloys depended on both impurity level of scraps and the starting temperature of centrifugation. Impurities in melt and processing temperature governed the microstructure of the primary Si. The purity of Si extracted from the scrap melt was 99.963%, which was comparable to that of Si extracted from a commercial Al-30 wt% Si alloy, 99.980%. The initial purity of the scrap was 2.2% lower than that of the commercial alloy. This result confirmed that die-casting scrap is a potential source of high-purity Si for solar cells.

  9. Transcranial static magnetic field stimulation of the human motor cortex.

    PubMed

    Oliviero, Antonio; Mordillo-Mateos, Laura; Arias, Pablo; Panyavin, Ivan; Foffani, Guglielmo; Aguilar, Juan

    2011-10-15

    The aim of the present study was to investigate in healthy humans the possibility of a non-invasive modulation of motor cortex excitability by the application of static magnetic fields through the scalp. Static magnetic fields were obtained by using cylindrical NdFeB magnets. We performed four sets of experiments. In Experiment 1, we recorded motor potentials evoked by single-pulse transcranial magnetic stimulation (TMS) of the motor cortex before and after 10 min of transcranial static magnetic field stimulation (tSMS) in conscious subjects. We observed an average reduction of motor cortex excitability of up to 25%, as revealed by TMS, which lasted for several minutes after the end of tSMS, and was dose dependent (intensity of the magnetic field) but not polarity dependent. In Experiment 2, we confirmed the reduction of motor cortex excitability induced by tSMS using a double-blind sham-controlled design. In Experiment 3, we investigated the duration of tSMS that was necessary to modulate motor cortex excitability. We found that 10 min of tSMS (compared to 1 min and 5 min) were necessary to induce significant effects. In Experiment 4, we used transcranial electric stimulation (TES) to establish that the tSMS-induced reduction of motor cortex excitability was not due to corticospinal axon and/or spinal excitability, but specifically involved intracortical networks. These results suggest that tSMS using small static magnets may be a promising tool to modulate cerebral excitability in a non-invasive, painless, and reversible way.

  10. Managing the disposition of potentially radioactive scrap metal.

    PubMed

    Chen, S Y

    2006-11-01

    In 2002, the National Council on Radiation Protection and Measurements (NCRP) issued Report No. 141, Managing Potentially Radioactive Scrap Metal. The report evaluates management policy and related issues regarding scrap metal generated in regulated facilities that have been under radiological control or have radiological concerns. It has been estimated that more than 9 million metric tons of scrap metal of all types that have been associated with the production or use of radioactive materials will be generated during the coming decades at various facilities across the United States. Currently, disposition of such metal has encountered particular obstacles, primarily because of the lack of a consistent disposition policy, systematic regulatory provisions, and, above all, public understanding. Without clarity in the regulatory passage, much of the scrap metal, including metal that has not been contaminated, could be mischaracterized as low-level radioactive waste, resulting in a costly disposition operation. NCRP Report No. 141 identifies this general category of metal as "potentially radioactive scrap metal" (PRSM) and discusses the viable disposition options for facilitating its management. Because much of the PRSM has been found to contain very low residual radioactivity or even none at all, one consideration is to release such metal outside of the radiological control framework. This would require the development and implementation of a set of strict release standards in the United States that would necessarily be risk-based and supported by a comprehensive management scheme. Developing a policy of this kind, however, would entail the resolution of many issues, not the least of which would be public acceptance, including that of the metal industry, of the possible recycling of PRSM in the general commerce.

  11. Sensitivity Enhancement in Magnetic Sensors Based on Ferroelectric-Bimorphs and Multiferroic Composites

    PubMed Central

    Sreenivasulu, Gollapudi; Qu, Peng; Petrov, Vladimir; Qu, Hongwei; Srinivasan, Gopalan

    2016-01-01

    Multiferroic composites with ferromagnetic and ferroelectric phases have been studied in recent years for use as sensors of AC and DC magnetic fields. Their operation is based on magneto-electric (ME) coupling between the electric and magnetic subsystems and is mediated by mechanical strain. Such sensors for AC magnetic fields require a bias magnetic field to achieve pT-sensitivity. Novel magnetic sensors with a permanent magnet proof mass, either on a ferroelectric bimorph or a ferromagnetic-ferroelectric composite, are discussed. In both types, the interaction between the applied AC magnetic field and remnant magnetization of the magnet results in a mechanical strain and a voltage response in the ferroelectric. Our studies have been performed on sensors with a Nd-Fe-B permanent magnet proof mass on (i) a bimorph of oppositely-poled lead zirconate titanate (PZT) platelets and (ii) a layered multiferroic composite of PZT-Metglas-Ni. The sensors have been characterized in terms of sensitivity and equivalent magnetic noise N. Noise N in both type of sensors is on the order of 200 pT/√Hz at 1 Hz, a factor of 10 improvement compared to multiferroic sensors without a proof mass. When the AC magnetic field is applied at the bending resonance for the bimorph, the measured N ≈ 700 pT/√Hz. We discuss models based on magneto-electro-mechanical coupling at low frequency and bending resonance in the sensors and theoretical estimates of ME voltage coefficients are in very good agreement with the data. PMID:26907290

  12. Sensitivity Enhancement in Magnetic Sensors Based on Ferroelectric-Bimorphs and Multiferroic Composites.

    PubMed

    Sreenivasulu, Gollapudi; Qu, Peng; Petrov, Vladimir; Qu, Hongwei; Srinivasan, Gopalan

    2016-02-20

    Multiferroic composites with ferromagnetic and ferroelectric phases have been studied in recent years for use as sensors of AC and DC magnetic fields. Their operation is based on magneto-electric (ME) coupling between the electric and magnetic subsystems and is mediated by mechanical strain. Such sensors for AC magnetic fields require a bias magnetic field to achieve pT-sensitivity. Novel magnetic sensors with a permanent magnet proof mass, either on a ferroelectric bimorph or a ferromagnetic-ferroelectric composite, are discussed. In both types, the interaction between the applied AC magnetic field and remnant magnetization of the magnet results in a mechanical strain and a voltage response in the ferroelectric. Our studies have been performed on sensors with a Nd-Fe-B permanent magnet proof mass on (i) a bimorph of oppositely-poled lead zirconate titanate (PZT) platelets and (ii) a layered multiferroic composite of PZT-Metglas-Ni. The sensors have been characterized in terms of sensitivity and equivalent magnetic noise N. Noise N in both type of sensors is on the order of 200 pT/√Hz at 1 Hz, a factor of 10 improvement compared to multiferroic sensors without a proof mass. When the AC magnetic field is applied at the bending resonance for the bimorph, the measured N ≈ 700 pT/√Hz. We discuss models based on magneto-electro-mechanical coupling at low frequency and bending resonance in the sensors and theoretical estimates of ME voltage coefficients are in very good agreement with the data.

  13. Hydrocoprocessing of scrap automotive tires and coal. Analysis of oils from autoclave coprocessing

    SciTech Connect

    Anderson, L.L.; Ding, W.; Liang, J.; Callen, M.; Mastral, A.M.; Mayoral, M.C.; Murillo, R.

    1997-11-01

    Hydrocoprocessing of scrap automotive tires and a low-rank coal was carried out in a magnetically stirred autoclave. Reaction temperature (400 C) and time (30 min) were kept constant in every experiment, while different pressures (10, 5, and 1 MPa of H{sub 2} and 0.1 MPa of N{sub 2}) were studied. An iron-based catalyst was used to improve yields. Derived oils were analyzed by GC-MS and TLC-FID. In terms of yields, it is shown that there is a synergism between these two materials, although it can only be observed working at low hydrogen pressure. The oils obtained in the coprocessing showed a more aromatic nature than those obtained when both materials are processed alone, and higher boiling points, suggesting that radicals from rubber and coal react between each other instead of reacting with hydrogen radicals.

  14. Helium temperature measurements in a hot filament magnetic mirror plasma using high resolution Doppler spectroscopy

    NASA Astrophysics Data System (ADS)

    Knott, S.; McCarthy, P. J.; Ruth, A. A.

    2016-09-01

    Langmuir probe and spectroscopic diagnostics are used to routinely measure electron temperature and density over a wide operating range in a reconfigured Double Plasma device at University College Cork, Ireland. The helium plasma, generated through thermionic emission from a negatively biased tungsten filament, is confined by an axisymmetric magnetic mirror configuration using two stacks of NdFeB permanent magnets, each of length 20 cm and diameter 3 cm placed just outside the 15 mm water cooling jacket enclosing a cylindrical vacuum vessel of internal diameter 25 cm. Plasma light is analysed using a Fourier Transform-type Bruker spectrometer with a highest achievable resolution of 0.08 cm-1 . In the present work, the conventional assumption of room temperature ions in the analysis of Langmuir probe data from low temperature plasmas is examined critically using Doppler spectroscopy of the 468.6 nm He II line. Results for ion temperatures obtained from spectroscopic data for a variety of engineering parameters (discharge voltage, gas pressure and plasma current) will be presented.

  15. Axial-flux modular permanent-magnet generator with a toroidal winding for wind-turbine applications

    SciTech Connect

    Muljadi, E.; Butterfield, C.P.; Wan, Y.H.

    1999-08-01

    Permanent-magnet (PM) generators have been used for wind turbines for many years. Many small wind-turbine manufacturers use direct-drive PM generators. For wind-turbine generators, the design philosophy must cover the following characteristics: low cost, light weight, low speed, high torque, and variable-speed generation. The generator is easy to manufacture and the design can be scaled up for a larger size without major retooling. A modular PM generator with axial flux direction was chosen. The permanent magnet used is NdFeB or ferrite magnet with flux guide to focus flux density in the air gap. Each unit module of the generator may consist of one, two, or more phases. Each generator can be expanded to two or more unit modules. Each unit module is built from simple modular poles. The stator winding is formed like a torus. Thus, the assembly process is simplified and the winding insertion in the slot is less tedious. The authors built a prototype of one unit module and performed preliminary tests in the laboratory. Follow-up tests will be conducted in the laboratory to improve the design.

  16. Simultaneous magnetic actuation and observation with ferromagnetic sensors

    NASA Astrophysics Data System (ADS)

    Czajkowski, J.; Kinnunen, P.; Haapanen, K.; Niinimäki, J.; Fabritius, T.

    2016-02-01

    We present a novel, non-contact, and non-optical approach to actuation and sensing. In the developed method, both functions are based only on the alternating magnetic field and take place simultaneously. The article demonstrates the technique in one of its potential applications, i.e. rheometry. The developed device uses two orthogonal pairs of inductor coils to generate a rotating magnetic field. The field actuates a rotor with an embedded NdFeB ring magnet. The angular displacement is simultaneously monitored with an angular AMR sensor, placed underneath the rotor. The device is used to study aqueous solutions at different concentrations of glycerol (10-95%). The accuracy of the angular sensing is verified using machine vision and pattern recognition, which is a technique widely used in the existing viscometers. A new approach to viscosity probing and phase slipping detection is introduced. So far, in non-contact rotational viscometers the dynamic viscosity was related to a critical frequency, determined by altering the frequency of the rotating magnetic field. However, we propose to alter the magnitude of the field, by changing the current in the inductor coils. The frequency is kept constant and the viscosity is proportional to the amplitude of current, for which the phase slipping occurs. The applied rate of rotation can be optimized for a particular measurement scenario. The results suggest a great potential of the technique in a variety of scenarios. Simultaneous magnetic actuation and sensing enables application in a broad frequency band, from dc to tens of kilohertz. Moreover, the design of a measurement device is simplified, so that its cost can be significantly lower than that of a conventional system. Furthermore, presented method is non-contact, does not require a clear optical path, and could be less susceptible to the environmental conditions (e.g. poor illumination, or full immersion in the studied solution).

  17. Novel design configurations for permanent magnet wind generators

    NASA Astrophysics Data System (ADS)

    Chen, Yicheng

    2004-12-01

    The aim of this research is to search for optimal designs of permanent magnet (PM) wind generators of different topologies. The dissertation deals with the development of analytical design equations and formulas for PM wind generators of different topologies, including equivalent magnetic circuit model for magnets, calculation of leakage flux, influence of d-q axis armature reaction, flux waveform analysis, as well as performance verification. 3-D and simplified 2-D finite element analysis is used to enhance the design precision, by which analytical formulas are modified. A new and improved formula is proposed for lamination loss calculations, based on a large experimental data set provided by steel manufacturers. The temperature stability of NdFeB magnets is analyzed and some proposals for eliminating irreversible demagnetization are presented. Two existing experimental machines are used to validate the design equations. The genetic algorithms are used to investigate the multi-objective design optimization of PM wind generators for a high efficiency and light-weight design. The reasoning behind the selection of the objective functions, design variables and constraints are given as guidance for the PM wind generator optimum design. The implementation of the genetic algorithm is also given. A comparison of PM wind generators of different topologies is presented. Conclusions are drawn for topology selections of PM wind generators. The group of soft magnetic composites (SMC) has recently been expanded by the introduction of new materials with significantly improved frequency properties. This has made SMC a viable alternative to steel laminations for a range of new applications, especially axial-flux wind generators. The isotropic nature of the SMC combined with the unique shaping possibilities opens up new design solutions for axial-flux wind generators. Through careful design, an axial-flux PM wind generator with SMC core is built and tested, demonstrating the

  18. Contaminated scrap-metal inventories at ORO-managed sites

    SciTech Connect

    Mack, J.E.

    1981-01-01

    Radioactively contaminated scrap metal inventories were surveyed at facilities operating under contract with the US Department of Energy and managed through the Oak Ridge Operations Office. Nearly 90,000 tons of nickel, aluminum, copper, and ferrous metals (steels) contaminated with low-enriched uranium have accumulated, primarily at the uranium enrichment facilities. The potential value of this metal on the scrap market is over $100 million. However, existing regulations do not permit sale for unlicensed use of materials contaminated with low-enriched uranium. Therefore, current handling practices include burial and above-ground storage. Smelting is also used for shape declassification, with subsequent storage of ingots. This survey of existing inventories, generation rates, and handling capabilities is part of an overall metal waste management program to coordinate related activities among the ORO-managed sites.

  19. 4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS COLLECTED INTO CANS AT INDIVIDUAL WORKSTATIONS. THE CANS WERE TRANSFERRED VIA THE CHAIN CONVEYOR TO A WORKSTATION IN MODULE C WHERE THE MATERIAL WAS COMPRESSED INTO BRIQUETTES FOR LATER USE. (6/20/93) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  20. Advanced technologies for decontamination and conversion of scrap metal

    SciTech Connect

    Muth, T.R.; Shasteen, K.E.; Liby, A.L.

    1995-12-01

    The Department of Energy (DOE) accumulated large quantities of radioactive scrap metal (RSM) through historic maintenance activities. The Decontamination and Decommissioning (D&D) of major sites formerly engaged in production of nuclear materials and manufacture of nuclear weapons will generate additional quantities of RSM, as much as 3 million tons of such metal according to a recent study. The recycling of RSM is quickly becoming appreciated as a key strategy in DOE`s cleanup of contaminated sites and facilities.

  1. Wastes from plutonium conversion and scrap recovery operations

    SciTech Connect

    Christensen, D.C.; Bowersox, D.F.; McKerley, B.J.; Nance, R.L.

    1988-03-01

    This report deals with the handling of defense-related wastes associated with plutonium processing. It first defines the different waste categories along with the techniques used to assess waste content. It then discusses the various treatment approaches used in recovering plutonium from scrap. Next, it addresses the various waste management approaches necessary to handle all wastes. Finally, there is a discussion of some future areas for processing with emphasis on waste reduction. 91 refs., 25 figs., 4 tabs.

  2. Use of scrap rubber in asphalt pavement surfaces. Special report

    SciTech Connect

    Eaton, R.A.; Roberts, R.J.; Blackburn, R.R.

    1991-12-01

    Scrap tire rubber was mixed into an asphalt concrete wearing course to study the effect of ice disbonding from the pavement surface under traffic. Rubber contents of 0, 3, 6, and 12% by weight were studied. Initial laboratory ice disbonding test results led to the development of a new paving material, Chunk Rubber Asphalt Concrete (CRAC), that uses larger pieces of rubber in a much denser asphalt concrete mix. Strength values doubled and ice disbonding performance was enhanced.

  3. Protocols for implementing DOE authorized release of radioactive scrap metals.

    PubMed

    Chen, S Y; Arnish, J; Kamboj, S; Nieves, L A

    1999-11-01

    A process to implement the U.S. Department of Energy's (DOE) policy for authorized release of radioactive materials from DOE facilities is provided in the Draft Handbook for Controlling Release for Reuse or Recycle of Property Containing Residual Radioactive Material, published by DOE in 1997 and distributed to DOE field offices for interim use and implementation. The authorized release of such property is intended to permit its beneficial use across the entire DOE complex. A computerized management tool--P2Pro(RSM)--has been developed to aid in carrying out the release process for radioactive metals. It contains protocols for the authorized release process and relevant information to facilitate the evaluation of scrap metals for reuse and recycle. The P2Pro(RSM) protocols provide DOE and its contractors with an effective, user-friendly tool for managing authorized release activities P2Pro(RSM) is designed to be used in the Windows environment. The protocols incorporate a relational database coupled with a graphic-user interface to guide the user through the appropriate steps so authorized release limits can be developed. With the information provided in the database, an as-low-as-reasonably-achievable (ALARA) optimization process can be easily set up and run for up to 10 alternatives for disposition of radioactive scrap metals. The results of the ALARA optimization process can be printed in a series of reports and submitted as part of the application for the authorized release of the radioactive scrap metals.

  4. Advanced technologies for decontamination and conversion of scrap metal

    SciTech Connect

    MacNair, V.; Muth, T.; Shasteen, K.; Liby, A.; Hradil, G.; Mishra, B.

    1996-12-31

    In October 1993, Manufacturing Sciences Corporation was awarded DOE contract DE-AC21-93MC30170 to develop and test recycling of radioactive scrap metal (RSM) to high value and intermediate and final product forms. This work was conducted to help solve the problems associated with decontamination and reuse of the diffusion plant barrier nickel and other radioactively contaminated scrap metals present in the diffusion plants. Options available for disposition of the nickel include decontamination and subsequent release or recycled product manufacture for restricted end use. Both of these options are evaluated during the course of this research effort. work during phase I of this project successfully demonstrated the ability to make stainless steel from barrier nickel feed. This paved the way for restricted end use products made from stainless steel. Also, after repeated trials and studies, the inducto-slag nickel decontamination process was eliminated as a suitable alternative. Electro-refining appeared to be a promising technology for decontamination of the diffusion plant barrier material. Goals for phase II included conducting experiments to facilitate the development of an electro-refining process to separate technetium from nickel. In parallel with those activities, phase II efforts were to include the development of the necessary processes to make useful products from radioactive scrap metal. Nickel from the diffusion plants as well as stainless steel and carbon steel could be used as feed material for these products.

  5. Advanced technologies for decontamination and conversion of scrap metals

    SciTech Connect

    Muth, T.R.; Moore, J.; Olson, D.; Mishra, B.

    1994-12-31

    Recycle of radioactive scrap metals (RSM) from decommissioning of DOE uranium enrichment and nuclear weapons manufacturing facilities is mandatory to recapture the value of these metals and avoid the high cost of disposal by burial. The scrap metals conversion project detailed below focuses on the contaminated nickel associated with the gaseous diffusion plants. Stainless steel can be produced in MSC`s vacuum induction melting process (VIM) to the S30400 specification using nickel as an alloy constituent. Further the case alloy can be rolled in MSC`s rolling mill to the mechanical property specification for S30400 demonstrating the capability to manufacture the contaminated nickel into valuable end products at a facility licensed to handle radioactive materials. Bulk removal of Technetium from scrap nickel is theoretically possible in a reasonable length of time with the high calcium fluoride flux, however the need for the high temperature creates a practical problem due to flux volatility. Bulk decontamination is possible and perhaps more desirable if nickel is alloyed with copper to lower the melting point of the alloy allowing the use of the high calcium fluoride flux. Slag decontamination processes have been suggested which have been proven technically viable at the Colorado School of Mines.

  6. Design and performances of the Scrap Neutron Multiplicity Counter

    NASA Astrophysics Data System (ADS)

    Marin Ferrer, Montserrat; Peerani, Paolo; Looman, Marc R.; Dechamp, Luc

    2007-05-01

    JRC has developed the Scrap Neutron Multiplicity Counter (SNMC): an advanced neutron multiplicity counter for the verification of inhomogeneous Pu samples, such as scrap material in MOX fuel fabrication plants. The innovative features of this counter with respect to existing ones rely on two aspects: (i) an optimised design based on Monte Carlo calculations in order to select the most appropriate materials, geometry and detector disposition for maximum efficiency and (ii) novel electronics based on digital signal processing (DSP) reducing the system dead time. The paper recalls the design process, the electronics, the construction and assembly of the counter. Then the results of the first experimental tests will be reported. We will show the characterization of the main physical parameters of the counter, the calibration and the verification of a wide variety of plutonium bearing samples available in the PERLA laboratory at JRC Ispra. This will include pure homogeneous samples (Pu dioxide powders, metal Pu, MOX powders and pellets) and some tests on heterogeneous samples representative of scrap material.

  7. Plutonium scrap processing at the Los Alamos Scientific Laboratory

    SciTech Connect

    Nixon, A.E.; McKerley, B.J.; Christensen, E.L.

    1980-01-01

    The Los Alamos Scientific Laboratory currently has the newest plutonium handling facility in the nation. Los Alamos has been active in the processing of plutonium almost since the discovery of this man-made element in 1941. One of the functions of the new facility is the processing of plutonium scrap generated at LASL and other sites. The feed for the scrap processing program is extremely varied, and a wide variety of contaminants are often encountered. Depending upon the scrap matrix and contaminants present, the majority of material receives a nitric acid/hydrofluoric acid or nitric acid/calcium fluoride leach. The plutonium nitrate solutions are then loaded onto an anion exchange column charged with DOWEX 1 x 4, 50 to 100 mesh, nitrate form resin. The column is eluted with 0.48 M hydroxyl amine nitrate. The Pu(NO/sub 3/)/sub 3/ is then precipitated as plutonium III oxalate which is calcined at 450 to 500/sup 0/C to yield a purified PuO/sub 2/ product.

  8. Technological and economical analysis of salient pole and permanent magnet synchronous machines designed for wind turbines

    NASA Astrophysics Data System (ADS)

    Gündoğdu, Tayfun; Kömürgöz, Güven

    2012-08-01

    Chinese export restrictions already reduced the planning reliability for investments in permanent magnet wind turbines. Today the production of permanent magnets consumes the largest proportion of rare earth elements, with 40% of the rare earth-based magnets used for generators and other electrical machines. The cost and availability of NdFeB magnets will likely determine the production rate of permanent magnet generators. The high volatility of rare earth metals makes it very difficult to quote a price. Prices may also vary from supplier to supplier to an extent of up to 50% for the same size, shape and quantity with a minor difference in quality. The paper presents the analysis and the comparison of salient pole with field winding and of peripheral winding synchronous electrical machines, presenting important advantages. A neodymium alloy magnet rotor structure has been considered and compared to the salient rotor case. The Salient Pole Synchronous Machine and the Permanent Magnet Synchronous Machine were designed so that the plate values remain constant. The Eddy current effect on the windings is taken into account during the design, and the efficiency, output power and the air-gap flux density obtained after the simulation were compared. The analysis results clearly indicate that Salient Pole Synchronous Machine designs would be attractive to wind power companies. Furthermore, the importance of the design of electrical machines and the determination of criteria are emphasized. This paper will be a helpful resource in terms of examination and comparison of the basic structure and magnetic features of the Salient Pole Synchronous Machine and Permanent Magnet Synchronous Machine. Furthermore, an economic analysis of the designed machines was conducted.

  9. Recycling metal scrap. (Latest citations from the EI compendex*plus database). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations concerning the processes, techniques, and benefits of recycling metal scrap. The recycling processes for aluminum, chromium, nickel, cobalt, lead, copper, and precious metals scrap are discussed. Recycling in the jewelry, electronics, milling, beverage, automotive, and aircraft industries is considered. Analyses of the current global scrap metal recycling trends are included. (Contains 250 citations and includes a subject term index and title list.)

  10. Magnetic actuator intended for left ventricular assist system

    NASA Astrophysics Data System (ADS)

    Saotome, H.; Okada, T.

    2006-04-01

    With the goal of developing an artificial heart, the authors fabricated a prototype pump employing a linear motion magnetic actuator, and carried out performance tests. The actuator is composed of two disk-shaped Nd-Fe-B magnets having a diameter of 80 mm and a thickness of 7 mm. The disks are magnetized in the direction normal to the circular surface, and are formed by semicircular pieces; one semicircle serves as a N pole and the other as a S pole. The magnets face each other in the actuator. One magnet is limited to spin around its axis while the second magnet is limited to move in linear motion along its axis. In this way, the circumferential rotation of one of the magnets produces reciprocating forces on the other magnet, causing it to move back and forth. This coupled action produces a pumping motion. Because the two magnets are magnetically coupled without any mechanical contact, the rotating magnet does not have to be implanted and should be placed outside the body. The rotating magnet is driven by a motor. The motor power is magnetically conveyed, via the rotating magnet, to the implanted linear motion magnet through the skin. The proposed system yields no problems with infection that would otherwise require careful treatment in a system employing a tube penetrating the skin for power transmission. Comparison of the proposed system with another system using a transcutaneous transformer shows that our system has good potential to occupy a smaller space in the body, because it obviates implantation of a secondary part of the transformer, a power supply, and armature windings. The dimensions of the trial pump are designed in accordance with the fluid mechanical specifications of a human left ventricle, by computing magnetic fields that provide the magnetic forces on the magnets. The output power of the trial pump, 1.0 W at 87 beats/min, is experimentally obtained under the pressure and flow conditions of water, 100 mm Hg and 4.5 l/min.

  11. United States copper metal and scrap use and trade patterns, 1995‒2014

    USGS Publications Warehouse

    Goonan, Thomas G.

    2016-06-17

    This report considers changes to the copper and copper scrap industries of the United States. For the study period, 1995 through 2014, U.S. refined copper production from all sources (primary and secondary materials) decreased from 2.28 million metric tons (Mt) of copper to 1.05 Mt (a 54 percent decrease). During the same period, U.S. copper scrap net exports increased from 0.203 Mt to 0.737 Mt (a 263 percent increase and a compound annual growth rate of about 7.0 percent per year). Copper and copper scrap prices (in constant 2014 dollars) rose such that 2014 prices were about 48 percent greater than 1995 prices. From 1995 through 2014, Chinese imports of copper scrap from the United States grew from 0.061 Mt to 0.569 Mt (an increase of about 830 percent and a compound annual growth rate of about 12.5 percent per year). In 2011, Chinese imports of U.S. copper scrap peaked at 0.745 Mt of contained copper. In 1995, Chinese imports of U.S. copper scrap accounted for 17 percent of U.S. copper scrap exports. By 2014, Chinese imports accounted for 69 percent of U.S. copper scrap exports (by weight), and Chinese imports of U.S. copper scrap were valued at $1.45 billion.

  12. Role of molten salt flux in melting of used beverage container (UBC) scrap

    SciTech Connect

    Ye, J.; Sahai, Y.

    1995-12-31

    Recycling of aluminum scrap, such as Used Beverage Container (UBC) scrap is steadily increasing. In secondary remelting of such scrap, it is a common practice to use protective molten salt cover. An appropriate salt protects metal from oxidation, promotes coalescence of the suspended metal droplets, and separates clean metal from the oxide contamination. The molten salt also reacts with metal. This causes metal loss and change of resulting metal composition. In this paper, role of molten salt fluxes in melting of UBC scrap is discussed, and selection criteria for molten salt are provided.

  13. A note on scrap in the 1992 U.S. input-output tables

    USGS Publications Warehouse

    Swisko, George M.

    2000-01-01

    Introduction A key concern of industrial ecology and life cycle analysis is the disposal and recycling of scrap. One might conclude that the U.S. input-output tables are appropriate tools for analyzing scrap flows. Duchin, for instance, has suggested using input-output analysis for industrial ecology, indicating that input-output economics can trace the stocks and flows of energy and other materials from extraction through production and consumption to recycling or disposal. Lave and others use input-output tables to design life cycle assessment models for studying product design, materials use, and recycling strategies, even with the knowledge that these tables suffer from a lack of comprehensive and detailed data that may never be resolved. Although input-output tables can offer general guidance about the interdependence of economic and environmental processes, data reporting by industry and the economic concepts underlying these tables pose problems for rigorous material flow examinations. This is especially true for analyzing the output of scrap and scrap flows in the United States and estimating the amount of scrap that can be recycled. To show how data reporting has affected the values of scrap in recent input-output tables, this paper focuses on metal scrap generated in manufacturing. The paper also briefly discusses scrap that is not included in the input-output tables and some economic concepts that limit the analysis of scrap flows.

  14. Supply Chain Modeling: Downstream Risk Assessment Methodology (DRAM) Demonstration of Capability

    DTIC Science & Technology

    2015-04-01

    demand for materials in their raw forms. This briefing demonstrates the operation of DRAM using the neodymium -iron-boron (NdFeB) magnet supply chain as...operation on neodymium magnet supply chain  Prototype test case developed from available data  Model for analysis of downstream supply chains for...using the neodymium -iron-boron (NdFeB) magnet supply chain as a test case. That demonstration was facilitated by using data that IDA had acquired on

  15. Solids loading evaluation for HB-line scrap recovery filters

    SciTech Connect

    Crowder, M.L.

    2000-08-08

    The HB-Line Scrap Recovery facility uses wire screen filters to remove solids from plutonium-containing solutions transferred from the slab tank dissolvers. At times, the accumulation of solids is large enough to cause blinding (i.e., pluggage) of the filters. If the solids contain undissolved plutonium, significant accumulation of fissile material could impact operations. To address this potential issue, experiments were performed to define the minimum solids required to completely blind a filter. The solids loading experiments were performed by arranging 25- and 10-{micro}m HB-Line filters in series to simulate the equipment in the scrap recovery process. Separate tests were performed using coarse and fine glass frit and cerium oxide powder suspended in 35 wt% sodium nitrate solution using a small turbine mixer. The solution and solids were transferred from a reservoir through the filter housings by vacuum. In each case, the 25-{micro}m filter blinded first and was full of wet cake. After drying and accounting for the sodium nitrate in the filter cake, the following results were obtained. The results of the solids loading tests demonstrated that at least 800 g of solids accumulated in the filter housing before flow stopped. The actual amount of collected material was dependent upon the physical properties of the solids such as density and particle size. The mass of solids collected by the blinded 25-{micro}m filter increased when successively finer solids were used in the experiments. Based on these results, one should anticipate that filters in the HB-Line Scrap Recovery Facility have the potential to collect similar quantities of material before transfer of solution from the dissolvers is severely impacted.

  16. Supply Chain Modeling: Downstream Risk Assessment Methodology (DRAM) Summary of Development and Application

    DTIC Science & Technology

    2015-04-01

    This briefing demonstrates the operation of DRAM using the neodymium -iron-boron (NdFeB) magnet supply chain as a test case. It can also serve as a...is necessary to assess risk more precisely and to evaluate and support proposed risk mitigation measures. Develop DRAM—Approach  Use neodymium ...the specific approach taken to develop the DRAM methodology and build a prototype supply chain model for neodymium iron boron (NdFeB) magnets. These

  17. Considerations in recycling contaminated scrap metal and rubble

    SciTech Connect

    Kluk, A.F. ); Hocking, E.K. )

    1992-01-01

    Management options for the Department of Energy's increasing amounts of contaminated scrap metal and rubble include reuse as is, disposal, and recycling. Recycling, with its promise of resource recovery, virgin materials conservation, and land disposal minimization, emerges as a preferred management technique. Implementing a cost effective recycling program requires resolution of several issues including: establishing release limits for contaminants, controlling use of recycled materials creating effective public communication programs; developing economical, reliable assay technologies; managing secondary waste streams, expanding availability of unrestricted markets; and solving conflicting legal considerations.

  18. Considerations in recycling contaminated scrap metal and rubble

    SciTech Connect

    Kluk, A.F.; Hocking, E.K.

    1992-07-01

    Management options for the Department of Energy`s increasing amounts of contaminated scrap metal and rubble include reuse as is, disposal, and recycling. Recycling, with its promise of resource recovery, virgin materials conservation, and land disposal minimization, emerges as a preferred management technique. Implementing a cost effective recycling program requires resolution of several issues including: establishing release limits for contaminants, controlling use of recycled materials creating effective public communication programs; developing economical, reliable assay technologies; managing secondary waste streams, expanding availability of unrestricted markets; and solving conflicting legal considerations.

  19. Carbothermic Aluminum Production Using Scrap Aluminum As A Coolant

    DOEpatents

    LaCamera, Alfred F.

    2002-11-05

    A process for producing aluminum metal by carbothermic reduction of alumina ore. Alumina ore is heated in the presence of carbon at an elevated temperature to produce an aluminum metal body contaminated with about 10-30% by wt. aluminum carbide. Aluminum metal or aluminum alloy scrap then is added to bring the temperature to about 900-1000.degree. C. and precipitate out aluminum carbide. The precipitated aluminum carbide is filtered, decanted, or fluxed with salt to form a molten body having reduced aluminum carbide content.

  20. 16 CFR 300.29 - Garments or products composed of or containing miscellaneous cloth scraps.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Garments or products composed of or containing miscellaneous cloth scraps. 300.29 Section 300.29 Commercial Practices FEDERAL TRADE COMMISSION... Labeling § 300.29 Garments or products composed of or containing miscellaneous cloth scraps. (a) For...

  1. Removal of contaminants in leachate from landfill by waste steel scrap and converter slag.

    PubMed

    Oh, Byung-Taek; Lee, Jai-Young; Yoon, Jeyong

    2007-08-01

    This study may be the first investigation to be performed into the potential benefits of recycling industrial waste in controlling contaminants in leachate. Batch reactors were used to evaluate the efficacy of waste steel scrap and converter slag to treat mixed contaminants using mimic leachate solution. The waste steel scrap was prepared through pre-treatment by an acid-washed step, which retained both zero-valent iron site and iron oxide site. Extensive trichloroethene (TCE) removal (95%) occurred by acid-washed steel scrap within 48 h. In addition, dehalogenation (Cl(-) production) was observed to be above 7.5% of the added TCE on a molar basis for 48 h. The waste steel scrap also removed tetrachloroethylene (PCE) through the dehalogenation process although to a lesser extent than TCE. Heavy metals (Cr, Mn, Cu, Zn, As, Cd, and Pb) were extensively removed by both acid-washed steel scrap and converter slag through the adsorption process. Among salt ions (NH (4)(+) , NO (3)(-) , and PO (4)(3-) ), PO (4)(3-) was removed by both waste steel scrap (100% within 8 h) and converter slag (100% within 20 min), whereas NO (3)(-) and NH (4)(+ ) were removed by waste steel scrap (100% within 7 days) and converter slag (up to 50% within 4 days) respectively. This work suggests that permeable reactive barriers (PRBs) with waste steel scrap and converter slag might be an effective approach to intercepting mixed contaminants in leachate from landfill.

  2. Enhanced high-solids anaerobic digestion of waste activated sludge by the addition of scrap iron.

    PubMed

    Zhang, Yaobin; Feng, Yinghong; Yu, Qilin; Xu, Zibin; Quan, Xie

    2014-05-01

    Anaerobic digestion of waste activated sludge usually requires pretreatment procedure to improve the bioavailability of sludge, which involves considerable energy and high expenditures. This study proposes a cost-effective method for enhanced anaerobic digestion of sludge without a pretreatment by directly adding iron into the digester. The results showed that addition of Fe(0) powder could enhance 14.46% methane yield, and Fe scrap (clean scrap) could further enhance methane yield (improving rate 21.28%) because the scrap has better mass transfer efficiency with sludge and liquid than Fe(0) powder. The scrap of Fe with rust (rusty scrap) could induce microbial Fe(III) reduction, which resulted in achieving the highest methane yield (improving rate 29.51%), and the reduction rate of volatile suspended solids (VSS) was also highest (48.27%) among Fe powder, clean scrap and rusty scrap. PCR-DGGE proved that the addition of rusty scrap could enhance diversity of acetobacteria and enrich iron-reducing bacteria to enhance degradation of complex substrates.

  3. 40 CFR 761.72 - Scrap metal recovery ovens and smelters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Scrap metal recovery ovens and..., AND USE PROHIBITIONS Storage and Disposal § 761.72 Scrap metal recovery ovens and smelters. Any person... § 761.60(b), metal surfaces in PCB remediation waste regulated under § 761.61, or metal surfaces in...

  4. 40 CFR 761.72 - Scrap metal recovery ovens and smelters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Scrap metal recovery ovens and..., AND USE PROHIBITIONS Storage and Disposal § 761.72 Scrap metal recovery ovens and smelters. Any person... § 761.60(b), metal surfaces in PCB remediation waste regulated under § 761.61, or metal surfaces in...

  5. 40 CFR 761.72 - Scrap metal recovery ovens and smelters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Scrap metal recovery ovens and..., AND USE PROHIBITIONS Storage and Disposal § 761.72 Scrap metal recovery ovens and smelters. Any person... § 761.60(b), metal surfaces in PCB remediation waste regulated under § 761.61, or metal surfaces in...

  6. 29 CFR 570.63 - Occupations involved in the operation of paper-products machines, scrap paper balers, and paper...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... machines, scrap paper balers, and paper box compactors (Order 12). 570.63 Section 570.63 Labor Regulations... involved in the operation of paper-products machines, scrap paper balers, and paper box compactors (Order..., scrap paper baler, paper box compactor, or vertical slotter. (ii) Platen die-cutting press,...

  7. The Militarization of the Prairie: Scrap Drives, Metaphors, and the "Omaha World-Herald's" 1942 "Nebraska Plan"

    ERIC Educational Resources Information Center

    Kimble, James J.

    2007-01-01

    In WW II, there was no nationwide shortage of scrap on the home front. In backyards, attics, barns, ditches, garages, and factory storage sheds across the country, all sorts of scrap material awaited transport and eventual conversion to arms. Yet the public's awareness of the scrap, and the national willpower necessary to collect it, seemed to be…

  8. Upgrading scrap automotive aluminum alloys with the impulse atomization and quench technique

    SciTech Connect

    Olsen, K.; Sterzik, G.; Henein, H.

    1995-12-31

    As aluminum alloy usage in automobiles grows, there are increasing demands on recycling processes and facilities to deal with mixed alloy automotive aluminum scrap. These processes and facilities strive to produce near virgin aluminum stock, which can be relatively costly and difficult. One alternative is to use physical processing methods to upgrade the scrap properties instead of chemically refining the scrap. The Impulse Atomization Process (IAP, patent pending) is a new process for making metallic and ceramic powders. It can produce fine homogeneous microstructures in scrap aluminum alloys due to high undercooling and rapid solidification. The particles have a very narrow size distribution and are in a convenient form for consolidation. This paper compares and contrasts the microstructural features of Impulse Atomized and quenched Impulse Atomized powders, for both AL6061 and a scrap aluminum alloy composition.

  9. Properties of concrete containing scrap-tire rubber--an overview.

    PubMed

    Siddique, Rafat; Naik, Tarun R

    2004-01-01

    Solid waste management is one of the major environmental concerns in the United States. Over 5 billion tons of non-hazardous solid waste materials are generated in USA each year. Of these, more than 270 million scrap-tires (approximately 3.6 million tons) are generated each year. In addition to this, about 300 million scrap-tires have been stockpiled. Several studies have been carried out to reuse scrap-tires in a variety of rubber and plastic products, incineration for production of electricity, or as fuel for cement kilns, as well as in asphalt concrete. Studies show that workable rubberized concrete mixtures can be made with scrap-tire rubber. This paper presents an overview of some of the research published regarding the use of scrap-tires in portland cement concrete. The benefits of using magnesium oxychloride cement as a binder for rubberized concrete mixtures are also presented. The paper details the likely uses of rubberized concrete.

  10. Synthesis of Samarium-Titanium and Neodymium Iron-Boron Magnetic Films with Special Anisotropies.

    NASA Astrophysics Data System (ADS)

    Wickramasekara, Lee

    Rare earth-transition metal film magnets of Nd -Fe-B and several new phases of Sm-Ti-Fe system have been synthesised by special sputtering methods to utilize the high magnetic anisotropies of these alloys. The magnetic properties of these film magnets were observed to be strongly dependent on the film textures. Thus, by varying the sputtering conditions we were able to synthesize films with crystal textures which gives rise to special anisotropies. Crystalline films of Sm(FeTi)(,2) and SmCo(,3) were synthesized with large perpendicular anisotropy of 10('6) erg/cc, whereas (SmTi)Fe(,5) and Sm(,2)(FeCoZr)(,17) were synthesized with inplane anisotropy and static energy product of 20 MG-Oe. The Nd(,2)Fe(,14)B film system is unique due to the fact that it can be synthesized with large perpendicular anisotropy of 1.5 x 10('7) erg/cc with 9 kG remanent and 16 kOe coercive force or inplane anisotropy with 16 MG-Oe static energy product by controlling the sputtering rate. In addition, SmCo(,5), (SmTi)Fe(,5), and Sm(,2)(FeCoZr)(,17) film systems were synthesized in amorphous states in the presence of inplane magnetic field of 2.5 kOe and exhibited large uniaxial inplane anisotropy of 10('6) erg/cc. In particular, upon annealing from the amorphous state in the same magnetic field, the SmCo(,5) phase exhibited a coercive force larger than 22 kOe and its moment could not be rotated within the film plane with a 22 kOe external field, thus increasing the uniaxial inplane anisotropy constant to at least 10('7) erg/cc.

  11. Magnetic microparticles for harvesting Dunaliella tertiolecta microalgae

    NASA Astrophysics Data System (ADS)

    Manousakis, Emmanouil; Manariotis, Ioannis D.

    2016-04-01

    Microalgae based biofuels have been considered as a sustainable alternative to traditional fuels due to the higher biomass yield and lipid productivity, and the ability to be cultivated in non arable land making them not antagonistic with food supply chain. Due to the dilute nature of algal cultures and the small size of algae cells, the cost of microalgae harvesting is so far a bottleneck in microalgal based biofuel production. It is estimated that the algal recovery cost is at least 20-30% of the total biomass production cost. Various processes have been employed for the recovery of microalgal biomass, which include centrifugation, gravity separation, filtration, flocculation, and flotation. Recently, magnetophoric harvesting has received increased attention for algal separation, although it has been first applied for algal removal since the mid of 1970s. The magnetic separation process is based on bringing in contact the algal cells with the magnetic particles, and separating them from the liquid by an external magnetic force. The aim of this work was to investigate the harvesting of microalgae cells using Fe3O4 magnetic microparticles (MPs). Dunaliella tertiolecta was selected as a representative for marine microalgae. D. tertiolecta was cultivated under continuous artificial light, in 20 L flasks. Fe3O4 MPs were prepared by microwave irradiation of FeSO4 7H2O in an alkaline solution. Numerous batch and flow-through experiments were conducted in order to investigate the effect of the magnetic material addition on microalgae removal. Batch experiments were conducted examining different initial algal and MPs concentration, and algal culture volume. Flow-through experiments were conducted in a laboratory scale column made of Plexiglass. External magnetic field was applied by arranging at various points across the column length NdFeB magnets. Algal removal in flow-through experiments ranged from 70 to 85% depending on the initial MPs concentration and the hydraulic

  12. CHANGING THE LANDSCAPE--LOW-TECH SOLUTIONS TO THE PADUCAH SCRAP METAL REMOVAL PROJECT ARE PROVIDING SAFE, COST-EFFECTIVE REMEDIATION OF CONTAMINATED SCRAP YARDS

    SciTech Connect

    Watson, Dan; Eyman, Jeff

    2003-02-27

    Between 1974 and 1983, contaminated equipment was removed from the Paducah Gaseous Diffusion Plant (PGDP) process buildings as part of an enrichment process upgrade program. The upgrades consisted of the dismantlement, removal, and on-site storage of contaminated equipment, cell components, and scrap material (e.g., metal) from the cascade facilities. Scrap metal including other materials (e.g., drums, obsolete equipment) not related to this upgrade program have thus far accumulated in nine contiguous radiologically-contaminated and non-contaminated scrap yards covering 1.05E5 m2 (26 acres) located in the northwestern portion of the PGDP. This paper presents the sequencing of field operations and methods used to achieve the safe removal and disposition of over 47,000 tonnes (53,000 tons) of metal and miscellaneous items contained in these yards. The methods of accomplishment consist of mobilization, performing nuclear criticality safety evaluations, moving scrap metal to ground level, inspection and segregation, sampling and characterization, scrap metal sizing, packaging and disposal, and finally demobilization. Preventing the intermingling of characteristically hazardous and non-hazardous wastes promotes waste minimization, allowing for the metal and materials to be segregated into 13 separate waste streams. Low-tech solutions such as using heavy equipment to retrieve, size, and package scrap materials in conjunction with thorough planning that integrates safe work practices, commitment to teamwork, and incorporating lessons learned ensures that field operations will be conducted efficiently and safely.

  13. Potential radioactive scrap metal quantities from nuclear power plants worldwide

    SciTech Connect

    Nieves, L.A.; Tilbrook, R.W.

    1996-01-01

    Approximately 12 million tons of scrap metals are likely to be generated worldwide during the next 50 years from decommissioning and dismantling nuclear power plants. A large portion of this material will be only slightly contaminated it at all, and, it it is releasable, it would have a scrap value of billions of dollars. Disposition of the metal is complicated because criteria for release of the metal vary among countries depending on whether the metal is surface of volumetrically contaminated. At present, there is no internationally accepted standard for release of low-level contaminated materials, though both the International Atomic Energy Agency and the Commission of European Communities are in the process of developing recommendations. If the metals are not releasable, they will most likely be disposed of as low-level waste. However, currently available low-level waste repository capacity is limited and costly. Using repositories to dispose of metals that could potentially be decontaminated and recycled is probably not good resource management. This article presents estimates of metal quantities by metal type and contamination that will be come available as nuclear power plants are retired. Topics discussed are major issues related to inventory estimates, methods used to estimate metal masses; and metal masses summarized by reference plant category and total for world region by metal type and activity category. 1 fig., 4 tabs.

  14. Assessment of DOE radioactive scrap metal disposition options: Economic analysis

    SciTech Connect

    Butler, C.R.; Kasper, K.M.; Bossert, S.J.

    1997-12-31

    The analysis defines a baseline management approach for the estimated 1.2 million tons of radioactive scrap metal (RSM) expected to be generated from DOE deactivation and decommissioning activities, and compares two options using a net cost model. The baseline and competing options are described here. Baseline: Packaging and land disposal of RSM using standard DOE procedures, and procurement of a virgin-metal waste container (for comparative analysis with competing options). Option 1: RSM recycling by melting and fabrication into limited reuse products, generally waste containers. The analysis considers different types of waste container products. Option 2: RSM recycling by decontamination and release of scrap metal into commercial markets, and procurement of a comparable virgin-metal waste container. The analysis concludes that, for standard waste container products, the net cost of recycling RSM under Option 2 is lower than the net cost of recycling RSM under Option 1, considering the projected costs of melting RSM and fabricating drums and boxes. The analysis also suggests that the preferred products for recycling under Option 1 are specialized waste containers fabricated with high-value metals (e.g. stainless steel Defense Waste Processing Facility canisters). Other factors favoring each of the recycling options, are also identified.

  15. Assessment of recycling or disposal alternatives for radioactive scrap metal

    SciTech Connect

    Murphie, W.E.; Lilly, M.J. III; Nieves, L.A.; Chen, S.Y.

    1993-10-01

    The US Department of Energy, Office of Environmental Restoration and Waste Management, is participating with the Organization for Economic Cooperation and Development (OECD) is an evaluation of management alternatives for radioactive scarp metals. For this purpose, Argonne National Laboratory is assessing alternatives for radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing environmental and societal implications of recycling and/or disposal process alternatives (with metal replacement). Findings will be presented in a report from the OECD Task Group. This paper focuses on the radiological risk assessment and dose estimate sensitivity analysis. A ``tiered`` concept for release categories, with and without use restrictions, is being developed. Within the tiers, different release limits may be indicated for specific groupings of radionuclides. Depending on the spectrum of radionuclides that are present and the level of residual activity after decontamination and/or smelting, the scrap may be released for unrestricted public use or for specified public uses, or it may be recycled within the nuclear industry. The conversatism of baseline dose estimates is examined, and both more realistic parameter values and protective measures for workers are suggested.

  16. Continuous Extraction of Nickel from Superalloy Scraps Using Zinc Circulation

    NASA Astrophysics Data System (ADS)

    Yagi, Ryohei; Okabe, Toru H.

    2017-02-01

    A novel technique for the continuous extraction of nickel (Ni) from Ni-based superalloy scraps using molten zinc (Zn) has been proposed, and its feasibility was experimentally demonstrated. The newly developed approach allows for extraction of Ni metal directly from superalloy scraps with simultaneous separation of the Zn from the resulting Zn-Ni alloy. The optimal conditions for the extraction of Ni and separation of valuable elements such as rhenium (Re), tantalum (Ta), and tungsten (W) were determined by varying major process parameters including the reaction time and configuration of the reaction chamber. The proposed method has been successfully utilized for the production of the superalloy containing 62.8 mass pct of Ni and 15.5 mass pct of refractory metals (Re, W, and Ta). Under certain conditions, 41 pct of the Ni contained in the superalloy could be extracted at 1173 K (900 °C) over 48 hours, producing an alloy containing 84.0 mass pct of Ni and 0.2 mass pct of the refractory metals.

  17. Volatilisation and oxidation of aluminium scraps fed into incineration furnaces.

    PubMed

    Biganzoli, Laura; Gorla, Leopoldo; Nessi, Simone; Grosso, Mario

    2012-12-01

    Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy.

  18. Mercury-impacted scrap metal: Source and nature of the mercury.

    PubMed

    Finster, Molly E; Raymond, Michelle R; Scofield, Marcienne A; Smith, Karen P

    2015-09-15

    The reuse and recycling of industrial solid wastes such as scrap metal is supported and encouraged both internationally and domestically, especially when such wastes can be used as substitutes for raw material. However, scrap metal processing facilities, such as mini-mills, have been identified as a source of mercury (Hg) emissions in the United States. This research aims to better define some of the key issues related to the source and nature of mercury in the scrap metal waste stream. Overall, it is difficult to pinpoint the key mercury sources feeding into scrap metal recycling facilities, quantify their associated mercury concentrations, or determine which chemical forms are most significant. Potential sources of mercury in scrap metal include mercury switches from discarded vehicles, electronic-based scrap from household appliances and related industrial systems, and Hg-impacted scrap metal from the oil and gas industry. The form of mercury associated with scrap metal varies and depends on the source type. The specific amount of mercury that can be adsorbed and retained by steel appears to be a function of both metallurgical and environmental factors. In general, the longer the steel is in contact with a fluid or condensate that contains measurable concentrations of elemental mercury, the greater the potential for mercury accumulation in that steel. Most mercury compounds are thermally unstable at elevated temperatures (i.e., above 350 °C). As such, the mercury associated with impacted scrap is expected to be volatilized out of the metal when it is heated during processing (e.g., shredding or torch cutting) or melted in a furnace. This release of fugitive gas (Hg vapor) and particulates, as well as Hg-impacted bag-house dust and control filters, could potentially pose an occupational exposure risk to workers at a scrap metal processing facility. Thus, identifying and characterizing the key sources of Hg-impacted scrap, and understanding the nature and extent

  19. Geomagnetic field modulates artificial static magnetic field effect on arterial baroreflex and on microcirculation

    NASA Astrophysics Data System (ADS)

    Gmitrov, Juraj

    2007-03-01

    Spreading evidence suggests that geomagnetic field (GMF) modulates artificial magnetic fields biological effect and associated with increased cardiovascular morbidity. To explore the underlying physiological mechanism we studied 350 mT static magnetic field (SMF) effect on arterial baroreflex-mediated skin microcirculatory response in conjunction with actual geomagnetic activity, reflected by K and K p indices. Fourteen experiments were performed in rabbits sedated by pentobarbital infusion (5 mg/kg/h). Mean femoral artery blood pressure, heart rate, and the ear lobe skin microcirculatory blood flow, measured by microphotoelectric plethysmogram (MPPG), were simultaneously recorded before and after 40 min of NdFeB magnets local exposure to sinocarotid baroreceptors. Arterial baroreflex sensitivity (BRS) was estimated from heart rate/blood pressure response to intravenous bolus injections of nitroprusside and phenylephrine. We found a significant positive correlation between SMF-induced increase in BRS and increment in microvascular blood flow (ΔBRS with ΔMPPG, r=0.7, p<0.009) indicated the participation of the arterial baroreflex in the regulation of the microcirculation and its enhancement after SMF exposure. Geomagnetic disturbance, as opposed to SMF, decreased both microcirculation and BRS, and counteracted SMF-induced increment in microcirculatory blood flow ( K-index with ΔMPPG; r s=-0.55, p<0.041). GMF probably affected central baroreflex pathways, diminishing SMF direct stimulatory effect on sinocarotid baroreceptors and on baroreflex-mediated vasodilatatory response. The results herein may thus point to arterial baroreflex as a possible physiological mechanism for magnetic-field cardiovascular effect. It seems that geomagnetic disturbance modifies artificial magnetic fields biological effect and should be taken into consideration in the assessment of the final effect.

  20. Bioleaching of electronic scrap by mixed culture of moderately thermophilic microorganisms

    NASA Astrophysics Data System (ADS)

    Ivǎnuş, D.; ǎnuş, R. C., IV; Cǎlmuc, F.

    2010-06-01

    A process for the metal recovery from electronic scrap using bacterial leaching was investigated. A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainages (AMDs) samples collected from several sulphide mines in Romania, and the bioleaching of electronic scrap was conducted both in shake flask and bioreactor. The results show that in the shake flask, the mixture can tolerate 50 g/L scrap after being acclimated to gradually increased concentrations of scrap. The copper extraction increases obviously in bioleaching of scrap with moderately thermophilic microorganisms supplemented with 0.4 g/L yeast extract at 180 r/min, 74% copper can be extracted in the pulp of 50 g/L scrap after 20 d. Compared with copper extractions of mesophilic culture, unacclimated culture and acclimated culture without addition of yeast extract, that of accliniated culture with addition of yeast extract is increased by 53%, 44% and 16%, respectively. In a completely stirred tank reactor, the mass fraction of copper and total iron extraction reach up to 81% and 56%, respectively. The results also indicate that it is necessary to add a large amount of acid to the pulp to extract copper from electronic scrap effectively.

  1. Detection and decontamination of residual energetics from ordnance and explosives scrap.

    PubMed

    Jung, Carina M; Newcombe, David A; Crawford, Don L; Crawford, Ronald L

    2004-02-01

    Extensive manufacturing of explosives in the last century has resulted in widespread contamination of soils and waters. Decommissioning and cleanup of these materials has also led to concerns about the explosive hazards associated with residual energetics still present on the surfaces of ordnance and explosives scrap. Typically, open burning or detonation is used to decontaminate ordinance and explosive scrap. Here the use of an anaerobic microbiological system applied as a bioslurry to decontaminate energetics from the surfaces of metal scrap is described. Decontamination of model metal scrap artificially contaminated with 2,4,6-trinitrotoluene and of decommissioned mortar rounds still containing explosives residue was examined. A portable ion mobility spectrometer was employed for the detection of residual explosives residues on the surfaces of the scrap. The mixed microbial populations of the bioslurries effectively decontaminated both the scrap and the mortar rounds. Use of the ion mobility spectrometer was an extremely sensitive field screening method for assessing decontamination and is a method by which minimally trained personnel can declare scrap clean with a high level of certainty.

  2. Magnetic ionic liquids as non-conventional extraction solvents for the determination of polycyclic aromatic hydrocarbons.

    PubMed

    Trujillo-Rodríguez, María J; Nacham, Omprakash; Clark, Kevin D; Pino, Verónica; Anderson, Jared L; Ayala, Juan H; Afonso, Ana M

    2016-08-31

    This work describes the applicability of magnetic ionic liquids (MILs) in the analytical determination of a group of heavy polycyclic aromatic hydrocarbons. Three different MILs, namely, benzyltrioctylammonium bromotrichloroferrate (III) (MIL A), methoxybenzyltrioctylammonium bromotrichloroferrate (III) (MIL B), and 1,12-di(3-benzylbenzimidazolium) dodecane bis[(trifluoromethyl)sulfonyl)]imide bromotrichloroferrate (III) (MIL C), were designed to exhibit hydrophobic properties, and their performance examined in a microextraction method for hydrophobic analytes. The magnet-assisted approach with these MILs was performed in combination with high performance liquid chromatography and fluorescence detection. The study of the extraction performance showed that MIL A was the most suitable solvent for the extraction of polycyclic aromatic hydrocarbons and under optimum conditions the fast extraction step required ∼20 μL of MIL A for 10 mL of aqueous sample, 24 mmol L(-1) NaOH, high ionic strength content of NaCl (25% (w/v)), 500 μL of acetone as dispersive solvent, and 5 min of vortex. The desorption step required the aid of an external magnetic field with a strong NdFeB magnet (the separation requires few seconds), two back-extraction steps for polycyclic aromatic hydrocarbons retained in the MIL droplet with n-hexane, evaporation and reconstitution with acetonitrile. The overall method presented limits of detection down to 5 ng L(-1), relative recoveries ranging from 91.5 to 119%, and inter-day reproducibility values (expressed as relative standard derivation) lower than 16.4% for a spiked level of 0.4 μg L(-1) (n = 9). The method was also applied for the analysis of real samples, including tap water, wastewater, and tea infusion.

  3. Beneficial reuse of US DOE Radioactive scrap metal

    SciTech Connect

    Motl, G.P.

    1995-01-19

    The US Department of Energy (DOE) has more than 2.5 million tons of radioactive scrap metal (RSM) that is either in inventory or expected to be generated over the next 25 years as major facilities within the weapons complex are decommissioned. Since much of this metal cannot be decontaminated easily, past practice has been to either retain this material in inventory or ship it to DOE disposal sites for burial. In an attempt to conserve natural resources and to avoid burial of this material at DOE disposal sites, options are now being explored to ``beneficially reuse`` this material. Under the beneficial reuse concept, RSM that cannot be decontaminated and free released is used in applications where the inherent contamination is not a detriment to its end use. This paper describes initiatives currently in progress in the United States that support the DOE beneficial reuse concept.

  4. INEL metal recycle radioactive scrap metal survey report

    SciTech Connect

    Funk, D.M.

    1994-09-01

    DOE requested that inventory and characterization of radioactive scrap metal (RSM) be conducted across the DOE complex. Past studies have estimated the metal available from unsubstantiated sources. In meetings held in FY-1993, with seven DOE sites represented and several DOE-HQ personnel present, INEL personnel discovered that these numbers were not reliable and that large stockpiles did not exist. INEL proposed doing in-field measurements to ascertain the amount of RSM actually available. This information was necessary to determine the economic viability of recycling and to identify feed stock that could be used to produce containers for radioactive waste. This inventory measured the amount of RSM available at the selected DOE sites. Information gathered included radionuclide content and chemical form, general radiation field, alloy type, and mass of metal.

  5. Recycling of metal bearing electronic scrap in a plasma furnace

    NASA Astrophysics Data System (ADS)

    Jarosz, Piotr; Małecki, Stanisław; Gargul, Krzysztof

    2011-12-01

    The recycling of electronic waste and the recovery of valuable components are large problems in the modern world economy. This paper presents the effects of melting sorted electronic scrap in a plasma furnace. Printed circuit boards, cables, and windings were processed separately. The characteristics of the obtained products (i.e., alloy metal, slag, dust, and gases) are presented. A method of their further processing in order to obtain commercial products is proposed. Because of the chemical composition and physical properties, the waste slag is environmentally inert and can be used for the production of abrasives. Process dusts containing large amounts of carbon and its compounds have a high calorific value. That makes it possible to use them for energy generation. The gas has a high calorific value, and its afterburning combined with energy recovery is necessary.

  6. Advanced technologies for decomtamination and conversion of scrap metal

    SciTech Connect

    Valerie MacNair; Steve Sarten; Thomas Muth; Brajendra Mishra

    1999-05-27

    The Department of Energy (DOE) faces the task of decommissioning much of the vast US weapons complex. One challenge of this effort includes the disposition of large amounts of radioactively contaminated scrap metal (RSM) including but not limited to steel, nickel, copper, and aluminum. The decontamination and recycling of RSM has become a key element in the DOE's strategy for cleanup of contaminated sites and facilities. Recycling helps to offset the cost of decommissioning and saves valuable space in the waste disposal facilities. It also reduces the amount of environmental effects associated with mining new metals. Work on this project is geared toward finding decontamination and/or recycling alternatives for the RSM contained in the decommissioned gaseous diffusion plants including approximately 40,000 tons of nickel. The nickel is contaminated with Technetium-99, and is difficult to remove using traditional decontamination technologies. The project, titled ``Advanced Technologies for Decontamination and Conversion of Scrap Metal'' was proposed as a four phase project. Phase 1 and 2 are complete and Phase 3 will complete May 31, 1999. Stainless steel made from contaminated nickel barrier was successfully produced in Phase 1. An economic evaluation was performed and a market study of potential products from the recycled metal was completed. Inducto-slag refining, after extensive testing, was eliminated as an alternative to remove technetium contamination from nickel. Phase 2 included successful lab scale and pilot scale demonstrations of electrorefining to separate technetium from nickel. This effort included a survey of available technologies to detect technetium in volumetrically contaminated metals. A new process to make sanitary drums from RSM was developed and implemented. Phase 3 included a full scale demonstration of electrorefining, an evaluation of electro-refining alternatives including direct dissolution, melting of nickel into anodes, a laser cutting

  7. Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

    SciTech Connect

    Biganzoli, Laura; Gorla, Leopoldo; Nessi, Simone; Grosso, Mario

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Aluminium packaging partitioning in MSW incineration residues is evaluated. Black-Right-Pointing-Pointer The amount of aluminium packaging recoverable from the bottom ashes is evaluated. Black-Right-Pointing-Pointer Aluminium packaging oxidation rate in the residues of MSW incineration is evaluated. Black-Right-Pointing-Pointer 80% of aluminium cans, 51% of trays and 27% of foils can be recovered from bottom ashes. - Abstract: Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy.

  8. Kinetics of scrap tyre pyrolysis under vacuum conditions

    SciTech Connect

    Lopez, Gartzen; Aguado, Roberto; Olazar, Martin Arabiourrutia, Miriam; Bilbao, Javier

    2009-10-15

    Scrap tyre pyrolysis under vacuum is attractive because it allows easier product condensation and control of composition (gas, liquid and solid). With the aim of determining the effect of vacuum on the pyrolysis kinetics, a study has been carried out in thermobalance. Two data analysis methods have been used in the kinetic study: (i) the treatment of experimental data of weight loss and (ii) the deconvolution of DTG (differential thermogravimetry) curve. The former allows for distinguishing the pyrolysis of the three main components (volatile components, natural rubber and styrene-butadiene rubber) according to three successive steps. The latter method identifies the kinetics for the pyrolysis of individual components by means of DTG curve deconvolution. The effect of vacuum in the process is significant. The values of activation energy for the pyrolysis of individual components of easier devolatilization (volatiles and NR) are lower for pyrolysis under vacuum with a reduction of 12 K in the reaction starting temperature. The kinetic constant at 503 K for devolatilization of volatile additives at 0.25 atm is 1.7 times higher than that at 1 atm, and that corresponding to styrene-butadiene rubber at 723 K is 2.8 times higher. Vacuum enhances the volatilization and internal diffusion of products in the pyrolysis process, which contributes to attenuating the secondary reactions of the repolymerization and carbonization of these products on the surface of the char (carbon black). The higher quality of carbon black is interesting for process viability. The large-scale implementation of this process in continuous mode requires a comparison to be made between the economic advantages of using a vacuum and the energy costs, which will be lower when the technologies used for pyrolysis require a lower ratio between reactor volume and scrap tyre flow rate.

  9. Leaching of DOC, DN, and inorganic constituents from scrap tires.

    PubMed

    Selbes, Meric; Yilmaz, Ozge; Khan, Abdul A; Karanfil, Tanju

    2015-11-01

    One concern for recycle and reuse of scrap tires is the leaching of tire constituents (organic and inorganic) with time, and their subsequent potential harmful impacts in environment. The main objective of this study was to examine the leaching of dissolved organic carbon (DOC), dissolved nitrogen (DN), and selected inorganic constituents from scrap tires. Different sizes of tire chips and crumb rubber were exposed to leaching solutions with pH's ranging from 3.0 to 10.0 for 28days. The leaching of DOC and DN were found to be higher for smaller size tire chips; however, the leaching of inorganic constituents was independent of the size. In general, basic pH conditions increased the leaching of DOC and DN, whereas acidic pH conditions led to elevated concentrations of metals. Leaching was minimal around the neutral pH values for all the monitored parameters. Analysis of the leaching rates showed that components associated with the rubbery portion of the tires (DOC, DN, zinc, calcium, magnesium, etc.) exhibited an initial rapid followed by a slow release. On the other hand, a constant rate of leaching was observed for iron and manganese, which are attributed to the metal wires present inside the tires. Although the total amounts that leached varied, the observed leaching rates were similar for all tire chip sizes and leaching solutions. Operation under neutral pH conditions, use of larger size tire chips, prewashing of tires, and removal of metal wires prior to application will reduce the impact of tire recycle and reuse.

  10. Composition related magnetic properties and coercivity mechanism for melt spun [(La0.5Ce0.5)1-xREx]10Fe84B6 (RE=Nd or Dy) nanocomposite alloys

    NASA Astrophysics Data System (ADS)

    Hussain, M.; Liu, J.; Zhao, L. Z.; Zhong, X. C.; Zhang, G. Q.; Liu, Z. W.

    2016-02-01

    Room temperature magnetic properties and coercivity mechanisms for nanocomposites [(La0.5Ce0.5)1-xREx]10Fe84B6 (RE=Nd or Dy; x=0, 0.3, 0.5, and 0.7) alloys prepared by melt-spinning have been investigated. Nd and Dy substitutions can improve the hard magnetic properties, especially the coercivity of [(La0.5Ce0.5)]10Fe84B6 alloy. The largest values of intrinsic coercivity Hc and maximum energy product (BH)max for the Dy substituted alloys are 714 kA/m and 41 kJ/m3, respectively, whereas for Nd substituted alloys, Hc=365 kA/m and (BH)max=120 kJ/m3 were obtained for x=0.7. The different elevated temperature behaviors were also found for Nd and Dy added alloys. The composition dependent coercivity mechanisms for Dy and Nd substituted alloys are evident based on the temperature dependence of coercivity described by domain wall pinning and reverse domain nucleation models. It is found that the domain wall pinning mechanism is possibly responsible for [(LaCe)Nd]FeB alloys while reverse domain nucleation is more likely responsible for[(LaCe)Dy]FeB alloys.

  11. The Study for Recycling NORM - Contaminated Steel Scraps from Steel Industry

    SciTech Connect

    Tsai, K. F.; Lee, Y. S.; Chao, H. E.

    2003-02-24

    Since 1994, most of the major steel industries in Taiwan have installed portal monitor to detect the abnormal radiation in metal scrap feed. As a result, the discovery of NORM (Naturally Occurring Radioactive Material) has increased in recent years. In order to save the natural resources and promote radiation protection, an experimental melting process for the NORM contaminated steel scraps was carried out by the Institute of Nuclear Energy Research (INER) Taiwan, ROC. The experimental melting process has a pretreatment step that includes a series of cutting and removal of scales, sludge, as well as combustible and volatile materials on/in the steel scraps. After pretreatment the surface of the steel scraps are relatively clean. Then the scraps are melted by a pilot-type induction furnace. This experiment finally produced seven ingots with a total weight of 2,849 kg and 96.8% recovery. All of the surface dose rates are of the background values. The activity concentrations of these ingots are also below the regulatory criteria. Thus, these NORM-bearing steel scraps are ready for recycling. This study has been granted by the regulatory authority.

  12. A Pilot Assessment of Occupational Health Hazards in the US Electronic Scrap Recycling Industry

    PubMed Central

    Ceballos, Diana M.; Gong, Wei; Page, Elena

    2015-01-01

    The National Institute for Occupational Safety and Health (NIOSH) surveyed a randomly selected sample of electronic scrap (e-scrap) recycling facilities nationwide to characterize work processes, exposures, and controls. Despite multiple attempts to contact 278 facilities, only 47 responded (17% response rate). Surveyed facilities reported recycling a wide variety of electronics. The most common recycling processes were manual dismantling and sorting. Other processes included shredding, crushing, and automated separation. Many facilities reported that they had health and safety programs in place. However, some facilities reported the use of compressed air for cleaning, a practice that can lead to increased employee dust exposures, and some facilities allowed food and drinks in the production areas, a practice that can lead to ingestion of contaminants. Although our results may not be generalizable to all US e-scrap recycling facilities, they are informative regarding health and safety programs in the industry. We concluded that e-scrap recycling has the potential for a wide variety of occupational exposures particularly because of the frequent use of manual processes. On-site evaluations of e-scrap recyclers are needed to determine if reported work processes, practices, and controls are effective and meet current standards and guidelines. Educating the e-scrap recycling industry about health and safety best practices, specifically related to safe handling of metal dust, would help protect employees. PMID:25738822

  13. Cost-Effective Consolidation of Fine Aluminum Scrap for Increased Remelting Effieciency

    SciTech Connect

    William Van Geertruyden

    2005-09-22

    The main objective of this research was to develop a new re-melting process for fine or light gauge aluminum scrap products that exhibits dramatic improvements in energy efficiency. Light gauge aluminum scrap in the form of chips, turnings, and borings has historically been underutilized in the aluminum recycling process due to its high surface area to volume ratio resulting in low melt recovery. Laboratory scale consolidation experiments were performed using loose aluminum powder as a modeling material as well as shredded aluminum wire scrap. The processing parameters necessary to create consolidated aluminum material were determined. Additionally, re-melting experiments using consolidated and unconsolidated aluminum powder confirmed the hypothesis that metal recovery using consolidated material will significantly improve by as much as 20%. Based on this research, it is estimated that approximately 495 billion Btu/year can be saved by implementation of this technology in one domestic aluminum rolling plant alone. The energy savings are realized by substituting aluminum scrap for primary aluminum, which requires large amounts of energy to produce. While there will be an initial capital investment, companies will benefit from the reduction of dependence on primary aluminum thus saving considerable costs. Additionally, the technology will allow companies to maintain in-house alloy scrap, rather than purchasing from other vendors and eliminate the need to discard the light gauge scrap to landfills.

  14. Process for removing copper in a recoverable form from solid scrap metal

    DOEpatents

    Hartman, Alan D.; Oden, Laurance L.; White, Jack C.

    1995-01-01

    A process for removing copper in a recoverable form from a copper/solid ferrous scrap metal mix is disclosed. The process begins by placing a copper/solid ferrous scrap metal mix into a reactor vessel. The atmosphere within the reactor vessel is purged with an inert gas or oxidizing while the reactor vessel is heated in the area of the copper/solid ferrous scrap metal mix to raise the temperature within the reactor vessel to a selected elevated temperature. Air is introduced into the reactor vessel and thereafter hydrogen chloride is introduced into the reactor vessel to obtain a desired air-hydrogen chloride mix. The air-hydrogen chloride mix is operable to form an oxidizing and chloridizing atmosphere which provides a protective oxide coating on the surface of the solid ferrous scrap metal in the mix and simultaneously oxidizes/chloridizes the copper in the mix to convert the copper to a copper monochloride gas for transport away from the solid ferrous scrap metal. After the copper is completely removed from the copper/solid ferrous scrap metal mix, the flows of air and hydrogen chloride are stopped and the copper monochloride gas is collected for conversion to a recoverable copper species.

  15. A Pilot Assessment of Occupational Health Hazards in the US Electronic Scrap Recycling Industry.

    PubMed

    Ceballos, Diana M; Gong, Wei; Page, Elena

    2015-01-01

    The National Institute for Occupational Safety and Health (NIOSH) surveyed a randomly selected sample of electronic scrap (e-scrap) recycling facilities nationwide to characterize work processes, exposures, and controls. Despite multiple attempts to contact 278 facilities, only 47 responded (17% response rate). Surveyed facilities reported recycling a wide variety of electronics. The most common recycling processes were manual dismantling and sorting. Other processes included shredding, crushing, and automated separation. Many facilities reported that they had health and safety programs in place. However, some facilities reported the use of compressed air for cleaning, a practice that can lead to increased employee dust exposures, and some facilities allowed food and drinks in the production areas, a practice that can lead to ingestion of contaminants. Although our results may not be generalizable to all US e-scrap recycling facilities, they are informative regarding health and safety programs in the industry. We concluded that e-scrap recycling has the potential for a wide variety of occupational exposures particularly because of the frequent use of manual processes. On-site evaluations of e-scrap recyclers are needed to determine if reported work processes, practices, and controls are effective and meet current standards and guidelines. Educating the e-scrap recycling industry about health and safety best practices, specifically related to safe handling of metal dust, would help protect employees.

  16. Recycling metal scrap. June 1970-January 1990 (A Bibliography from the COMPENDEX database). Report for June 1970-January 1990

    SciTech Connect

    Not Available

    1990-03-01

    This bibliography contains citations concerning the processes, techniques, and benefits of recycling metal scrap. The recycling processes for aluminum, chromium, nickel, cobalt, lead, copper, and precious metals scrap are discussed. Recycling in the jewelry, electronics, milling, beverage, automotive, and aircraft industries is considered. Analyses of the current global scrap metal recycling trends are included. (This updated bibliography contains 362 citations, 21 of which are new entries to the previous edition.)

  17. Resource recovery of scrap silicon solar battery cell.

    PubMed

    Lee, Ching-Hwa; Hung, Chi-En; Tsai, Shang-Lin; Popuri, Srinivasa R; Liao, Ching-Hua

    2013-05-01

    In order to minimize pollution problems and to conserve limited natural resources, a hydrometallurgical procedure was developed in this study to recover the valuable resources of silicon (Si), silver (Ag) and aluminum (Al) from scrap silicon solar battery cells. In this study, several methods of leaching, crystallization, precipitation, electrolysis and replacement were employed to investigate the recovery efficiency of Ag and Al from defective monocrystalline silicon solar battery cells. The defective solar battery cells were ground into powder followed by composition analysis with inductively coupled plasma-atomic emission spectrometry. The target metals Ag and Al weight percentage were found to be 1.67 and 7.68 respectively. A leaching process was adopted with nitric acid (HNO3), hydrochloric acid, sulfuric acid (H2SO4) and sodium hydroxide as leaching reagent to recover Ag and Al from a ground solar battery cell. Aluminum was leached 100% with 18N H2SO4 at 70°C and Ag was leached 100% with 6N HNO3. Pure Si of 100% was achieved from the leaching solution after the recovery of Ag and Al, and was analyzed by scanning electron microscope-energy dispersive spectroscopy. Aluminum was recovered by crystallization process and silver was recovered by precipitation, electrolysis and replacement processes. These processes were applied successfully in the recovery of valuable metal Ag of 98-100%.

  18. Distillation of granulated scrap tires in a pilot plant.

    PubMed

    López, Félix A; Centeno, Teresa A; Alguacil, Francisco José; Lobato, Belén

    2011-06-15

    This paper reports the pyrolytic treatment of granulated scrap tires (GST) in a pilot distillation unit at moderate temperature (550°C) and atmospheric pressure, to produce oil, char and gas products. Tire-derived oil is a complex mixture of organic C(5)-C(24) compounds, including a very large proportion of aromatic compounds. This oil has a high gross calorific value (∼ 43 MJ kg(-1)) and N and S contents of 0.4% and 0.6%, respectively, falling within the specifications of certain heating fuels. The distillation gas is composed of hydrocarbons; methane and n-butane are the most abundant, investing the distillation gas with a very high gross calorific value (∼ 68 MJ Nm(-3)). This gas is transformed into electric power by a co-generation turbine. The distillation char is mostly made of carbon but with significant inorganic impurities (∼ 12 wt%). The quality of the solid residue of the process is comparable to that of some commercial chars. The quantity of residual solids, and the qualities of the gas, liquid and solid fractions, are similar to those obtained by conventional pyrolytic treatments of waste tires. However, the simplicity of the proposed technology and its low investment costs make it a very attractive alternative.

  19. Microwave induced fast pyrolysis of scrap rubber tires

    NASA Astrophysics Data System (ADS)

    Ani, Farid Nasir; Mat Nor, Nor Syarizan

    2012-06-01

    Pyrolysis is the thermal degradation of carbonaceous solid by heat in the absence of oxygen. The feedstocks, such as biomass or solid wastes are heated to a temperature between 400 and 600°C, without introducing oxygen to support the reaction. The reaction produces three products: gas, pyro-fuel oil and char. This paper presents the techniques of producing pyro-oil from waste tires, as well as investigation of the fuel properties suitable for diesel engine applications. In this study, microwave heating technique is employed to pyrolyse the used rubber tires into pyro-oil. Thermal treatment of as received used rubber tires is carried out in a modified domestic microwave heated fixed bed technology. It has been found that, rubber tires, previously used by various researchers, are poor microwave absorbers. Studies have shown that an appropriate microwave-absorbing material, such as biomass char or activated carbon, could be added to enhance the pyrolysis process; thus producing the pyro-oil. The characteristics of pyro-oil, as well as the effect of microwave absorber on its yield, are briefly described in this paper. The temperature profiles during the microwave heating process are also illustratively emphasized. The study provides a means of converting scrap tires into pyro-oil and pyrolytic carbon black production. The proposed microwave thermal conversion process therefore has the potentials of substantially saving time and energy.

  20. On the pyrolysis kinetics of scrap automotive tires.

    PubMed

    Chen, J H; Chen, K S; Tong, L Y

    2001-06-01

    Pyrolysis kinetics of scrap tires of passenger car and truck have been investigated thermogravimetrically under heating rates of 5, 10, 20 and 30K/min and temperature range 373-1273K in nitrogen. The results show that the initial reaction temperatures are 482-521K for the tire of passenger car and 458-511K for truck tire. Both tires exhibit similar behaviors that the initial reaction temperature decreases, but reaction range and reaction rate increase when heating rate is increased. The overall rate equation for each tire can be modeled satisfactorily by a simple one equation from which the kinetic parameters such as the activation energy (E), the pre-exponential factor (A), and the reaction order (n) of unreacted material based on Arrhenius form are determined using Friedman's method. The results show that two tires behave similarly and the average kinetic parameters of two tires are E = 147.95 +/- 0.21kJ/mol, A = (6.295 +/- 1.275)x10(10)min(-1), and n = 1.81 +/- 0.18. The predicted rate equations compare fairly well with the measured data.

  1. Reductive denitrification of nitrate by scrap iron filings.

    PubMed

    Hao, Zhi-Wei; Xu, Xin-Hua; Wang, Da-Hui

    2005-03-01

    Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial concentration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed.

  2. The Levitation Characteristics of MGB2 Plates on Tracks of Permanent Magnets

    NASA Astrophysics Data System (ADS)

    Perini, E.; Bassani, E.; Giunchi, G.

    2010-04-01

    The bulk MgB2 can be manufactured in large plates by an innovative process: the reactive liquid Mg infiltration (Mg-RLI). According to this process it is possible to produce, even at lab scale, plates of 10÷20 cm in lateral dimensions. The superconducting material resulting is very dense and, even if it is in polycrystalline form, it levitates with respect to Permanent Magnets (PM), like the textured YBCO samples, up to 35 K. In order to control the levitation forces and stiffnesses of an MgB2 plate (10×10×1 cm3) moving with respect to a track of PM's (NdFeB bars arranged in 4 lines according to an Halbach disposition and separated by Iron flux concentrators), we have used an instrumented Cryogenic Levitation Apparatus (CLA). We have studied different kind of movements of the PM's track with respect to the MgB2 plate. First, we consider the vertical movement, assumed z direction, which describes the properly levitation characteristics. Secondly, we consider two kinds of lateral movements of the track, assumed x direction, with the long size of the magnets either perpendicular or parallel to the movement direction. The resulting configurations simulate the main movements that a superconducting levitating vehicle will do in a real track, either of axial or of guidance type. The levitation axial forces, measured in Field Cooling or Zero Field Cooling conditions, indicate that at the distance between superconducting plate and PM's of 4 mm it is possible to have an overall levitating pressure of 7 N/cm2.

  3. Determining minimum alarm activities of orphan sources in scrap loads; Monte Carlo simulations, validated with measurements

    NASA Astrophysics Data System (ADS)

    Takoudis, G.; Xanthos, S.; Clouvas, A.; Potiriadis, C.

    2010-02-01

    Portal monitoring radiation detectors are commonly used by steel industries in the probing and detection of radioactivity contamination in scrap metal. These portal monitors typically consist of polystyrene or polyvinyltoluene (PVT) plastic scintillating detectors, one or more photomultiplier tubes (PMT), an electronic circuit, a controller that handles data output and manipulation linking the system to a display or a computer with appropriate software and usually, a light guide. Such a portal used by the steel industry was opened and all principal materials were simulated using a Monte Carlo simulation tool (MCNP4C2). Various source-detector configurations were simulated and validated by comparison with corresponding measurements. Subsequently an experiment with a uniform cargo along with two sets of experiments with different scrap loads and radioactive sources ( 137Cs, 152Eu) were performed and simulated. Simulated and measured results suggested that the nature of scrap is crucial when simulating scrap load-detector experiments. Using the same simulating configuration, a series of runs were performed in order to estimate minimum alarm activities for 137Cs, 60Co and 192Ir sources for various simulated scrap densities. The minimum alarm activities as well as the positions in which they were recorded are presented and discussed.

  4. Assessment of DOE radioactive scrap metal disposition options

    SciTech Connect

    Butler, C.R.; Kasper, K.M.; Bossart, S.J.

    1997-02-01

    The DOE has amassed a large amount of radioactively-contaminated scrap metal (RSM) as a result of past operations and decontamination and decommissioning (D&D) projects. The volume of RSM will continue to increase as a result of the D&D of more than 6,000 surplus facilities and many of the 14,000 operating facilities in the DOE complex. RSM can be either surface contaminated or volumetrically contaminated, or both, with varying amounts of radioactivity. Several options exist for the disposition of this RSM, including disposal as radioactive waste, recycling by decontamination and free-release for unrestricted use, or recycling for restricted reuse inside a DOE controlled area. The DOE Office of Science and Technology (EM-50) has been actively investing in technology and strategy development in support of restricted-reuse RSM recycling for the past several years. This paper will assess the nature of the RSM recycling issue, review past investment by DOE to develop technologies and strategies to recycle RSM, and then discuss some recommendations concerning future investments in support of RSM management. Available information on the supply of RSM will be presented in Section II. The regulatory and policy framework concerning recycling RSM will be presented in Section III. A review of DOE investment in RSM recycling technology and current programs will be presented in Section IV. The current and projected industrial capacity will be described in Section V. And, finally, a discussion of issues and recommendations regarding DOE technology development interests in RSM recycling will be presented in Section VI and VII, respectively.

  5. Investigation of chemical composition and crystal structure in sintered Ce{sub 15}Nd{sub 15}Fe{sub bal}B{sub 1} magnet

    SciTech Connect

    Huang, Shu-lin; Feng, Hai-bo; Zhu, Ming-gang; Li, An-hua; Li, Wei; Zhang, Yue

    2014-10-15

    The substitution of cerium, a more abundant rare-earth element, for sintered Nd-Fe-B magnets has drawn intense interest. In the present work, nominal composition of Ce{sub 15}Nd{sub 15}Fe{sub bal}B{sub 1} (wt. %), with cerium constitutes increased to 50% of the total rare-earth content, was used. And Ce-free Nd{sub 30}Fe{sub bal}B{sub 1} (wt. %) was prepared by the same preparation process as comparison. The microstructure of the sintered magnets has been investigated by means of X-ray diffraction and transmission electron microscope. The results show that there are three kinds of RE-rich phases in the same magnet, i.e., fcc-(Ce,Nd)O{sub x} (a=0.547nm), hcp-(Ce,Nd){sub 2}O{sub 3} (a=0.386nm, c=0.604nm) and bcc-(Ce,Nd){sub 2}O{sub 3} (a=1.113nm). Ors of (140)(Ce,Nd){sub 2}Fe{sub 14}B// (1-21)bcc-(Ce,Nd){sub 2}O{sub 3}(∼3°), [001](Ce,Nd){sub 2}Fe{sub 14}B// [-214]bcc-(Ce,Nd){sub 2}O{sub 3}; (01-1)(Ce,Nd){sub 2}Fe{sub 14}B// (101)fcc- (Ce,Nd)O{sub x}(∼2°), [101](Ce,Nd){sub 2}Fe14B// [12-1]fcc-(Ce,Nd)O{sub x} were found through selected area electron diffraction (SAED) analysis. According to the analysis, it can be concluded that cerium has partly substituted for neodymium by occupying the corresponding atom sites in the Ce{sub 15}Nd{sub 15}Fe{sub bal}B{sub 1} magnet, without changing the crystal configuration.

  6. System using electric furnace exhaust gas to preheat scrap for steelmaking

    SciTech Connect

    Takai, K.; Iwasaki, K.

    1987-09-08

    A method is described for clean preheating of scrap contaminated with oil and organic matter, for steelmaking, using heat from exhaust gas flow from an electric furnace. It consists of: burning any combustibles present in the exhaust gas flow and simultanously separating out dust particles from the exhaust gas flow; heating a predetermined amount of the scrap by heat exchange with a predetermined portion of the exhaust gas flow; removing and collecting dust from the exhaust gas flow after preheating of scrap thereby; sensing the temperature of the exhaust flow; scrubbing the exhaust gas flow with an aqueous solution of a deodorant solvent flowing at a rate regulated to be in a predetermined relationship related to the exhaust gas temperature sensed prior to scrubbing, thereby generating saturated vapor and reducing the temperature of the exhaust gas flow by a predetermined amount; and electrostatically precipitating out oil mist attached to saturated water vapor and liquid droplets in the exhaust gas flow.

  7. Effects of mechanical milling on the carbothermal reduction of oxide of WC/Co hardmetal scrap

    NASA Astrophysics Data System (ADS)

    Lee, Gil-Geun; Ha, Gook-Hyun

    2016-03-01

    The effects of mechanical milling on the carbothermal reduction of oxidized WC/Co hardmetal scrap with solid carbon were examined. Mixed powders were manufactured by milling the WC/Co hard metal scrap oxide and carbon powder in either a tumbler-ball mill or a planetary-ball mill. The milling type affected the carbothermal reduction of the oxide owing to the differing collision energies (mechanical milling energies) in the mills. The hardmetal scrap oxide powder (WO3, CoWO4) milled at high energy was more greatly reduced and at a lower temperature than that milled at lower mechanical energy. The formation of WC by the carburization reaction with solid carbon reached completion at a lower temperature after higher-energy milling than after lower-energy milling. The WC/Co composite particles synthesized by the combined oxidationmechanical milling-carbothermal reduction process were smaller when the initial powder was milled at higher mechanical energy.

  8. Thermogravimetric characteristics and kinetics of scrap tyre and Juglans regia shell co-pyrolysis.

    PubMed

    Uzun, B B; Yaman, E

    2014-10-01

    The degradation kinetics of Juglans regia shell, scrap tyre and their blends were investigated using a thermogravimetric analysis method. Experiments were performed under dynamic conditions and a nitrogen atmosphere in the range 293 to 973 K at different heating rates. During pyrolysis of J. regia shell three mass loss zones were specified as removal of water, decomposition of hemicelluloses and cellulose, and decomposition of lignin. The degradation curves of scrap tyre showed merely one stage which was due to decomposition of styrene butadiene rubber. The kinetic parameters were calculated using both Arrhenius and Coats-Redfern methods. By adopting the Arrhenius method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blends were found to be 69.22, 71.48 and 47.03 kJ mol(-1), respectively. Additionally, by using the Coats-Redfern method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blend were determined as 99.85, 78.72 and 63.81 kJ mol(-1), respectively. The addition of J. regia shell to scrap tyre caused a reduction in the activation energies. The difference of weight loss was measured to examine interactions between raw materials. The maximum difference between experimental and theoretical mass loss was 5% at about 648 K with a heating rate of 20 K min(-1). These results indicated a significant synergistic effect was available during co-pyrolysis of J. regia shell and scrap tyre in the high temperature region.

  9. A model for recovery of scrap monolithic uranium molybdenum fuel by electrorefining

    NASA Astrophysics Data System (ADS)

    Van Kleeck, Melissa A.

    The goal of the Reduced Enrichment for Research and Test Reactors program (RERTR) is toreduce enrichment at research and test reactors, thereby decreasing proliferation risk at these facilities. A new fuel to accomplish this goal is being manufactured experimentally at the Y12 National Security Complex. This new fuel will require its own waste management procedure,namely for the recovery of scrap from its manufacture. The new fuel is a monolithic uraniummolybdenum alloy clad in zirconium. Feasibility tests were conducted in the Planar Electrode Electrorefiner using scrap U-8Mo fuel alloy. These tests proved that a uranium product could be recovered free of molybdenum from this scrap fuel by electrorefining. Tests were also conducted using U-10Mo Zr clad fuel, which confirmed that product could be recovered from a clad version of this scrap fuel at an engineering scale, though analytical results are pending for the behavior of Zr in the electrorefiner. A model was constructed for the simulation of electrorefining the scrap material produced in the manufacture of this fuel. The model was implemented on two platforms, Microsoft Excel and MatLab. Correlations, used in the model, were developed experimentally, describing area specific resistance behavior at each electrode. Experiments validating the model were conducted using scrap of U-10Mo Zr clad fuel in the Planar Electrode Electrorefiner. The results of model simulations on both platforms were compared to experimental results for the same fuel, salt and electrorefiner compositions and dimensions for two trials. In general, the model demonstrated behavior similar to experimental data but additional refinements are needed to improve its accuracy. These refinements consist of a function for surface area at anode and cathode based on charge passed. Several approximations were made in the model concerning areas of electrodes which should be replaced by a more accurate function describing these areas.

  10. Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

    NASA Astrophysics Data System (ADS)

    Lu, Canhui; Zhang, Xinxing; Zhang, Wei

    2015-05-01

    The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

  11. Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

    SciTech Connect

    Lu, Canhui; Zhang, Xinxing; Zhang, Wei

    2015-05-22

    The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

  12. Economic and policy instrument analyses in support of the scrap tire recycling program in Taiwan.

    PubMed

    Chang, Ni-Bin

    2008-02-01

    Understanding the cost-effectiveness and the role of economic and policy instruments, such as the combined product tax-recycling subsidy scheme or a tradable permit, for scrap tire recycling has been of crucial importance in a market-oriented environmental management system. Promoting product (tire) stewardship on one hand and improving incentive-based recycling policy on the other hand requires a comprehensive analysis of the interfaces and interactions in the nexus of economic impacts, environmental management, environmental valuation, and cost-benefit analysis. This paper presents an assessment of the interfaces and interactions between the implementation of policy instruments and its associated economic evaluation for sustaining a scrap tire recycling program in Taiwan during the era of the strong economic growth of the late 1990s. It begins with an introduction of the management of the co-evolution between technology metrics of scrap tire recycling and organizational changes for meeting the managerial goals island-wide during the 1990s. The database collected and used for such analysis covers 17 major tire recycling firms and 10 major tire manufacturers at that time. With estimates of scrap tire generation and possible scale of subsidy with respect to differing tire recycling technologies applied, economic analysis eventually leads to identify the associated levels of product tax with respect to various sizes of new tires. It particularly demonstrates a broad perspective of how an integrated econometric and engineering economic analysis can be conducted to assist in implementing policy instruments for scrap tire management. Research findings indicate that different subsidy settings for collection, processing, and end use of scrap tires should be configured to ameliorate the overall managerial effectiveness. Removing the existing boundaries between designated service districts could strengthen the competitiveness of scrap tires recycling industry, helping to

  13. Health risk and impact evaluation for recycling of radioactive scrap metal

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Murphie, W.E.; Lilly, M.J. III

    1994-03-01

    The DoE, Office of Environmental Restoration and Waste Management, is participating with the Organization for Economic Cooperation and Development in providing analytical support for developing international standards for recycling of radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing health, environmental and societal implications of recycling and/or disposal process alternatives. This effort includes development of international inventory estimates for contaminated metals; investigation of international scrap metal markets; assessment of radiological and non-radiological human health risks; impacts on environmental quality and resources; and investigation of social and political factors. The RSM disposal option is being assessed with regard to the environmental and health impacts of replacing the metals if they are withdrawn from use. Impact estimates are developed for steel as an illustrative example because steel comprises a major portion of the scrap metal inventory. Current and potential sources of RSM include nuclear power plants, fuel cycle and weapons production facilities, industrial and medical facilities and equipment, and petroleum and phosphate rock extraction equipment. Millions of metric tons (t) of scrap iron and steel, stainless steel, and copper, as well as lesser quantities of aluminum, nickel, lead, and zirconium, are likely to become available in the future as these facilities are withdrawn from service.

  14. US Department of Energy`s weapons complex scrap metal inventory. Research report

    SciTech Connect

    Duda, J.R.

    1993-07-01

    Two tasks comprise the thrust of this contracted effort. Task 1 is the development of a Source List and is based on determining a list of public documents pertaining to contaminated/uncontaminated scrap metals, equipment, and other materials of value, were they not contaminated or could they be decontaminated. Task 2 is to develop an inventory of such materials from the Task 1 list of public documentation. In more detail, the Task 2 Inventory Report is based upon fulfillment of the following requirement to prepare and submit an Inventory Report based on the information obtained in the Source List. The Inventory Report shall define the type, quantity, and location of used equipment, scrap metal, and other materials existing within DOE`s system. The Inventory Report shall list: the site where the equipment, scrap metal, or other material resides; the type and size of equipment; the type and volume and/or weight of scrap metal or other material; its source; the type and level of contamination; its accessibility; the current annual rate of generation; and the projected annual rate of generation of the material.

  15. Noneconomic factors influencing scrap metal disposition decisions at DOE and NRC-licensed nuclear facilities

    SciTech Connect

    Ewen, M.D.; Robinson, L.A.

    1997-02-01

    The U.S. Environmental Protection Agency (EPA) is currently developing radiation protection standards for scrap metal, which will establish criteria for the unconditional clearance of scrap from nuclear facilities. In support of this effort, Industrial Economics, Incorporated is assessing the costs and benefits attributable to the rulemaking. The first step in this analysis is to develop an in-depth understanding of the factors influencing scrap disposition decisions, so that one can predict current and future practices under existing requirements and compare them to the potential effects of EPA`s rulemaking. These baseline practices are difficult to predict due to a variety of factors. First, because decommissioning activities are just beginning at many sites, current practices do not necessarily provide an accurate indicator of how these practices may evolve as site managers gain experience with related decisions. Second, a number of different regulations and policies apply to these decisions, and the interactive effects of these requirements can be difficult to predict. Third, factors other than regulatory constraints and costs may have a significant effect on related decisions, such as concerns about public perceptions. In general, research suggests that these factors tend to discourage the unconditional clearance of scrap metal.

  16. Process for removing and detoxifying cadmium from scrap metal including mixed waste

    SciTech Connect

    Kronberg, J.W.

    1994-07-01

    Cadmium-bearing scrap from nuclear applications, such as neutron shielding and reactor control and safety rods, must usually be handled as mixed waste since it is radioactive and the cadmium in it is both leachable and highly toxic. Removing the cadmium from this scrap, and converting it to a nonleachable and minimally radioactive form, would greatly simplify disposal or recycling. A process now under development will do this by shredding the scrap; leaching it with reagents which selectively dissolve out the cadmium; reprecipitating the cadmium as its highly insoluble sulfide; then fusing the sulfide into a glassy matrix to bring its leachability below EPA limits before disposal. Alternatively, the cadmium may be recovered for reuse. A particular advantage of the process is that all reagents (except the glass frit) can easily be recovered and reused in a nearly closed cycle, minimizing the risk of radioactive release. The process does not harm common metals such as aluminum, iron and stainless steel, and is also applicable to non-nuclear cadmium-bearing scrap such as nickel-cadmium batteries.

  17. Plutonium scrap waste processing based on aqueous nitrate and chloride media

    SciTech Connect

    Navratil, J D

    1985-05-13

    A brief review of plutonium scrap aqueous waste processing technology at Rocky Flats is given. Nitric acid unit operations include dissolution and leaching, anion exchange purification and precipitation. Chloride waste processing consists of cation exchange and carbonate precipitation. Ferrite and carrier precipitation waste treatment processes are also described. 3 figs.

  18. 40 CFR 63.10885 - What are my management practices for metallic scrap and mercury switches?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 15 2013-07-01 2013-07-01 false What are my management practices for... Iron and Steel Foundries Area Sources Pollution Prevention Management Practices for New and Existing Affected Sources § 63.10885 What are my management practices for metallic scrap and mercury switches?...

  19. 40 CFR 63.10885 - What are my management practices for metallic scrap and mercury switches?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 15 2012-07-01 2012-07-01 false What are my management practices for... Iron and Steel Foundries Area Sources Pollution Prevention Management Practices for New and Existing Affected Sources § 63.10885 What are my management practices for metallic scrap and mercury switches?...

  20. 20. Scrapping C112 U.S.S. Marblehead. Naval Shipyard Philadelphia. January 10, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Scrapping C1-12 U.S.S. Marblehead. Naval Shipyard Philadelphia. January 10, 1946. Original Photograph In Collection of National Archives, Mid-Atlantic Regional Records Center, Philadelphia. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Dry Dock No. 4, Broad Street south of Government Avenue, Philadelphia, Philadelphia County, PA