Science.gov

Sample records for blank continuous casting

  1. Prediction of cracks in continuously cast steel beam blank through fully coupled analysis of fluid flow, heat transfer, and deformation behavior of a solidifying shell

    SciTech Connect

    Lee, J.E.; Yeo, T.J.; Oh, K.H.; Yoon, J.K.; Yoon, U.S.

    2000-01-01

    A mathematical model has been developed for the prediction of cracks in the continuously cast steel beam blank through the fully coupled analysis of fluid flow, heat transfer, and deformation behavior of a solidifying shell. Fluid flow and heat transfer in the strand mold were analyzed with a three-dimensional (3-D) finite-volume method (FVM). For the complex geometry of the beam blank, a body-fitted coordinate (BFC) system was employed, Thermo-elastic-plastic deformation behavior in the strand was analyzed using the finite-element method (FEM) based on the two-dimensional (2-D) slice model. The thermal fields of the strand calculated with the FVM were used in the analysis of the deformation behavior of the strand. Through the iterative analysis of the fluid flow, heat-transfer, and deformation behavior, the coupling parameter of the heat-transfer coefficient between the strand and the mold was obtained. In order to describe the thermophysical properties and thermomechanical behavior of steel in the mushy zone, the microsegregation of solute elements was assessed. Consequently, some characteristic temperatures of steel as well as variations of phase fractions with temperature were determined. The probability of cracking in the strand, originating form an interdendritic liquid film, was quantified as a crack susceptibility coefficient. Recirculating flows were developed in the web and flange-tip regions. The development of a solidifying shell in the flange-center region was retarded by the inlet flow from a submerged entry nozzle (SEN). An air gap was formed mainly near the flange-tip corner. Surface cracks in the web and fillet regions and internal cracks in the flange-tip region were predicted.

  2. Steps toward 8m honeycomb mirror blanks. III - 1.8m honeycomb sandwich blanks cast from borosilicate glass

    NASA Technical Reports Server (NTRS)

    Angel, J. R. P.; Hill, J. M.

    1984-01-01

    The design, fabrication techniques, and equipment used for producing two 1.8-m honeycomb sandwich blanks, eventually leading to production of 8-m blanks, are reported. The procedure employed 85 cast hexagonal tiles at the bottom section, affixed against flotation by SiC bolts. The two plano concave mirrors are 1.83 m thick, weight 500 kg, and are each designed for 19 supports of astatic-lever type. Both blanks are of high quality and with an adequately low bubble content; one is to be figured to high-precision 0.25-arcsecond images, and is to be tested on the Multiple Mirror Telescope. Construction of a spin-casting facility based on the same principle is being planned for test-fabricating spin-cast mirrors on a smaller scale.

  3. (Continuous casting 1985)

    SciTech Connect

    Wilde, R.A.

    1985-06-12

    The report covers the Continuous Casting '85 Conference including informal discussions with conference attendees. In general, the papers presented at the conference concerned an overview of continuous steel casting worldwide, state-of-the-art aspects of steel continuous casting technology including caster startup problems, modifications, control system strategies, energy use profiles, quality control aspects, steel chemistry control, refractories, operational aspects of continuous casters, etc. No papers were presented in the development of thin section or thin strip casting of steel. Informal discussions were held with several conference attendees including (1) Bernard Trentini, Executive Director of the Association Technique De La Siderurgie Francaise in Paris, France (similar to the American Iron and Steel Institute); (2) Dr. Wolfgang Reichelt and Dr. Peter Voss-Spilker both of Mannesmann Demag Huttentechnik -a continuous casting and other steel making machine builder in-lieu of meeting at their plant in Duisburg, FRG on May 31; (3) Ewan C. Hewitt of Devote McKee Corp., Sheffield, England; (4) Wilfried Heinemann, head of R D Dept. at Concast Standard AG in Zurich, Switzerland; and (5) Hideo Ueno, engineer of melting section, Mitsubishi Steel Mfg. Co. Ltd, Tokyo Japan. A visit was made to the Teesside Laboratories of British Steel Corp. for discussions of their thin section casting research program in particular and R D program in general.

  4. Microstructure-Texture-Mechanical Properties in Hot Rolling of a Centrifugal Casting Ring Blank

    NASA Astrophysics Data System (ADS)

    Qin, Fang-cheng; Li, Yong-tang; Qi, Hui-ping; Ju, Li

    2016-03-01

    Deformation characteristic of centrifugal casting 25Mn steel was investigated by compression tests, and then processing maps were established. According to the deformation parameters identified from the established processing maps and hot ring rolling (HRR) process, the industrial test for the 25Mn ring blank was performed. Optical microscope (OM) and electron backscatter diffraction (EBSD) techniques were used for detecting grain boundary features and textures of deformation structures. The morphologies and mechanisms of tensile and impact fracture were revealed. The results show that softening effect plays a dominant role in higher temperatures of 1050-1150 °C and strain rates lower than 0.1 s-1. The average grain size of the rolled 25Mn ring is about 28 μm, but the grains are more coarse and inhomogeneous on the middle layer than that on rest of the areas. The texture on the outer layer is characterized by strong {110} <112> and weak {112} <111>, followed by {001} <100> and {001} <110> on the inner layer and {110} <110> on the center layer, which is mainly associated with the shear deformation. The rolled ring with precise geometrical dimensions and sound mechanical properties is fabricated by HRR. Tensile fracture is composed of clear river-shaped pattern and a little dimple near the inner layer and outer layer, and the fracture mechanism is mainly quasi-cleavage fracture, accompanied by dimple fracture. The morphologies of impact fracture consist of tear ridge and cleavage platform.

  5. Iron/Phosphorus Alloys for Continuous Casting

    NASA Technical Reports Server (NTRS)

    Dufresne, E. R.

    1986-01-01

    Continuous casting becomes practicable because of reduced eutectic temperature. Experimental ferrous alloy has melting point about 350 degrees C lower than conventional steels, making possible to cast structural members and eliminating need for hot rolling. Product has normal metal structure and good physical properties. Process used to make rails, beams, slabs, channels, and pipes.

  6. The optimisation of the viscosity of lubricating slags used in the continuous casting of steel

    NASA Astrophysics Data System (ADS)

    Gheorghiu, Csaba Attila; Hepuť, Teodor; Popa, Erika

    2016-06-01

    In the steel continuous casting process, the mould lubrication has a very important technological role, with direct effects on the continuous cast blank quality. The lubrication process is directly influenced by the synthetic flux viscosity (slag thickness), which is determined on its turn by the chemical composition and the temperature. The researches made aimed to establish some correlation relationships between the viscosity, chemical composition and temperature, analytically and graphically expressed, by processing the data in the Matlab program. Based on these correlations the best chemical compositions of the lubrication fluxes are established.

  7. Solidification modeling of continuous casting process

    NASA Astrophysics Data System (ADS)

    Lerner, V. S.; Lerner, Y. S.

    2005-04-01

    The aim of the present work was to utilize a new systematic mathematical-informational approach based on informational macrodynamics (IMD) to model and optimize the casting process, taking as an example horizontal continuous casting (HCC). The IMD model takes into account the interrelated thermal, diffusion, kinetic, hydrodynamic, and mechanical effects that are essential for the given casting process. The optimum technological process parameters are determined by the simultaneous solution of problems of identification and optimal control. The control functions of the synthesized optimal model are found from the extremum of the entropy functional having a particular sense of an integrated assessment of the continuous cast bar physicochemical properties. For the physical system considered, the IMD structures of the optimal model are connected with controllable equations of nonequilibrium thermodynamics. This approach was applied to the HCC of ductile iron, and the results were compared with experimental data and numerical simulation. Good agreement was confirmed between the predicted and practical data, as well as between new and traditional methods.

  8. Multiphysics modeling of the steel continuous casting process

    NASA Astrophysics Data System (ADS)

    Hibbeler, Lance C.

    This work develops a macroscale, multiphysics model of the continuous casting of steel. The complete model accounts for the turbulent flow and nonuniform distribution of superheat in the molten steel, the elastic-viscoplastic thermal shrinkage of the solidifying shell, the heat transfer through the shell-mold interface with variable gap size, and the thermal distortion of the mold. These models are coupled together with carefully constructed boundary conditions with the aid of reduced-order models into a single tool to investigate behavior in the mold region, for practical applications such as predicting ideal tapers for a beam-blank mold. The thermal and mechanical behaviors of the mold are explored as part of the overall modeling effort, for funnel molds and for beam-blank molds. These models include high geometric detail and reveal temperature variations on the mold-shell interface that may be responsible for cracks in the shell. Specifically, the funnel mold has a column of mold bolts in the middle of the inside-curve region of the funnel that disturbs the uniformity of the hot face temperatures, which combined with the bending effect of the mold on the shell, can lead to longitudinal facial cracks. The shoulder region of the beam-blank mold shows a local hot spot that can be reduced with additional cooling in this region. The distorted shape of the funnel mold narrow face is validated with recent inclinometer measurements from an operating caster. The calculated hot face temperatures and distorted shapes of the mold are transferred into the multiphysics model of the solidifying shell. The boundary conditions for the first iteration of the multiphysics model come from reduced-order models of the process; one such model is derived in this work for mold heat transfer. The reduced-order model relies on the physics of the solution to the one-dimensional heat-conduction equation to maintain the relationships between inputs and outputs of the model. The geometric

  9. Continuation of Crosscutting Technology Development at Cast

    SciTech Connect

    Yoon, Roe-Hoan

    2012-03-31

    This Final Technical Report describes progress made on the sub-projects awarded in the Cooperative Agreement DE-FC26-05NT42457: Continuation of Crosscutting Technology Development at Center for Advanced Separation Technologies (CAST). The final reports for each sub-project are attached in the appendix. Much of the research to be conducted with Cooperative Agreement funds will be longer-term, high-risk, basic research and will be carried out in five broad areas: a) Solid-solid separation b) Solid-liquid separation c) Chemical/Biological Extraction d) Modeling and Control, and e) Environmental Control.

  10. Initial solidification phenomena in continuous casting

    NASA Astrophysics Data System (ADS)

    Badri, Adam

    Continuous casting is the main process route for the mass production of steel today, yielding in excess of 560 million tons annually, corresponding to 80% of total steel production worldwide. As with any process, as improvements are introduced and quality is enhanced, there is the ever greater push to reduce problems that were once minor. The restrictions on quality for certain products require that defects be kept to a minimum. Currently, the industry has developed a wealth of experience in how to deal with slabs with oscillation marks. However, these practices are circumventions of the symptoms of the problems, not solutions for the causes. By understanding the formation mechanism, one can then develop practices based on a logical consideration oft he causes. The goals of this current work were to develop a mold simulator that could replicate the surface quality of industrial slabs. The techniques developed allowed for a more detailed examination of the heat transfer interactions during continuous casting, such that the variations of heat flux due to irregular solidification could be observed. It is shown that the mechanisms proposed in the literature are not individually sufficient for the formation of an oscillation mark, but several are necessary and must occur in concert for one to form. A mechanism is proposed for the formation of oscillation marks based upon the experimental results. This hypothesis is formulated as a series of necessary conditions that must be satisfied for an oscillation mark to be formed. This hypothesis is described, and shown to be in agreement with the trends observed and reported in the literature. It can explain both the overflow- and depression-type mark seen in industrial slabs. Additionally, this hypothesis was successfully used as a method of predicting the locations of oscillation marks on cast shells based upon the mold heat transfer measurements.

  11. Estimation of primary dendrite arm spacings in continuous casting products

    SciTech Connect

    Cicutti, C.; Bilmes, P.; Boeri, R.

    1997-09-01

    The proportion of steels produced by continuous casting has grown drastically during the last two decades, increasing to such an extent that in some countries, several grades of steel are exclusively made by this process. Many investigations recognized the significant influence of the solidification structure on the quality of cast products, and pointed out the importance of the development of appropriate tools to predict the microstructure as a function of thermal and physical parameters. The estimation of secondary dendrite arm spacings in continuously cast steel products has received some attention. However, very little effort has been focused on the prediction of primary dendrite arm spacings, to the best of the authors` knowledge. The main objective of this study is to develop simple expressions to estimate the variation of primary dendrite arm spacings through the section of continuous casting steel products.

  12. Electromagnetic continuous casting project: Final report

    SciTech Connect

    Battles, J.E.; Rote, D.M.; Misra, B.; Praeg, W.F.; Hull, J.R.; Turner, L.R.; Shah, V.L.; Lari, R.J.; Gopalsami, N.; Wiencek, T.

    1988-10-01

    This report describes the work on development of an electromagnetic casting process for steel, which was carried out at Argonne National Laboratory between January 1985 and December 1987. This effort was concerned principally with analysis and design work on magnet technology, liquid metal feed system, coolant system, and sensors and process controllers. Experimentation primarily involved (1) electromagnetic studies to determine the conditions and controlling parameters for stable levitation and (2) feed-system studies to establish important parameters that control and influence fluid flow from the liquid metal source to the caster. 73 refs., 91 figs., 11 tabs.

  13. Comparison of phosphor bronze metal sheet produced by twin roll casting and horizontal continuous casting

    NASA Astrophysics Data System (ADS)

    Hwang, J. D.; Li, B. J.; Hwang, W. S.; Hu, C. T.

    1998-08-01

    Much effort recently has been expended to study the strip casting process used to produce thin metal strip with a near final thickness. This process eliminates the need for hot rolling, consumes less energy, and offers a feasible method of producing various hard-to-shape alloys. The finer microstructure that results from the high cooling rate used during the casting process enhances mechanical properties. In this study, strips of phosphor bronzes (Cu-Sn-P) metal were produced using a twin roll strip casting process as well as a conventional horizontal continuous casting (HCC) process. The microstructures, macrosegregations, textures, and mechanical properties of the as-cast and as-rolled metal sheet produced by these two methods were examined carefully for comparative purposes. The results indicate that cast strip produced by a twin roll caster exhibit significantly less inverse segregation of tin compared to that produced by the HCC process. The mechanical properties including tensile strength, elongation, and microhardness of the products produced by the twin roll strip casting process are comparable to those of the HCC processed sheet. These properties meet specifications JIS H3110 and ASTM B 103M for commercial phosphor bronze sheet. The texture of the as-rolled sheet from these two processes, as measured from XRD pole figures, were found to be virtually the same, even though a significant difference exists between them in the as-cast condition.

  14. Continuous Casting for Aluminum Sheet: a Product Perspective

    NASA Astrophysics Data System (ADS)

    Sanders, Robert E.

    2012-02-01

    Continuous casting processes have been used successfully for more than 50 years to reduce the cost of manufacturing a variety of aluminum rolled products. Approximately 25% of North American flat-rolled sheet and foil is sourced from twin-roll cast or slab cast processes. Twin roll-casters provide a cost-effective solution for producing foil and light-gauge sheet from relatively low-alloyed aluminum (1xxx and 8xxx alloys). Slab casters, particularly Hazelett twin-belt machines, are well utilized in the production of 3xxx or 5xxx painted building products which require moderate strength and good corrosion resistance. Both foil and painted sheet are cost-sensitive commodity products with well-known metallurgical and quality requirements. There have been extensive trials and modest successes with continuous cast can stock and automotive sheet. However, they have not been widely adopted commercially due to generally lower levels of surface quality and formability compared with sheet produced from scalped direct chill (DC) cast ingot. The metallurgical requirements for can and auto sheet are considered in more detail with emphasis on the microstructural features which limit their application, e.g., particle distribution, grain size, and texture. Looking forward, slab casting offers the most viable opportunity for producing strong (i.e., higher alloy content), formable structural auto sheet with acceptable surface quality.

  15. Cooling system for continuous metal casting machines

    DOEpatents

    Draper, R.; Sumpman, W.C.; Baker, R.J.; Williams, R.S.

    1988-06-07

    A continuous metal caster cooling system is provided in which water is supplied in jets from a large number of small nozzles against the inner surface of rim at a temperature and with sufficient pressure that the velocity of the jets is sufficiently high that the mode of heat transfer is substantially by forced convection, the liquid being returned from the cooling chambers through return pipes distributed interstitially among the nozzles. 9 figs.

  16. Cooling system for continuous metal casting machines

    DOEpatents

    Draper, Robert; Sumpman, Wayne C.; Baker, Robert J.; Williams, Robert S.

    1988-01-01

    A continuous metal caster cooling system is provided in which water is supplied in jets from a large number of small nozzles 19 against the inner surface of rim 13 at a temperature and with sufficient pressure that the velocity of the jets is sufficiently high that the mode of heat transfer is substantially by forced convection, the liquid being returned from the cooling chambers 30 through return pipes 25 distributed interstitially among the nozzles.

  17. Thermo-mechanical phenomena in high speed continuous casting processes

    NASA Astrophysics Data System (ADS)

    Park, Joong Kil

    Thermo-mechanical phenomena during continuous thin slab casting have been studied with the objectives of understanding the mechanism of mold crack formation, and the effect of mold design upon the mechanical behavior of the stand. To achieve these goals, several finite element models have been developed in conjunction with a series of industrial plant trials. First, an investigation of mold crack formation in thin slab casting was undertaken to elucidate the mechanism by which cracks develop and to evaluate possible solutions to the problem. Three-dimensional finite-element thermal-stress models were developed to predict temperature, distortion, and residual stress in thin-slab casting molds, comparing funnel-shaped to parallel molds. Mold wall temperatures were obtained from POSCO in Korea and analyzed to determine the corresponding heat-flux profiles in thin-slab molds. This data was utilized in an elastic-visco-plastic analysis to investigate the deformation of the molds in service for the two different mold shapes. The results of a metallurgical investigation of mold samples containing cracks were used together with the results of the mathematical models, to determine mechanisms and to suggest solutions for the formation of mold cracks. Large cyclic inelastic strains were found in the funnel transition region just below the meniscus, due to the slightly higher temperature at that location. The cracks appear to have propagated by thermal fatigue caused by major level fluctuations. Next, two-dimensional thermo-elastic-visco-plastic analysis was performed for a horizontal slice of the solidifying strand, which moves vertically down the mold during casting. The model calculates the temperature distributions, the stresses and the strains in the solidifying shell, and the air gap between the casting mold and the solidifying strand. Model predictions were verified with an analytical solution and plant trials that were carried out during billet casting at POSCO. The

  18. Solidification Conditions and Microstructure in Continuously Cast Aluminum

    NASA Astrophysics Data System (ADS)

    Buxmann, K.; Gold, E.

    1982-04-01

    The well-known relationship between cell size or dendrite spacing and local solidification time gives the possibility of calculating the thermal parameters of solidification from the microstructure of the as-cast product. As a basis for such calculations, the dendrite spacing of different aluminum castings (DC cast ingots of different diameters, cast in conventional and electromagnetic molds; cast strip from roll casters, belt casters, and block casters; and Properzi cast rod) has been measured through their cross sections. Based on these measurements, a qualitative discussion of the thermal conditions during the solidification of these products is given, and the influence of a variation in the casting conditions discussed.

  19. A comparative study of the microstructures observed in statically cast and continuously cast Bi-In-Sn ternary eutectic alloy

    SciTech Connect

    Sengupta, S.; Soda, H.; McLean, A.; Rutter, J.W.

    2000-01-01

    A ternary eutectic alloy with a composition of 57.2 pct Bi, 24.8 pct In, and 18 pct Sn was continuously cast into wire of 2 mm diameter with casting speeds of 14 and 79 mm/min using the Ohno Continuous Casting (OCC) process. The microstructures obtained were compared with those of statically cast specimens. Extensive segregation of massive Bi blocks, Bi complex structures, and tin-rich dendrites was found in specimens that were statically cast. Decomposition of {radical}Sn by a eutectoid reaction was confirmed based on microstructural evidence. Ternary eutectic alloy with a cooling rate of approximately 1 C/min formed a double binary eutectic. The double binary eutectic consisted of regions of BiIn and decomposed {radical}Sn in the form of a dendrite cell structure and regions of Bi and decomposed {radical}Sn in the form of a complex-regular cell. The Bi complex-regular cells, which are a ternary eutectic constituent, existed either along the boundaries of the BiIn-decomposed {radical}Sn dendrite cells or at the front of elongated dendrite cell structures. In the continuously cast wires, primary Sn dendrites coupled with a small Bi phase were uniformly distributed within the Bi-In alloy matrix. Neither massive Bi phase, Bi complex-regular cells, no BiIn eutectic dendrite cells were observed, resulting in a more uniform microstructure in contrast to the heavily segregated structures of the statically cast specimens.

  20. 7 CFR 201.35 - Blank spaces.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Blank spaces. 201.35 Section 201.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS Labeling in General § 201.35 Blank spaces. Blank spaces on the label shall be deemed to imply...

  1. 7 CFR 201.35 - Blank spaces.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Blank spaces. 201.35 Section 201.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS Labeling in General § 201.35 Blank spaces. Blank spaces on the label shall be deemed to imply...

  2. 7 CFR 201.35 - Blank spaces.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Blank spaces. 201.35 Section 201.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS Labeling in General § 201.35 Blank spaces. Blank spaces on the label shall be deemed to imply...

  3. 7 CFR 201.35 - Blank spaces.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Blank spaces. 201.35 Section 201.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS Labeling in General § 201.35 Blank spaces. Blank spaces on the label shall be deemed to imply...

  4. 7 CFR 201.35 - Blank spaces.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Blank spaces. 201.35 Section 201.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS Labeling in General § 201.35 Blank spaces. Blank spaces on the label shall be deemed to imply...

  5. Asymptotic analysis of surface waves in continuous strip casting processes

    NASA Astrophysics Data System (ADS)

    Kluwick, Alfred; Scheichl, Stefan

    2000-09-01

    This paper presents a two-dimensional analysis of surface waves possibly emerging in a specific open channel flow with continuous solidification, i.e. the fluid consisting of molten material is cooled from below and solidifies. In modern metallurgical engineering such processes are of importance for the strip casting of steel and other metals. The study is based on the assumption that the wavelengths are large compared to the characteristic depth of the melt but small compared to the solidification length. Within the framework of a weakly nonlinear theory the use of the Euler equations supplemented with the appropriate boundary conditions at the solidification front and the free surface yields two Korteweg-de Vries equations with varying coefficients, which govern the propagation of the waves. However, the adopted form of the asymptotic expansions ceases to be valid as the point of complete solidification is approached, where the displacements at the free boundary and the depth of the melt are of the same order. Thus, a separate investigation for this region is carried out in order to describe the further evolution of the surface waves and its influence on the final shape of the fully solidified metal sheet.

  6. Experimental study of the continuous casting of a binary solution

    SciTech Connect

    DeZego, S.; Jones, K. Jr.; Burton, R.; Yang, G.; Dong, Z.; Ebadian, M.A.

    1995-12-31

    Continuous casting is currently the primary method for producing sheet metal, plastic and other materials. Here, a laboratory scale test facility has been designed to simulate solidification by using binary solutions (NH{sub 4}Cl-H{sub 2}O). The solid/liquid front evolution and the temperature distributions were recorded during the tests. Solidification for 10% and 30% NH{sub 4}Cl-H{sub 2}O solutions were conducted. The results showed totally different behavior of the solidification process between the two solutions. After reaching steady state, the hypoeutectic solution illustrated thick columnar dendrites in the mushy zone, with U-shaped temperature contours. It indicated that the warm fluid that was added penetrated deep along the centerline. On the other hand, the hypereutectic solution produced a wide open liquid pool, with short dendrites on the side walls. There existed a deep loose mushy zone at the bottom of the liquid pool, which was formed by the settling of equiaxed dendrites. Temperature gradients along the center line were observed for the hypereutectic solution due to the existence of stratified layers in the liquid pool.

  7. Modern processes of production of thin sheets and strips by continuous casting

    NASA Astrophysics Data System (ADS)

    Smirnov, A. N.

    2012-06-01

    The history of the development of producing thin sheets and strips by continuous casting methods is considered. The mechanism of this sheet formation during casting of steel in a two-roll continuous caster is described. The advantages of this process over the corresponding traditional technologies are discussed.

  8. Simulation of solidification process for billet with ϕ350mm section, continuous casted

    NASA Astrophysics Data System (ADS)

    Ardelean, E.; Lăscuţoni, A.; Ardelean, M.; Socalici, A.; Hepuţ, T.

    2016-02-01

    The quality of continuous casting product depends both on the quality of the steel, and on technological parameters adopted during the casting and how solidification of billets is conducted. A simulation of the solidifying process is very useful in the industrial casting practice, providing specialists with information about the phenomena during the process and the manner in which certain parameters may vary in order to obtain the desired effects. This paper presents a two-dimensional simulation model that can be used in the continuous casting process, when micro-coolers are used in order to control thermal regime during solidification.

  9. Numerical Simulation of Horizontal Continuous Casting Process of C194 Copper Alloy

    NASA Astrophysics Data System (ADS)

    Huang, Guojie; Xie, Shuisheng; Cheng, Lei; Cheng, Zhenkang

    2007-05-01

    Horizontal Continuous Casting (H.C.C) is an important method to cast C194 copper ingot. In this paper, numerical simulation is adopted to investigate the casting process in order to optimize the H.C.C technical parameters, such as the casting temperature, casting speed and cooling intensity. According to the numerical results, the reasonable parameters are that the casting temperature is between 1383K˜1463K, the casting speed is between 7.2m/h˜10.8m/h and the speed of cooling water is between 3.6m/s˜4.6m/s. The results of numerical simulation provide the significant reference to the subsequent experiments.

  10. Structural Factors Affecting Formability of Continuous Cast Aluminum Alloys

    SciTech Connect

    2001-10-01

    This research will focus on determining the influence of the cast microstructure and the spatial distribution of the intermetallic constituents and dispersion phases of the microtexture during deformation and recrystallization.

  11. Influence of mold length and mold heat transfer on horizontal continuous casting of nonferrous alloy rods

    NASA Astrophysics Data System (ADS)

    Verwijs, J. P.; Weckman, D. C.

    1988-04-01

    The influence of mold length and mold heat transfer on the conventional hot-top D.C. continuous casting process was studied through numerical simulations and experiments with horizontally cast 20 mm diameter lead and zinc rods. The minimum casting speed was found to be a nonlinear function of the mold length. For short molds, an inverse relationship between mold length and minimum casting speed was observed. However, the minimum casting speed for zinc cast from molds longer than 12 mm was constant at 2.5 mm/s. For lead cast in molds longer than 12 mm, the minimum observed casting speed was constant at 4.0 mm/s. The observed nonlinear relationship between minimum casting speed and mold length was predicted using a numerical model of the process. For this, an analytical expression for the mold boundary conditions was derived which included the influence of gas gap formation between the rod and the mold due to thermoelastic deformations of both the rod and the mold. Correlation between observed and predicted behavior was demonstrated for both the lead and zinc rods. Maximum casting speed was observed to increase with increased mold length; however, this speed was found to be critically dependent on process attributes such as mold and pinch wheel alignment and mold lubrication.

  12. Characterization of Continuous Cast AA2037 Al Alloy

    SciTech Connect

    Kenik, Edward A; Zeng, Qiang; Zhai, Tongguang

    2009-01-01

    The microstructure of a contiuous cast Al alloy was characterized with transmission and scanning transmission electron microscopy, as well as x-ray microanalysis. Several precipitate phases were identified as a function of prior thermomechanical treatment in order to understand the improvement of fatigue properties resulting from those treatments.

  13. Continuous Casting of Single Crystal Ingots by the O.C.C. Process

    NASA Astrophysics Data System (ADS)

    Ohno, A.

    1986-01-01

    To prevent the nucleation of crystals on the mold wall in the continuous casting of metals, a heated mold that maintained that temperature above the solidification temperature of the cast metal was used instead of the conventional cold mold. The cooling of the ingot was conducted outside of the mold. Heat was conducted axially along the ingot from the mold zone to the cooling zone. The principle of the O.C.C. (Ohno Continuous Casting) Process® was applied to the horizontal casting and vertical (upward) casting of wire and platelike ingots of Sn and Al. The ingots consisted of a completely unidirectionally solidified structure. It was possible to obtain a long single crystal ingot as a result of the growth competition of crystals.

  14. Possibility of combining electroslag remelting and continuous casting for the production of hollow ingots

    NASA Astrophysics Data System (ADS)

    Medovar, L. B.; Stovpchenko, A. P.; Fedorovskii, B. B.; Noshchenko, G. V.

    2012-06-01

    The fundamental possibility of a combination of ESR and continuous casting for the production of hollow tube billets is considered, and the problems to be solved to put this process into operation are discussed.

  15. Application of continuous casting steel 100Cr6 (SAE 52100) for bearing balls

    SciTech Connect

    Stahl, F.; Hirsch, Th.; Mayr, P.

    1998-12-31

    The objective of the investigation was to study the feasibility of applying continuous casting steel 100Cr6 (SAE 52100) for bearing balls. It was found that two of three continuous casted steel batches have longer or at least similar rolling contact fatigue lifetimes compared to one ingot casted batch. For one of the continuous casted batches, the rolling contact fatigue lifetime was 30% less. The micro- and macrostructure and the residual stresses below the surface of the balls were comparable. There is also no obvious difference between the four batches in the metallurgical parameters like contents of oxygen, titanium and sulfur as well as in the distribution of carbides and their network. The reason for the shorter lifetime of one batch finally was found to be due not to the continuous casting process itself. There was a difference in the cross section of the different casting moulds, and by this in the speed of solidification. As a consequence an increased segregation of alloying elements was observed. So the primary carbides of this batch were of bigger size and higher amounts have been detected within a larger cross section of the bloom. Finally the inferior distribution and size of carbides in the layers of maximum equivalent stress below the surface were found to be crack initiation points. The reduced lifetime of one batch therefore could be correlated to these metallurgical differences. It has been demonstrated that bearing balls made from continuous casted steel 100Cr6 (SAE 52100) have similar or better rolling contact fatigue lifetime than bearing balls made from ingot casted material. However, it is necessary to have minimal amounts of micro- and macro-inclusions as well as a homogeneous distribution of carbides, particularly in the main segregation areas. For that reason, the steel quality of every type of continuous casting machine has to be evaluated separately.

  16. Electroslag melting of blanks for valve bodies of atomic electric power plants

    SciTech Connect

    Rabinovich, V.I.; Borodin, M.A.; Chistyakov, G.A.; Kriger, Yu.N.

    1983-01-01

    The application of electroslag melting (ESM) makes it possible to obtain high quality castings. In the power engineering industry, the ESM method is used to manufacture blanks for the control valves of atomic electric power plants which were formerly made by forging. Valve body blanks made from sand steel castings are cheaper than blanks obtained by ESM, but of inferior quality.

  17. Macrosegregation Improvement by Swirling Flow Nozzle for Bloom Continuous Castings

    NASA Astrophysics Data System (ADS)

    Sun, Haibo; Zhang, Jiaquan

    2014-06-01

    Based on mathematical model coupling electromagnetism, fluid flow, heat transfer, and solute transport, the metallurgical performances of conventional straight nozzle, swirling flow nozzle (SFN), and M-EMS have been evaluated and compared. The soundness improvement of bloom castings has been investigated by casting tests of adopting the newly designed SFN. As compared to the normal nozzle, center porosity has been eliminated along with the popular center radial crack, and a better chemical homogeneity was obtained by employing the SFN accordingly, where the maximum segregation degree of C and S at the strand cross section is decreased from 1.28 to 1.02 and from 1.32 to 1.06, respectively. Combined with the results of numerical simulation, the positive effect obtained can be attributed to the remarkable superheat dissipation under the implementation of SFN, where, compared with the normal nozzle, the melt superheat degree at the mold exit is reduced by 15.5 K, 9.8 K, and 17.3 K (15.5 °C, 9.8 °C, and 17.3 °C) under the other three casting measures of SFN, normal nozzle with M-EMS, and SFN with M-EMS, respectively.

  18. Numerical simulation of the solidification processes of copper during vacuum continuous casting

    NASA Astrophysics Data System (ADS)

    Tsai, D. C.; Hwang, W. S.

    2012-03-01

    A numerical simulation method is used to analyze the microstructure evolution of 8-mm-diameter copper rods during the vacuum continuous casting (VCC) process. The macro-microscopic coupling method is adopted to develop a temperature field model and a microstructure prediction model. The effects of casting parameters, including casting speed, pouring temperature, cooling rate, and casting dimension on the location and shape of the solid-liquid (S/L) interface and solidified microstructure are considered. Simulation results show that the casting speed has a large effect on the position and shape of the S/L interface and grain morphology. With an increase of casting speed, the shape of the S/L interface changes from a planar shape into an elliptical shape or a narrow, pear shape, and the grain morphology indicates a change from axial growth to axial-radial growth or completely radial growth. The simulation predictions agree well with the microstructure observations of cast specimens. Further analysis of the effects of other casting parameters on the position and shape of the S/L interface reveals that the casting dimension has more influence on the position and shape of the S/L interface and grain morphology than do pouring temperature and cooling rate. The simulation results can be summarized to obtain a discriminant of shape factor (η), which defines the shape of the S/L interface and grain morphology.

  19. Technological aspects at continuous casting of semi-finished products with ϕ270mm

    NASA Astrophysics Data System (ADS)

    Ardelean, E.; Ardelean, M.; Hepuţ, T.; Lăscuţoni, A.

    2015-06-01

    Continuous casting installation especially appreciated because steel can be poured in a more varied assortment. The flexibility of the system is not sufficient if the casting parameters are not properly adopted and adapted to the specific brand of steel. This paper presents some technical aspects relative to continuous casting of semi-finished products with ϕ270mm section. Graphical dependencies obtained in Excel and analytical equations of this allows to specialists from industry to adopt values for the addicted parameters according to the independent ones, already known.

  20. Modeling on Fluid Flow and Inclusion Motion in Centrifugal Continuous Casting Strands

    NASA Astrophysics Data System (ADS)

    Wang, Qiangqiang; Zhang, Lifeng; Sridhar, Seetharaman

    2016-05-01

    During the centrifugal continuous casting process, unreasonable casting parameters can cause violent level fluctuation, serious gas entrainment, and formation of frozen shell pieces at the meniscus. Thus, in the current study, a three-dimensional multiphase turbulent model was established to study the transport phenomena during centrifugal continuous casting process. The effects of nozzle position, casting and rotational speed on the flow pattern, centrifugal force acting on the molten steel, level fluctuation, gas entrainment, shear stress on mold wall, and motion of inclusions during centrifugal continuous casting process were investigated. Volume of Fluid model was used to simulate the molten steel-air two-phase. The level fluctuation and the gas entrainment during casting were calculated by user-developed subroutines. The trajectory of inclusions in the rotating system was calculated using the Lagrangian approach. The results show that during centrifugal continuous casting, a large amount of gas was entrained into the molten steel, and broken into bubbles of various sizes. The greater the distance to the mold wall, the smaller the centrifugal force. Rotation speed had the most important influence on the centrifugal force distribution at the side region. Angular moving angle of the nozzle with 8° and keeping the rotation speed with 60 revolutions per minute can somehow stabilize the level fluctuation. The increase of angular angle of nozzle from 8 to 18 deg and rotation speed from 40 to 80 revolutions per minute favored to decrease the total volume of entrained bubbles, while the increase of distance of nozzle moving left and casting speed had reverse effects. The trajectories of inclusions in the mold were irregular, and then rotated along the strand length. After penetrating a certain distance, the inclusions gradually moved to the center of billet and gathered there. More work, such as the heat transfer, the solidification, and the inclusions entrapment

  1. Modeling on Fluid Flow and Inclusion Motion in Centrifugal Continuous Casting Strands

    NASA Astrophysics Data System (ADS)

    Wang, Qiangqiang; Zhang, Lifeng; Sridhar, Seetharaman

    2016-08-01

    During the centrifugal continuous casting process, unreasonable casting parameters can cause violent level fluctuation, serious gas entrainment, and formation of frozen shell pieces at the meniscus. Thus, in the current study, a three-dimensional multiphase turbulent model was established to study the transport phenomena during centrifugal continuous casting process. The effects of nozzle position, casting and rotational speed on the flow pattern, centrifugal force acting on the molten steel, level fluctuation, gas entrainment, shear stress on mold wall, and motion of inclusions during centrifugal continuous casting process were investigated. Volume of Fluid model was used to simulate the molten steel-air two-phase. The level fluctuation and the gas entrainment during casting were calculated by user-developed subroutines. The trajectory of inclusions in the rotating system was calculated using the Lagrangian approach. The results show that during centrifugal continuous casting, a large amount of gas was entrained into the molten steel, and broken into bubbles of various sizes. The greater the distance to the mold wall, the smaller the centrifugal force. Rotation speed had the most important influence on the centrifugal force distribution at the side region. Angular moving angle of the nozzle with 8° and keeping the rotation speed with 60 revolutions per minute can somehow stabilize the level fluctuation. The increase of angular angle of nozzle from 8 to 18 deg and rotation speed from 40 to 80 revolutions per minute favored to decrease the total volume of entrained bubbles, while the increase of distance of nozzle moving left and casting speed had reverse effects. The trajectories of inclusions in the mold were irregular, and then rotated along the strand length. After penetrating a certain distance, the inclusions gradually moved to the center of billet and gathered there. More work, such as the heat transfer, the solidification, and the inclusions entrapment

  2. Numerical simulation on the solidification structure of Ø600mm continuous casting round bloom

    NASA Astrophysics Data System (ADS)

    Fang, Q.; Ni, H. W.; Wang, S. J.; Zang, H.

    2016-03-01

    A FE (Finite Element)—CA (Cellular Automation) coupling model was developed for the simulation of solidification structure formation during the Ø600mm round bloom continuous casting process of Q345E steel. The simulation result of the temperature field was consistent with the nail-shooting experimental result, and the simulated solidification structure of the bloom was in great agreement with corrosion testing under the same casting condition. The simulation results showed that the centre equiaxed crystal ratio increased slightly with the increase of secondary cooling water rate and decreased with the increase of casting temperature and casting speed. When the secondary cooling water rate was over 0.08L/kg, it had less effect on the solidification structure. As the casting temperature increased by 1°C or the casting speed increased by 0.01m/min, the centre equiaxed crystal ratio would decrease by 0.4%∼1.2% and 3%∼0.8% respectively. According to the simulation results, the optimized continuous casting process of Ø600mm round bloom should be the secondary cooling water rate of 0.08L/kg, the casting temperature of 1532°C∼1539°C and the casting speed of 0.20m/min∼0.22m/min. It was found that the solidification structure of Ø600mm Q345E steel round bloom was much improved after the optimized continuous casting process was adopted in practical production.

  3. A Thermal Simulation Method for Solidification Process of Steel Slab in Continuous Casting

    NASA Astrophysics Data System (ADS)

    Zhong, Honggang; Chen, Xiangru; Han, Qingyou; Han, Ke; Zhai, Qijie

    2016-07-01

    Eighty years after the invention of continuous cast of steels, reproducibility from few mm3 samples in the laboratory to m3 product in plants is still a challenge. We have engineered a thermal simulation method to simulate the continuous casting process. The temperature gradient (G L ) and dendritic growth rate (v) of the slab were reproduced by controlling temperature and cooling intensity at hot and chill end, respectively, in our simulation samples. To verify that our samples can simulate the cast slab in continuous casting process, the heat transfer, solidification structure, and macrosegregation of the simulating sample were compared to those of a much larger continuous casting slab. The morphology of solid/liquid interface, solidified shell thickness, and dendritic growth rate were also investigated by in situ quenching the solidifying sample. Shell thickness (δ) determined by our quenching experiment was related to solidification time (τ) by equation: δ = 4.27 × τ 0.38. The results indicated that our method closely simulated the solidification process of continuous casting.

  4. Niobium carbide and tin precipitation in continuously cast microalloyed steels

    NASA Astrophysics Data System (ADS)

    Stock, Julian

    With high yield strength, toughness and good weldability, microalloyed steels are widely used in the automotive, pipeline and transportation industries. Microalloying elements such as niobium (Nb), titanium (Ti) and vanadium (V) in concentrations of less than 0.1 wt. pct. are typical. For optimal benefits in the final product, it is usually desired for Ti to form fine precipitates during and after solidification and for Nb to be in solution prior to hot-rolling. Vanadium precipitates at lower temperatures and is less involved in the solidification/casting process. In one aspect of the investigation, the effects of cooling rate on the titanium nitride (TiN) precipitation size distribution were investigated in a Ti-added low-carbon steel. Prior research reported an inverse relationship between the average TiN precipitation size and the post-solidification cooling rate and the present work was undertaken to examine this behavior over a wider range of cooling rates. Using the GleebleRTM 3500's casting simulation capabilities along with controlled cooling rates, the TiN precipitation behavior in thick-slab, thin-slab and thin-strip material was simulated using a commercially produced 0.04C, 1.23Mn steel with near-stoichiometric Ti and N levels. Transmission electron microscopy (TEM) investigation of carbon extraction replicas was carried out to characterize the influence of cooling rates on precipitate size distributions. Decreasing particle sizes with increasing cooling rates were found. Average particle sizes as low as 6.7 nm were present in thin-strip simulations and might be of interest, as fine particles could contribute to strengthening of rapidly cooled steels. In a second aspect of the investigation, niobium carbide (NbC) precipitation during the compact strip production (CSP) process was investigated in two Nb-added low-carbon steels. Instead of industrial sampling, the GleebleRTM was used for casting simulations using two CMn(Nb) steels with high and low- Nb

  5. Twin-belt continuous caster with containment and cooling of the exiting cast product for enabling high-speed casting of molten-center product

    DOEpatents

    Dykes, Charles D.; Daniel, Sabah S.; Wood, J. F. Barry

    1990-02-20

    In continuously casting molten metal into cast product by a twin-belt machine, it is desirable to achieve dramatic increases in speed (linear feet per minute) at which cast product exits the machine, particularly in installations where steel cast product is intended to feed a downstream regular rolling mill (as distinct from a planetary mill) operating in tandem with the twin-belt caster. Such high-speed casting produces product with a relatively thin shell and molten interior, and the shell tends to bulge outwardly due to metallostatic head pressure of the molten center. A number of cooperative features enable high-speed, twin-belt casting: (1) Each casting belt is slidably supported adjacent to the caster exit pulley for bulge control and enhanced cooling of cast product. (2) Lateral skew steering of each belt provides an effective increase in moving mold length plus a continuity of heat transfer not obtained with prior art belt steering apparatus. (3) The exiting slab is contained and supported downstream from the casting machine to prevent bulging of the shell of the cast product, and (4) spray cooling is incorporated in the exit containment apparatus for secondary cooling of cast product.

  6. On-line surface inspection for continuous cast aluminum strip

    NASA Astrophysics Data System (ADS)

    Fernandez, Carlos; Campoy, Pascual; Platero, Carlos; Sebastian, Jose M.; Aracil, Rafael

    1993-12-01

    A general architecture for detecting and analyzing surface defects in aluminum strip is described. Information concerning visual information from the aluminum surface, surface temperature and strip dimensions--profile thickness-is processed jointly by means of an expert system in order to determine the quality level of each aluminum coil produced; control actions over the casting process, derived from this information, are also suggested by an expert system. This paper shows in deep work related to surface image analysis. The data volume to be processed, up to 20 Mbytes/s, has forced up the development of a high parallel architecture for high-speed image processing. A specially suitable lighting system has been developed for enhancing matrical image acquisition from metallic surfaces that includes reflect avoidance as well as uniform incident angle of light along the scanned portion of surface--about 120000 square mm.

  7. Solidification Microstructure of AISI M2 High Speed Steel Manufactured by the Horizontal Continuous Casting Process

    NASA Astrophysics Data System (ADS)

    Zhou, X. F.; Fang, F.; Jiang, J. Q.

    2011-01-01

    In the present work, AISI M2 high speed steel is produced by the horizontal continuous casting process. The difference of solidification microstructure in ingots by mould casting and continuous casting has been examined by means of scanning electron microscope (SEM), electron back-scatter diffraction (EBSD), transmission electron microscope (TEM) and high resolution electron microscope (HREM). The results show that the as-cast structure consists of iron matrix and networks of M2C eutectic carbides, which are greatly refined in the continuous casting ingot compared to the case of ingot by mould casting. Meanwhile, the morphology of M2C eutectic carbides changes from the plate-like shape into the fibrous one. Micro-twining and stacking faults are observed in the plate-like M2C, whereas they are rarely identified in the fibrous M2C. Based on the characteristic of morphology and microstructure, it is expected that the plate-like M2C is a faceted phase while the fibrous M2C is a non-faceted phase.

  8. Improvement of internal quality of continuously cast slabs by introducing consumable vibrating macrocoolers in a mold

    NASA Astrophysics Data System (ADS)

    Golenkov, M. A.

    2014-12-01

    The methods of controlling metal solidification by introducing consumable internal macrocoolers in the form of strips, wires, and powders are considered. The effect of this technology on the structure of continuously cast slabs is described. The results of full-scale experiments on the introduction of a steel strip as a macrocooler into the molds of continuous casters of various types are presented.

  9. 40 CFR 420.60 - Applicability; description of the continuous casting subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the continuous casting subcategory. 420.60 Section 420.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE...

  10. Microstructure and properties of continuously cast, lead-alloy strip for lead/acid battery grids

    NASA Astrophysics Data System (ADS)

    Tang, N.-Y.; Valeriote, E. M. L.; Sklarchuk, J.

    Lead/acid battery grid alloys, such as low-antimony-lead and lead-calcium-tin alloys with and without silver, are successfully continuously cast into strip using Cominco's Multi-Alloy Caster™. The mechanical and electrochemical properties of the continuously cast, low-antimony-lead strip are strongly dependent on the arsenic content in the alloys. On the other hand, the tin:calcium (Sn:Ca) ratio in the PbCaSn alloys plays an important role in the development of the microstructure and the mechanical properties of these alloys.

  11. Effect of the defect initial shape on the fatigue lifetime of a continuous casting machine roll

    NASA Astrophysics Data System (ADS)

    Yasniy, Oleh P.; Lapusta, Yuri

    2016-08-01

    The article deals with the influence of the defect initial shape on the residual lifetime of a continuous casting machine roll made of 25Cr1MoV steel. Based on this approach, previously proposed by some authors, the growth of the surface fatigue crack was modeled in a roll under loading and temperature conditions that are close to operational ones, taking into account the statistical distribution of the C parameter of Paris' equation. Dependencies of the continuous casting machines roll fatigue lifetime on the initial defect shape and critical defect sizes are obtained.

  12. The effect of residuals on the presence of intergranular surface cracks on continuously cast billets

    SciTech Connect

    Wijngaarden, M.J.U.T. van; Visagie, G.P.

    1996-12-31

    During 1991, Iscor Vereeniging experienced a dramatic increase in the rejection rate of specialty steel bars rolled from continuously cast billets due to the presence of seams on the bars. The seams originated from tearing of the billets during the first 2 passes in the roughing mill during hot rolling. The defective billets were found to contain fine intergranular cracks on the surface. Such cracks have been described in the literature and have been attributed to the presence of high levels of residuals resulting in the well-known phenomenon of surface hot shortness which results from the enrichment of residuals at the grain boundaries after preferential oxidation of iron during scaling of the steel. The present investigation revealed that the effect of residuals on intergranular surface cracking is a complex interaction between steel composition and casting conditions such as casting speed, intensity of secondary cooling, section size, and mold type. This paper quantifies the effect of residuals on the intergranular surface cracking of continuously cast billets and quantitatively relates the incidence of these cracks to parameters which can be controlled during steelmaking and continuous casting.

  13. Engineering solution to the problem of ingot solidification in slab continuous-casting machines

    NASA Astrophysics Data System (ADS)

    Shichkov, A. N.; Bykasova, E. N.; Bashirov, N. G.; Klochai, V. V.; Bystrov, L. G.

    1995-03-01

    An engineering solution to ingot solidification and the regularities of growth of an ingot envelope thickness and the coordinate of the end of slab solidification directly on slab continuous-casting machines (SCCM) are given, and ingot solidification conditions are determined. Examples of calculation of the envelope thickness and the coordinate of the end of solidification are provided for slab continuous-casting machines utilized at the Cherepovetsk integrated metallurgical complex (CherMC) and at the cast-and-iron works of the Aisenhüttenstadt Joint-Stock Company. A graphical algorithm for determining the cooling capacity of the secondary cooling zone is presented, and a nomogram for calibration of the cooling capacity of forced secondary cooling against the major and minor radii of an SCCM is developed.

  14. Modified blank ammunition injuries.

    PubMed

    Ogunc, Gokhan I; Ozer, M Tahir; Coskun, Kagan; Uzar, Ali Ihsan

    2009-12-15

    Blank firing weapons are designed only for discharging blank ammunition cartridges. Because they are cost-effective, are easily accessible and can be modified to live firearms plus their unclear legal situation in Turkish Law makes them very popular in Turkey. 2004 through 2008, a total of 1115 modified blank weapons were seized in Turkey. Blank firing weapons are easily modified by owners, making them suitable for discharging live firearm ammunition or modified blank ammunitions. Two common methods are used for modification of blank weapons. After the modification, these weapons can discharge the live ammunition. However, due to compositional durability problems with these types of weapons; the main trend is to use the modified blank ammunitions rather than live firearm ammunition fired from modified blank firing weapons. In this study, two types of modified blank weapons and two types of modified blank cartridges were tested on three different target models. Each of the models' shooting side was coated with 1.3+/-2 mm thickness chrome tanned cowhide as a skin simulant. The first model was only coated with skin simulant. The second model was coated with skin simulant and 100% cotton police shirt. The third model was coated with skin simulant and jean denim. After the literature evaluation four high risky anatomic locations (the neck area; the eyes; the thorax area and inguinal area) were pointed out for the steel and lead projectiles are discharged from the modified blank weapons especially in close range (0-50 cm). The target models were designed for these anatomic locations. For the target models six Transparent Ballistic Candle blocks (TCB) were prepared and divided into two test groups. The first group tests were performed with lead projectiles and second group with steel projectile. The shortest penetration depth (lead projectile: 4.358 cm; steel projectile 8.032 cm) was recorded in the skin simulant and jean denim coated block for both groups. In both groups

  15. Superplastic Response of Continuously Cast AZ31B Magnesium Sheet Alloys

    NASA Astrophysics Data System (ADS)

    Boileau, J. M.; Friedman, P. A.; Houston, D. Q.; Luckey, S. G.

    2010-06-01

    Magnesium sheet is typically produced for commercial applications with the traditional DC-ingot casting method. As a result of the hexagonal close-packed crystallographic structure in magnesium, multiple rolling passes and annealing steps are required to reduce the thickness of the ingots. Thus, high fabrication costs characterize the creation of magnesium sheet suitable for common forming operations. Recently, continuous casting (CC) technology, where molten metal is solidified directly into sheet form, has been applied to magnesium alloys; this method has shown the potential to significantly reduce the cost of fabricating magnesium sheet alloys. In order to understand the viability of the CC process, a study was conducted to investigate the superplastic potential of alloys produced by this method. This study focused on AZ31B Mg that was continuously-cast on twin-roll casters from three different suppliers. These three materials were compared with a production DC-cast AZ31B alloy in terms of microstructure, elevated-temperature tensile properties, and superplastic forming response. The data from this study found that microstructural features such as grain size and segregation can significantly affect the forming response. Additionally, the CC alloys can have equivalent or superior SPF response compared to DC-cast alloys, as demonstrated in both elevated temperature tensile tests and superplastic forming trials using a rectangular pan die.

  16. A Theoretical Analysis of the Interaction Between Pores and Inclusions During the Continuous Casting of Steel

    NASA Astrophysics Data System (ADS)

    Nick, Arash Safavi; Vynnycky, Michael; Fredriksson, Hasse

    2016-06-01

    A mathematical model is derived to predict the trajectories of pores and inclusions that are nucleated in the interdendritic region during the continuous casting of steel. Using basic fluid mechanics and heat transfer, scaling analysis, and asymptotic methods, the model accounts for the possible lateral drift of the pores as a result of the dependence of the surface tension on temperature and sulfur concentration. Moreover, the soluto-thermocapillary drift of such pores prior to final solidification, coupled to the fact that any inclusions present can only have a vertical trajectory, can help interpret recent experimental observations of pore-inclusion clusters in solidified steel castings.

  17. Si-STEEL Thin-Strip Prepared by Twin-Roll Continuous Casting

    NASA Astrophysics Data System (ADS)

    Yi, Yu; Zhou, Zehua; Wang, Zehua; Jiang, Shaoqun; Huang, Weidong

    The fabrication process of Si-steel thin-strip by twin-roll continuous casting was described and the quality of the obtained Si-steel thin-strip was measured. Si-steel strips with 0.5-6.5 wt.% Si content were successfully prepared, and proper parameters including pouring temperature, height of molten pool, casting speed and pouring head mode were optimized, and their mechanisms were discussed. The relationship between quality factors of Si-steel including cracks, strip thickness, impurity and process parameters such as Si content and so on were discussed. The morphologies of the strips with different Si content were studied.

  18. A numerical benchmark test for continuous casting of steel III

    NASA Astrophysics Data System (ADS)

    Šarler, B.; Vertnik, R.

    2015-06-01

    This paper represents a continuation of numerical results regarding the recently proposed industrial benchmark test [1], obtained by a meshless method. A part of the benchmark test, involving turbulent fluid flow with solidification in two dimensions, was elaborated in [2]. A preliminary macrosegregation upgrade was presented in [3], and in [4], a first three dimensional test was performed. Previous tests were bound to calculations in mold and sub-moldregions only. In the present paper, reference calculations in two dimensions are presented for the entire strand. The physical model is established on a set of macroscopic equations for mass, energy, momentum, species, turbulent kinetic energy, and dissipation rate. The mixture continuum model is used to treat the solidification system. The mushy zone is modeled as a Darcy porous media with Kozeny-Karman permeability relation, where the morphology of the porous media is modeled by a constant value. The incompressible turbulent flow of the molten steel is described by the Low-Reynolds-Number k-ε turbulence model, closed by the Abe-Kondoh-Nagano closure coefficients and damping functions. Lever microsegregation model is used. The numerical method is established on explicit time-stepping, collocation with scaled multiquadrics radial basis functions with adaptive selection of its shape on non-uniform five-nodded influence domains. The velocity-pressure coupling of the incompressible flow is resolved by the explicit Chorin'sfractional step method. The advantages of the method are its simplicity and efficiency, since no polygonisation is involved, easy adaptation of the nodal points in areas with high gradients, almost the same formulation in two and three dimensions, high accuracy and low numerical diffusion.

  19. Photomultiplier blanking circuit

    NASA Technical Reports Server (NTRS)

    Mcclenahan, J. O.

    1972-01-01

    Circuit for protecting photomultiplier equipment from current surges which occur when exposed to brilliant illumination is discussed. Components of circuit and details of operation are provided. Circuit diagram to show action of blanking pulse on zener diode is included.

  20. A Study of the Oscillation Marks' Characteristics of Continuously Cast Incoloy Alloy 825 Blooms

    NASA Astrophysics Data System (ADS)

    Saleem, Saud; Vynnycky, Michael; Fredriksson, Hasse

    2016-06-01

    A comprehensive experimental study of oscillation mark (OM) formation and its characteristics during the solidification of Incoloy alloy 825 in the continuous casting of blooms is investigated by plant trials and metallographic study. The experiments involved two heats with the same casting and mold conditions and sampling at different locations across the strand. The metallographic study combined macro/micro-examinations of OMs and segregation analysis of Cr, Mn, Mo, Ni, and Si by microprobe analysis. The results show that OMs have widely different characteristics, such as mark type, depth, segregation, and accompanying microstructure. Furthermore, the mark pitch can vary considerably even for the similar casting conditions, leading to different conditions for the marks' formation in relation to the mold's cyclic movement. Finally, a mechanism for the OM formation is discussed and proposed. Possible solutions for minimizing the observed defects by optimizing the mold conditions are suggested.

  1. A Study of the Oscillation Marks' Characteristics of Continuously Cast Incoloy Alloy 825 Blooms

    NASA Astrophysics Data System (ADS)

    Saleem, Saud; Vynnycky, Michael; Fredriksson, Hasse

    2016-08-01

    A comprehensive experimental study of oscillation mark (OM) formation and its characteristics during the solidification of Incoloy alloy 825 in the continuous casting of blooms is investigated by plant trials and metallographic study. The experiments involved two heats with the same casting and mold conditions and sampling at different locations across the strand. The metallographic study combined macro/micro-examinations of OMs and segregation analysis of Cr, Mn, Mo, Ni, and Si by microprobe analysis. The results show that OMs have widely different characteristics, such as mark type, depth, segregation, and accompanying microstructure. Furthermore, the mark pitch can vary considerably even for the similar casting conditions, leading to different conditions for the marks' formation in relation to the mold's cyclic movement. Finally, a mechanism for the OM formation is discussed and proposed. Possible solutions for minimizing the observed defects by optimizing the mold conditions are suggested.

  2. Differences in microstructure and texture of Al-Mg sheets produced by twin-roll continuous casting and by direct-chill casting

    SciTech Connect

    Slamova, M.; Karlik, M.; Robaut, F.; Slama, P.; Veron, M

    2002-10-15

    Over the last two decades, the use of aluminum sheets in automotive applications has increased. Aluminum sheets are currently produced from direct-chill (DC) cast plates. The need for low-cost aluminum sheets is a challenge for the development of new materials produced by twin-roll continuous (TRC) casting and cold rolling. It is expected that the sheets produced from these different casting procedures can differ in their microstructure. Therefore, they can exhibit different formability behavior. The paper presents the results of the microstructural characterization and texture evaluation of aluminum sheets produced by both technologies. Sheets produced from twin-roll cast materials have much finer and more numerous second-phase particles, the grain structures of both types of materials are similar. Electron backscatter diffraction (EBSD) and X-ray diffraction techniques were used for texture evaluation and both confirmed the presence of stronger cube texture in the strips produced from DC-cast plates.

  3. Evaluation and Characterization of In-Line Annealed Continuous Cast Aluminum Sheet

    SciTech Connect

    Dr Subodh K. Das

    2006-01-17

    This R&D program will develop optimized, energy-efficient thermo-mechanical processing procedures for in-line annealing of continuously cast hot bands of two 5000 series aluminum alloys (5754 and 5052). The implementation of the R&D will result in the production of sheet with improved formability at high levels of productivity consistency and quality. The proposed R&D involves the following efforts: (1) Design and build continuous in-line annealing equipment for plant-scale trials; (2) Carry out plant-scale trials at Commonwealth Aluminum Corp.'s (CAC) plant in Carson; (3) Optimize the processing variables utilizing a metallurgical model for the kinetics of microstructure and texture evolution during thermo-mechanical processing; (4) Determine the effects of processing variables on the microstructure, texture, mechanical properties, and formability of aluminum sheet; (5) Develop design parameters for commercial implementation; and (6) Conduct techno-economic studies of the recommended process equipment to identify impacts on production costs. The research and development is appropriate for the domestic industry as it will result in improved aluminum processing capabilities and thus lead to greater application of aluminum in various industries including the automotive market. A teaming approach is critical to the success of this effort as no single company alone possesses the breadth of technical and financial resources for successfully carrying out the effort. This program will enable more energy efficient aluminum sheet production technology, produce consistent high quality product, and have The proposal addresses the needs of the aluminum industry as stated in the aluminum industry roadmap by developing new and improved aluminum processes utilizing energy efficient techniques. The effort is primarily related to the subsection on Rolling and Extrusion with the R&D to address energy and environmental efficiencies in aluminum manufacturing and will provide

  4. Fabrication of Porous Copper with Directional Pores by Continuous Casting Technique Through Thermal Decomposition of Hydride

    NASA Astrophysics Data System (ADS)

    Ide, Takuya; Tsunemi, Akihiro; Nakajima, Hideo

    2014-08-01

    Lotus-type porous copper with aligned long cylindrical pores was fabricated by continuous casting technique through thermal decomposition method (TDM) in an argon atmosphere of 0.1 MPa. A pellet of titanium hydride was supplied into molten copper with adjusting the time interval to maintain the constant concentration of hydrogen to be dissolved in the melt, when the transfer velocity of the unidirectional solidification is changed. Long lotus-type porous copper slabs were fabricated with constant solidification velocity. The effect of the transfer velocity on the porosity and pore size was investigated. The average pore diameter was independent of the transfer velocity, but the porosity is slightly dependent on the velocity. It is apparent that the continuous casting technique can be applicable for production of lotus metals through TDM.

  5. Thermo-Mechanical Behavior of the Continuous Casting Bloom in the Heavy Reduction Process

    NASA Astrophysics Data System (ADS)

    Ji, Cheng; Wu, Chen-hui; Zhu, Miao-yong

    2016-08-01

    A two-stage sequential heavy reduction (HR) method, in which the reduction amount was increased both before and after the solidification end, is presented to simultaneously improve the homogeneity and compactness of the continuous casting bloom. With bearing steel GCr15 chosen as the specific research steel, a three-dimensional thermal-mechanical finite element model was developed to simulate and analyze the thermal and mechanical behaviors of the continuous casting bloom during the HR process. In order to ensure the accuracy of the simulation, the constitutive model parameters were derived from the experimental results. The predicted temperature distribution and shell thickness were verified using a thermal infrared camera and nail shooting results, respectively. The real measured relationship between the HR pressure and amount were applied to verify the mechanical model. The explorative application results showed that the quality of the bloom center and compactness of rolled bars have both been significantly improved after the HR was applied.

  6. Control of solidification boundary in continuous casting by asymmetric cooling and mold offset

    NASA Technical Reports Server (NTRS)

    Siegel, R.

    1985-01-01

    A solution, developed to obtain solidification-interface shapes for complex situations in which both the ingot cooling and mold geometry are asymmetric, is analyzed. The effect of mold offsett and of unequal ingot side temperatures on the interface shapes is illustrated in graphs. The results of the analysis show how the solidification interface in continuous casting can be controlled by asymmetries in both mold geometry and cooling of the ingot sides.

  7. Austenite Grain Growth and the Surface Quality of Continuously Cast Steel

    NASA Astrophysics Data System (ADS)

    Dippenaar, Rian; Bernhard, Christian; Schider, Siegfried; Wieser, Gerhard

    2014-04-01

    Austenite grain growth does not only play an important role in determining the mechanical properties of steel, but certain surface defects encountered in the continuous casting industry have also been attributed to the formation of large austenite grains. Earlier research has seen innovative experimentation, the development of metallographic techniques to determine austenite grain size and the building of mathematical models to simulate the conditions pertaining to austenite grain growth during the continuous casting of steel. Oscillation marks and depressions in the meniscus region of the continuously casting mold lead to retarded cooling of the strand surface, which in turn results in the formation of coarse austenite grains, but little is known about the mechanism and rate of formation of these large austenite grains. Relevant earlier research will be briefly reviewed to put into context our recent in situ observations of the delta-ferrite to austenite phase transition. We have confirmed earlier evidence that very large delta-ferrite grains are formed very quickly in the single-phase region and that these large delta-ferrite grains are transformed to large austenite grains at low cooling rates. At the higher cooling rates relevant to the early stages of the solidification of steel in a continuously cast mold, delta-ferrite transforms to austenite by an apparently massive type of transformation mechanism. Large austenite grains then form very quickly from this massive type of microstructure and on further cooling, austenite transforms to thin ferrite allotriomorphs on austenite grain boundaries, followed by Widmanstätten plate growth, with almost no regard to the cooling rate. This observation is important because it is now well established that the presence of a thin ferrite film on austenite grain boundaries is the main cause of reduction in hot ductility. Moreover, this reduction in ductility is exacerbated by the presence of large austenite grains.

  8. Numerical study of steady turbulent flow through bifurcated nozzles in continuous casting

    SciTech Connect

    Najjar, F.M.; Thomas, B.G.; Hershey, D.E.

    1995-08-01

    Bifurcated nozzles are used in continuous casting of molten steel, where they influence the quality of the cast steel slabs. The present study performs two-dimensional (2-D) and three-dimensional (3-D) simulations of steady turbulent (K-{epsilon}) flow in bifurcated nozzles, using a finite-element (FIDAP) model, which has been verified previously with water model experiments. The effects of nozzle design and casting process operating variables on the jet characteristics exiting the nozzle are investigated. The nozzle design parameters studied include the shape, angle, height, width, and thickness of the ports and the bottom geometry. The process operating practices include inlet velocity profile and angle as well as port curvature caused by erosion or inclusion buildup. Results show that the jet angle is controlled mainly by the port angle but is steeper with larger port area and thinner walls. The degree of swirl is increased by larger or rounder ports. The effective port area, where there is no recirculation, is increased by smaller or curved ports. Flow asymmetry is more severe with skewed or angled inlet conditions or unequal port sizes. Turbulence levels in the jet are higher with higher casting speed and small ports.

  9. Analysis of Mold Friction in a Continuous Casting Using Wavelet Entropy

    NASA Astrophysics Data System (ADS)

    Yong, Ma; Fangyin, Wang; Cheng, Peng; Wei, Gui; Bohan, Fang

    2016-06-01

    By studying mold friction (MDF), we observed that monitoring and controlling of the friction between the strand and the mold is very important for continuous casting to improve lubrication and prevent breakout. However, existing analysis technologies of MDF do not support the continuous casting very well. In addition, we found that the wavelet entropy has multiscale and statistical properties. Informed by these observations, in this article, we use wavelet entropy to judge the lubrication state between the strand and the mold. First, we demonstrate the implementation and superiority of wavelet entropy and how it helps in efficient evaluation of the lubrication state in mold. A study of wavelet entropy of MDF, which is obtained from the abnormal continuous casting production, such as level fluctuation, submerged entry nozzle broken, and breakout, has been performed to achieve relevant conclusions. The results indicate that the information of MDF in time and frequency domains could be obtained simultaneously by the application of wavelet entropy and that the wavelet entropy has a good sensibility for the study of disorder of MDF, which could further reveal the nature of MDF.

  10. EUVL Mask Blank Repair

    SciTech Connect

    Barty, A; Mirkarimi, P; Stearns, D G; Sweeney, D; Chapman, H N; Clift, M; Hector, S; Yi, M

    2002-05-22

    EUV mask blanks are fabricated by depositing a reflective Mo/Si multilayer film onto super-polished substrates. Small defects in this thin film coating can significantly alter the reflected field and introduce defects in the printed image. Ideally one would want to produce defect-free mask blanks; however, this may be very difficult to achieve in practice. One practical way to increase the yield of mask blanks is to effectively repair multilayer defects, and to this effect they present two complementary defect repair strategies for use on multilayer-coated EUVL mask blanks. A defect is any area on the mask which causes unwanted variations in EUV dose in the aerial image obtained in a printing tool, and defect repair is correspondingly defined as any strategy that renders a defect unprintable during exposure. The term defect mitigation can be adopted to describe any strategy which renders a critical defect non-critical when printed, and in this regard a non-critical defect is one that does not adversely affect device function. Defects in the patterned absorber layer consist of regions where metal, typically chrome, is unintentionally added or removed from the pattern leading to errors in the reflected field. There currently exists a mature technology based on ion beam milling and ion beam assisted deposition for repairing defects in the absorber layer of transmission lithography masks, and it is reasonable to expect that this technology will be extended to the repair of absorber defects in EUVL masks. However, techniques designed for the repair of absorber layers can not be directly applied to the repair of defects in the mask blank, and in particular the multilayer film. In this paper they present for the first time a new technique for the repair of amplitude defects as well as recent results on the repair of phase defects.

  11. Quantification of the Solidification Microstructure in Continuously-Cast High-Carbon Steel Billets

    NASA Astrophysics Data System (ADS)

    Ganguly, Suvankar; Choudhary, S. K.

    2009-06-01

    In this work, an attempt has been made to investigate the relationship between the cast microstructure and solidification variables in industrial scale, continuously-cast (CC) high-carbon steel billets. Toward these, theoretical and experimental studies are undertaken to predict the evolution of dendrite arm spacing (DAS) in the columnar zone of CC billets. Several billet samples collected from the continuous casting shop of Tata Steel are used to characterize the solidification microstructure, and interdendritic arm spacings (both primary and secondary) are measured. Macrostructural examination of the billet samples indicates predominantly columnar structure in all billets. Dendrite arm spacings vary over a wide range indicating nonuniform secondary cooling. A mathematical model is also developed to describe the relationship between dendrite structures and solidification parameters. The model considers the effect of change of volume on solidification and provides a quantitative estimation of variation of DAS as a function of distance from the product surface. Results predicted by the mathematical model are compared with the experimental measurements and good agreement can be observed in this regard, thereby establishing the authenticity of the proposed formulation.

  12. Simulation of macrosegregation in a large vertical continuous casting of steel

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Wu, M.; Kharicha, A.; Ludwig, A.

    2016-07-01

    A three-phase mixed columnar-equiaxed solidification model considering fluid flow, heat and solute transport is applied to simulate the solidification in a vertical continuous casting. The key features of solidification phenomena in this process, such as evolution of columnar phase, evolution and floatation/sedimentation of equi- axed crystals, thermal solutal convection of the melt and the flow caused by crystal sedimentation, development of as-cast structure, the columnar-to-equiaxed transition (CET), and formation of macrosegregation, are simulated. It is predicted that there is an equiaxed zone in the central part of the strand, and the rest section is filled with columnar phase (or dominant with columnar phase). A relatively strong negative segregation in the equiaxed zone and a mostly neutral concentration in the columnar region are found. Near the CET, there is a so-called middle radius positive segregation band. Formation mechanisms of this segregation pattern are discussed.

  13. Optimization of flow control devices in a single-strand slab continuous casting tundish

    NASA Astrophysics Data System (ADS)

    Ding, Ning; Bao, Yan-Ping; Sun, Qi-Song; Wang, Li-Feng

    2011-06-01

    The optimization of flow control devices in a single-slab continuous casting tundish was carried out by physical modeling, and the optimized scheme was presented. With the optimal tundish configuration, the minimum residence time of liquid steel was increased by 1.4 times, the peak concentration time was increased by 97%, and the dead volume fraction was decreased by 72%. A mathematical model for molten steel in the tundish was established by using the fluid dynamics package Fluent. The velocity field, concentration field, and the residence time distribution (RTD) curves of molten steel flow before and after optimization were obtained. Experimental results showed that the reasonable configuration with flow control devices can improve the fluid flow characteristics in the tundish. The results of industrial application show that the nonmetallic inclusion area ratio in casting slabs is decreased by 32% with the optimal tundish configuration.

  14. Method and apparatus for improved melt flow during continuous strip casting

    SciTech Connect

    Follstaedt, D.W.; King, E.L.; Schneider, K.C.

    1991-11-12

    The continuous casting of metal strip using the melt overflow process is improved by controlling the weir conditions in the nozzle to provide a more uniform flow of molten metal across the width of the nozzle and reducing the tendency for freezing of metal along the interface with refractory surfaces. A weir design having a sloped rear wall and tapered sidewalls and critical gap controls beneath the weir has resulted in the drastic reduction in edge tearing and a significant improvement in strip uniformity. The floor of the container vessel is preferably sloped and the gap between the nozzle and the rotating substrate is critically controlled. The resulting flow patterns observed with the improved casting process have reduced thermal gradients in the bath, contained surface slag and eliminated undesirable solidification near the discharge area by increasing the flow rates at those points. 8 figures.

  15. Numerical simulation of solid liquid interface behavior during continuous strip casting process.

    PubMed

    Lee, Changbum; Yoon, Wooyoung; Shin, Seungwon; Lee, Jaewoo; Jang, Bo-Yun; Kim, Joonsoo; Ahn, Youngsoo; Lee, Jinseok

    2013-05-01

    A new metal-strip-casting process called continuous strip-casting (CSC) has been developed for making thin metal strips. A numerical simulation model to help understand solid-liquid interface behavior during CSC has been developed and used to identify the solidification morphologies of the strips and to determine the optimum processing conditions. In this study, we used a modified level contour reconstruction method (LCRM) and the sharp interface method to modify interface tracking, and performed a simulation analysis of the CSC process. The effects of process parameters such as heat-transfer coefficient and extrusion velocity on the behavior of the solid-liquid interface were estimated and used to improve the apparatus. A Sn (Tin) plate of dimensions 200 x 50 x 1 mm3 was successfully produced by CSC for a heat-transfer coefficient of 104 W/m2 K and an extrusion velocity of 0.2 m/s. PMID:23858856

  16. Transient thermal model of the continuous single-wheel thin-strip casting process

    NASA Astrophysics Data System (ADS)

    Li, Guowei; Thomas, Brian G.

    1996-06-01

    A transient heat-transfer model (STRIP1D) has been developed to simulate the single-roll continuous strip-casting process. The model predicts temperature in the solidifying strip coupled with heat transfer in the rotating wheel, using an explicit finite difference procedure. The model has been calibrated using strip thickness data from a test caster at ARMCO Inc. (Middletown, OH) and verified with a range of other available measurements. The strip/wheel interface contact resistance and heat transfer were investigated in particular, and an empirical formula to calculate this heat-transfer coefficient as a function of contact time was obtained. Wheel temperature and final strip thickness are investigated as a function of casting speed, liquid steel pool depth, superheat, coatings on the wheel hot surface, strip detachment point, wheel wall thickness, and wheel material.

  17. Method and apparatus for improved melt flow during continuous strip casting

    SciTech Connect

    Follstaedt, Donald W.; King, Edward L.; Schneider, Ken C.

    1991-11-12

    The continuous casting of metal strip using the melt overflow process is improved by controlling the weir conditions in the nozzle to provide a more uniform flow of molten metal across the width of the nozzle and reducing the tendency for freezing of metal along the interface with refractory surfaces. A weir design having a sloped rear wall and tapered sidewalls and critical gap controls beneath the weir has resulted in the drastic reduction in edge tearing and a significant improvement in strip uniformity. The floor of the container vessel is preferably sloped and the gap between the nozzle and the rotating substrate is critically controlled. The resulting flow patterns observed with the improved casting process have reduced thermal gradients in the bath, contained surface slag and eliminated undesirable solidification near the discharge area by increasing the flow rates at those points.

  18. A comparison of microstructure, texture and formability of direct chill cast versus continuous cast aluminum-magnesium alloys

    NASA Astrophysics Data System (ADS)

    Zhao, Yumin

    In this dissertation, microstructure and texture evolution of Al-Mg alloys produced by direct chill (DC) cast and continuous cast processes (CC) during thermo-mechanical processing were compared and the differences in formability between DC and CC alloys were identified. At the same time, the underlining mechanisms that cause the difference in structure, texture and formability between DC and CC alloys were analyzed. The recrystallization temperature of the DC AA5052 hot band was about 55°C lower than that of the CC AA5052 hot band. After complete recrystallization, DC AA5052 hot band possessed a stronger cube component than the CC AA5052 hot band. This result was associated with the particle structures of DC and CC AA5052 hot bands. Two different phase particles, Al6((Mn,Fe) and Mg2Si, existed in the DC and CC AA5052 hot bands. CC AA5052 hot band contained more Mg2Si particles than did the DC AA5052 hot band due to the absence of homogenization of the CC material before hot rolling. Mg2Si particles were easily dissolved at high treatment temperatures. After preheating at 454°C for 4 hours, the particle density in the preheated CC AA5052 hot band is closer to that in DC AA5052 alloy due to the dissolution of the Mg2Si particles. Therefore, the differences on recrystallization behaviors of the 80% cold rolled materials decreased, if the DC and CC materials were preheated at 454°C for 4 hours before cold rolling. If the as-received DC and CC AA5052 hot bands were directly cold rolled to 80% reduction, the cold rolled CC AA5052 alloy had a higher recrystallization temperature and a weaker cube recrystallization texture than the cold rolled DC AA5052 alloy. There still existed differences in texture evolution during cold rolling and isothermal annealing between DC and CC AA5052 and AA5182 materials, although the preheat treatment decreased the differences in particle structures and recrystallization temperature between DC and CC materials. Texture evolution during

  19. Modeling the Effects of Strand Surface Bulging and Mechanical Softreduction on the Macrosegregation Formation in Steel Continuous Casting

    NASA Astrophysics Data System (ADS)

    Domitner, Josef; Wu, Menghuai; Kharicha, Abdellah; Ludwig, Andreas; Kaufmann, Bernhard; Reiter, Jürgen; Schaden, Thomas

    2013-10-01

    Positive centerline macrosegregation is an undesired casting defect that frequently occurs in the continuous casting process of steel strands. Mechanical softreduction (MSR) is a generally applied technology to avoid this casting defect in steel production. In the current paper, the mechanism of MSR is numerically examined. Therefore, two 25-m long horizontal continuous casting strand geometries of industrial scale are modeled. Both of these strand geometries have periodically bulged surfaces, but only one of them considers the cross-section reduction due to a certain MSR configuration. The macrosegregation formation inside of these strands with and without MSR is studied for a binary Fe-C-alloy based on an Eulerian multiphase model. Comparing the macrosegregation patterns obtained for different casting speed definitions allows investigating the fundamental influence of feeding, bulging and MSR mechanisms on the formation of centerline macrosegregation.

  20. Method for determining molten metal pool level in twin-belt continuous casting machines

    DOEpatents

    Kaiser, Timothy D.; Daniel, Sabah S.; Dykes, Charles D.

    1989-03-21

    A method for determining level of molten metal in the input of a continuous metal casting machine having at least one endless, flexible, revolving casting belt with a surface which engages the molten metal to be cast and a reverse, cooled surface along which is directed high velocity liquid coolant includes the steps of predetermining the desired range of positions of the molten metal pool and positioning at least seven heat-sensing transducers in bearing contact with the moving reverse belt surface and spaced in upstream-downstream relationship relative to belt travel spanning the desired pool levels. A predetermined temperature threshold is set, somewhat above coolant temperature and the output signals of the transducer sensors are scanned regarding their output signals indicative of temperatures of the moving reverse belt surface. Position of the molten pool is determined using temperature interpolation between any successive pair of upstream-downstream spaced sensors, which follows confirmation that two succeeding downstream sensors are at temperature levels exceeding threshold temperature. The method accordingly provides high resolution for determining pool position, and verifies the determined position by utilizing full-strength signals from two succeeding downstream sensors. In addition, dual sensors are used at each position spanning the desired range of molten metal pool levels to provide redundancy, wherein only the higher temperature of each pair of sensors at a station is utilized.

  1. Monitoring of solidification in the continuous casting mold by temperature sensors

    NASA Astrophysics Data System (ADS)

    Pyszko, René; Příhoda, Miroslav; Čarnogurská, Mária

    2016-06-01

    Defects of continuously cast strand, such as unevenness of shell thickness or cracks as well as unstable casting parameters result in changes of strand surface temperature which affect heat flux and temperature field in the mold wall. Methods based on the principle of measurement and mathematical processing of temperatures in the mold wall are used for the purposes of diagnostics of the shell formation process, prediction of surface and subsurface quality and breakout danger, adjustment of the casting axis or condition monitoring of the oscillating mechanism. Measured values of temperatures in the wall depend on the exact position of the sensor in the wall, especially in the normal direction to the mold working surface. Ensuring the accurate and constant distance between the sensor and the mold surface is technically demanding; therefore it is necessary to correct the measured temperatures mathematically. The article describes two methods for correcting the measured temperatures, based on physical and statistical principles that have been developed and used in a real diagnostics system. Practical applications of the methods for diagnostics of strand surface quality and breakout prediction are presented.

  2. Transient Thermo-fluid Model of Meniscus Behavior and Slag Consumption in Steel Continuous Casting

    NASA Astrophysics Data System (ADS)

    Jonayat, A. S. M.; Thomas, Brian G.

    2014-10-01

    The behavior of the slag layer between the oscillating mold wall, the slag rim, the slag/liquid steel interface, and the solidifying steel shell, is of immense importance for the surface quality of continuous-cast steel. A computational model of the meniscus region has been developed, that includes transient heat transfer, multi-phase fluid flow, solidification of the slag, and movement of the mold during an oscillation cycle. First, the model is applied to a lab experiment done with a "mold simulator" to verify the transient temperature-field predictions. Next, the model is verified by matching with available literature and plant measurements of slag consumption. A reasonable agreement has been observed for both temperature and flow-field. The predictions show that transient temperature behavior depends on the location of the thermocouple during the oscillation relative to the meniscus. During an oscillation cycle, heat transfer variations in a laboratory frame of reference are more severe than experienced by the moving mold thermocouples, and the local heat transfer rate is increased greatly when steel overflows the meniscus. Finally, the model is applied to conduct a parametric study on the effect of casting speed, stroke, frequency, and modification ratio on slag consumption. Slag consumption per unit area increases with increase of stroke and modification ratio, and decreases with increase of casting speed while the relation with frequency is not straightforward. The match between model predictions and literature trends suggests that this methodology can be used for further investigations.

  3. Solidification interface shape for continuous casting in an offset mold - Two analytical methods

    NASA Astrophysics Data System (ADS)

    Siegel, R.

    1984-02-01

    A solution method for finding the unknown solidification interface in manufacturing slab ingots as a continuous casting is presented, which involves a product solution in the potential plane and the use of conjugate harmonic functions. It is argued that the method may be more direct for some geometries than the Cauchy boundary value method. Moreover, the usefulness of the Cauchy boundary value method is demonstrated through the example of a nonsymmetric horizontal mold where the walls are offset to support the lower ingot boundary.

  4. Solidification interface shape for continuous casting in an offset mold - Two analytical methods

    NASA Technical Reports Server (NTRS)

    Siegel, R.

    1984-01-01

    A solution method for finding the unknown solidification interface in manufacturing slab ingots as a continuous casting is presented, which involves a product solution in the potential plane and the use of conjugate harmonic functions. It is argued that the method may be more direct for some geometries than the Cauchy boundary value method. Moreover, the usefulness of the Cauchy boundary value method is demonstrated through the example of a nonsymmetric horizontal mold where the walls are offset to support the lower ingot boundary.

  5. Use of NH4Cl-H2O Analogue Castings to Model Aspects of Continuous Casting. Part 1; Asymmetry in Inclined Moulds

    NASA Technical Reports Server (NTRS)

    Jang, J.; Hellawell, A.

    1991-01-01

    Crystallisation of NH4Cl from aqueous solutions has been used to examine grain formation in a configuration similar to that existing in the curved mould of a continuous, steel casting machine. The observations show how falling equiaxed crystals accumulate at the lower (outer) columnar front earlier than at the upper (inner) front and, thus, lead to an asymmetric grain structure. The usefulness of the aqueous system as a realistic model for steel casting is discussed in terms of relative temperature profiles, materials properties, and observed columnar and eutectic growth rates.

  6. Mask Blank Defect Detection

    SciTech Connect

    Johnson, M A; Sommargren, G E

    2000-02-04

    Mask blanks are the substrates that hold the master patterns for integrated circuits. Integrated circuits are semiconductor devices, such as microprocessors (mPs), dynamic random access memory (DRAMs), and application specific integrated circuits (ASICs) that are central to the computer, communication, and electronics industries. These devices are fabricated using a set of master patterns that are sequentially imaged onto light-sensitive coated silicon wafers and processed to form thin layers of insulating and conductive materials on top of the wafer. These materials form electrical paths and transistors that control the flow of electricity through the device. For the past forty years the semiconductor industry has made phenomenal improvements in device functionality, compactness, speed, power, and cost. This progress is principally due to the exponential decrease in the minimum feature size of integrated circuits, which has been reduced by a factor of {radical}2 every three years. Since 1992 the Semiconductor Industry Association (SIA) has coordinated the efforts of producing a technology roadmap for semiconductors. In the latest document, ''The International Technology Roadmap for Semiconductors: 1999'', future technology nodes (minimum feature sizes) and targeted dates were specified and are summarized in Table 1. Lithography is the imaging technology for producing a de-magnified image of the mask on the wafer. A typical de-magnification factor is 4. Mask blank defects as small as one-eighth the equivalent minimum feature size are printable and may cause device failure. Defects might be the result of the surface preparation, such as polishing, or contamination due to handling or the environment. Table 2 shows the maximum tolerable defect sizes on the mask blank for each technology node. This downward trend puts a tremendous burden on mask fabrication, particularly in the area of defect detection and reduction. A new infrastructure for mask inspection will be

  7. Center crack detection during continuous casting of aluminum by laser ultrasonic measurements

    NASA Astrophysics Data System (ADS)

    Grün, Hubert; Mitter, Thomas; Roither, Jürgen; Betz, Andreas; Bozorgi, Salar; Burgholzer, Peter

    2014-05-01

    Crack detection during continuous direct chill casting of aluminum is a matter of economics. Determining cracks during production process saves money, energy and raw material. Of course, a non-destructive method is required for this evaluation. Because of temperature concerns conventional ultrasound is not applicable. One non-contact alternative is laser ultrasonics. In laser ultrasonics short laser pulses illuminate the sample. The electromagnetic energy gets absorbed at the surface of the sample and results in local heating followed by expansion. Thereby broadband ultrasonic waves are launched which propagate through the sample and get back reflected or scattered at interfaces (cracks, blowholes,…) like conventional ultrasonic waves. Therefore laser ultrasonics is an alternative thermal infrared technology. By using an interferometer also the detection of the ultrasonic waves at the sample surface is done in a remote manner. During preliminary examinations in the lab by scanning different aluminum studs it was able to distinguish between studs with and without cracks. The prediction of the dimension of the crack by evaluation of the damping of the broadband ultrasonic waves was possible. With simple image reconstruction methods one can localize the crack and give an estimation of its extent and even its shape. Subsequent first measurements using this laser ultrasonic setup during the continuous casting of aluminum were carried out and showed the proof of principle in an industrial environment with elevated temperatures, dust, cooling water and vibrations.

  8. Influence of FC-Mold on the Full Solidification of Continuous Casting Slab

    NASA Astrophysics Data System (ADS)

    Wang, Qiangqiang; Zhang, Lifeng

    2016-03-01

    A three-dimensional model coupling fluid flow, heat transfer, solidification for slab continuous casting process with flow control mold (FC-Mold) was constructed. The full solidification process from the meniscus to the solidification end of slab was obtained for the first time. The calculation domain was designed according to the actual dimension of the continuous caster. The main results show that the calculated flow speed on the meniscus at different casting speeds and the calculated shell profile had a good agreement with the measured flow speed using nail board measurement and the shell with breakout. The application of FC-Mold could improve the symmetry of flow in width, and suppress the formation of vortices on the meniscus. The decrease of upper magnetic field intensity of FC-Mold reduced the washing effect on the solidifying front, and favored the shell growth in the mold region. In the secondary cooling zone, the shell thickness increased gradually, and the shell grew quickly at the final stage of solidification for the whole mushy form of steel. In addition, FC-Mold had an effect on the shape and position of the solidification end.

  9. 46 CFR 56.25-7 - Blanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... requirements of 104.5.3 of ASME B31.1 (incorporated by reference; see 46 CFR 56.01-2). ... 46 Shipping 2 2011-10-01 2011-10-01 false Blanks. 56.25-7 Section 56.25-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Pipe...

  10. 46 CFR 56.25-7 - Blanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... requirements of 104.5.3 of ASME B31.1 (incorporated by reference; see 46 CFR 56.01-2). ... 46 Shipping 2 2013-10-01 2013-10-01 false Blanks. 56.25-7 Section 56.25-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Pipe...

  11. 46 CFR 56.25-7 - Blanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... requirements of 104.5.3 of ASME B31.1 (incorporated by reference; see 46 CFR 56.01-2). ... 46 Shipping 2 2014-10-01 2014-10-01 false Blanks. 56.25-7 Section 56.25-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Pipe...

  12. 46 CFR 56.25-7 - Blanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... requirements of 104.5.3 of ASME B31.1 (incorporated by reference; see 46 CFR 56.01-2). ... 46 Shipping 2 2012-10-01 2012-10-01 false Blanks. 56.25-7 Section 56.25-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Pipe...

  13. 46 CFR 56.25-7 - Blanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Blanks. 56.25-7 Section 56.25-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Pipe Flanges... requirements of 104.5.3 of ASME B31.1 (incorporated by reference; see 46 CFR 56.01-2)....

  14. The use of water cooling during the continuous casting of steel and aluminum alloys

    NASA Astrophysics Data System (ADS)

    Sengupta, J.; Thomas, B. G.; Wells, M. A.

    2005-01-01

    In both continuous casting of steel slabs and direct chill (DC) casting of aluminum alloy ingots, water is used to cool the mold in the initial stages of solidification, and then below the mold, where it is in direct contact with the newly solidified surface of the metal. Water cooling affects the product quality by (1) controlling the heat removal rate that creates and cools the solid shell and (2) generating thermal stresses and strains inside the solidified metal. This work reviews the current state-of-the-art in water cooling for both processes, and draws insights by comparing and contrasting the different practices used in each process. The heat extraction coefficient during secondary cooling depends greatly on the surface temperature of the ingot, as represented by boiling water-cooling curves. Thus, the heat extraction rate varies dramatically with time, as the slab/ingot surface temperature changes. Sudden fluctuations in the temperature gradients within the solidifying metal cause thermal stresses, which often lead to cracks, especially near the solidification front, where even small tensile stresses can form hot tears. Hence, a tight control of spray cooling for steel, and practices such as CO2 injection/pulse water cooling for aluminum, are now used to avoid sudden changes in the strand surface temperature. The goal in each process is to match the rate of heat removal at the surface with the internal supply of latent and sensible heat, in order to lower the metal surface temperature monotonically, until cooling is complete.

  15. Contactless inductive flow tomography: basic principles and first applications in the experimental modelling of continuous casting

    NASA Astrophysics Data System (ADS)

    Stefani, F.; Eckert, S.; Ratajczak, M.; Timmel, K.; Wondrak, T.

    2016-07-01

    Contactless inductive flow tomography (CIFT) aims at reconstructing the flow structure of a liquid metal from the magnetic fields measured at various positions outside the fluid body which are induced by the flow under the influence of one or multiple applied magnetic fields. We recap the basic mathematical principles of CIFT and the results of an experiment in which the propeller-driven three-dimensional flow in a cylindrical had been reconstructed. We also summarize the recent activities to utilize CIFT in various problems connected with the experimental simulation of the continuous casting process. These include flow reconstructions in single-phase and two-phase flow problems in the Mini-LIMMCAST model of slab-casting, studies of the specific effects of an electromagnetic stirrer attached to the Submerged Entry Nozzle (SEN), as well as first successful applications of CIFT on the background of a strong electromagnetic brake field. We conclude by discussing some remaining obstacles for the deployment of CIFT in a real caster.

  16. Large Eddy Simulations of Double-Ruler Electromagnetic Field Effect on Transient Flow During Continuous Casting

    NASA Astrophysics Data System (ADS)

    Singh, Ramnik; Thomas, Brian G.; Vanka, Surya P.

    2014-06-01

    Transient flow during nominally steady conditions is responsible for many intermittent defects during the continuous casting of steel. The double-ruler electromagnetic field configuration, or "FC-Mold EMBr," is popular in commercial slab casting as it provides independent control of the applied static field near the jet and free surface regions of the mold. In the current study, transient flow in a typical commercial caster is simulated in the absence and in the presence of a double-ruler magnetic field, with rulers of equal strengths. Large eddy simulations with the in-house code CU-FLOW resolve the important transient behavior, using grids of over five million cells with a fast parallel solver. In the absence of a magnetic field, a double-roll pattern is observed, with transient unbalanced behavior, high surface velocities (~0.5 m/s), surface vortex formation, and very large surface-level fluctuations (~±12 mm). Applying the magnetic field suppresses the unbalanced behavior, producing a more complex mold flow pattern, but with much lower surface velocities (~0.1 m/s), and a flat surface level with small level fluctuations (<±1 mm). Nail board measurements taken at this commercial caster, in the absence of the field, matched reasonably well with the calculated results, both quantitatively and qualitatively.

  17. The research and development of CCD-based slab continuous casting mold copper surface imaging system

    NASA Astrophysics Data System (ADS)

    Wang, Xingdong; Zhang, Liugang; Xie, Haihua; Long, Liaosha; Yu, Wenyong

    2011-11-01

    An imaging system for the continuous casting mold copper surface is researched and developed, to replace the on-line manual measuring method, which is used to checking Copper defects such as wearing, scratches and coating loss and other phenomena. Method: The imaging system proposes a special optical loop formed by three Mirrors, selects light source, CCD camera and lens type, designs mechanical transmission system and installation platform. Result: the optical loop and light source can insure imaging large-format object in narrow space. The CCD camera and lens determine the accuracy of horizontal scanning, and the mechanical transmission system ensures accuracy of the vertical scan. The installation platform supplies base and platform for the system. Conclusions: CCD-based copper surface imaging system effectively prevent defects such as missed measuring and low efficiency, etc. It can automatically and accurately shoot copper surface images on-line, and supply basis for image processing, defects identification and copper changing in the late.

  18. Analysis of grain orientation in cold crucible continuous casting of photovoltaic Si

    NASA Astrophysics Data System (ADS)

    Gallien, B.; Duffar, Th.; Lay, S.; Robaut, F.

    2011-03-01

    Grain orientation in multi-crystalline photovoltaic silicon is analyzed in the case of a square shaped ingot produced by cold crucible continuous casting (4C). This technique leads to a specific grain structure: horizontal on the wall where nucleation occurs and vertical at the center of the ingot. EBSD analysis along a solidification path shows that successive Σ3 twinning is the predominant source of variation in grain orientation. In fact, depending on the location along the solidification path, only 15-35% of grain boundaries are random boundaries without Σ3n twinning relationship (1≤n≤5) and 34-48% are Σ3 twins. The grain orientation distribution is similar at the beginning and end of solidification, and the number of low angle grain boundaries is negligible.

  19. Reasonable Temperature Schedules for Cold or Hot Charging of Continuously Cast Steel Slabs

    NASA Astrophysics Data System (ADS)

    Li, Yang; Chen, Xin; Liu, Ke; Wang, Jing; Wen, Jin; Zhang, Jiaquan

    2013-12-01

    Some continuously cast steel slabs are sensitive to transverse fracture problems during transportation or handling away from their storage state, while some steel slabs are sensitive to surface transverse cracks during the following rolling process in a certain hot charging temperature range. It is revealed that the investigated steel slabs with high fracture tendency under room cooling condition always contain pearlite transformation delayed elements, which lead to the internal brittle bainitic structure formation, while some microalloyed steels exhibit high surface crack susceptibility to hot charging temperatures due to carbonitride precipitation. According to the calculated internal cooling rates and CCT diagrams, the slabs with high fracture tendency during cold charging should be slowly cooled after cutting to length from hot strand or charged to the reheating furnace directly above their bainite formation temperatures. Based on a thermodynamic calculation for carbonitride precipitation in austenite, the sensitive hot charging temperature range of related steels was revealed for the determination of reasonable temperature schedules.

  20. Simulation of fluid flow induced by opposing ac magnetic fields in a continuous casting mold

    SciTech Connect

    Chang, F.C.; Hull, J.R.; Beitelman, L.

    1995-07-01

    A numerical simulation was performed for a novel electromagnetic stirring system employing two rotating magnetic fields. The system controls stirring flow in the meniscus region of a continuous casting mold independently from the stirring induced within the remaining volume of the mold by a main electromagnetic stirrer (M-EMS). This control is achieved by applying to the meniscus region an auxiliary electromagnetic field whose direction of rotation is opposite to that of the main magnetic field produced by the M-EMS. The model computes values and spatial distributions of electromagnetic parameters and fluid flow in the stirred pools of mercury in cylindrical and square geometries. Also predicted are the relationships between electromagnetics and fluid flows pertinent to a dynamic equilibrium of the opposing stirring swirls in the meniscus region. Results of the numerical simulation compared well with measurements obtained from experiments with mercury pools.

  1. Method and apparatus for separating continuous cast strip from a rotating substrate

    DOEpatents

    King, E.L.; Follstaedt, D.W.; Sussman, R.C.

    1991-08-20

    The continuous casting of strip, ribbon and wire is improved by using a free jet nozzle which provides a fluid that follows a rotating substrate surface to the separation point. The nozzle includes an inclined surface having a ratio of its length to the gap between the substrate and the nozzle edge of 5:1 to 15:1. The inclined surface improves the ability of the jet to tangentially follow the substrate in a direction opposite to its rotation to the separation point. This also allows a close positioning of the nozzle to the substrate which serves to provide a back-up mechanical separation means by using the edge of nozzle lip. The nozzle may be rotated from its operating position for cleaning of the substrate and the nozzle. 4 figures.

  2. Method and apparatus for separating continuous cast strip from a rotating substrate

    DOEpatents

    King, Edward L.; Follstaedt, Donald W.; Sussman, Richard C.

    1991-01-01

    The continuous casting of strip, ribbon and wire is improved by using a free jet nozzle which provides a fluid that follows a rotating substrate surface to the separation point. The nozzle includes an inclined surface having a ratio of its length to the gap between the substrate and the nozzle edge of 5:1 to 15:1. The inclined surface improves the ability of the jet to tangentially follow the substrate in a direction opposite to its rotation to the separation point. This also allows a close positioning of the nozzle to the substrate which serves to provide a back-up mechanical separation means by using the edge of nozzle lip. The nozzle may be rotated from its operating position for cleaning of the substrate and the nozzle.

  3. On the evolution of unsteady disturbances in continuous strip casting processes

    NASA Astrophysics Data System (ADS)

    Kluwick, A.; Scheichl, St.

    1997-12-01

    Continuous solidification processes in thin layers of molten metal are of central importance in many fields of modern metallurgical engineering. This paper deals with unsteady disturbances possibly emerging at the free surface or the phase boundary within the solidification zone of a horizontal strip casting process. Assuming that the wave lengths of the disturbances are large compared to the characteristic depth of the melt, we can apply governing equations for one-dimensional flow. Furthermore, we assume the amplitudes of the disturbances to be so small that their evolution can be regarded as weakly nonlinear. Since unsteady wave propagation phenomena can arise from temperature variations as well as from the excitation of waves at the free surface or the solidification front, both mechanisms will be studied in the following. In the latter case the disturbances at the surface are found to be governed by the inviscid Burgers equations with varying coefficients and will then, in general, develop shock discontinuities.

  4. A power transducer system for the ultrasonic lubrication of the continuous steel casting.

    PubMed

    Iula, Antonio; Caliano, Giosué; Caronti, Alessandro; Pappalardo, Massimo

    2003-11-01

    A critical point in the continuous steel casting process exists in the meniscus zone of the cooled mould, i.e., the region in which the steel stream flowing out of the tundish nozzle starts to solidify. This is a critical point because of the sticking that occurs between the solid shell of steel and the mould. In this work, a new system for the ultrasonic lubrication of the continuous steel casting is proposed and experimentally tested. The basic idea is to excite one of the mould's natural vibration modes by means of a distributed ultrasonic source. This source is composed of an array of power emitters, with each of them placed upon an antinode of the mould. An experimental characterization of the vibrational behavior of a square mould was first carried out. The most active resonance modes of the mould were detected with an experimental technique based on a simple impedance measurement. The modal shape of the selected mode, and hence the position of antinodes, was obtained by means of interferometer measurements. Additional experimental investigations were performed by exciting mould vibrations with up to four piezoceramic disks placed on different sets of antinodes. Some positioning criteria to maximize the superposition effect were derived. Measurements were obtained through excitation of the mould with up to four Langevin-type power emitters, designed and manufactured to work at the mould's selected resonance frequency. These measurements have shown that, by increasing the number of emitters, the ultrasonic power transmitted to the mould and, consequently, the maximum available displacement, increases. Other practical advantages of the proposed system are highlighted and discussed. PMID:14682633

  5. Experimental and numerical modelling of the fluid flow in the continuous casting of steel

    NASA Astrophysics Data System (ADS)

    Timmel, K.; Miao, X.; Wondrak, T.; Stefani, F.; Lucas, D.; Eckert, S.; Gerbeth, G.

    2013-03-01

    This article gives an overview of recent research activities with respect to the mold flow in the continuous casting of steel in presence of DC magnetic fields. The magnetic fields appear to be an attractive tool for controlling the melt flow in a contactless way. Various kinds of magnetic systems are already in operation in industrial steel casting, but the actual impact on the melt flow has not been sufficiently verified by experimental studies. The rapid development of innovative diagnostic techniques in low-melting liquid metals over the last two decades enables new possibilities for systematic flow measurements in liquid metal model experiments. A new research program was initiated at HZDR comprising three experimental facilities providing a LIquid Metal Model for continuous CASTing of steel (LIMMCAST). The facilities operate in a temperature range from room temperature up to 400∘C using the low-melting alloys GaInSn and SnBi, respectively. The experimental program is focused on quantitative flow measurements in the mold, the submerged entry nozzle and the tundish. Local potential probes, Ultrasonic Doppler Velocimetry (UDV) and Contactless Inductive Flow Tomography (CIFT) are employed to measure the melt flow. The behavior of two-phase flows in case of argon injection is investigated by means of the Mutual Inductance Tomography (MIT) and X-ray radioscopy. The experimental results provide a substantial data basis for the validation of related numerical simulations. Numerical calculations were performed with the software package ANSYS-CFX with an implemented RANS-SST turbulence model. The non-isotropic nature of MHD turbulence was taken into account by specific modifications of the turbulence model. First results of the LIMMCAST program reveal important findings such as the peculiar, unexpected phenomenon that the application of a DC magnetic field may excite non-steady, non-isotropic large-scale flow oscillations in the mold. Another important result of our

  6. Prediction of Inhomogeneous Distribution of Microalloy Precipitates in Continuous-Cast High-Strength, Low-Alloy Steel Slab

    NASA Astrophysics Data System (ADS)

    Roy, Suparna; Patra, Sudipta; Neogy, S.; Laik, A.; Choudhary, S. K.; Chakrabarti, Debalay

    2012-06-01

    Spatial distribution in size and frequency of microalloy precipitates have been characterized in two continuous-cast high-strength, low-alloy steel slabs, one containing Nb, Ti, and V and the other containing only Ti. Microsegregation during casting resulted in an inhomogeneous distribution of Nb and Ti precipitates in as-cast slabs. A model has been proposed in this study based on the detailed characterization of cast microalloy precipitates for predicting the spatial distribution in size and volume fraction of precipitates. The present model considers different models, which have been proposed earlier. Microsegregation during solidification has been predicted from the model proposed by Clyne and Kurz. Homogenization of alloying elements during cooling of the cast slab has been predicted following the approach suggested by Kurz and Fisher. Thermo-Calc software predicted the thermodynamic stability and volume fraction of microalloy precipitates at interdendritic and dendritic regions. Finally, classical nucleation and growth theory of precipitation have been used to predict the size distribution of microalloy precipitates at the aforementioned regions. The accurate prediction and control over the precipitate size and fractions may help in avoiding the hot-cracking problem during casting and selecting the processing parameters for reheating and rolling of the slabs.

  7. Effect of Stopper-Rod Misalignment on Fluid Flow in Continuous Casting of Steel

    NASA Astrophysics Data System (ADS)

    Chaudhary, R.; Lee, Go-Gi; Thomas, B. G.; Cho, Seong-Mook; Kim, Seon-Hyo; Kwon, Oh-Duck

    2011-04-01

    Misalignment of metal-delivery systems can cause asymmetric fluid flow in the mold region of continuous casters, leading to abnormal surface turbulence, insufficient superheat transport to the meniscus, slag entrainment, inclusion entrapment, and other quality problems. This work investigates the effect of stopper-rod misalignment on nozzle and mold flow velocities in a conventional continuous casting process using both a water model and a computational model. Three stopper-rod configurations are studied (aligned, front misaligned by 2 mm, and left misaligned by 2 mm). The 3-D steady k- ɛ finite-volume model matched well with impeller probe measurements of both velocity and its fluctuations. Negligible asymmetry was found near the narrow faces. Asymmetry close to submerged entry nozzle is the main cause of vortex formation observed in all cases. The left-misaligned stopper-rod produces a shallower jet with a higher flow rate from the right port, leading to higher surface velocities on the right surface. This produced substantially more large vortices on the left side. The asymmetry produced by the nozzle length bore diameter ratio of ~21 in this work is consistent with the theoretical critical entrance length of ~24 for turbulent pipe flow.

  8. Mechanical Strength and Failure Characteristics of Cast Mg-9 pctAl-1 pctZn Alloys Produced by a Heated-Mold Continuous Casting Process: Tensile Properties

    NASA Astrophysics Data System (ADS)

    Okayasu, Mitsuhiro; Takeuchi, Shuhei; Ohfuji, Hiroaki

    2014-11-01

    The mechanical properties and failure characteristics of a cast Mg alloy (AZ91: Mg-Al8.9-Zn0.6-Mn0.2) produced by a heated-mold continuous casting process (HMC) are investigated. In a modification of the original HMC process, the cooling of the liquid alloy by direct water spray is carried out in an atmosphere of high-purity argon gas. The HMC-AZ91 alloy exhibits excellent mechanical properties (high strength and high ductility) that are about twice as high as those for the same alloy produced by conventional gravity casting. The increased material strength and ductility of the HMC sample are attributed to nanoscale and microscale microstructural characteristics. The fine grains and tiny spherical eutectic structures ( e.g., Mg17Al12 and Al6Mn) distributed randomly in the matrix of the HMC alloy result in resistance to dislocation movement, leading to high tensile strength. Basal slip on (0001) planes in the relatively organized crystal orientation of the HMC alloy, as well as grain boundary sliding through tiny spherical eutectic structures, results in high ductility. Details of the failure mechanism under static loading in the HMC alloy are also discussed using failure models.

  9. Final inspection of photomask blanks

    NASA Astrophysics Data System (ADS)

    Schubert, Fredi; Sauerbrei, Hartmut; Aschke, Lutz; Knapp, Konrad

    2001-04-01

    In order to increase the quality in manufacturing of future photon mask generations Schott Lithotec is brought in a brand new, much increased automatic laser inspection system into a new manufacturing line of photo mask blanks. It is in a position to detect additionally to the standard defect types further defect types like dim- and bright-chrome defects. The resolution of the system is less than 100 nm. With a quickly inspecting time per blank of less than three minutes and for the first time in the world used automatic SMIF-pod-handling this is a tool for the 100 percent final inspection in the manufacturing of photo mask blanks.

  10. Analysis of Internal Cracks in Continuous Casting Slabs with Soft Reduction

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Zhang, Jiongming; Xiao, Chao; Wang, Shunxi; Song, Wei

    2016-03-01

    The formation of internal cracks in continuous casting slabs is mainly attributed to the strain status and microsegregation near the solidifying front of the slabs. By analyzing the internal cracks of medium carbon microalloy steel, the obtained conclusions are that C, P, S, etc. enrich in dendrites and exist in grain boundaries, but these are just the internal causes, and the root cracking causes the tensile stress of solidification front. When the slab passes through the straightening segments, the liquid core thickness is large, and the liquid steel in the space of columnar crystals is not completely frozen. Therefore, the reduction effect of rollers results in the strain of solidification front exceeding the critical value. However, the corresponding strain in the arc and horizontal segments does not exceed this critical value, so the solidification front in the straightening segments would be much easy to crack. The statistics analysis shows that after soft reduction and straightening process are separately carried out, the occurrence rate of intermediate cracks is reduced by 41.3%.

  11. Mathematical Modelling of Solidification in a Curved Strand During Continuous Casting of Steel

    NASA Astrophysics Data System (ADS)

    Maurya, Ambrish; Jha, Pradeep Kumar

    2016-06-01

    A two dimensional fluid flow, heat transfer and solidification model has been developed for a curved shape continuous steel slab caster. The strand has been divided in various sections depending upon cooling conditions in the mold and Secondary Cooling Zone (SCZ). The model was validated against the experimental results reported in the literature for solid shell thickness in the mold. CFD software ANSYS Fluent has been used for solving the differential equations of heat transfer and fluid flow. Surface temperature distribution has been predicted while; the thickness of solid shell formed in the mold and SCZ has been calculated by finding the liquid fraction of steel within the domain. Process parameters such as, casting speed and cooling rate has been varied to analyse their effects on metallurgical length and solid shell thickness at the mold exit. The analysis was based on keeping the shell thickness between 10 and 14 mm at mold exit and metallurgical length less than the cut-off length but having complete solidification after the straightening zone.

  12. Effect of V and N on the microstructure evolution during continuous casting of steel

    NASA Astrophysics Data System (ADS)

    Santillana, B.; Eskin, D. G.; Boom, R.; Katgerman, L.

    2012-01-01

    Low Carbon (LC) steel is not expected to be sensitive to hot tearing and/or cracking while microalloyed steels are known for their high cracking sensitivity during continuous casting. Experience of the Direct Sheet Plant caster at Tata Steel in Ijmuiden (the Netherlands), seems to contradict this statement. It is observed that a LC steel grade has a high risk of cracking alias hot tearing, while a High Strength Low Alloyed (HSLA) steel has a very low cracking occurrence. Another HSLA steel grade, with a similar composition but less N and V is however very sensitive to hot tearing. An extreme crack results in a breakout. A previous statistical analysis of the breakout occurrence reveals a one and a half times higher possibility of a breakout for the HSLA grade compared to the LC grade. HSLA with extra N, V shows a four times smaller possibility of breakout than LC. This study assigns the unexpected effect of the chemical composition on the hot tearing sensitivity to the role of some alloying elements such as V and N as structure refiners.

  13. Characterization and formability of continuous-cast AZ31B magnesium alloy sheets

    SciTech Connect

    Rohatgi, Aashish; Herling, Darrell R; Nyberg, Eric A

    2009-09-24

    The goal of this work is to understand the inter-relationship between the initial properties of continuous-cast magnesium alloy (AZ31B) sheets and their subsequent formability and post-formed mechanical performance for use in cost-effective, lightweight, automotive body panels. As-received sheets, provided by the Automotive Metals Division (AMD-602) team, were characterized by surface roughness measurements using mechanical profilometry. The arithmetic mean deviation of profile (Ra) and the maximum two-point height of profile (Ry) of the as-received sheets ranged from ~0.2-2 μm and ~2-15 μm, respectively. Several commercial lubricants were evaluated by thermal analysis and the liquid phase of the lubricants was found to evaporate/decompose upon heating leaving behind a solid residue upon heating to temperatures exceeding ~125-150°C. Elevated temperature bending-under-tension (BUT) friction tests were conducted at 350°C and the coefficient-of-friction values ranged from a minimum of ~0.1 (for tungsten disulfide lubricant) to ~0.7 when no lubricant was used. These results, in conjunction with those from the forming trials conducted by the AMD-602 team, will be eventually used to determine the role of sheet-die friction in determining the formability of AZ31B sheets.

  14. Large Eddy Simulation of Transient Flow, Solidification, and Particle Transport Processes in Continuous-Casting Mold

    NASA Astrophysics Data System (ADS)

    Liu, Zhongqiu; Li, Linmin; Li, Baokuan; Jiang, Maofa

    2014-07-01

    The current study developed a coupled computational model to simulate the transient fluid flow, solidification, and particle transport processes in a slab continuous-casting mold. Transient flow of molten steel in the mold is calculated using the large eddy simulation. An enthalpy-porosity approach is used for the analysis of solidification processes. The transport of bubble and non-metallic inclusion inside the liquid pool is calculated using the Lagrangian approach based on the transient flow field. A criterion of particle entrapment in the solidified shell is developed using the user-defined functions of FLUENT software (ANSYS, Inc., Canonsburg, PA). The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern inside the liquid pool exhibits quite satisfactory agreement with the corresponding measurements. The predicted complex instantaneous velocity field is composed of various small recirculation zones and multiple vortices. The transport of particles inside the liquid pool and the entrapment of particles in the solidified shell are not symmetric. The Magnus force can reduce the entrapment ratio of particles in the solidified shell, especially for smaller particles, but the effect is not obvious. The Marangoni force can play an important role in controlling the motion of particles, which increases the entrapment ratio of particles in the solidified shell obviously.

  15. Numerical Simulation of Dendritic Growth of Continuously Cast High Carbon Steel

    NASA Astrophysics Data System (ADS)

    Wang, Weiling; Luo, Sen; Zhu, Miaoyong

    2015-01-01

    Considering the influence of the latent heat released during the solidification of high carbon liquid steel, a cellular automaton (CA) model coupled with the heat transfer was developed to investigate the growth of equiaxed dendrites which is controlled by the solute diffusion during the continuous casting process. Additionally, the growth of columnar dendrites and primary dendrite arm spacings were predicted and measured. The results show that the CA model is able to describe the growth behavior of equiaxed dendrites, especially at 5 K to 7 K melt undercoolings, and the approach adjusting the cooling medium temperature is reliable to keep the undercooling condition stable for equiaxed dendrites although its hysteresis is reinforced as the pre-set undercooling increases. With the increase of the melt undercooling, the growth of equiaxed dendrites becomes faster, and the thickness of dendritic arms increases slightly, however, the thickness of the diffusion layer in front of dendritic tips keeps constant. The growth of thin and tiny columnar dendrites will be confined due to the competition and absorbed by neighboring strong columnar dendrites, giving rise to the coarsening of columnar dendrites, which is observed both from the experimental observation and the numerical simulation. With the decrease of the cooling intensity, columnar dendrites get sparser, primary dendrite arm spacings increase, and secondary dendritic arms become undeveloped.

  16. Simulation of transient fluid flow in mold region during steel continuous casting

    NASA Astrophysics Data System (ADS)

    Liu, R.; Thomas, B. G.; Sengupta, J.

    2012-07-01

    A system of models has been developed to study transient flow during continuous casting and applied to simulate an event of multiple stopper-rod movements. It includes four sub-models to incorporate different aspects in this transient event. A three-dimensional (3-D) porous-flow model of the nozzle wall calculates the rate argon gas flow into the liquid steel, and the initial mean bubble size is estimated. Transient CFD models simulate multiphase flow of steel and gas bubbles in the Submerged Entry Nozzle (SEN) and mold and have been validated with experimental data from both nail dipping and Sub-meniscus Velocity Control (SVC) measurements. To obtain the transient inlet boundary conditions for the simulation, two semi-empirical models, a stopper-rod-position based model and a metal-level-based model, predict the liquid steel flow rate through the SEN based on recorded plant data. Finally the model system was applied to study the effects of stopper rod movements on SEN/mold flow patterns. Meniscus level fluctuations were calculated using a simple pressure method and compared well with plant measurements. Insights were gained from the simulation results to explain the cause of meniscus level fluctuations and the formation of sliver defects during stopper rod movements.

  17. Quantitative Characterization of Inclusions in Continuously Cast High-Carbon Steel

    NASA Astrophysics Data System (ADS)

    Faraji, Masoumeh; Wilcox, David P.; Thackray, Richard; Howe, Andrew A.; Todd, Iain; Tsakiropoulos, Panos

    2015-12-01

    Existing standards for the characterization of the size, morphology, chemistry, and distribution of inclusions in steels using different techniques are briefly reviewed in this work. Strengths and shortfalls of different methods are discussed, and a combination of different criteria is used to quantitatively characterize the inclusions in a continuously cast high-carbon steel. It is shown that the main elements in the inclusions for the studied steel were Mn, S, Ti, Al, and oxygen and that alongside MnS and some Al2O3 inclusions many non-metallic inclusions appeared in complex forms, consisting of silicates, sulfides, and different types of oxides. Duplex inclusions, mainly cores of Al2O3, or SiO2 surrounded by MnS were the most common complex multiphase inclusions in this steel. An industrial approach was used to classify the inclusions into thirteen different oxide types. Based upon this approach, data are presented according to the chemistry of inclusions using diagrams featuring different quantitative parameters. Furthermore, it is shown that the number of oxides per unit area and the size of oxides, respectively, decreased and increased with increasing distance from the surface of the bloom which had solidified at the highest cooling rate.

  18. Solution of Macrosegregation in Continuously Cast Billets by a Meshless Method

    NASA Astrophysics Data System (ADS)

    Vertnik, R.; Šarler, B.; Senčič, B.

    2012-01-01

    The main aim of this paper is to demonstrate the applicability and the advantages of a novel meshless method for simulation of macrosegregation in steel billets. The physical model is established on a set of macroscopic equations for mass, energy, momentum, species, turbulent kinetic energy, and dissipation rate in two dimensions. The mixture continuum model is used to treat the solidification system. The mushy zone is modelled as a Darcy porous media with Kozeny-Karman permeability relation, where the morphology of the porous media is modelled by a constant value. The incompressible turbulent flow of the molten steel is described by the Low-Reynolds-Number (LRN) k-epsilon turbulence model, closed by the Launder and Sharma closure coefficients and damping functions. The microsegregation equations rely on lever rule. The numerical method is established on explicit timestepping, and collocation with multiquadrics radial basis functions on non-uniform five-noded influence domains, and adaptive upwinding technique. The velocity-pressure coupling of the incompressible flow is resolved by the explicit Chorin's fractional step method, with the intermediate velocity field, calculated without the pressure term. A recently proposed standard continuous casting configuration with Fe-C system has been used for verification of the model. The advantages of the method are its simplicity and efficiency, since no polygonisation is involved, easy adaptation of the nodal points in areas with high gradients, almost the same formulation in two and three dimensions, high accuracy and low numerical diffusion.

  19. Transient Simulation of Mold Heat Transfer and Solidification Phenomena of Continuous Casting of Steel

    NASA Astrophysics Data System (ADS)

    El-Bealy, Mostafa Omar

    2016-07-01

    A comprehensive model of heat transfer and solidification phenomena has been developed including microstructure evolution and fluctuation macrosegregation in continuously cast steel slabs with an objective of evaluation of various mold cooling conditions. The study contains plant trials, metallographic examinations, and formulation of mathematical modeling. The plant trials involved sample collection from three slab casters in use at two different steel plants. The metallographic study combined measurements of dendrite arm spacings and macrosegregation analysis of collected samples. A one-dimensional mathematical model has been developed to characterize the thermal, solidification phases, microstructure evolution, interdendritic strain, and therefore, the macrosegregation distributions. Two cooling approaches were proposed in this study to evaluate the Newtonian heat transfer coefficient in various mold regions. The first approach is a direct estimation approach (DEA), whereas the second one is a coupled approach of the interfacial resistor model and direct estimation approach (CIR/DEA). The model predictions and standard analytical models as well as the previous measurements were compared to verify and to calibrate the model where good agreements were obtained. The comparison between the model predictions and the measurements of dendrite arm spacings and fluctuated carbon concentration profiles were performed to determine the model accuracy level with different cooling approaches. Good agreements were obtained by different accuracy levels with different cooling approaches. The model predictions of thermal parameters and isotherms were analyzed and discussed.

  20. Effect of an Electromagnetic Brake on the Turbulent Melt Flow in a Continuous-Casting Mold

    NASA Astrophysics Data System (ADS)

    Miao, Xincheng; Timmel, Klaus; Lucas, Dirk; Ren, Zhongmin; Eckert, Sven; Gerbeth, Gunter

    2012-08-01

    This article presents numerical and experimental investigations with respect to the fluid flow in the continuous-casting process under the influence of an external direct current (DC) magnetic field. Numerical calculations were performed by means of the software package CFX (Ansys, Inc., Canonsburg, PA) with an implemented Reynolds-averaged Navier-Stokes (RANS)-SST turbulence model. The nonisotropic nature of the magnetohydrodynamic (MHD) turbulence was taken into account by specific modifications of the turbulence model. The numerical results were validated by flow measurements carried out in a small-scale mockup using the eutectic alloy GaInSn. The jet flow discharging from the submerged entry nozzle was exposed to a level magnetic field spanning across the entire wide side of the mold. The comparison between our numerical calculations and the experimental results displays a good agreement; in particular, we reconstructed the peculiar phenomenon of an excitation of nonsteady, nonisotropic, large-scale flow perturbations caused by the application of the DC magnetic field. Another important result of our study is the feature that the electrical boundary conditions, namely the wall conductivity ratio, have a serious influence on the mold flow while it is exposed to an external magnetic field.

  1. Machinability of Austempered Ductile Iron (ADI) Produced by Integrated Green Technology of Continuous Casting-Heat Treatment Processes

    SciTech Connect

    Meena, A.; El Mansori, M.; Ghidossi, P.

    2011-01-17

    This study presents the novel processing technique known as continuous casting-heat treatment processes to produce Austempered Ductile Iron (ADI) which is a new class of ductile iron. ADI is characterized by improved mechanical properties but has low machinability as compared to other cast irons and steel of similar strength. The novel technique is developed by the integration of casting (in die casting) and heat treatment processes in foundry to save cost energy and time. Specimens just after casting were austenitized at 930 deg. C for 90 min and then austempered in fluidized bed at 380 deg. C for 90 and 120 min. Hence, the effect of austempering time on the morphology of retained austenite and mechanical properties of the material were examined and compared with conventionally produced ADI. Drilling tests were then carried out to evaluate the machinability of ADI in terms of cutting forces, chip micro-hardness, chip morphology and surface roughness. The mechanical properties of ADI austempered for 120 min have found to be better as compare to the ADI austempered for 90 min.

  2. Machinability of Austempered Ductile Iron (ADI) Produced by Integrated Green Technology of Continuous Casting-Heat Treatment Processes

    NASA Astrophysics Data System (ADS)

    Meena, A.; El Mansori, M.; Ghidossi, P.

    2011-01-01

    This study presents the novel processing technique known as continuous casting-heat treatment processes to produce Austempered Ductile Iron (ADI) which is a new class of ductile iron. ADI is characterized by improved mechanical properties but has low machinability as compared to other cast irons and steel of similar strength. The novel technique is developed by the integration of casting (in die casting) and heat treatment processes in foundry to save cost energy and time. Specimens just after casting were austenitized at 930° C for 90 min and then austempered in fluidized bed at 380° C for 90 and 120 min. Hence, the effect of austempering time on the morphology of retained austenite and mechanical properties of the material were examined and compared with conventionally produced ADI. Drilling tests were then carried out to evaluate the machinability of ADI in terms of cutting forces, chip micro-hardness, chip morphology and surface roughness. The mechanical properties of ADI austempered for 120 min have found to be better as compare to the ADI austempered for 90 min.

  3. Modeling and Measurements of Multiphase Flow and Bubble Entrapment in Steel Continuous Casting

    NASA Astrophysics Data System (ADS)

    Jin, Kai; Thomas, Brian G.; Ruan, Xiaoming

    2016-02-01

    In steel continuous casting, argon gas is usually injected to prevent clogging, but the bubbles also affect the flow pattern, and may become entrapped to form defects in the final product. To investigate this behavior, plant measurements were conducted, and a computational model was applied to simulate turbulent flow of the molten steel and the transport and capture of argon gas bubbles into the solidifying shell in a continuous slab caster. First, the flow field was solved with an Eulerian k- ɛ model of the steel, which was two-way coupled with a Lagrangian model of the large bubbles using a discrete random walk method to simulate their turbulent dispersion. The flow predicted on the top surface agreed well with nailboard measurements and indicated strong cross flow caused by biased flow of Ar gas due to the slide-gate orientation. Then, the trajectories and capture of over two million bubbles (25 μm to 5 mm diameter range) were simulated using two different capture criteria (simple and advanced). Results with the advanced capture criterion agreed well with measurements of the number, locations, and sizes of captured bubbles, especially for larger bubbles. The relative capture fraction of 0.3 pct was close to the measured 0.4 pct for 1 mm bubbles and occurred mainly near the top surface. About 85 pct of smaller bubbles were captured, mostly deeper down in the caster. Due to the biased flow, more bubbles were captured on the inner radius, especially near the nozzle. On the outer radius, more bubbles were captured near to narrow face. The model presented here is an efficient tool to study the capture of bubbles and inclusion particles in solidification processes.

  4. Leukemia studies continue to draw a blank

    SciTech Connect

    Williams, N.

    1996-04-19

    When large numbers of childhood thyroid cancer cases began showing up in the three most heavily contaminated republics about Chernobyl 5 years after the accident, many thought there would be a jump in the incidence of leukemia. Studies of Japanese atomic bomb survivors and other radiation accidents have pinpointed leukemia as the key early indicator of the effects of radiation. But so far, thyroid cancer remains an anomaly. Three major international studies have so far failed to detect any measurable increase in leukemia - or any other cancers - in the general population. This paper describes the studies and discusses possible reasons as well as what might happen in the future.

  5. Effect of oscillation-mark formation on the surface quality of continuously cast steel slabs

    NASA Astrophysics Data System (ADS)

    Takeuchi, E.; Brimacombe, J. K.

    1985-09-01

    In a study of early solidification during the continuous casting of steel slabs, the effect of the formation of oscillation marks on the surface quality of the slabs has been examined by metallographic in-vestigation of slab samples and by performing a set of mathematical analyses. Positive segregation of solute elements, especially phosphorus and manganese, has been observed at the bottom of the oscillation marks and has been classified into two categories. One type is observed at the end of the overflow region on subsurface hooks which originate from partial solidification of the meniscus. A heat-flow model which takes into account the shape of the oscillation marks has revealed that this type of positive segregation is caused by local delay of solidification at the bottom of the oscillation marks. The other type of positive segregation has been found in a layer on the bottom of the oscillation marks without subsurface hooks. This form of segregation cannot be explained by the heat-flow model, but is likely due to a penetration mechanism in which the negative pressure in the flux channel generated during the upward motion of the mold draws out interdendritic liquid from the semi-solidified shell. Transverse cracks are found along the bottom of oscillation marks. The surface of the transverse cracks exhibits an interdendritic appearance in the vicinity of the slab surface, which implies that the cracks are initiated as hot tears in the mold region. A heat-flow analysis predicts that deep oscillation marks cause nonuniformity of the shell in the mold, which also was observed in the metallographic in-vestigation. According to the heat-flow analysis, not only the depth but also the pitch of the oscillation marks affects the shell profile. Therefore increasing the frequency of mold oscillation effectively reduces transverse cracks, by decreasing both the depth and the pitch of oscillation marks.

  6. Comparison of different Methods to model Transient Turbulent Magnetohydrodynamic Flow in Continuous Casting Molds

    NASA Astrophysics Data System (ADS)

    Kratzsch, C.; Asad, A.; Schwarze, R.

    2016-07-01

    Modeling of the processes in the continuous casting mold engaged many scientists once the computer-technology was able to accomplish that task. Despite that, CFD modeling of the fluid flow is still challenging. The methods allow deeper and deeper inside views into transient flow processes. Mostly two kinds of methods are applied for this purpose. URANS simulations are used for a coarse overview of the transient behavior on scales determined by the big rollers inside the mold. Besides, LES were done to study the processes on smaller scales. Unfortunately, the effort to set up a LES is orders of magnitude higher in time and space compared to URANS. Often, the flow determining processes take place in small areas inside the flow domain. Hence, scale resolving methods (SRS) came up, which resolve the turbulence in some amount in these regions, whereas they go back to URANS in the regions of less importance. It becomes more complex when dealing with magnetic fields in terms of EMBr devices. The impact of electro magnetically forces changes the flow structure remarkably. Many important effects occur, e.g. MHD turbulence, which are attributable to processes on large turbulent scales. To understand the underlying phenomena in detail, SRS allows a good inside view by resolving these processes partially. This study compares two of these methods, namely the Scale Adaptive Simulation (SAS) and the Delayed Detached Eddy Simulation (DDES), with respect to rendition of the results known from experiments and URANS simulation. The results show, that the SAS as well as the DDES are able to deliver good results with higher mesh resolutions in important regions in the flow domain

  7. Study on the Macrosegregation Behavior for the Bloom Continuous Casting: Model Development and Validation

    NASA Astrophysics Data System (ADS)

    Sun, Haibo; Zhang, Jiaquan

    2014-06-01

    With the aid of a coupling electromagnetic-thermal-solute transportation model validated by the industrial investigation, a three-dimensional (3-D) plus two-dimensional (2-D) hybrid modeling method has been presented for the exploration of the macrosegregation and macroscale transport phenomena in the bloom continuous casting (CC) processes of high-carbon GCr15-bearing steel. The evolution and characteristics of solute distribution and its influence on the porosity formation in the strand during CC process have been revealed. Solute segregation degree changes from a positive to a negative value with distance from strand surface in the region of initial solidification shell within thickness of 25 mm, which can be attributed to the circulation flow ahead the solidification front and the floatation of solute-rich molten steel at the upper part of the mold. The discontinuous, nonfrozen band induced by the zigzag solute distribution is proven to be the main reason that leads to the porosity formation in the final solidification stage of the CC strand. As the solidification proceeds, the segregation degree of C at the strand center is increased from 1.0 to 1.2, while the melt liquidus temperature is reduced from 1726 K (1453 °C) to 1706.91 K (1433.91 °C) during the CC process. Moreover, with the action of gravity and thermosolutal convection, a negative segregation region in the concave shape and an irregular positive segregation zone are produced in the fixed and loosened side of shell, respectively.

  8. Detection of Non-metallic Inclusions in Centrifugal Continuous Casting Steel Billets

    NASA Astrophysics Data System (ADS)

    Wang, Qiangqiang; Zhang, Lifeng; Seetharaman, Sridhar; Yang, Shufeng; Yang, Wen; Wang, Yi

    2016-06-01

    In the current study, automated particle analysis was employed to detect non-metallic inclusions in steel during a centrifugal continuous casting process of a high-strength low alloy steel. The morphology, composition, size, area fraction, amount, and spatial distribution of inclusions in steel were obtained. Etching experiment was performed to reveal the dendrite structure of the billet and to discuss the effect of centrifugal force on the distribution of oxide inclusions in the final solidified steel by comparing the solidification velocity with the critical velocity reported in literature. It was found that the amount of inclusions was highest in samples from the tundish (~250 per mm2), followed by samples from the mold (~200 per mm2), and lowest in billet samples (~86 per mm2). In all samples, over 90 pct of the inclusions were smaller than 2μm. In steel billets, the content of oxides, dual-phase oxide-sulfides, and sulfides in inclusions were found to be 10, 30, and 60 pct, respectively. The dual-phase inclusions were oxides with sulfides precipitated on the outer surface. Oxide inclusions consisted of high Al2O3 and high MnO which were solid at the molten steel temperature, implying that the calcium treatment was insufficient. Small oxide inclusions very uniformly distributed on the cross section of the billet, while there were more sulfide inclusions showing a banded structure at the outside 25 mm layer of the billet. The calculated solidification velocity was higher than the upper limit at which inclusions were entrapped by the solidifying front, revealing that for oxide inclusions smaller than 8μm in this study, the centrifugal force had little influence on its final distribution in billets. Instead, oxide inclusions were rapidly entrapped by solidifying front.

  9. Numerical simulation of temperature field in horizontal core-filling continuous casting for copper cladding aluminum rods

    NASA Astrophysics Data System (ADS)

    Su, Ya-jun; Liu, Xin-hua; Wu, Yong-fu; Huang, Hai-you; Xie, Jian-xin

    2013-07-01

    The steady-state temperature field of horizontal core-filling continuous casting (HCFC) for producing copper cladding aluminum rods was simulated by finite element method to investigate the effects of key processing parameters on the positions of solid-liquid interfaces (SLIs) of copper and aluminum. It is found that mandrel tube length and mean withdrawing speed have significant effects on the SLI positions of both copper and aluminum. Aluminum casting temperature ( T Al) (1003-1123 K) and secondary cooling water flux (600-900 L·h-1) have little effect on the SLI of copper but cause the SLI of aluminum to move 2-4 mm. When T Al is in a range of 1043-1123 K, the liquid aluminum can fill continuously into the pre-solidified copper tube. Based on the numerical simulation, reasonable processing parameters were determined.

  10. The influence of chemical composition of the slags on the surface tension used in the continuous casting of steel

    NASA Astrophysics Data System (ADS)

    Gheorghiu, Csaba Attila; Ardelean, Erika; Heput, Teodor

    2016-06-01

    An important factor that can influence the surface quality of the continuous cast is the lubrication slag used in the crystallizer. The paper introduces the multiple 2nd degree correlations between the slags surface tension (dependent parameter) and its major oxides (independent parameters). The graphic correlations allow the determination of the variation limits for the independent parameters so as to range the values of the dependent parameters within a given domain.

  11. Effects of Processing Parameters on the Fabrication of Copper Cladding Aluminum Rods by Horizontal Core-Filling Continuous Casting

    NASA Astrophysics Data System (ADS)

    Su, Ya-Jun; Liu, Xin-Hua; Huang, Hai-You; Wu, Chun-Jing; Liu, Xue-Feng; Xie, Jian-Xin

    2011-02-01

    Copper cladding aluminum (CCA) rods with a diameter of 30 mm and a sheath thickness of 3 mm were fabricated by horizontal core-filling continuous casting (HCFC) technology. The effects of key processing parameters, such as the length of the mandrel tube of composite mold, aluminum casting temperature, flux of the secondary cooling water, and mean withdrawing speed were optimized based on some quality criteria, including the uniformity of the sheath thickness, integrality of the rods, and thickness of the interface. The causes of internal flaws formation of CCA rods were also discussed. The results showed that the continuity of the liquid aluminum core-filling process and the interface reaction control between solid copper and liquid aluminum were two key problems that strongly affected the stability of the casting process and the product quality. Our research indicated that for the CCA rod with the previously mentioned size, the optimal length of mandrel tube was 210 mm. A shorter mandrel tube allowed of easier erosion at the interface, which led to a nonuniform sheath thickness. Conversely, it tended to result in a discontinuous filling process of liquid aluminum, which causes shrinkage or cold shuts. The optimal casting temperatures of copper and aluminum were 1503 K (1230 °C) and 1043 K to 1123 K (770 °C to 850 °C), respectively. When the casting temperature of aluminum was below 1043 K (770 °C), the casting process would be discontinuous, resulting in shrinkages or cold shuts. Nevertheless, when the casting temperature of aluminum was higher than 1123 K (850 °C), a severe interface reaction between solid copper and liquid aluminum would occur. The proper flux of the secondary cooling water and the mean withdrawing speed were determined as 600 to 800 L/h and 60 to 87 mm/min, respectively. In the previously mentioned proper ranges of processing parameters, the interfacial shear strengths of CCA rods were 40.5 to 67.9 MPa.

  12. Internal Crack Propagation in a Continuously Cast Austenitic Stainless Steel Analyzed by Actual Residual Stress Tensor Distributions

    NASA Astrophysics Data System (ADS)

    Saito, Youichi; Tanaka, Shun-Ichiro

    2016-04-01

    Initiation, propagation, and termination of internal cracks in a continuously cast austenitic stainless steel has been investigated with emphasis on stress loading of the solidified shell during casting. Cracks were formed at the center of the slab, parallel to the width of the cast, and were observed near the narrow faces. Optimized two-dimensional X-ray diffraction method was employed to measure residual stress tensor distributions around the cracks in the as-cast slab with coarse and strongly preferentially oriented grains. The tensor distributions had a sharp peak, as high as 430 MPa, at the crack end neighboring the columnar grains. On the other hand, lower values were measured at the crack end neighboring the equiaxed grains, where the local temperatures were higher during solidification. The true residual stress distributions were determined by evaluating the longitudinal elastic constant for each measured position, resulting in more accurate stress values than before. Electron probe micro-analysis at the terminal crack position showed that Ni, Ti, and Si were concentrated at the boundaries of the equiaxed grains, where the tensile strength was estimated to be lower than at the primary grains. A model of the crack formation and engineering recommendations to reduce crack formation are proposed.

  13. Low-resolution FTIR continuous monitoring/process control system to minimize HCl emissions in aluminum casting operations

    NASA Astrophysics Data System (ADS)

    Dunder, Thomas A.

    1999-12-01

    In a Department of Energy funded project, a low resolution Fourier Transform IR Continuous Emissions Monitoring (FTIR CEM) and Process Control system was developed and evaluated for use in minimizing HCl emissions during aluminum casting operations. In the casting process, molten aluminum is treated by fluxing with chlorine to remove alkali and hydrogen impurities. The industry has traditionally used a stoichiometric excess of chlorine to ensure metal quality, with resulting atmospheric emissions of HCl. The FTIR system can potentially be used to reduce emission when employed as a closed-loop process control device to monitor the HCl concentration and thereby reduce chlorine usage while maintaining product quality. In the initial project phase, tests were conducted under varying process conditions at a pilot-scale casting facility. The goals of these test included demonstrating that the FTIR monitor could provide closed-loop control of chlorine use, correlating HCl emission with metal quality, and verifying that the instrumentation could operate under harsh casting facility conditions. The system will subsequently be tested at two aluminum production facilities. This paper summarizes the results from the initial evaluation of the FTIR CEM/Process Control system.

  14. Transverse Crack Modeling of Continuously Casted Slabs through Finite Element Method in Roughing Rolling at Wide Strip Mill

    NASA Astrophysics Data System (ADS)

    Pesin, A.; Salganik, V.; Pustovoytov, D.

    2010-06-01

    In the pipe billet production at the wide strip mills of hot rolling big metal losses are caused by surface defects that affect most parts of the finished strips. The rolling surface defects are referred to the breach of steelmaking technology. Specialists mostly face defects of metal surface such as "scab" and "crack". The only area suffered from these defects is a slab edge. This area has the least surface temperature at the unbending of the continuous-casting machine, and together with deep buckles made by reciprocating motion of the crystallizer it is mostly subjected to transverse cracks that can be up to several millimeters. Each surface defect of the continuously casted slab will further turn into the surface defect of the strip bar. For some grade sets, mostly made of pipe steel grades the amount of strips with these defects can reach up to 60-70%. The area that is mostly prone to these defects is the edge of the strip. The work reveals investigation of the form change peculiarities in the transverse cracks of the continuously casted slab in roughing rolling in the horizontal rollers. The finite element method with software DEFORM 3D V6.1 has been applied in modeling. The work gives a form change mechanism of transverse cracks of slabs in deformation. Further crack growth in rolling is assessed due to Cockroft-Latham criteria.

  15. Solidification structures grown under induced flow and continuous casting of steel

    NASA Technical Reports Server (NTRS)

    Tsavaras, A. A.

    1984-01-01

    The use of induced flow as a means to control solidification structures in strand cast steel is investigated. The quality problems in strand cast steel stemming from columnar growth can be partially controlled, by Electro Magnetic Stirring (EMS). Induced flow changes the normal morphology of dendrites. Solids grown under intense stirring conditions show both negative and positive segregation which is considered unacceptable by some steel producers. The inclusion size and population is strongly affected by induced flow (EMS). Laboratory and industrial data show substantial reduction in inclusion size and content, but the overall effect of flow on inclusions is affected by the particular type of flow patterns utilized in each case. Productivity and quality are raised substantially in steel strand casting by utilizing EMS.

  16. Quantitative analysis of texture evolution of cold-rolled direct-chill-cast and continuous-cast AA5052 and AA5182 aluminum alloys during isothermal annealing

    NASA Astrophysics Data System (ADS)

    Zhao, Y. M.; Liu, W. C.; Morris, J. G.

    2004-11-01

    The as-received direct-chill-cast (DC) and continuous-cast (CC) AA5052 and AA5182 hot bands were preheated at 454 °C for 4 hours, followed by cold rolling to an 80 pct reduction in thickness. The texture evolution of these cold-rolled samples during isothermal annealing was investigated by X-ray diffraction. The variation in texture volume fractions with annealing time was quantitatively analyzed by using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation. The differences in recrystallization textures between the AA5052 and AA5182 alloys and between the DC and CC alloys were compared. It was found that the AA5052 alloy possessed a stronger cube recrystallization texture than the AA5182 alloy for the DC and CC materials. The recrystallization textures of the AA5182 alloy were affected strongly by the annealing temperature. As the annealing temperature increased, the cube recrystallization texture strengthened, whereas the R texture weakened. The annealing temperature had little influence on the recrystallization textures of the AA5052 alloy. The DC AA5052 and 5182 alloys also exhibited stronger cube recrystallization textures than the corresponding CC alloys. For the DC and CC AA5052 alloys, the n value in the JMAK-type equation increased with an increase in the annealing temperature, while the n values varied only slightly with the annealing temperature for the DC and CC AA5182 alloys.

  17. Textured substrate method for the direct continuous casting of steel sheet; Final report

    SciTech Connect

    Gaspar, T.; Hackman, L.E.; Hsiao, Yu-Hsian; Daehn, G.

    1990-03-30

    The three goals of this research project were to demonstrate the feasibility of casting steel strip up to 2 mm (0.079 in) thick on a textured chill roll, to develop the thermal-mechanical processing to optimize the properties of the steel strip and to measure the properties of the steel strip as a function of casting and metalworking variables. Each of these goals have been realized. Type 304 stainless strip measuring up to 329 mm (12.9 in) wide and up to 1.98 mm (0.078 in) thick was cast on a 600 mm (24 in) copper chill roll with a 14 pitch, 60 degree diamond knurl pattern machined on it`s circumference. The casting speed was 0.15 m/s and the depth of liquid steel in contact with the chill roll was approximately 127 m (5 in). The most important process variables are the texture on the chill roll, the chemistry and temperature of the liquid steel, the depth of liquid in contact with the chill roll and the casting speed. It has been shown that thermal mechanical treatment can significantly improve both the surface finish and mechanical properties of Type 304 stainless steel. Cold rolling in excess of 30% reduction serves to completely eliminate the textured pattern from direct cast Type 304 stainless steel strips. Furthermore, cold rolling followed by annealing can produce commercial ingot metallurgy steels. Specifically, for Type 304 stainless steel, 30% cold rolling followed by a 40 minute anneal at 1100 {degree}C (2012 {degree}F) produced equiaxed austenite grains with an average diameter of approximately 20 {mu}m (0.0008 in), and this material gives approximately 45% elongation to failure with and ultimate tensile strength of 660 MPa (96 ksi). 27 refs., 40 figs., 7 tabs.

  18. Textured substrate method for the direct continuous casting of steel sheet: Technical progress report No. 4

    SciTech Connect

    Gaspar, T.

    1989-07-14

    The overall objective of this research project will be to demonstrate the feasibility of casting rapidly solidified steel strip 2 mm (0.080 in.) thick or greater using a textured chill block as described in US Patent No. 4,705,095, issues on November 10, 1987, to Ribbon Technology Corporation. The effect of melt overflow process variables on strip dimensions and uniformity will be investigated. Process variables include, but are not limited to, the following: super heat of the melt; wetting of substrate material; tundish design; and casting speed. Type 304 stainless and AISI 1020 standard carbon steel will be investigated.

  19. Textured substrate method for the direct continuous casting of steel sheet: Technical progress report No. 1

    SciTech Connect

    Gaspar, T.

    1988-10-21

    The overall objective of this research project will be to demonstrate the feasibility of casting rapidly solidified steel strip 2 mm (0.080 in.) thick or greater using a textured chill block as described in US Patent No. 4,705,095, issued on November 10, 1987, to Ribbon Technology Corporation. The effect of melt overflow process variables on strip dimensions and uniformity will be investigated. Process variables include, but are not limited to, the following: super heat of the melt; wetting of substrate material; tundish design; and casting speed. Type 304 stainless steel and AISI 1020 standard carbon steel will be investigated.

  20. The formation of oscillation marks in the continuous casting of steel slabs

    NASA Astrophysics Data System (ADS)

    Takeuchi, E.; Brimacombe, J. K.

    1984-09-01

    The formation of oscillation marks on the surface of continuously cast slabs has been studied by metallographically examining slab samples and by performing a set of mathematical analyses of heat flow, lubrication, and meniscus shape in the meniscus region of the mold. The metallographic study has revealed that, in agreement with previous work, the oscillation marks can be classified principally according to the presence or absence of a small “hook” in the subsurface structure at the base of individual oscillation marks. The depth of the oscillation marks exhibiting subsurface hooks varies with the carbon content, reaching a maximum at about 0.1 pct carbon, while the oscillation marks without hooks show no carbon dependence. The analysis of heat flow at the meniscus, which is based on a measured mold heat-flux distribution, indicates that depending on the level of superheat, the meniscus may partially freeze within the period of a typical mold oscillation cycle. Lubrication theory has shown that, owing to the geometry of the mold flux channel between the solidifying shell at the meniscus and the straight mold wall, significant pressure gradients capable of deforming the meniscus can be generated in the flux by the reciprocating motion of the mold relative to the shell. A force balance on the interface between the steel and the mold flux has been applied to compute the shape of the meniscus as a function of the pressure developed in the lubricating flux at different stages in the mold oscillation cycle. This has demonstrated that the “contact” point between the meniscus and mold moves out of phase with (by π/2), and has a greater amplitude than, the mold displacement so that just at, or near, the end of the negative strip time molten steel can overflow at the meniscus. From these studies a reasonable mechanism of oscillation-mark formation emerges which involves interaction between the oscillating mold and the meniscus via pressure gradients in the mold

  1. Numerical simulation of MHD for electromagnetic edge dam in continuous casting.

    SciTech Connect

    Chang, F. C.

    1999-03-30

    A computer model was developed to predict eddy currents and fluid flows in molten steel. The model was verified by comparing predictions with experimental results of liquid-metal containment and fluid flow in electromagnetic (EM) edge dams (EMDs) designed at Inland Steel for twin-roll casting. The model can optimize the EMD design so it is suitable for application, and minimize expensive, time-consuming full-scale testing. Numerical simulation was performed by coupling a three-dimensional (3-D) finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA is able to predict the eddy-current distribution and the electromagnetic forces in complex geometries. CaPS-EM is capable of modeling fluid flows with free surfaces. Results of the numerical simulation compared measurements obtained from a static test.

  2. Computer modeling of electromagnetic fields and fluid flows for edge containment in continuous casting

    SciTech Connect

    Chang, F.C.; Hull, J.R.; Wang, Y.H.; Blazek, K.E.

    1996-02-01

    A computer model was developed to predict eddy currents and fluid flows in molten steel. The model was verified by comparing predictions with experimental results of liquid-metal containment and fluid flow in electromagnetic (EM) edge dams (EMDs) designed at Inland Steel for twin-roll casting. The model can optimize the EMD design so it is suitable for application, and minimize expensive, time-consuming full-scale testing. Numerical simulation was performed by coupling a three-dimensional (3-D) finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA is able to predict the eddy- current distribution and the electromagnetic forces in complex geometries. CaPS-EM is capable of modeling fluid flows with free surfaces. Results of the numerical simulation compared well with measurements obtained from a static test.

  3. Thermal Stress Cracking of Slide-Gate Plates in Steel Continuous Casting

    NASA Astrophysics Data System (ADS)

    Lee, Hyoung-Jun; Thomas, Brian G.; Kim, Seon-Hyo

    2016-04-01

    The slide-gate plates in a cassette assembly control the steel flow through the tundish nozzle, and may experience through-thickness cracks, caused by thermal expansion and/or mechanical constraint, leading to air aspiration and safety concerns. Different mechanisms for common and rare crack formation are investigated with the aid of a three-dimensional finite-element model of thermal mechanical behavior of the slide-gate plate assembly during bolt pretensioning, preheating, tundish filling, casting, and cooling stages. The model was validated with previous plant temperature measurements of a ladle plate during preheating and casting, and then applied to a typical tundish-nozzle slide-gate assembly. The formation mechanisms of different types of cracks in the slide-gate plates are investigated using the model and evaluated with actual slide-gate plates at POSCO. Common through-thickness radial cracks, found in every plate, are caused during casting by high tensile stress on the outside surfaces of the plates, due to internal thermal expansion. In the upper plate, these cracks may also arise during preheating or tundish filling. Excessive bolt tightening, combined with thermal expansion during casting may cause rare radial cracks in the upper and lower plates. Rare radial and transverse cracks in middle plate appear to be caused during tundish filling by impingement of molten steel on the middle of the middle plate that generates tensile stress in the surrounding refractory. The mechanical properties of the refractory, the bolt tightening conditions, and the cassette/plate design are all important to service life.

  4. Experimental und numerical investigations on cooling efficiency of Air-Mist nozzles on steel during continuous casting

    NASA Astrophysics Data System (ADS)

    Arth, G.; Taferner, M.; Bernhard, C.; Michelic, S.

    2016-07-01

    Cooling strategies in continuous casting of steel can vary from rapid cooling to slow cooling, mainly controlled by adjusting the amount of water sprayed onto the surface of the product. Inadequate adjustment however can lead to local surface undercooling or reheating, leading to surface and inner defects. This paper focuses on cooling efficiency of Air-Mist nozzles on casted steel and the experimental and numerical prediction of surface temperature distributions over the product width. The first part explains the determination of heat transfer coefficients (HTC) on laboratory scale, using a so called nozzle measuring stand (NMS). Based on measured water distributions and determined HTC's for air-mist nozzles using the NMS, surface temperatures are calculated by a transient 2D-model on a simple steel plate, explained in the second part of this paper. Simulations are carried out varying water impact density and spray water distribution, consequently influencing the local HTC distribution over the plate width. Furthermore, these results will be interpreted with regard to their consequence for surface and internal quality of the cast product. The results reveal the difficulty of correct adjustment of the amount of sprayed water, concurrent influencing water distribution and thus changing HTC distribution and surface temperature.

  5. A silicon sheet casting experiment. [for solar cell water production

    NASA Technical Reports Server (NTRS)

    Bickler, D. B.; Sanchez, L. E.; Sampson, W. J.

    1980-01-01

    The casting of silicon blanks for solar cells directly without slicing is an exciting concept. An experiment was performed to investigate the feasibility of developing a machine that casts wafers directly. A Czochralski furnace was modified to accept a graphite ingot-simulating fixture. Silicon was melted in the middle of the ingot simulator in a boron nitride mold. Sample castings showed reasonable crystal size. Solar cells were made from the cast blanks. The performance is reported.

  6. Population Balance Modeling of Polydispersed Bubbly Flow in Continuous-Casting Using Multiple-Size-Group Approach

    NASA Astrophysics Data System (ADS)

    Liu, Zhongqiu; Li, Linmin; Qi, Fengsheng; Li, Baokuan; Jiang, Maofa; Tsukihashi, Fumitaka

    2015-02-01

    A population balance model based on the multiple-size-group (MUSIG) approach has been developed to investigate the polydispersed bubbly flow inside the slab continuous-casting mold and bubble behavior including volume fraction, breakup, coalescence, and size distribution. The Eulerian-Eulerian approach is used to describe the equations of motion of the two-phase flow. All the non-drag forces (lift force, virtual mass force, wall lubrication force, and turbulent dispersion force) and drag force are incorporated in this model. Sato and Sekiguchi model is used to account for the bubble-induced turbulence. Luo and Svendsen model and Prince and Blanch model are used to describe the bubbles breakup and coalescence behavior, respectively. A 1/4th water model of the slab continuous-casting mold was applied to investigate the distribution and size of bubbles by injecting air through a circumferential inlet chamber which was made of the specially-coated samples of mullite porous brick, which is used for the actual upper nozzle. Against experimental data, numerical results showed good agreement for the gas volume fraction and local bubble Sauter mean diameter. The bubble Sauter mean diameter in the upper recirculation zone decreases with increasing water flow rate and increases with increasing gas flow rate. The distribution of bubble Sauter mean diameter along the width direction of the upper mold increases first, and then gradually decreases from the SEN to the narrow wall. Close agreements between the predictions and measurements demonstrate the capability of the MUSIG model in modeling bubbly flow inside the continuous-casting mold.

  7. Population Balance Modeling of Polydispersed Bubbly Flow in Continuous-Casting Using Multiple-Size-Group Approach

    NASA Astrophysics Data System (ADS)

    Liu, Zhongqiu; Li, Linmin; Qi, Fengsheng; Li, Baokuan; Jiang, Maofa; Tsukihashi, Fumitaka

    2014-09-01

    A population balance model based on the multiple-size-group (MUSIG) approach has been developed to investigate the polydispersed bubbly flow inside the slab continuous-casting mold and bubble behavior including volume fraction, breakup, coalescence, and size distribution. The Eulerian-Eulerian approach is used to describe the equations of motion of the two-phase flow. All the non-drag forces (lift force, virtual mass force, wall lubrication force, and turbulent dispersion force) and drag force are incorporated in this model. Sato and Sekiguchi model is used to account for the bubble-induced turbulence. Luo and Svendsen model and Prince and Blanch model are used to describe the bubbles breakup and coalescence behavior, respectively. A 1/4th water model of the slab continuous-casting mold was applied to investigate the distribution and size of bubbles by injecting air through a circumferential inlet chamber which was made of the specially-coated samples of mullite porous brick, which is used for the actual upper nozzle. Against experimental data, numerical results showed good agreement for the gas volume fraction and local bubble Sauter mean diameter. The bubble Sauter mean diameter in the upper recirculation zone decreases with increasing water flow rate and increases with increasing gas flow rate. The distribution of bubble Sauter mean diameter along the width direction of the upper mold increases first, and then gradually decreases from the SEN to the narrow wall. Close agreements between the predictions and measurements demonstrate the capability of the MUSIG model in modeling bubbly flow inside the continuous-casting mold.

  8. Interfacial Microstructure and Bonding Strength of Copper Cladding Aluminum Rods Fabricated by Horizontal Core-Filling Continuous Casting

    NASA Astrophysics Data System (ADS)

    Su, Ya-Jun; Liu, Xin-Hua; Huang, Hai-You; Liu, Xue-Feng; Xie, Jian-Xin

    2011-12-01

    Copper cladding aluminum (CCA) rods with a diameter of 30 mm and a sheath thickness of 3 mm were fabricated by horizontal core-filling continuous casting (HCFC) technology. The microstructure and morphology, distribution of chemical components, and phase composition of the interface between Cu and Al were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive spectrometer (EDS). The formation mechanism of the interface and the effects of key processing parameters, e.g., aluminum casting temperature, secondary cooling intensity, and mean withdrawing speed on the interfacial microstructure and bonding strength were investigated. The results show that the CCA rod has a multilayered interface, which is composed of three sublayers—sublayer I is Cu9Al4 layer, sublayer II is CuAl2 layer, and sublayer III is composed of α-Al/CuAl2 pseudo eutectic. The thickness of sublayer III, which occupies 92 to 99 pct of the total thickness of the interface, is much larger than the thicknesses of sublayers I and II. However, the interfacial bonding strength is dominated by the thicknesses of sublayers I and II; i.e., the bonding strength decreases with the rise of the thicknesses of sublayers I and II. When raising the aluminum casting temperature, the total thickness of the interface increases while the thicknesses of sublayers I and II decrease and the bonding strength increases. Either augmenting the secondary cooling intensity or increasing the mean withdrawing speed results in the decrease in both total thickness of the interface and the thicknesses of sublayers I and II, and an increase in the interfacial bonding strength. The CCA rod with the largest interfacial bonding strength of 67.9 ± 0.5 MPa was fabricated under such processing parameters as copper casting temperature 1503 K (1230 °C), aluminum casting temperature 1063 K (790 °C), primary cooling water flux 600 L/h, secondary cooling water flux 700 L/h, and

  9. Transient Turbulent Flow in a Liquid-Metal Model of Continuous Casting, Including Comparison of Six Different Methods

    NASA Astrophysics Data System (ADS)

    Chaudhary, R.; Ji, C.; Thomas, B. G.; Vanka, S. P.

    2011-10-01

    Computational modeling is an important tool to understand and stabilize transient turbulent fluid flow in the continuous casting of steel to minimize defects. The current work combines the predictions of two steady Reynolds-averaged Navier-Stokes (RANS) models, a "filtered" unsteady RANS model, and two large eddy simulation (LES) models with ultrasonic Doppler velocimetry (UDV) measurements in a small-scale liquid GaInSn model of the continuous casting mold region fed by a bifurcated well-bottom nozzle with horizontal ports. Both mean and transient features of the turbulent flow are investigated. LES outperformed all models while matching the measurements, except in locations where measurement problems are suspected. The LES model also captured high-frequency fluctuations, which the measurements could not detect. Steady RANS models were the least accurate methods. Turbulent velocity variation frequencies and energies decreased with distance from the nozzle port regions. Proper orthogonal decomposition analysis, instantaneous velocity patterns, and Reynolds stresses reveal that velocity fluctuations and flow structures associated with the alternating-direction swirl in the nozzle bottom lead to a wobbling jet exiting the ports into the mold. These turbulent flow structures are responsible for patterns observed in both the time average flow and the statistics of their fluctuations.

  10. Geologic continuous casting below continental and deep-sea detachment faults and at the striated extrusion of Sacsayhuaman, Peru

    USGS Publications Warehouse

    Spencer, J.E.

    1999-01-01

    In the common type of industrial continuous casting, partially molten metal is extruded from a vessel through a shaped orifice called a mold in which the metal assumes the cross-sectional form of the mold as it cools and solidifies. Continuous casting can be sustained as long as molten metal is supplied and thermal conditions are maintained. I propose that a similar process produced parallel sets of grooves in three geologic settings, as follows: (1) corrugated metamorphic core complexes where mylonized mid-crustal rocks were exhumed by movement along low-angle normal faults known as detachment faults; (2) corrugated submarine surfaces where ultramafic and mafic rocks were exhumed by normal faulting within oceanic spreading centers; and (3) striated magma extrusions exemplified by the famous grooved outcrops at the Inca fortress of Sacsayhuaman in Peru. In each case, rocks inferred to have overlain the corrugated surface during corrugation genesis molded and shaped a plastic to partially molten rock mass as it was extruded from a moderate- to high-temperature reservoir.

  11. 7 CFR 51.2001 - Blank.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Blank. 51.2001 Section 51.2001 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Filberts in the Shell 1 Definitions § 51.2001 Blank. Blank means a...

  12. 7 CFR 51.2001 - Blank.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Blank. 51.2001 Section 51.2001 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Filberts in the Shell 1 Definitions § 51.2001 Blank. Blank means a...

  13. The Effect of Temperature Rise in a Fine Blanking Tool

    NASA Astrophysics Data System (ADS)

    Kim, Su-Hyun; Kang, JeongJin; Lee, Dong-Jae; Lee, Kwan-Young; Kim, Heon-Young; Kim, Hyung-Jong

    2007-05-01

    This study was performed to investigate the influence of the tool temperature rise in a fine blanking process. It is known that most of the plastic deformation energy changes into heat and the heat raises tool temperature increasingly in the continual fine blanking process. Real-time measurement of the temperature distribution on the tool surfaces was carried out using a thermal infrared camera. Finite element analysis for the fine blanking process considering the heat transfer and thermal expansion was also performed, and the result was compared with the experimental data. It is found that the tool temperature rises rapidly within one minute (20 to 30 strokes) from the beginning of the continual process and thereafter increases very slowly. It is thought that the increase of tool temperature affects the decrease tendency of fracture zone in blanked workpiece. The phenomena could be properly predicted using finite element method and it is expected that effective information for the design and manufacture of die in a fine blanking process could be given through finite element analysis.

  14. Development of three-wavelength CCD image pyrometer used for the temperature field measurements of continuous casting billets.

    PubMed

    Xie, Zhi; Bai, Haicheng

    2014-02-01

    This paper develops an imaging based three-color pyrometer for the monitoring of temperature distribution in a continuous casting billet. A novel optical device, together with an embedded electronic system, is designed to sequentially collect a dark image and three thermal images with specified wavelengths on a same monochromatic charge-coupled-device (CCD). The three thermal images provide the basis for the determination of target temperature, while the dark image is used to online eliminate the dark noise of CCD with a differential method. This image pyrometer is not only independent of target emissivity but also overcomes the dissimilarity of measuring accuracy between the micro-sensors of CCD resulted from the non-uniformity of pixels' intensity response and the vignetting of optical system. Furthermore, a precise two-color temperature field measuring model on the CCD pyrometer is established, based on which a self-adaptive light-integration mechanism is presented. Compared with the traditional fixed light-integration method, the measuring range of the pyrometer is greatly extended and its sensitivity in low temperature segment is improved. The test results in a steel factory demonstrate that the pyrometer is capable of meeting the requirement of surface temperature measurements about casting billets. Reliability and accuracy of measurement results are also discussed herein. PMID:24593387

  15. Determination for the Entrapment Criterion of Non-metallic Inclusions by the Solidification Front During Steel Centrifugal Continuous Casting

    NASA Astrophysics Data System (ADS)

    Wang, Qiangqiang; Zhang, Lifeng

    2016-06-01

    In the current study, the three-dimensional fluid flow, heat transfer, and solidification in steel centrifugal continuous casting strands were simulated. The volume of fluid model was used to solve the multiphase phenomena between the molten steel and the air. The entrapment and final distribution of inclusions in the solidified shell were studied with the discussion on the effect of rotation behavior of the caster system. Main results indicate that after applying the rotation of the shell, the fluid flow transformed from a recirculation flow to a rotation flow in the mold region and was driven to flow around in the casting direction. As the distance below the meniscus increased, the distribution of the tangential speed of the flow and the centrifugal force along one diameter of the strand became symmetrical gradually. The jet flow from the nozzle hardly impinged on the same location on the shell due to the rotation of the shell during solidification. Thus, the shell thickness on the same height was uniform around, and the thinning shell and a hot spot on the surface of shell were avoided. Both of the measurement and the calculation about the distribution of oxide inclusions along the radial direction indicated the number of inclusions at the side and the center was more than that at the quarter on the cross section of billet. With a larger diameter, inclusions tended to be entrapped toward the center area of the billet.

  16. Development of three-wavelength CCD image pyrometer used for the temperature field measurements of continuous casting billets

    SciTech Connect

    Xie, Zhi; Bai, Haicheng

    2014-02-15

    This paper develops an imaging based three-color pyrometer for the monitoring of temperature distribution in a continuous casting billet. A novel optical device, together with an embedded electronic system, is designed to sequentially collect a dark image and three thermal images with specified wavelengths on a same monochromatic charge-coupled-device (CCD). The three thermal images provide the basis for the determination of target temperature, while the dark image is used to online eliminate the dark noise of CCD with a differential method. This image pyrometer is not only independent of target emissivity but also overcomes the dissimilarity of measuring accuracy between the micro-sensors of CCD resulted from the non-uniformity of pixels’ intensity response and the vignetting of optical system. Furthermore, a precise two-color temperature field measuring model on the CCD pyrometer is established, based on which a self-adaptive light-integration mechanism is presented. Compared with the traditional fixed light-integration method, the measuring range of the pyrometer is greatly extended and its sensitivity in low temperature segment is improved. The test results in a steel factory demonstrate that the pyrometer is capable of meeting the requirement of surface temperature measurements about casting billets. Reliability and accuracy of measurement results are also discussed herein.

  17. Determination for the Entrapment Criterion of Non-metallic Inclusions by the Solidification Front During Steel Centrifugal Continuous Casting

    NASA Astrophysics Data System (ADS)

    Wang, Qiangqiang; Zhang, Lifeng

    2016-03-01

    In the current study, the three-dimensional fluid flow, heat transfer, and solidification in steel centrifugal continuous casting strands were simulated. The volume of fluid model was used to solve the multiphase phenomena between the molten steel and the air. The entrapment and final distribution of inclusions in the solidified shell were studied with the discussion on the effect of rotation behavior of the caster system. Main results indicate that after applying the rotation of the shell, the fluid flow transformed from a recirculation flow to a rotation flow in the mold region and was driven to flow around in the casting direction. As the distance below the meniscus increased, the distribution of the tangential speed of the flow and the centrifugal force along one diameter of the strand became symmetrical gradually. The jet flow from the nozzle hardly impinged on the same location on the shell due to the rotation of the shell during solidification. Thus, the shell thickness on the same height was uniform around, and the thinning shell and a hot spot on the surface of shell were avoided. Both of the measurement and the calculation about the distribution of oxide inclusions along the radial direction indicated the number of inclusions at the side and the center was more than that at the quarter on the cross section of billet. With a larger diameter, inclusions tended to be entrapped toward the center area of the billet.

  18. Effect of superheat on macrostructure and macrosegregation in continuous cast low-alloy steel slabs

    NASA Astrophysics Data System (ADS)

    Pikkarainen, T.; Vuorenmaa, V.; Rentola, I.; Leinonen, M.; Porter, D.

    2016-03-01

    The effect of superheat on grain sedimentation and macrosegregation has been investigated using experimental castings of a low-alloyed steel grade. With a high superheat of ∼ 40 °C, the central equiaxed parts of the slabs consisted of randomly oriented fine dendrites but with a low superheat of ∼ 10 °C, coarse globular structures formed. The mean carbon content measured with optical emission spectroscopy was of the order of 15% smaller with coarse globular structures than in fine equiaxed dendritic structures. Electron probe microanalysis of other alloying elements indicates that the negative segregation in the slab central zones is caused by sedimentation of globulites. With superheat in the range ∼ 20 - 40 °C, the equiaxed zone is bordered by a columnar to equiaxed transition (CET) zone. In this region a positive macrosegregation of carbon and other alloying elements was observed. These phenomena are important when considering the through-thickness properties of the slabs and final products.

  19. Control of Crystal Morphology for Mold Flux During High-Aluminum AHSS Continuous Casting Process

    NASA Astrophysics Data System (ADS)

    GUO, Jing; SEO, Myung-Duk; SHI, Cheng-Bin; CHO, Jung-Wook; KIM, Seon-Hyo

    2016-05-01

    In the present manuscript, the efforts to control the crystal morphology are carried out aiming at improving the lubrication of lime-alumina-based mold flux for casting advanced high-strength steel with high aluminum. Jackson α factors for crystals of melt crystallization in multi-component mold fluxes are established and reasonably evaluated by applying thermodynamic databases to understand the crystal morphology control both in lime-alumina-based and lime-silica-based mold fluxes. The results show that Jackson α factor and supercooling are the most critical factors to determine the crystal morphology in a mold flux. Crystals precipitating in mold fluxes appear with different morphologies due to their different Jackson α factors and are likely to be more faceted with higher Jackson α factor. In addition, there is a critical supercooling degree for crystal morphology dendritic transition. When the supercooling over the critical value, the crystals transform from faceted shape to dendritic ones in morphology as the kinetic roughening occurs. Typically, the critical supercooling degrees for cuspidine dendritic transition in the lime-silica-based mold fluxes are evaluated to be between 0.05 and 0.06. Finally, addition of a small amount of Li2O in the mold flux can increase the Jackson α factor and decrease the supercooling for cuspidine precipitation; thus, it is favorable to enhance a faceted cuspidine crystal.

  20. Control of Crystal Morphology for Mold Flux During High-Aluminum AHSS Continuous Casting Process

    NASA Astrophysics Data System (ADS)

    GUO, Jing; SEO, Myung-Duk; SHI, Cheng-Bin; CHO, Jung-Wook; KIM, Seon-Hyo

    2016-08-01

    In the present manuscript, the efforts to control the crystal morphology are carried out aiming at improving the lubrication of lime-alumina-based mold flux for casting advanced high-strength steel with high aluminum. Jackson α factors for crystals of melt crystallization in multi-component mold fluxes are established and reasonably evaluated by applying thermodynamic databases to understand the crystal morphology control both in lime-alumina-based and lime-silica-based mold fluxes. The results show that Jackson α factor and supercooling are the most critical factors to determine the crystal morphology in a mold flux. Crystals precipitating in mold fluxes appear with different morphologies due to their different Jackson α factors and are likely to be more faceted with higher Jackson α factor. In addition, there is a critical supercooling degree for crystal morphology dendritic transition. When the supercooling over the critical value, the crystals transform from faceted shape to dendritic ones in morphology as the kinetic roughening occurs. Typically, the critical supercooling degrees for cuspidine dendritic transition in the lime-silica-based mold fluxes are evaluated to be between 0.05 and 0.06. Finally, addition of a small amount of Li2O in the mold flux can increase the Jackson α factor and decrease the supercooling for cuspidine precipitation; thus, it is favorable to enhance a faceted cuspidine crystal.

  1. Analysis of cracking phenomena in continuous casting of 1Cr13 stainless steel billets with final electromagnetic stirring

    NASA Astrophysics Data System (ADS)

    Xu, Yu; Xu, Rong-jun; Fan, Zheng-jie; Li, Cheng-bin; Deng, An-yuan; Wang, En-gang

    2016-05-01

    Solidification cracking that occurs during continuous casting of 1Cr13 stainless steel was investigated with and without final electromagnetic stirring (F-EMS). The results show that cracks initiates and propagates along the grain boundaries where the elements of carbon and sulfur are enriched. The final stirrer should be appropriately placed at a location that is 7.5 m away from the meniscus, and the appropriate thickness of the liquid core in the stirring zone is 50 mm. As a stirring current of 250 A is imposed, it can promote columnar-equiaxed transition, decrease the secondary dendrite arm spacing, and reduce the segregation of both carbon and sulfur. F-EMS can effectively decrease the amount of cracks in 1Cr13 stainless steel.

  2. Effect of Posttreatment on Microstructure and Magnetic Properties of Si Steel Strips Prepared by Twin-Roll Continuous Casting Process

    NASA Astrophysics Data System (ADS)

    Yi, Yu; Zhou, Zehua; Wang, Zehua; Jiang, Shaoqun; Huang, Weidong

    2012-10-01

    On the basis of early works, Si-steel strips with 3.0 wt pct Si content were prepared by twin-roll continuous casting (TRCC); posttreatment of double cold-rolling with different annealing temperature was completed, and accordingly, optimum parameters were ascertained. The microstructure and magnetic properties of the strips before and after posttreatment were investigated. The results indicated that Si steel strips could be successfully prepared by TRCC, and the best annealing conditions for posttreatment were 1223 K (950 °C) × 3 minutes in the Ar. Si steel strips exhibited the best magnetic properties after optimum posttreatment: core loss of 4.31 W/Kg and magnetic induction intensity of 1.69T. Moreover, proper posttreatment resulted in ordering of Fe3Si of the Si steel strips, and this ordering was a key factor on improvement of magnetic properties.

  3. A Study for Initial Solidification of Sn-Pb Alloy During Continuous Casting: Part II. Effects of Casting Parameters on Initial Solidification and Shell Surface

    NASA Astrophysics Data System (ADS)

    Zhou, Dong; Wang, Wanlin; Zhang, Haihui; Ma, Fanjun; Chen, Ken; Zhou, Lejun

    2014-06-01

    The initial shell solidification of liquid steel in the mold has significant influence on both surface and internal quality of the final slab, and it is mainly determined by the high transient high temperature thermodynamics occurring in the mold. This study investigated the effects of casting parameters like casting temperature, mold oscillation frequency, and stroke on the initial solidification of a Sn-Pb alloy through the use of a mold simulator to allow the clear understanding of the inter-relationship between irregular shell solidification, heat transfer, negative strip time (NST), and casting conditions. Results suggested that the shell surface oscillation marks (OMs) are strongly depending upon the fluctuations of meniscus responding temperatures and heat flux. An abrupt sudden fluctuation of high frequency temperature and heat flux at the meniscus during the NST would deteriorate the shell surface and leads to deep OMs. The fluctuations of responding temperature and heat flux are determined by the NST, meniscus solidification, and oil infiltration, which in turn are influenced by casting conditions, like casting temperature, oscillation frequency, stroke, etc.

  4. Phase-field modelling of microstructure formation during the solidification of continuously cast low carbon and HSLA steels

    NASA Astrophysics Data System (ADS)

    Böttger, B.; Apel, M.; Santillana, B.; Eskin, D. G.

    2012-07-01

    Cracking in continuous casting of steels has been one of the main problems for decades. Many of the cracks that occur during solidification are hot tears. To better understand the factors leading to this defect, microstructure formation is simulated for a low carbon (LCAK) and two high strength low alloyed (HSLA) steel grades during the initial stage of the process where the first solidified shell is formed inside the mould and where breakouts typically occur. 2D simulation is performed using the multiphase-field software MICRESS [1], which is coupled to the thermodynamic database TCFE6 [2] and the mobility database MOB2 [2], taking into account all elements which may have a relevant effect on the mechanical properties and structure formation during or subsequent to solidification. The use of a moving-frame boundary condition allows travelling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. A heterogeneous nucleation model is included to permit the description of morphological transitions between the initial solidification and the subsequent columnar growth region. Furthermore, a macroscopic one-dimensional temperature solver is integrated to account for the transient and nonlinear temperature field during the initial stage of continuous casting. The external heat flux boundary conditions for this process were derived from thermal process data of the industrial slab caster. The simulation results for the three steel grades have been validated by thickness measurements of breakout shells and microstructure observation of the corresponding grades. Furthermore, the primary dendrite spacing has been measured across the whole thickness of the shell and compared with the simulated microstructures. Significant microstructure differences between the steel grades are discussed and correlated with their hot-cracking behavior.

  5. Deformed ellipsoidal diffraction grating blank

    NASA Technical Reports Server (NTRS)

    Decew, Alan E., Jr.

    1994-01-01

    The Deformed Ellipsoidal Grating Blank (DEGB) is the primary component in an ultraviolet spectrometer. Since one of the major concerns for these instruments is throughput, significant efforts are made to reduce the number of components and subsequently reflections. Each reflection results in losses through absorption and scattering. It is these two sources of photon loss that dictated the requirements for the DEGB. The first goal is to shape the DEGB in such a way that the energy at the entrance slit is focused as well as possible on the exit slit. The second goal is to produce a surface smooth enough to minimize the photon loss due to scattering. The program was accomplished in three phases. The first phase was the fabrication planning. The second phase was the actual fabrication and initial testing. The last phase was the final testing of the completed DEGB.

  6. Urinary casts

    MedlinePlus

    ... Casts in the urine; Fatty casts; Red blood cell casts; White blood cell casts ... The absence of cellular casts or presence of a few hyaline casts is normal. The examples above are common measurements for results of ...

  7. Urinary casts

    MedlinePlus

    ... people with advanced kidney disease and chronic kidney failure . White blood cell (WBC) casts are more common ... Hyaline casts; Granular casts; Renal tubular epithelial casts; Waxy casts; Casts in the ...

  8. Numerical Simulation of the Fluid Flow, Heat Transfer, and Solidification in a Twin-Roll Strip Continuous Casting Machine

    NASA Astrophysics Data System (ADS)

    Xu, Mianguang; Zhu, Miaoyong; Wang, Guodong

    2015-03-01

    In this paper, a three-dimensional enthalpy-porosity mixture solidification model is employed to describe the basic rules of heat transfer and solidification in a twin-roll strip continuous casting machine equipped with a multi-port trough-shaped feeding system, and reasons for the formation of these rules are analyzed. The two-layer zonal turbulence model is used to incorporate the turbulence in fluid flow, and the fluid flow in the wedge-shaped pool region in various conditions is studied. The results show that the fluid flow field in the pool region is quite different with/without the consideration of rotating rolls when the solidification is ignored, which indicates the importance of the consideration of rotating rolls in the water modeling equipment design. There are three aspects including molten steel jet impingement, roll rotating, and backward flow of the mushy zone, which strongly influence the temperature distribution in the pool region. The solidification process in the pool region could be divided into three stages: at the first stage, there exists a fast solidification region which obeys the square root law, and an approximately linear growth region could be found at the second stage, while a parabolic growth region could be found at the last stage. The formation of the first stage and the last stage could be mainly due to the geometry of the feeding system and the backward flow of the mushy zone, respectively. The first stage of solidification could be modified by a better designed feeding system, but the backward flow of mushy zone determined by the properties of metals and casting parameters could be one of the biggest obstacles for commercial production of steel sheets by a twin-roll caster.

  9. Visualization of Liquid Metal Two-phase Flows in a Physical Model of the Continuous Casting Process of Steel

    NASA Astrophysics Data System (ADS)

    Timmel, Klaus; Shevchenko, Natalia; Röder, Michael; Anderhuber, Marc; Gardin, Pascal; Eckert, Sven; Gerbeth, Gunter

    2015-04-01

    We present an experimental study concerned with investigations of the two-phase flow in a mock-up of the continuous casting process of steel. A specific experimental facility was designed and constructed at HZDR for visualizing liquid metal two-phase flows in the mold and the submerged entry nozzle (SEN) by means of X-ray radioscopy. This setup operates with the low melting, eutectic alloy GaInSn as model liquid. The argon gas is injected through the tip of the stopper rod into the liquid metal flow. The system operates continuously under isothermal conditions. First results will be presented here revealing complex flow structures in the SEN widely differing from a homogeneously dispersed bubbly flow. The patterns are mainly dominated by large bubbles and large-area detachments of the liquid metal flow from the inner nozzle wall. Various flow regimes can be distinguished depending on the ratio between the liquid and the gas flow rate. Smaller gas bubbles are produced by strong shear flows near the nozzle ports. The small bubbles are entrained by the submerged jet and mainly entrapped by the lower circulation roll in the mold. Larger bubbles develop by coalescence and ascend toward the free surface.

  10. Microstructure and mechanical properties of BFe10 cupronickel alloy tubes fabricated by a horizontal continuous casting with heating-cooling combined mold technology

    NASA Astrophysics Data System (ADS)

    Mei, Jun; Liu, Xin-hua; Xie, Jian-xin

    2012-04-01

    A new horizontal continuous casting method with heating-cooling combined mold (HCCM) technology was explored for fabricating high-quality thin-wall cupronickel alloy tubes used for heat exchange pipes. The microstructure and mechanical properties of BFe10 cupronickel alloy tubes fabricated by HCCM and traditional continuous casting (cooling mold casting) were comparatively investigated. The results show that the tube fabricated by HCCM has smooth internal and external surfaces without any defects, and its internal and external surface roughnesses are 0.64 μm and 0.85 μm, respectively. The tube could be used for subsequent cold processing without other treatments such as surface planning, milling and acid-washing. This indicates that HCCM can effectively reduce the process flow and improve the production efficiency of a BFe10 cupronickel alloy tube. The tube has columnar grains along its axial direction with a major casting texture of left\\{ {012} right\\}left< {6bar 21} rightrangle. Compared with cooling mold casting ( δ = 36.5%), HCCM can improve elongation ( δ = 46.3%) by 10% with a slight loss of strength, which indicates that HCCM remarkably improves the cold extension performance of a BFe10 cupronickel alloy tube.

  11. Large Eddy Simulation of Transient Flow and Inclusions Transport in Continuous Casting Mold under Different Electromagnetic Brakes

    NASA Astrophysics Data System (ADS)

    Liu, Zhongqiu; Li, Linmin; Li, Baokuan

    2016-06-01

    A mathematical model has been developed to analyze transient fluid flow and inclusions transport in a slab continuous casting mold, considering the effects of electromagnetic brake (EMBr) arrangement and magnetic field strength. Transient flow of molten steel in the mold is calculated by using the large eddy simulation. The electromagnetic force is incorporated into the Navier-Stokes equation. The transport of inclusion inside the mold is calculated using the Lagrangian approach based on the transient flow field. The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern and inclusion transport inside the mold exhibits satisfactory agreement with the corresponding measurements. With electromagnetic brake effect, the velocities around the braking region are significantly suppressed, and the recirculating flow in the lower part drops and tends to develop a plug-like flow. The EMBr arrangement has an insignificant effect on the overall removal fraction of inclusions, especially for larger inclusions. The inclusion removal rate for the flow-control mold (FCM arrangement) reduces instead compared with no EMBr, especially for smaller inclusions.

  12. Hot Ductility and Deformation Behavior of C-Mn/Nb-Microalloyed Steel Related to Cracking During Continuous Casting

    NASA Astrophysics Data System (ADS)

    Lanjewar, H. A.; Tripathi, Pranavkumar; Singhai, M.; Patra, P. K.

    2014-10-01

    Hot ductility studies have been performed on C-Mn and C-Mn-Nb steels with an approach to simulate the effect of cooling conditions experienced by steel in secondary cooling zone during continuous casting. Thermal oscillations prior to tensile straining deteriorate hot ductility of steel by deepening and widening the hot ductility trough. C-Mn steels are found to exhibit ductility troughs in three distinct zones whereas C-Mn-Nb steel shows drop in ductility only at low temperature in the vicinity of ferrite transformation temperatures. Start of ferrite transformation in steels causes yield ratio to increase while work hardening rates and strength coefficient decrease with decrease in test temperature in presence of thermal oscillation prior to tensile testing. Inhibition of recrystallization due to build-up of AlN particles along with the presence of MnS particles in structure and low work hardening rates causes embrittlement of steel in austenitic range. Alloying elements enhancing work hardening rates in austenitic range can be promoted to improve hot ductility. The presence of low melting phase saturated with impurities along the austenitic grain boundaries causes intergranular fracture at high temperature in C-Mn steels.

  13. Computation of Phase Fractions in Austenite Transformation with the Dilation Curve for Various Cooling Regimens in Continuous Casting

    NASA Astrophysics Data System (ADS)

    Dong, Zhihua; Chen, Dengfu; Long, Mujun; Li, Wei; Chen, Huabiao; Vitos, Levente

    2016-03-01

    A concise model is applied to compute the microstructure evolution of austenite transformation by using the dilation curve of continuously cast steels. The model is verified by thermodynamic calculations and microstructure examinations. When applying the model, the phase fractions and the corresponding transforming rates during austenite transformation are investigated at various cooling rates and chemical compositions. In addition, ab initio calculations are performed for paramagnetic body-centered-cubic Fe to understand the thermal expansion behavior of steels at an atomic scale. Results indicate that by increasing the cooling rate, the final volume fraction of ferrite/pearlite will gradually increase/decrease with a greater transforming rate of ferrite. The ferrite fraction increases after austenite transformation with lowering of the carbon content and increasing of the substitutional alloying fractions. In the austenite transformation, the thermal expansion coefficient is sequentially determined by the forming rate of ferrite and pearlite. According to the ab initio theoretical calculations for the single phase of ferrite, thermal expansion emerges from magnetic evolution and lattice vibration, the latter playing the dominant role. The theoretical predictions for volume and thermal expansion coefficient are in good agreement with the experimental data.

  14. Comparison of Experimentally Measured Temperature Gradient and Finite-Element-Method Simulations for Two Continuously Cast Bloom Heating Strategies

    NASA Astrophysics Data System (ADS)

    Kvíčala, M.; Frydrýšek, K.; Štamborská, M.

    2015-03-01

    This paper deals with the comparison of experimentally measured temperature gradients and finite-element-method (FEM) simulations of two heating strategies that were used for continuously cast bloom soaking. The temperature gradient between the bloom surface and center was measured by two thermocouples incorporated directly into the bloom. Scanning electron microscopy equipped by energy dispersive X-ray spectroscopy analysis, hot tensile tests, and interdendritic solidification software was used for modeling of steel thermophysical properties with respect to the alloying-elements macrosegregation. The model of the bloom was programmed in the Fortran language. The FEM software MARC/MENTAT 2012 was used for simulation of two heating strategies (plane strain formulation). The first heating model was fitted to the commonly used heating strategy when internal defects grew above the critical limit. The second heating model was a newly proposed strategy that consisted of slower heating up to 1073 K when the first warming-through period occurred. The FEM simulations included determinations of the temperature gradient, the equivalent of stress, the equivalent of elastic strain, the equivalent of plastic strain, and the equivalent of total strain. The simulation results were in good agreement with experimental observations. The new heating strategy based on the FEM simulations led to significantly lower occurrence of internal defects in hot-rolled billets that are used for cylinder production.

  15. Development of a Mold Cracking Simulator: The Study of Breakout and Crack Formation in Continuous Casting Mold

    NASA Astrophysics Data System (ADS)

    Zhang, Yexin; Wang, Wanlin; Zhang, Haihui

    2016-08-01

    Based on the mold simulator technology, a mold-cracking simulator has been successfully developed to study the process of breakout and the shell surface crack formation during the initial solidification of molten steel inside the continuous casting mold. First, a spheroidal protrusion was installed on the mold hot surface to mimic the abnormal force that generated by mold wall deformation, and then the external force was applied to the initial solidified shell, to facilitate the formation of breakout and shell surface cracks. Second, the responding temperature and heat flux across mold hot surface were recovered by an inverse heat conduction problem. The experimental results indicated that the mold breakout occurs around the shell tip by the combined efforts from external horizontal force, ferrostatic pressure, and thermal stresses during positive strip time. The breakout tends to introduce the peak of the responding temperature and heat flux across the mold hot surface. The vertical propagation velocity of the rupture point in the solidification shell has been calculated as 0.42 m/s in this study, which is in good agreement with industrial slabs. The paper also suggested that surface transverse crack formation is related to the segregation of sulfur during the initial solidification of molten steel.

  16. Development of a Mold Cracking Simulator: The Study of Breakout and Crack Formation in Continuous Casting Mold

    NASA Astrophysics Data System (ADS)

    Zhang, Yexin; Wang, Wanlin; Zhang, Haihui

    2016-06-01

    Based on the mold simulator technology, a mold-cracking simulator has been successfully developed to study the process of breakout and the shell surface crack formation during the initial solidification of molten steel inside the continuous casting mold. First, a spheroidal protrusion was installed on the mold hot surface to mimic the abnormal force that generated by mold wall deformation, and then the external force was applied to the initial solidified shell, to facilitate the formation of breakout and shell surface cracks. Second, the responding temperature and heat flux across mold hot surface were recovered by an inverse heat conduction problem. The experimental results indicated that the mold breakout occurs around the shell tip by the combined efforts from external horizontal force, ferrostatic pressure, and thermal stresses during positive strip time. The breakout tends to introduce the peak of the responding temperature and heat flux across the mold hot surface. The vertical propagation velocity of the rupture point in the solidification shell has been calculated as 0.42 m/s in this study, which is in good agreement with industrial slabs. The paper also suggested that surface transverse crack formation is related to the segregation of sulfur during the initial solidification of molten steel.

  17. Computation of Phase Fractions in Austenite Transformation with the Dilation Curve for Various Cooling Regimens in Continuous Casting

    NASA Astrophysics Data System (ADS)

    Dong, Zhihua; Chen, Dengfu; Long, Mujun; Li, Wei; Chen, Huabiao; Vitos, Levente

    2016-06-01

    A concise model is applied to compute the microstructure evolution of austenite transformation by using the dilation curve of continuously cast steels. The model is verified by thermodynamic calculations and microstructure examinations. When applying the model, the phase fractions and the corresponding transforming rates during austenite transformation are investigated at various cooling rates and chemical compositions. In addition, ab initio calculations are performed for paramagnetic body-centered-cubic Fe to understand the thermal expansion behavior of steels at an atomic scale. Results indicate that by increasing the cooling rate, the final volume fraction of ferrite/pearlite will gradually increase/decrease with a greater transforming rate of ferrite. The ferrite fraction increases after austenite transformation with lowering of the carbon content and increasing of the substitutional alloying fractions. In the austenite transformation, the thermal expansion coefficient is sequentially determined by the forming rate of ferrite and pearlite. According to the ab initio theoretical calculations for the single phase of ferrite, thermal expansion emerges from magnetic evolution and lattice vibration, the latter playing the dominant role. The theoretical predictions for volume and thermal expansion coefficient are in good agreement with the experimental data.

  18. Simulation and validation of two-phase turbulent flow and particle transport in continuous casting of steel slabs

    NASA Astrophysics Data System (ADS)

    Jin, K.; Thomas, B. G.; Liu, R.; Vanka, S. P.; Ruan, X. M.

    2015-06-01

    In continuous steel casting, argon gas is usually injected at the slide gate or stopper rod to prevent clogging, but entrapped bubbles may cause defects in the final product. To better understand this, the flow of molten steel and the transport and capture of argon gas bubbles have been simulated and compared with plant measurements. First, the flow field was solved with an Eulerian k-s model of the steel, which was two-way coupled with a Lagrangian model of the large bubbles using a Discrete Random Walk method to include dispersion of bubbles due to turbulence. The asymmetrical flow pattern predicted on the top surface agreed well with nailboard measurements. Then, the motion and capture of over two million bubbles were simulated using two different capture criteria. Results with the advanced capture criterion agreed well with measurements of the number, locations, and sizes of captured bubbles, especially for larger bubbles. The relative capture fraction of 0.3% was close to the measured 0.2% for 1mm bubbles, and occurred very near the top surface. The model presented here is an efficient tool to study the capture of bubbles and inclusion particles in solidification processes.

  19. Casting Technology.

    ERIC Educational Resources Information Center

    Wright, Michael D.; And Others

    1992-01-01

    Three articles discuss (1) casting technology as it relates to industry, with comparisons of shell casting, shell molding, and die casting; (2) evaporative pattern casting for metals; and (3) high technological casting with silicone rubber. (JOW)

  20. Magnetron sputtering for the production of EUV mask blanks

    NASA Astrophysics Data System (ADS)

    Kearney, Patrick; Ngai, Tat; Karumuri, Anil; Yum, Jung; Lee, Hojune; Gilmer, David; Vo, Tuan; Goodwin, Frank

    2015-03-01

    Ion Beam Deposition (IBD) has been the primary technique used to deposit EUV mask blanks since 1995 when it was discovered it could produce multilayers with few defects. Since that time the IBD technique has been extensively studied and improved and is finally approaching usable defectivities. But in the intervening years, the defectivity of magnetron sputtering has been greatly improved. This paper evaluates the suitability of a modern magnetron tool to produce EUV mask blanks and the ability to support HVM production. In particular we show that the reflectivity and uniformity of these tools are superior to current generation IBD tools, and that the magnetron tools can produce EUV films with defect densities comparable to recent best IBD tool performance. Magnetron tools also offer many advantages in manufacturability and tool throughput; however, challenges remain, including transitioning the magnetron tools from the wafer to mask formats. While work continues on quantifying the capability of magnetron sputtering to meet the mask blank demands of the industry, for the most part the remaining challenges do not require any fundamental improvements to existing technology. Based on the recent results and the data presented in this paper there is a clear indication that magnetron deposition should be considered for the future of EUV mask blank production.

  1. Physical and Mathematical Modeling of Thin Steel Slab Continuous Casting Secondary Cooling Zone Air-Mist Impingement

    NASA Astrophysics Data System (ADS)

    de León B., Melecio; Castillejos E., A. Humberto

    2015-10-01

    This study is an attempt to unveil the fluid dynamic phenomena occurring during interaction of air-mists with the surface of the steel strand during its pass through the continuous casting secondary cooling system. Air-mists generated under conditions of practical interest are studied while impacting on a vertical wall at room temperature. Experimentally a spatial multiple-counting technique based on capturing instantaneous double-exposure shadowgraphs is used to visualize the internal structure of mists at distances between 0 and 4 mm from the wall. Analysis of single exposure images allows determination of size distributions of primary (impinging) and secondary (ejecting) drops and of fluctuating thickness of water films formed on the wall surface. Besides, examination of image pairs enables measurement of velocity and trajectory angles of both kinds of drops. These results aided in the formulation and validation of a transient, turbulent, 3D, multiphase fluid dynamic model for simulating impinging air-mists. The model is based on KIVA-3V and for simulating the airborne mist region it solves the continuity equations—mass, momentum, turbulence quantities—for the air coupled with the equation of motion for drops sampled randomly from distributions assumed to govern their size and volume flux at the nozzle orifice. While for the impingement region submodels are established to estimate the results of drop/wall interaction, i.e., the dynamics of secondary drops and water films formed by the impingement of primary drops. The model forecasts reasonably well the random distributions of diameters, velocities, trajectory angles, and Weber numbers of both kind of drops moving near the wall. Additionally, it predicts well the average thickness of the water film and the important effect that air nozzle pressure has on the normal impinging velocity of drops; high pressures result in large drop velocities favoring intimate contact with the surface.

  2. A Study for Initial Solidification of Sn-Pb Alloy during Continuous Casting: Part I. The Development of the Technique

    NASA Astrophysics Data System (ADS)

    Zhang, Haihui; Wang, Wanlin; Zhou, Dong; Ma, Fanjun; Lu, Boxun; Zhou, Lejun

    2014-06-01

    The importance of initial solidification of molten steel in the mold has been widely acknowledged. However, very few studies have been effectively developed because of the high transient nature of thermodynamics and fluid flow in the upper mold. Based on the recently developed mold simulator technology, a novel technique has been successfully developed to study the initial solidification behavior of Sn-Pb alloy, which gives rise to the clear understanding of the interrelationship between complex meniscus heat transfer, casting surface oscillation marks (OM), and mold hot-surface responding temperatures. The results suggested that the variations of the responding temperatures and heat flux at meniscus may be associated with the movement of mold in/out of the bath, the infiltration of silicon oil, and the latent heat release due to the solidification of meniscus during negative strip time (NST). The presence of positive peaks in the derivative of the heat flux are corresponding to each of the OM during NST, which suggests the significant increase of heat flux during the formation of OM. These could be explained as the meniscus is deformed and gets closer to the coldest mold at the beginning of NST, such that the liquid meniscus that gives rise to the increase of heat flux would be solidified. With the enhancement of oil infiltration from the mid-NST to end-NST, the thermal resistance between the solidified meniscus and mold decreases; therefore, the shell continues to grow, and the resulting heat-transfer and mold temperatures also continue to increase.

  3. New decade of shaped beryllium blanks

    NASA Astrophysics Data System (ADS)

    Hashiguchi, Don H.; Heberling, Jody; Campbell, Jeffrey; Morales, Amanda; Sayer, Aaron

    2015-09-01

    Near-net-shape powder consolidation technology has been developing over the past 30+ years. One relatively recent example is production of hexagonal shaped beryllium mirror blanks made for the James Webb Space Telescope. More cost saving examples, specifically from the past decade, utilizing growing experience and lesson's learned whether from a mirror substrate or structure will be discussed to show the latitude of production technology. Powder consolidation techniques include Hot Isostatic Pressing (HIP) for either round or shaped blanks and Vacuum Hot Pressing (VHP) consolidation for round blanks. The range of sizes will be presented to further illustrate the latitude of current production capability.

  4. Inspection of lithographic mask blanks for defects

    DOEpatents

    Sommargren, Gary E.

    2001-01-01

    A visible light method for detecting sub-100 nm size defects on mask blanks used for lithography. By using optical heterodyne techniques, detection of the scattered light can be significantly enhanced as compared to standard intensity detection methods. The invention is useful in the inspection of super-polished surfaces for isolated surface defects or particulate contamination and in the inspection of lithographic mask or reticle blanks for surface defects or bulk defects or for surface particulate contamination.

  5. Seeing Red and Shooting Blanks: A Study of Red Quasars and Blank Field X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald J. (Technical Monitor); Elvis, Martin

    2004-01-01

    One type of "Blank Field X-ray Source" is now being seen in deep Chandra and XMM-Newton surveys. These are the newly dubbed "XBONGs" (X-ray Bright, Optically Normal Galaxies). The study of the brighter counterparts from ROSAT and XMM- Newton serendipitous surveys is therefore of renewed interest and topicality. We continue to define the properties of the ROSAT sample which is the basis of this grant. We expect to publish the SEDs of these sources soon.

  6. Casting Stainless-Steel Models Around Pressure Tubes

    NASA Technical Reports Server (NTRS)

    Vasquez, Peter; Micol, John R.

    1992-01-01

    Survivability of thin-wall stainless-steel tubing increased to nearly 100 percent. Improves state of art in pressure-model castings and reduces cost associated with machining complete model from stainless-steel blank.

  7. Development of an advanced gas-fired furnace for high-temperature heating of continuously cast thin-section steel products. Final report, January-December 1986

    SciTech Connect

    Franz, D.G.

    1987-01-01

    The project involved the development of preliminary design parameters for two different types of gas-fired furnaces capable of reheating thin sections (i.e., 1-inch thick) of continuously cast steel. These reheated thin steel sections are sent directly into with Hot Strip Mill finishing stands without further reductions. For the Hot Strip Mill configurations where a thin section continuous caster may be close coupled in-line with the finishing stands, a roller hearth furnace was developed. This furnace was designed to reheat the as-cast thin section in flat form at a production rate of 250 tons/hour. For the Hot Strip Mill configuration where a thin section caster may have to be located remote from the finishing stands, a car bottom furnace was developed. This furnace was designed to reheat the thin section in coiled form at a production rate of 125 tons/hour. Either of these thin section reheat furnaces will require only 32% of the fuel requirement of existing reheat furnace operations that process continuously cast steel slabs.

  8. Formability Studies on Transverse Tailor Welded Blanks

    SciTech Connect

    Bhaskar, V. Vijay; Narasimhan, K.

    2005-08-05

    Tailor Welded Blanks (TWB) technology is one of the several approaches that have been used to reduce the weight of the automobile body. TWBs are made up of two or more blanks having different/same properties (geometry, material etc.) prior to forming. The formability of these blanks depends on material and geometric parameters like strength ratio and thickness ratio. The study of these blanks can be classified on the basis of the weld orientation chosen viz. transverse weld or longitudinal weld with respect to the major straining direction.This paper studies the formability issues related to transverse TWB by FE simulation. The formability is assessed by analyzing tensile and Limit Dome Height (LDH) tests. The weld region is assumed to be a line in all the simulations. While modeling the tensile test, ultimate tensile strength (UTS) and elongation are monitored, and in LDH testing, pole height and maximum load (in near plane strain condition) are monitored. LDH testing shows that as thickness ratio increases, the load bearing capacity and the pole height decreases. There is a contribution from both the thicker and the thinner blank to the overall deforming volume. Failure location analysis shows that there is an abrupt change in the location of the failure from punch nose region to weld line region as the thickness ratio reaches a critical magnitude (1.08).The study of material properties shows that as the yield strength ratio (S ratio) and strain hardening exponent ratio (N ratio) between the blanks increases, the maximum load which the blank can sustain without failure (UTS) increases. This becomes constant and comparable to that of single sheet at higher N and S ratios.

  9. Size and Velocity Characteristics of Droplets Generated by Thin Steel Slab Continuous Casting Secondary Cooling Air-Mist Nozzles

    NASA Astrophysics Data System (ADS)

    Minchaca M, J. I.; Castillejos E, A. H.; Acosta G, F. A.

    2011-06-01

    Direct spray impingement of high temperature surfaces, 1473 K to 973 K (1200 °C to 700 °C), plays a critical role in the secondary cooling of continuously cast thin steel slabs. It is known that the spray parameters affecting the local heat flux are the water impact flux w as well as the droplet velocity and size. However, few works have been done to characterize the last two parameters in the case of dense mists ( i.e., mists with w in the range of 2 to 90 L/m2s). This makes it difficult to rationalize how the nozzle type and its operating conditions must be selected to control the cooling process. In the present study, particle/droplet image analysis was used to determine the droplet size and velocity distributions simultaneously at various locations along the major axis of the mist cross section at a distance where the steel strand would stand. The measurements were carried out at room temperature for two standard commercial air-assisted nozzles of fan-discharge type operating over a broad range of conditions of practical interest. To achieve statistically meaningful samples, at least 6000 drops were analyzed at each location. Measuring the droplet size revealed that the number and volume frequency distributions were fitted satisfactorily by the respective log-normal and Nukiyama-Tanasawa distributions. The correlation of the parameters of the distribution functions with the water- and air-nozzle pressures allowed for reasonable estimation of the mean values of the size of the droplets generated. The ensemble of measurements across the mist axis showed that the relationship between the droplet velocity and the diameter exhibited a weak positive correlation. Additionally, increasing the water flow rate at constant air pressure caused a decrease in the proportion of the water volume made of finer droplets, whereas the volume proportion of faster droplets augmented until the water flow reached a certain value, after which it decreased. Diminishing the air

  10. Automatic classification of blank substrate defects

    NASA Astrophysics Data System (ADS)

    Boettiger, Tom; Buck, Peter; Paninjath, Sankaranarayanan; Pereira, Mark; Ronald, Rob; Rost, Dan; Samir, Bhamidipati

    2014-10-01

    Mask preparation stages are crucial in mask manufacturing, since this mask is to later act as a template for considerable number of dies on wafer. Defects on the initial blank substrate, and subsequent cleaned and coated substrates, can have a profound impact on the usability of the finished mask. This emphasizes the need for early and accurate identification of blank substrate defects and the risk they pose to the patterned reticle. While Automatic Defect Classification (ADC) is a well-developed technology for inspection and analysis of defects on patterned wafers and masks in the semiconductors industry, ADC for mask blanks is still in the early stages of adoption and development. Calibre ADC is a powerful analysis tool for fast, accurate, consistent and automatic classification of defects on mask blanks. Accurate, automated classification of mask blanks leads to better usability of blanks by enabling defect avoidance technologies during mask writing. Detailed information on blank defects can help to select appropriate job-decks to be written on the mask by defect avoidance tools [1][4][5]. Smart algorithms separate critical defects from the potentially large number of non-critical defects or false defects detected at various stages during mask blank preparation. Mechanisms used by Calibre ADC to identify and characterize defects include defect location and size, signal polarity (dark, bright) in both transmitted and reflected review images, distinguishing defect signals from background noise in defect images. The Calibre ADC engine then uses a decision tree to translate this information into a defect classification code. Using this automated process improves classification accuracy, repeatability and speed, while avoiding the subjectivity of human judgment compared to the alternative of manual defect classification by trained personnel [2]. This paper focuses on the results from the evaluation of Automatic Defect Classification (ADC) product at MP Mask

  11. Penetrating ocular trauma associated with blank cartridge

    PubMed Central

    2014-01-01

    Background Blank cartridge guns are generally regarded as being harmless and relative safe. However recent published articles demonstrated that the gas pressure from the exploding propellant of blank cartridge is powerful enough to penetrate the thoracic wall, abdominal muscle, small intestine and the skull. And there has been a limited number of case reports of ocular trauma associated with blank cartridge injury. In addition, no report on case with split extraocular muscle injury with traumatic cataract and penetrating corneoscleral wound associated with blank cartridge has been previously documented. This report describes the case of patient who sustained penetrating ocular injury with extraocular muscle injury by a close-distance blank cartridge that required surgical intervention. Case presentation A 20-year-old man sustained a penetrating globe injury in the right eye while cleaning a blank cartridge pistol. His uncorrected visual acuity at presentation was hand motion and he had a flame burn of his right upper and lower lid with multiple missile wounds. On slit-lamp examination, there was a 12-mm laceration of conjunctiva along the 9 o'clock position with two pinhole-like penetrating injuries of cornea and sclera. There was also a 3-mm corneal laceration between 9 o'clock and 12 o'clock and the exposed lateral rectus muscle was split. Severe Descemet's membrane folding with stromal edema was observed, and numerous yellow, powder-like foreign bodies were impacted in the cornea. Layered anterior chamber bleeding with traumatic cataract was also noted. Transverse view of ultrasonography showed hyperechoic foreign bodies with mild reduplication echoes and shadowing. However, a computed tomographic scan using thin section did not reveal a radiopaque foreign body within the right globe. Conclusion To our best knowledge, this is the first case report of split extraocular muscle injury with traumatic cataract and penetrating ocular injury caused by blank cartridge

  12. Liquid-solid interface control of BFe10-1-1 cupronickel alloy tubes during HCCM horizontal continuous casting and its effect on the microstructure and properties

    NASA Astrophysics Data System (ADS)

    Mei, Jun; Liu, Xin-hua; Jiang, Yan-bin; Chen, Song; Xie, Jian-xin

    2013-08-01

    Based on horizontal continuous casting with a heating-cooling combined mold (HCCM) technology, this article investigated the effects of processing parameters on the liquid-solid interface (LSI) position and the influence of LSI position on the surface quality, microstructure, texture, and mechanical properties of a BFe10-1-1 tube (ϕ50 mm × 5 mm). HCCM efficiently improves the temperature gradient in front of the LSI. Through controlling the LSI position, the radial columnar-grained microstructure that is commonly generated by cooling mold casting can be eliminated, and the axial columnar-grained microstructure can be obtained. Under the condition of 1250°C melting and holding temperature, 1200-1250°C mold heating temperature, 50-80 mm/min mean drawing speed, and 500-700 L/h cooling water flow rate, the LSI position is located at the middle of the transition zone or near the entrance of the cooling section, and the as-cast tube not only has a strong axial columnar-grained microstructure due to strong axial heating conduction during solidification but also has smooth internal and external surfaces without cracks, scratches, and other macroscopic defects due to short solidified shell length and short contact length between the tube and the mold at high temperature. The elongation and tensile strength of the tube are 46.0%-47.2% and 210-221 MPa, respectively, which can be directly used for the subsequent cold-large-strain processing.

  13. Material Characterization of Austempered Ductile Iron (ADI) Produced by a Sustainable Continuous Casting-Heat Treatment Process

    NASA Astrophysics Data System (ADS)

    Meena, Anil; El Mansori, Mohamed

    2012-12-01

    Selecting a suitable manufacturing process is one way of achieving sustainability of a product by diminishing energy consumption during its production cycle and improving material efficiency. The article attempts to explore the new processing technology for direct manufacturing of lightweight austempered ductile iron (ADI) casting in a permanent mold. The new processing technology is based on the innovative integrated approach toward casting and heat-treatment process. In this technology, the ductile iron samples obtained using the permanent mold are first austenized immediately after solidification process followed by austempering heat treatment in the fluidized bed and then air cooled at room temperature to obtain ADI material. The influence of austempering time on the microstructural characteristics, mechanical properties, and strain-hardening behavior of ADI was studied. Optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses were performed to correlate the mechanical properties with microstructural characteristics. It was observed that the mechanical properties of resulting ADI samples were influenced by the microstructural transformations and varied retained austenite volume fractions obtained due to different austempering time. The results indicate that the strain-hardening behavior of the ADI material is influenced by the carbon content of retained austenite.

  14. Comparison of Uniform and Non-uniform Water Flux Density Approaches Applied on a Mathematical Model of Heat Transfer and Solidification for a Continuous Casting of Round Billets

    NASA Astrophysics Data System (ADS)

    Assuncao, Charles Sostenes; Tavares, Roberto Parreiras; Oliveira, Guilherme; Pereira, Luiz Carlos

    2015-02-01

    In the present work, the water flux densities of nozzles with flat jet and full cone jet were experimentally measured using an apparatus in industrial scale that reproduces the secondary cooling of the continuous casting of round billets of Vallourec Tubos do Brasil. A mathematical function was defined to express the water flux density in both longitudinal and angular directions of the strand. A mathematical model for heat transfer and solidification for the continuous casting of round billets was developed applying the experimental water flux density profile, establishing a non-uniform water distribution approach. The mathematical model was validated by experimental measurements of the billet superficial temperature, performed at the industrial plant. The results of the mathematical model using both uniform and non-uniform water flux density approaches were compared. The non-uniform water distribution approach enabled to identify important variations of the heat transfer coefficients and the billet temperatures, especially in the first cooling zones where the steel temperature is higher, and to assess more accurately the local effects of the water distribution on the thermal behavior of the strand. The non-uniform water flux density approach applied to the mathematical model was a useful and more accurate tool to improve the comprehension of the thermal behavior of the steel along the secondary cooling.

  15. Geologic continuous casting below continental and deep-sea detachment faults and at the striated extrusion of Sacsayhuamán, Peru

    NASA Astrophysics Data System (ADS)

    Spencer, Jon E.

    1999-04-01

    In one common type of industrial continuous casting, partially molten metal is extruded from a vessel through a shaped orifice called a mold in which the metal assumes the cross-sectional form of the mold as it cools and solidifies. Continuous casting can be sustained as long as molten metal is supplied and thermal conditions are maintained. I propose that a similar process produced parallel sets of grooves in three geologic settings, as follows: (1) corrugated metamorphic core complexes where mylonitized mid-crustal rocks were exhumed by movement along low-angle normal faults known as detachment faults; (2) corrugated submarine surfaces where ultramafic and mafic rocks were exhumed by normal faulting within oceanic spreading centers; and (3) striated magma extrusions exemplified by the famous grooved outcrops at the Inca fortress of Sacsayhuamán in Peru. In each case, rocks inferred to have overlain the corrugated surface during corrugation genesis molded and shaped a plastic to partially molten rock mass as it was extruded from a moderate- to high-temperature reservoir.

  16. Mask blank particle inspection in vacuum environments

    NASA Astrophysics Data System (ADS)

    Sekine, Akihiko; Nagahama, Hiroyuki; Tojo, Toru; Akeno, Kiminobu; Hirano, Ryoichi

    2002-10-01

    The mask blank surface inspection system for the electron beam mask writing system (EB mask writer) has developed. This system, that has the small vacuum chamber attachable to EB mask writer, inspects a mask blank that is just before EB writing in vacuum environments. It can inspect whole area of the 230mm mask at 0.3micrometer sensitivity. It also can perform fast inspection by applying the original scanning algorithm for the laser beam. It has the wide detective range from 0.3 to 2.0 micrometers of particle size. It can distinguish sizes of particles in that range. The auto focus function is most important factor for maintaining the sensitivity.

  17. Seeing Red and Shooting Blanks: Study of Red Quasars and Blank X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald (Technical Monitor); Elvis, Martin

    2005-01-01

    A major paper describing the technique and providing a list of 'blanks' was published in the Astrophysical Journal (abstract below). The results revealed a fascinating trove of novel X-ray sources: high redshift clusters of galaxies found efficiently; X-ray absorbed, optically clean AGN, which may be the bright prototypes of Chandra Deep Survey sources; and several with a still unknown nature. Recent XMM-Newton results confirm the existence of this class of X-ray source with much refined positions. During the first year of this project we have made a major discovery. The second 'blanks' X-ray source observed with Chandra was found to be extended. Using Chandra data and ground-based R and K band imaging we estimated this to be a high redshift cluster of galaxies with z approx. 0.85. Spectroscopy agrees with this estimate (z=0.89). This success shows that our method of hunting down 'blank' field X-ray sources is a highly efficient method of finding the otherwise elusive high redshift clusters. With extensive follow-up we should be able to use 'blanks' to make cosmological tests. The paper is now in press in the Astrophysical Journal (abstract below.) The other Chandra source is point-like, showing that there are a variety of 'blank' source types. Other follow-up observations with XMM-Newton, and (newly approved in cycle 2) with Chandra are eagerly awaited. A follow-up paper uses a large amount of supporting data for the remaining blanks. A combination of ROSAT, Chandra and ground based data convincingly identified one of the blanks as a Ultra-luminous X-ray source (ULX) in a spiral galaxy (abstract below). This program resulted in 3 refereed papers in major journals, 4 conference proceedings and a significant fraction of the PhD thesis of Dr. Ilaria Cagnoni. Details of the publications are given.

  18. One-Way Coupling of an Advanced CFD Multi-Physics Model to FEA for Predicting Stress-Strain in the Solidifying Shell during Continuous Casting of Steel

    NASA Astrophysics Data System (ADS)

    Svensson, Johan; Ramírez López, Pavel E.; Jalali, Pooria N.; Cervantes, Michel

    2015-06-01

    One of the main targets for Continuous Casting (CC) modelling is the actual prediction of defects during transient events. However, the majority of CC models are based on a statistical approach towards flow and powder performance, which is unable to capture the subtleties of small variations in casting conditions during real industrial operation or the combined effects of such changes leading eventually to defects. An advanced Computational Fluid Dynamics (CFD) model; which accounts for transient changes on lubrication during casting due to turbulent flow dynamics and mould oscillation has been presented on MCWASP XIV (Austria) to address these issues. The model has been successfully applied to the industrial environment to tackle typical problems such as lack of lubrication or unstable flows. However, a direct application to cracking had proven elusive. The present paper describes how results from this advanced CFD-CC model have been successfully coupled to structural Finite Element Analysis (FEA) for prediction of stress-strains as a function of irregular lubrication conditions in the mould. The main challenge for coupling was the extraction of the solidified shell from CFD calculations (carried out with a hybrid structured mesh) and creating a geometry by using iso-surfaces, re-meshing and mapping loads (e.g. temperature, pressure and external body forces), which served as input to mechanical stress-strain calculations. Preliminary results for CC of slabs show that the temperature distribution within the shell causes shrinkage and thermal deformation; which are in turn, the main source of stress. Results also show reasonable stress levels of 10-20 MPa in regions, where the shell is thin and exposed to large temperature gradients. Finally, predictions are in good agreement with prior works where stresses indicate compression at the slab surface, while tension is observed at the interior; generating a characteristic stress-strain state during solidification in CC.

  19. Casting materials

    DOEpatents

    Chaudhry, Anil R.; Dzugan, Robert; Harrington, Richard M.; Neece, Faurice D.; Singh, Nipendra P.

    2011-06-14

    A foam material comprises a liquid polymer and a liquid isocyanate which is mixed to make a solution that is poured, injected or otherwise deposited into a corresponding mold. A reaction from the mixture of the liquid polymer and liquid isocyanate inside the mold forms a thermally collapsible foam structure having a shape that corresponds to the inside surface configuration of the mold and a skin that is continuous and unbroken. Once the reaction is complete, the foam pattern is removed from the mold and may be used as a pattern in any number of conventional casting processes.

  20. Effect of thermal conditions and alloying constituents (Ni, Cr) on macrosegregation in continuously cast high-carbon (0.8 Pct), low-alloy steel

    NASA Astrophysics Data System (ADS)

    Shah, Nitin A.; Moore, John J.

    1989-12-01

    The aim of this study was to investigate the influences of heat transfer, thermal gradient, solidification rate, and the addition of up to 1 pct Ni and 1 pct Cr on the solidification and macrosegregation of high-carbon (0.8 pct), low-alloy steel. Sixteen 13.6-kg laboratory ingots were horizontally and unidirectionally cast in a static moll, fitted on one face with a water-cooled copper chill to simulate a continuous casting mold. Thermocouples, placed in the chill and the mold, were used to calculate heat flux, thermal gradient, and solidification rate. The ingots were examined with respect to macro- and microstructures, distribution of phases, dendrite arm spacing, and solute element distribution. The extent of macrosegregation of carbon and sulfur was determined by wet chemical analysis of drillings, and a TANDEM VAN DE GRAAFF accelerator was used for A1, Si, P, V, S, C, Mn, Ni, and Cu. The extent of macrosegregation of these elements was correlated with heat transfer and thermodynamic distribution coefficient data.

  1. Attachment of Alumina on the Wall of Submerged Entry Nozzle During Continuous Casting of Al-Killed Steel

    NASA Astrophysics Data System (ADS)

    Deng, Zhiyin; Zhu, Miaoyong; Zhou, Yelian; Sichen, Du

    2016-06-01

    The mechanisms of the formation of different attachments on the walls of submerged entry nozzle (SEN) were studied for the processes of Al-killed steel (Ca-treated, HSLA) and ultra-low carbon Al-killed steel (ULC). To understand the mechanism, the types of inclusions in the steel taken in tundish and in bloom (or slab) were identified. In the case of ULC, the reoxidation product, micro-alumina particles were found to be the source of attachment on the inner wall of the SEN. To avoid reoxidation of the steel by the top slag, removal of the slag could be considered in order to improve the situation. No attached layer was found on the outer surface of the SEN after casting of the ULC steel. In the case of HSLA steel, an attached layer composed of plate-like alumina crystals was found in some trials. The entrainment of oxygen through the mold powder due to improper operation would be the reason for the formation of this type of attachment. The formation of the plate-like crystals was discussed with the help of CFD calculation.

  2. Validation of a systematic approach to modeling spray quenching of aluminum alloy extrusions, composites, and continuous castings

    SciTech Connect

    Hall, D.D.; Mudawar, I.; Morgan, R.E.; Ehlers, S.L.

    1997-02-01

    Optimal cooling of aluminum alloys following the high-temperature extrusion process suppresses precipitation of intermetallic compounds and results in a part capable of possessing maximum strength and hardness after the subsequent age-hardening process. Rapid quenching suppresses precipitation but can lad to large spatial temperature gradients in complex-shaped parts, causing distortion, cracking, high residual stress, and/or nonuniform mechanical properties. Conversely, slow cooling significantly reduces or eliminates these undesirable conditions but allows considerable precipitation, resulting in low strength, soft spots, and/or low corrosion resistance. This study presents a systematic method of locating and operating multiple spray nozzles for any shaped extrusion such that uniform, rapid cooling and superior mechanical and metallurgical properties are achieved. New correlations, offering increased accuracy and less computational time, were formulated for the high-temperature boiling regimes which have a critical influence on final mechanical properties. The quench factor technique related predicted thermal history to metallurgical transformations occurring within the extrusion to predict hardness distribution. The validity of this unique approach was demonstrated by comparing model predictions to the temperature response (and hardness after artificial aging) of an L-shaped Al2024-T6 extrusion to quenches with multiple, overlapping water sprays. The validation study reported herein concludes by exploring the possibility of applying quenching technology to improving the properties of extruded metal-matrix composites such as SiC{sub p}/Al6061 and cast alloys.

  3. Attachment of Alumina on the Wall of Submerged Entry Nozzle During Continuous Casting of Al-Killed Steel

    NASA Astrophysics Data System (ADS)

    Deng, Zhiyin; Zhu, Miaoyong; Zhou, Yelian; Sichen, Du

    2016-02-01

    The mechanisms of the formation of different attachments on the walls of submerged entry nozzle (SEN) were studied for the processes of Al-killed steel (Ca-treated, HSLA) and ultra-low carbon Al-killed steel (ULC). To understand the mechanism, the types of inclusions in the steel taken in tundish and in bloom (or slab) were identified. In the case of ULC, the reoxidation product, micro-alumina particles were found to be the source of attachment on the inner wall of the SEN. To avoid reoxidation of the steel by the top slag, removal of the slag could be considered in order to improve the situation. No attached layer was found on the outer surface of the SEN after casting of the ULC steel. In the case of HSLA steel, an attached layer composed of plate-like alumina crystals was found in some trials. The entrainment of oxygen through the mold powder due to improper operation would be the reason for the formation of this type of attachment. The formation of the plate-like crystals was discussed with the help of CFD calculation.

  4. Optimization of a Six-Strand Continuous Casting Tundish: Industrial Measurements and Numerical Investigation of the Tundish Modifications

    NASA Astrophysics Data System (ADS)

    Merder, Tomasz; Warzecha, Marek

    2012-08-01

    The main differences in the transient zone extent between the individual strands for the former industrial six-strand tundish configuration is the basis for undertaking this study. The aim this study was to improve the casting conditions by proposing the optimal equipment of the tundish working space. For economic reasons, only the variants with different baffles configurations were considered. It was also dictated by the simplicity of construction and the possibility of its implementation by the base operating steel mill. In the current study, industrial plant measurements and mathematical modeling were used. Industrial experimental data were used to diagnose the current state of the industrial tundish and then validate the numerical simulations. After this, the influence of different baffle configurations installed in the tundish on the steel flow characteristic was modeled mathematically. Residence time distribution (RTD) curves are plotted, and individual flow shares for the investigated tundish were estimated based on the curves. Finally, the industrial plant was rebuilt according to the numerical results and additional plant measurements were performed. A result of the appearance of the baffles in the tundish working space was the reduction of the transient zone extent. The results indicate the increasing share of the dispersed plug flow and a decreasing share of the dead volume flow, with a practically unchanging share of well-mixed volume flow in the modified tundish.

  5. Hydroforming Of Patchwork Blanks — Numerical Modeling And Experimental Validation

    NASA Astrophysics Data System (ADS)

    Lamprecht, Klaus; Merklein, Marion; Geiger, Manfred

    2005-08-01

    In comparison to the commonly applied technology of tailored blanks the concept of patchwork blanks offers a number of additional advantages. Potential application areas for patchwork blanks in automotive industry are e.g. local reinforcements of automotive closures, structural reinforcements of rails and pillars as well as shock towers. But even if there is a significant application potential for patchwork blanks in automobile production, industrial realization of this innovative technique is decelerated due to a lack of knowledge regarding the forming behavior and the numerical modeling of patchwork blanks. Especially for the numerical simulation of hydroforming processes, where one part of the forming tool is replaced by a fluid under pressure, advanced modeling techniques are required to ensure an accurate prediction of the blanks' forming behavior. The objective of this contribution is to provide an appropriate model for the numerical simulation of patchwork blanks' forming processes. Therefore, different finite element modeling techniques for patchwork blanks are presented. In addition to basic shell element models a combined finite element model consisting of shell and solid elements is defined. Special emphasis is placed on the modeling of the weld seam. For this purpose the local mechanical properties of the weld metal, which have been determined by means of Martens-hardness measurements and uniaxial tensile tests, are integrated in the finite element models. The results obtained from the numerical simulations are compared to experimental data from a hydraulic bulge test. In this context the focus is laid on laser- and spot-welded patchwork blanks.

  6. Evaluation and improvement in the accuracy of a charge-coupled-device-based pyrometer for temperature field measurements of continuous casting billets

    NASA Astrophysics Data System (ADS)

    Bai, Haicheng; Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei

    2013-06-01

    This paper presents a radiometric high-temperature field measurement model based on a charge-coupled-device (CCD). According to the model, an intelligent CCD pyrometer with a digital signal processor as the core is developed and its non-uniformity correction algorithm for reducing the differences in accuracy between individual pixel sensors is established. By means of self-adaptive adjustment for the light-integration time, the dynamic range of the CCD is extended and its accuracy in low-temperature range is improved. The non-uniformity correction algorithm effectively reduces the accuracy differences between different pixel sensors. The performance of the system is evaluated through a blackbody furnace and an integrating sphere, the results of which show that the dynamic range of 400 K is obtained and the accuracy in low temperature range is increased by 7 times compared with the traditional method based on the fixed light-integration time. In addition, the differences of accuracy between the on-axis pixel and the most peripheral pixels are decreased from 19.1 K to 2.8 K. Therefore, this CCD pyrometer ensures that the measuring results of all pixels tend to be equal-accuracy distribution across the entire measuring ranges. This pyrometric system has been successfully applied to the temperature field measurements in continuous casting billets.

  7. Effects of Fe content on the microstructure and properties of CuNi10FeMn1 alloy tubes fabricated by HCCM horizontal continuous casting

    NASA Astrophysics Data System (ADS)

    Jiang, Yan-bin; Xu, Jun; Liu, Xin-hua; Xie, Jian-xin

    2016-04-01

    Heating-cooling combined mold (HCCM) horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuNi10FeMn1 alloy tubes with different Fe contents. The effects of Fe content (1.08wt%-2.01wt%) on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.

  8. Transient Two-Phase Flow in Slide-Gate Nozzle and Mold of Continuous Steel Slab Casting with and without Double-Ruler Electro-Magnetic Braking

    NASA Astrophysics Data System (ADS)

    Cho, Seong-Mook; Thomas, Brian G.; Kim, Seon-Hyo

    2016-07-01

    Transient mold flow could produce undesirable surface instabilities and slag entrainments, leading to the formation of defects during continuous slab casting of steel. In this work, two Large Eddy Simulations coupled with Discrete Phase Model are run, with and without MagnetoHydroDynamic model, to gain new insights into the surface variations of molten steel-argon gas flow with anisotropic turbulence in the slide-gate nozzle and the mold, with and without double-ruler Electro-Magnetic Braking (EMBr). The model calculations are validated with plant measurements, and applied to investigate the flow variations related to the slide gate on nozzle swirl, jet wobbling, and surface flow variations by quantifying the variations of velocity, horizontal angle, and vertical angle of the transient flow. Transient flow in the slide-gate nozzle bottom is almost always swirling, alternating chaotically between clockwise and counter-clockwise rotation. The clockwise swirl, caused by stronger flow down the same side of the nozzle as the open area near the Outside Radius side of the slide-gate middle plate, produces faster jet flow and higher velocity flow across the top surface of the mold. Counter-clockwise swirl produces slower jet and surface flow, but with more variations. The double-ruler EMBr decreases the asymmetry and duration of velocity variations during nozzle swirl flipping, resulting in less flow variations in the jet and across the surface in the mold.

  9. Trials at Clemson University, SC of method for continuous casting of non-ferrous strips: Final report, June 28--August 6, 1987

    SciTech Connect

    Palmer, F.M.

    1987-09-16

    This project was an attempt to prove a process using a metered flow of molten metal onto two counter-rotating drums, near their apexes, which when semi-solidified and carried over to the gap between the two drums would form a thin continuous strip. Such a strip could be fortified with filaments or whiskers to manufacture metal matrix composites at lowered cost. Preliminary work with lead had demonstrated that relatively simple equipment and procedures would produce strip on one drum with an adequate surface on the side contacting the drum. It was, therefore, expected that two drum casting could be used to produce strip with an adequate surface on both sides and that the process could be adapted for aluminum using the same equipment. The original plan had been to carry out the work in the foundry facility at Pennsylvania State University during 1986. However, various delays occurred, and when the sponsoring professor, Dr. Alan B. Draper, died, it was decided to move the project to Clemson University, SC, which had aluminum melting facilities, and to carry out the work during the summer of 1987. 4 figs.

  10. The Effect of Fe Content on Recrystallization Texture Evolution, Microstructures, and Earing of Cold Rolled Continuous Cast AA5052 Alloy Sheets

    NASA Astrophysics Data System (ADS)

    Wen, Xiyu; Wen, Wei; Zhang, Yuanbin; Xu, Bin; Zeng, Qiang; Liu, Yansheng; Tong, Lirong; Zhai, Tongguang; Li, Zhong

    2016-04-01

    Continuous cast AA5052 Al alloys, containing iron contents of 0.120 and 0.466 wt pct, respectively, were cold rolled and annealed at temperatures ranging from 505 K to 755 K (232 °C to 482 °C). The recrystallization textures in the two alloys were analyzed using X-ray diffraction and electron back scatter diffraction, respectively. It was found that higher Fe content promoted the formation of deformation textures and retarded the formation of cube texture in the two alloys. Most cube-oriented grains formed in both these alloys were associated with coarse particles, whereas the P—{011}<566>, R—{123}<634>, and Goss or randomly oriented grains were often related to particle stringers consisted of fine particles along the rolling direction. It was also found that the volume fraction of each texture component was a Johnson-Mehl-Avrami-Kolmogorov-type function of annealing temperature in the two alloys. The texture evolution rate with the annealing temperature was calculated from this function and used to determine the onset temperature of each recrystallization texture component.

  11. Novel acid-free cleaning process for mask blanks

    NASA Astrophysics Data System (ADS)

    Koster, Harald; Branz, Karsten; Dietze, Uwe; Dress, Peter; Hess, Guenter

    2005-06-01

    Knowledge of particle removal during the mask cleaning was transferred to the blank cleaning and vice versa. The experiments are focusing on a variety of blank substrates (glass substrates, chrome on glass blanks and phase shift mask blanks substrates). The principal equipment concept and the process optimization strategies for cleaning of those different kinds of blank substrates are presented. With a fixed process flow, including UV-treatment, Fulljet and MegaSonic treatment, Rinse and Dry, process parameters are varied to define the optimum process conditions. Criteria for an optimum process are particle removal efficiency in general and optical integrity for phase shift mask blanks in particular. The particle removal efficiency for all investigated blank types is within a range of 96-100%. Especially for Ta/SiO2 phase shift mask blanks we demonstrate that during the cleaning process the optical properties only change by 0.07° phase loss and 0.01% transmission loss per cleaning cycle, respectively.

  12. Forming of tailor-welded blanks

    NASA Astrophysics Data System (ADS)

    Saunders, F. I.; Wagoner, R. H.

    1996-09-01

    Beginning in 1992, tailor-welded blanks (TWBs) were used in the United States automotive industry to consolidate parts, reduce tolerances, save weight, and increase stiffness. This business is expanding rapidly; more than 500 million of annual TWB sales are expected by 1997. Welds in steel are generally stronger than the base material, such that weld failure by preferential localization is not a critical issue. However, the forming characteristics of TWBs must be understood in order to design and produce high-quality parts with reasonable production and tooling costs. Three formability issues were addressed in this study: the intrinsic ductility and relative formability of three weld types (CO2 and Nd:YAG laser welds and mash-seam welds with and without mechanical postweld processing); the value and correspondence of mechanical tests to each other and to press performance; and the prediction of the forming behavior using the finite element method (FEM). Two failure modes for TWBs were identified. While the local ductility of welds can differ greatly, little difference in press formability was measured among the weld types. More important than weld ductility are the changed deformation patterns which depend on the differential strength but depend little on local weld prop-erties. Finite element method (FEM) simulations of dome tests and scale fender-forming operations show good agreement with measurements, as long as boundary conditions are known accurately. The importance of weld-line displacement is discussed and several simulations are compared with ex-periments.

  13. Blank fire configuration for automatic pistol

    DOEpatents

    Teague, Tommy L.

    1990-01-01

    A pistol configured to fire blank cartridges includes a modified barrel with a breech portion connected to an aligned inner sleeve. Around the inner sleeve, there is disposed an outer sleeve having a vent therein through which the cartridge discharges. The breech portion is connected to a barrel anchor to move backward in a slight arc when the pistol is fired. A spring retention rod projects from the barrel anchor and receives a shortened recoil spring therearound which recoil spring has one end abutting a stop on the barrel anchor and the other end in abutment with the end of a spring retaining cup. The spring retaining cup is engaged by a flange projecting from a slide so that when the pistol is fired, the slide moves rearwardly against the compression of the spring to eject the spent cartridge and then moves forwardly under the urging of the spring to load a fresh cartridge into the breech portion. The spring then returns all of the slidable elements to their initial position so that the pistol may again be fired.

  14. Blank fire configuration for automatic pistol

    SciTech Connect

    Teague, T.L.

    1990-03-13

    This patent describes a pistol configured to fire blank cartridges that includes a modified barrel with a breech portion connected to an aligned inner sleeve. Around the inner sleeve, there is disposed an outer sleeve having a vent therein through which the cartridge discharges. The breech portion is connected to a barrel anchor to move backward in a slight arc when the pistol is fired. A spring retention rod projects from the barrel anchor and receives a shortened recoil spring therearound which recoil spring has one end abutting a stop on the barrel anchor and the other end in abutment with the end of a spring retaining cup. The spring retaining cup is engaged by a flange projecting from a slide so that when the pistol is fired, the slide moves rearwardly against the compression of the spring to eject the spent cartridge and then moves forwardly under the urging of the spring to load a fresh cartridge into the breech portion. The spring then returns all of the slidable elements to their initial position so that the pistol may again be fired.

  15. Blank fire configuration for automatic pistol

    SciTech Connect

    Teague, T.L.

    1988-08-31

    A pistol configured to fire blank cartridges includes a modified barrel with a breach portion connected to an aligned inner sleeve. Around the inner sleeve, there is disposed an outer sleeve having a vent therein through which the cartridge discharges. The breach portion is connected to a barrel anchor to move backward in a slight arc when the pistol is fired. A spring retaining rod projects from the barrel anchor and receives a coiled recoil spring therearound which recoil spring has one end abutting a stop on the barrel anchor and the other end in abutment with the end of a spring retaining cup. The spring retaining cup is engaged by a flange projecting from the slider so that when the pistol is fired, the slider moves rearwardly against the compression of the spring to eject the spent cartridge and then moves forwardly under the urging of the spring to load a fresh cartridge into the breach portion. The spring then returns all of the slidable elements to their initial position so that the pistol may again be fired. 4 figs.

  16. Failure Prediction in Fine Blanking Process with Stress Limit Model

    NASA Astrophysics Data System (ADS)

    Tong, Longchang; Manopulo, Niko; Hora, Pavel

    2010-06-01

    Extremely small blanking clearance and nearly sharp edges of blanking tool are the characteristics of fine blanking that produces near net shape parts. The extreme forming conditions make the failure prediction for fine blanking more difficult than for ordinary forming processes. Stress Limit Criterion (SLC) is adopted in this work to perform the failure prediction of 3D fine blanking process. In comparison with the stress triaxiality diagram, SLC is not sensitively affected by complex nonlinear deformation paths and can perform the task as well. However, the parameters that support the model have to be obtained with combination of dedicatedly designed experiments and numerical simulation. The FEM simulation must also be able to provide stable and reliable results.

  17. Electroslag melting of tubular blanks with a curvilinear axis

    SciTech Connect

    Alikin, A.P.; Parshutin, I.A.; Fomin, A.S.; Sidorov, V.M.

    1987-03-01

    The authors propose a new method for replacing the current method for the fabrication of a pipeline bend which involves separate pressing followed by subsequent welding of the two halves of the bend. Their method consists of continuous electroslag casting of the bend. They conduct a comparative analysis which demonstrates the reduction in labor and energy intensity of their method over the old method and also carry out ultrasonic and mechanical tests to validate the reduction in defects and the increase in mechanical properties in which their method results.

  18. Production of the 4.26 m ZERODUR mirror blank for the Advanced Technology Solar telescope (ATST)

    NASA Astrophysics Data System (ADS)

    Jedamzik, Ralf; Werner, Thomas; Westerhoff, Thomas

    2014-07-01

    The Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope, ATST) will be the most powerful solar telescope in the world. It is currently being built by the Association of Universities for Research in Astronomy (AURA) in a height of 3000 m above sea level on the mountain Haleakala of Maui, Hawaii. The primary mirror blank of diameter 4.26 m is made of the extremely low thermal expansion glass ceramic ZERODUR® of SCHOTT AG Advanced Optics. The DKIST primary mirror design is extremely challenging. With a mirror thickness of only 78 to 85 mm it is the smallest thickness ever machined on a mirror of 4.26 m in diameter. Additionally the glassy ZERODUR® casting is one of the largest in size ever produced for a 4 m class ZERODUR® mirror blank. The off axis aspherical mirror surface required sophisticated grinding procedures to achieve the specified geometrical tolerance. The small thickness of about 80 mm required special measures during processing, lifting and transport. Additionally acid etch treatment was applied to the convex back-surface and the conical shaped outer diameter surface to improve the strength of the blank. This paper reports on the challenging tasks and the achievements on the material property and dimensional specification parameter during the production of the 4.26 m ZERODUR® primary mirror blank for AURA.

  19. The Development of CaO-SiO2-B2O3-based Fluorine-Free Mold Flux for a Continuous Casting Process

    NASA Astrophysics Data System (ADS)

    Zhou, Lejun; Wang, Wanlin

    2016-05-01

    Designing and developing high-performance fluorine-free (F-free) mold flux has become a hot topic in steel continuous casting processes, with concerns of environment protection and energy saving. In conventional commercial mold flux, fluorine plays important roles on the properties as it works as a fluxing agent; however, it tends to cause serious environmental and health problems. In this paper, a new F-free mold flux based on the CaO-SiO2-B2O3 slag system has been introduced through summarizing previous works. The melting temperature range of F-free mold flux decreases with the addition of Na2O/Li2O and B2O3; the viscosity and heat flux decrease with the increase of basicity and Na2O/Li2O, as well as the decrease of B2O3 contents. Also, the crystallization temperatures of F-free mold fluxes increase with the increase of basicity and Na2O/Li2O content. The analyses of EDS and XRD show that Ca11Si4B2O22 and Ca14Mg2(SiO4)8 are the two main precipitated crystalline phases in F-free mold fluxes, and that the Ca11Si4B2O22 is a common and stable crystalline phase in the designed F-free mold fluxes system that shows the potential to replace Ca4Si2O7F2 in conventional flourine-containing mold fluxes.

  20. Mathematical Modeling on the Growth and Removal of Non-metallic Inclusions in the Molten Steel in a Two-Strand Continuous Casting Tundish

    NASA Astrophysics Data System (ADS)

    Ling, Haitao; Zhang, Lifeng; Li, Hong

    2016-07-01

    In the current study, mathematical models were developed to predict the transient concentration and size distribution of inclusions in a two-strand continuous casting tundish. The collision and growth of inclusions were considered. The contribution of turbulent collision and Stokes collision was evaluated. The removal of inclusions from the top surface was modeled by considering the properties of inclusions and the molten steel, such as the wettability, density, size, and interfacial tension. The effect of composition of inclusions on the collision of inclusions was included through the Hamaker constant. Meanwhile, the effect of the turbulent fluctuation velocity on the removal of inclusions at the top surface was also studied. Inclusions in steel samples were detected using automatic SEM Scanning so that the amount, morphology, size, and composition of inclusions were achieved. In the simulation, the size distribution of inclusions at the end steel refining was used as the initial size distribution of inclusions at tundish inlet. The equilibrium time when the collision and coalescence of inclusions reached the steady state was equal to 3.9 times of the mean residence time. When Stokes collision, turbulent collision, and removal by floating were included, the removal fraction of inclusions was 16.4 pct. Finally, the removal of solid and liquid inclusions, such as Al2O3, SiO2, and 12CaO·7Al2O3, at the interface between the molten steel and slag was studied. Compared with 12CaO·7Al2O3 inclusions, the silica and alumina inclusions were much easier to be removed from the molten steel and their removal fractions were 36.5 and 39.2 pct, respectively.

  1. Mold Simulator Study of the Initial Solidification of Molten Steel in Continuous Casting Mold: Part II. Effects of Mold Oscillation and Mold Level Fluctuation

    NASA Astrophysics Data System (ADS)

    Zhang, Haihui; Wang, Wanlin

    2016-04-01

    The surface quality of the continuous casting strands is closely related to the initial solidification of liquid steel in the vicinity of the mold meniscus, and thus the clear understanding of the behavior of molten steel initial solidification would be of great importance for the control of the quality of final slab. With the development of the mold simulator techniques, the complex interrelationship between the solidified shell surface profile, heat flux, shell thickness, mold level fluctuation, and the infiltrated slag film was well illustrated in our previous study. As the second part, this article investigated the effect of the mold oscillation frequency, stroke, and mold level fluctuation on the initial solidification of the molten steel through the conduction of five different experiments. Results suggested that in the case of the stable mold level, the oscillation marks (OMs) exhibit equally spaced horizon depressions on the shell surface, where the heat flux at the meniscus area raises rapidly during negative strip time (NST) period and the presence of each OMs on the shell surface is corresponding to a peak value of the heat flux variation rate. Otherwise, the shell surface is poorly defined by the existence of wave-type defects, such as ripples or deep depressions, and the heat flux variation is irregular during NST period. The rising of the mold level leads to the longer-pitch and deeper OMs formation; conversely, the falling of mold level introduces shorter-pitch and shallower OMs. With the increase of the mold oscillation frequency, the average value of the low-frequency heat flux at the meniscus increases; however, it decreases when the mold oscillation stroke increases. Additionally, the variation amplitude of the high-frequency temperature and the high-frequency heat flux decreases with the increase of the oscillation frequency and the reduction of the oscillation stroke.

  2. Ladle and Continuous Casting Process Models for Reduction of SiO2 in SiO2-Al2O3-CaO Slags by Al in Fe-Al(-Si) Melts

    NASA Astrophysics Data System (ADS)

    Park, Jiwon; Sridhar, S.; Fruehan, Richard J.

    2015-02-01

    Based on a mixed control or two-phase mass transfer model considering mass transport in the metal and the slag phases, process models for ladle and continuous castor mold were developed to predict the changes in the metal and the slag chemistry and viscosity. In the ladle process model, the rate of reaction is primarily determined by stirring gas flow rate, which greatly alters the mass transports of the metal and the slag phases. In the continuous casting process model, the effects of the Al, Si, and SiO2 contents in the incoming flow of the fluid phases, casting speed, mold flux consumption rate, and depth of the liquid mold flux pool on the steady-state compositions of the metal and the mold flux were assessed.

  3. 2. D Street facade and rear (east) blank wall of ...

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

    2. D Street facade and rear (east) blank wall of parking garage. Farther east is 408 8th Street (National Art And Frame Company). - PMI Parking Garage, 403-407 Ninth Street, Northwest, Washington, District of Columbia, DC

  4. 12. BUILDING 227. BLANK AMMUNITION LOADING PLANT. ELEVATIONS AND SECTIONS. ...

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

    12. BUILDING 227. BLANK AMMUNITION LOADING PLANT. ELEVATIONS AND SECTIONS. November 1, 1940 - Frankford Arsenal, Building No. 227, South side of Hagner Road between Ripley & Mellon Streets, Philadelphia, Philadelphia County, PA

  5. Numerical Simulation of the Fluid Flow, Heat Transfer, and Solidification During the Twin-Roll Continuous Casting of Steel and Aluminum

    NASA Astrophysics Data System (ADS)

    Xu, Mianguang; Zhu, Miaoyong

    2016-02-01

    The commercialization of aluminum twin-roll casting was realized in the early 1950s, while it is still a dream for engineers to produce steel strip by this process. In the present paper, a two-dimensional mathematical model is employed to study the fluid flow, heat transfer, and solidification during the twin-roll casting for both steel and aluminum. The turbulent flow in the pool is examined using the Lam and Bremhorst low-Reynolds-number turbulence model. In order to facilitate the comparison and analysis, a new transformed coordinate system ( r, φ) is established. Characteristics of the momentum boundary layer and the solidification front are described. Reasons of the formation of the wedge-shaped zone near the surface of rotating roll are given. In the transformed coordinate system ( r, φ), the effect of the centrifugal force induced by the rotating roll is presented using the velocity component in the r direction and the pressure gradient in the r direction. At last, the evaluation of the solidified shell in the pool is analyzed. The results show that the twin-roll casting is a roll-rotating-driven process. The variation of the thickness of the momentum boundary layer can be divided into three stages and its thickness is very uniform at the last stage. Near the roll surface, there exists a wedge-shaped zone induced by the near-roll-surface shear flow that washes the mushy zone front, which increases the depth of the liquid pool and decreases the length of the rolling region. The rotating roll gives rise to the stirring effect to the pool region and the metal is moving away from the roll surface in the positive radial velocity region, and the effect of the centrifugal force becomes weak in the lower part of the pool. At the solidification front, the non-dimensional effective heat transfer coefficient distribution in steel twin-roll casting is larger than that in aluminum twin-roll casting. Considering that the turbulence level is determined by the flow

  6. Determinants of attentive blank stares. An EFRP study.

    PubMed

    Fudali-Czyż, Agnieszka; Francuz, Piotr; Augustynowicz, Paweł

    2014-10-01

    Attentive blank stares mean a failure to notice changes in a visual scene, despite looking at the area of change (Caplovitz, Fendrich, & Hughes, 2008). In this research project we have shown that people differ in terms of attentive blank stare incidences. Novices tend to fail to notice changes in the target area more often than experts. This effect is greater in persons with low visual working memory capacity (VWMC) than with high VWMC. In addition, in a group of novices with low VWMC, attentive blank stares are more frequent compared to a group with high VWMC. Attentive blank stares did not disappear even after the high VWMC group were given expertise training. With the method of eye-fixation-related potentials (EFRP) we analyzed the amplitude of lambda response, which may reflect the state of the attentional system, during encoding information about a change, prior to a decision whether a change has occurred or not. We demonstrate that the cases of attentive blank stares are accompanied by significantly lower amplitude of the lambda response compared with cases involving change detection. In addition, we discovered greater lambda responses in a group with expertise who noticed the change than in novices. The EFRP record coming from occipital electrodes in the 80-180ms window function was marked by left-sided asymmetry in the cases of change detection and by right-sided asymmetry in the cases of attentive blank stares. PMID:25087155

  7. Elemental segregation and subsequent precipitation during solidification of continuous cast Nb–V–Ti high-strength low-alloy steels

    SciTech Connect

    Zheng, Shuguo; Davis, Claire; Strangwood, Martin

    2014-09-15

    In this study, elemental segregation during solidification and subsequent precipitation behaviour in a continuous cast Nb–V–Ti high-strength low-alloy steel was investigated by optical microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and thermodynamic modelling. It is known that for steels with low carbon contents the pearlite that forms on slow cooling does so where the interdendritic liquid was present prior to final solidification. The alloying elements of Nb, Ti, Mn and V segregate into the interdendritic liquid during solidification, while Al preferentially segregates into the solidifying solid phase. The composition analysis on the slab samples verified the predicted element segregation behaviour, with a smaller difference in the concentrations of Mn and V in the pearlite and dendritic ferrite regions being observed compared to the Nb levels. Small (30–100 nm) spherical or irregular shaped Nb-rich precipitates (Nb(C, N) and (Nb, V)(C, N)) were mainly found in the pearlite regions, while angular Al-rich (60–300 nm) precipitates were found in the dendritic ferrite regions, in the form of AlN and complex AlN–V(C, N) precipitates. Small isolated ferrite regions surrounded by pearlite were observed in the microstructure and has two origins: one type is dendritic ferrite that appears as an isolated island due to a sectioning effect when observing the two-dimensional microstructure; the other is a ferrite idiomorph that forms in the interdendritic region due to the low carbon content of the steel. Accordingly, in these isolated ferrite islands two different precipitation behaviours are found; predominantly Al-rich particles in the dendritic regions or predominantly Nb-rich precipitates in the interdendritic ferrite idiomorphs. No Al-rich precipitates were observed in the interdendritic regions (pearlite or isolated ferrite idiomorphs) despite the Thermo-Calc predictions indicating a higher volume fraction of AlN in these

  8. Pigmented casts.

    PubMed

    Miteva, Mariya; Romanelli, Paolo; Tosti, Antonella

    2014-01-01

    Pigmented casts have been reported with variable frequency in scalp biopsies from alopecia areata, trichotillomania, chemotherapy-induced alopecia and postoperative (pressure induced) alopecia. Their presence and morphology in other scalp disorders has not been described. The authors assessed for the presence and morphology of pigmented casts in 308 transversely bisected scalp biopsies from nonscarring and scarring alopecia, referred to the Department of Dermatology, University of Miami within a year. The pigmented casts were present in 21 of 29 cases of alopecia areata (72%), 7 of 7 cases of trichotillomania (100%), 1 case of friction alopecia, 4 of 28 cases of central centrifugal cicatricial alopecia (14%), and 4 of 4 cases of dissecting cellulitis (100%). They did not show any distinguishing features except for the morphology in trichotillomania, which included twisted, linear (zip), and "button"-like pigment aggregation. The linear arrangement was found also in friction alopecia and dissecting cellulitis. Pigmented casts in the hair canals of miniaturized/vellus hairs was a clue to alopecia areata. Pigmented casts can be observed in biopsies of different hair disorders, but they are not specific for the diagnosis. Horizontal sections allow to better assess their morphology and the follicular level of presence of pigmented casts, which in the context of the other follicular findings may be a clue to the diagnosis. PMID:23823025

  9. Seeing Red and Shooting Blanks: A Study of Red Quasars And Blank Field X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald J. (Technical Monitor); Elvis, Martin

    2003-01-01

    The primary source catalog of 'blanks' (bright ROSAT sources with no optical counterparts) has been published in the Astrophysical Journal. The first follow-up paper has also been published. This paper used a combination of ROSAT, Chandra and ground based data to convincingly identify one of the blanks as a Ultra-luminous X-ray source (ULX) in a spiral galaxy. A paper detailing optical and near-IR imaging observations of the remaining sources is underway.

  10. Actinic defect counting statistics over 1 cm2 area of EUVL mask blank

    SciTech Connect

    Jeong, Seongtae; Lai, Chih-Wei; Rekawa, Seno; Walton, Chris W.; Bokor, Jeffrey

    2000-02-18

    As a continuation of comparison experiments between EUV inspection and visible inspection of defects on EUVL mask blanks, we report on the result of an experiment where the EUV defect inspection tool is used to perform at-wavelength defect counting over 1 cm{sup 2} of EUVL mask blank. Initial EUV inspection found five defects over the scanned area and the subsequent optical scattering inspection was able to detect all of the five defects. Therefore, if there are any defects that are only detectable by EUV inspection, the density is lower than the order of unity per cm2. An upgrade path to substantially increase the overall throughput of the EUV inspection system is also identified in the manuscript.

  11. High-throughput automatic defect review for 300mm blank wafers with atomic force microscope

    NASA Astrophysics Data System (ADS)

    Zandiatashbar, Ardavan; Kim, Byong; Yoo, Young-kook; Lee, Keibock; Jo, Ahjin; Lee, Ju Suk; Cho, Sang-Joon; Park, Sang-il

    2015-03-01

    While feature size in lithography process continuously becomes smaller, defect sizes on blank wafers become more comparable to device sizes. Defects with nm-scale characteristic size could be misclassified by automated optical inspection (AOI) and require post-processing for proper classification. Atomic force microscope (AFM) is known to provide high lateral and the highest vertical resolution by mechanical probing among all techniques. However, its low throughput and tip life in addition to the laborious efforts for finding the defects have been the major limitations of this technique. In this paper we introduce automatic defect review (ADR) AFM as a post-inspection metrology tool for defect study and classification for 300 mm blank wafers and to overcome the limitations stated above. The ADR AFM provides high throughput, high resolution, and non-destructive means for obtaining 3D information for nm-scale defect review and classification.

  12. Amplitude blanking in seismic profiles from Lake Baikal

    USGS Publications Warehouse

    Lee, M.W.; Agena, W.F.; Hutchinson, D.R.

    1996-01-01

    Imaging of the deepest sedimentary section in Lake Baikal using multichannel seismic profiling was hampered by amplitude blanking that is regionally extensive, is associated with water depths greater than about 900 m and occurs at sub-bottom depths of 1-2 km in association with the first water-bottom multiple. Application of a powerful multiple suppression technique improved the quality of occasional discontinuous, dipping primary reflections, but failed to substantially alter the non-reflective character of the blanking zone. Detailed analysis of amplitudes from original data and synthetic models show that the threshold for detecting primary energy in deep water of Lake Baikal occurs when the primary is about 14-20 dB less than the multiple energy. The blanking occurs because of anomalously low reflectivities of the deep sediments coupled with this 20 dB limitation in real data processing. The blanking cuts across seismic stratal boundaries, and is therefore probably unrelated to depositional lithologies. The deepest, early rift deposits, inferred to come from a mixed fluvial and lacustrine setting, do not easily explain the widespread and uniform character of the blanked deposits. More likely, blanking occurs because of processes or phenomena that physically alter the deposits, causing them to be non-reflective and/or highly attenuating. No single process explains all the observations, but a combination of diagenesis, overpressure, and the presence of dispersed free gas at sub-bottom depths of 1-2 km, offer plausible and possible conditions that contribute to blanking. Copyright ?? 1996 Published by Elsevier Science Ltd.

  13. Experimental and Numerical Study on Blanking Process with Negative Clearance

    NASA Astrophysics Data System (ADS)

    Hirota, Kenji; Yanaga, Hiroki; Fukushima, Katsunori

    This study summarizes the characteristics of blanking behavior with a negative clearance. Several experiments were performed for two aluminum sheets over a wide range of clearances including negative values. Blanking with negatively large clearances was found to produce fine cut edges with less roll-over and no fracture zone even for a brittle material. Corresponding simulations were performed using the Ayada's criterion for predicting ductile fracture initiation. Each zone of blanked part edges such as roll-over and fractured zone agreed well with that obtained in the experiments except a few cases accompanied by secondary shear. The reason for prevention of fracture by using negative clearances was explained with the change of the damage value during the process; the damage value was kept low throughout the blanking operation since the mean stress dominating the damage value became compressive around the die edge. Influences of blanking parameters on load-stroke curves were also investigated. The curves for negative clearances showed gradual increase in load toward the end of stroke. The earlier fracture initiated, the earlier the load reached a peak. Simulated curves showed the same tendency and in good agreement with the experimental ones quantitatively.

  14. 47 CFR 73.646 - Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal. 73.646 Section 73.646 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Television Broadcast Stations § 73.646 Telecommunications Service on...

  15. Seeing Red and Shooting Blanks: A Study of Red Quasars and Blank Field X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    We have identified a population of 'blank field sources' (or 'blanks') among the ROSAT (Roentgen Satellite) bright unidentified X-ray sources with faint optical counterparts. The extreme X-ray over optical flux ratio of blank field sources is not compatible with the main classes of X-ray emitters except for extreme BL Lacertae objects at fx/fv is equal to or less than 35. From the analysis of ROSAT archival data we found evidence for only three sources, out of 16, needing absorption in excess of the Galactic value and no indication of variability. We also found evidence for an extended nature for only one of the five blanks with a serendipitous HRI (High Resolution Imager) detection; this source (1WGA J1226.9+3332) was confirmed as a z=0.89 cluster of galaxies. Palomar images reveal the presence of a red (O - E is equal to or greater than 2) counterpart in the X-ray error circle for six blanks. The identification process brought to the discovery of another high z cluster of galaxies, one (possibly extreme) BL Lac and two apparently normal type 1 AGNs (Active Galactic Nuclei). These AGNs, together with four more AGN-like objects seem to form a well defined group: they present type 1 X-ray spectra but red Palomar counterparts. We discuss the possible explanations for the discrepancy between the X-ray and optical data, among which: a suppressed big blue bump emission, an extreme dust to gas (approximately 40 - 60 the Galactic ratio) ratio value and a high redshift (z is greater than or equal to 3.5) QSO (Quasi-Stellar Object) nature. These AGN-like blanks seem to be the bright (and easier to study) analogs of the sources which are being found in deep Chandra observations. Five more blanks have a still an unknown nature.

  16. NHEXAS PHASE I REGION 5 STUDY--QA ANALYTICAL RESULTS FOR METALS IN BLANKS

    EPA Science Inventory

    This data set includes analytical results for measurements of metals in 205 blank samples and for particles in 64 blank samples. Measurements were made for up to 12 metals in blank samples of air, dust, soil, water, food and beverages, blood, hair, and urine. Blank samples were u...

  17. NHEXAS PHASE I MARYLAND STUDY--QA ANALYTICAL RESULTS FOR METALS IN BLANKS

    EPA Science Inventory

    The Metals in Blanks data set contains the analytical results of measurements of up to 11 metals in 115 blank samples from 58 households. Measurements were made in blank samples of indoor and outdoor air, drinking water, beverages, urine, and blood. Blank samples were used to a...

  18. Modeling and control of casting and welding processes

    SciTech Connect

    Kou, S.; Mehrabian, R.

    1986-01-01

    This book contains papers divided among the following sections: process monitor and control in welding; plasma processing and refining; strip casting; modelling of welding processes; CAD/CAM in casting; investment and die casting; ingot, continuous and other shape casting; and rapid solidification and microstructural evolution.

  19. CO2 laser tailored blank welding: process monitoring

    NASA Astrophysics Data System (ADS)

    D'Angelo, Giuseppe; Borello, Elena; Pallaro, Nereo

    1996-09-01

    Tailored blank welding has been a rapidly growing segment of the automotive industry over the last five years. It allows to choose the optimal thickness of the sheets for different zones taking into account different mechanical stresses, vehicle safety reinforcement. Through the elimination of extra reinforcement parts, the use of tailored blanks allows to produce lighter car bodies and to simplify the production cycle. As more laser welding systems are being installed in industry, in order to increase the productivity and maintain constant quality of the products, the demand for the development of process monitoring systems increases. In this paper a monitoring system, based on the measurement of the radiation from the plasma plume during the CO2 tailored blanks laser welding, is presented. Using an appropriate combination of optical components, detectors and a special software, a complete apparatus has been developed. The signals were found to be correlated to weld quality parameters including the defects such as holes, overlapping and open butts.

  20. Hardening of the surface layers of a hollow billet formed by centrifugal casting

    NASA Astrophysics Data System (ADS)

    Chumanov, V. I.; Chumanov, I. V.; Anikeev, A. N.; Garifulin, R. R.

    2010-12-01

    One of the methods to increase the mechanical properties of steel is its hardening via the introduction of a refractory fine-grained phase into a melt. A method of fabrication of a tube blank by centrifugal casting accompanied by hardening with a refractory phase is considered. The introduction of fine tungsten and silicon carbides is shown to improve the structure of grade 15 steel and to increase the wear resistance of a tube blank made of this steel.

  1. Structural analysis of a new type lightweight optical mirror blank

    NASA Astrophysics Data System (ADS)

    Li, Yeping; Cui, Xiangqun; Hu, Ningsheng

    2010-07-01

    To reduce the cost and increase the feasibility of the astronomical optical telescope, modern large optical telescope is normally required to be as light as possible. Therefore lightweight mirror is always pursued by large telescopes development. In this paper, a new type lightweight optical mirror blank, the evaluation of its technical feasibility and the reduction of cost are introduced. For the purpose of applying active optics with this lightweight mirror blank, the structural analysis, thermal analysis and optical performance simulation by the finite element method have been presented.

  2. Additional evidence of EUV blank defects first seen by wafer printing

    NASA Astrophysics Data System (ADS)

    Jonckheere, Rik; Van den Heuvel, Dieter; Bret, Tristan; Hofmann, Thorsten; Magana, John; Aharonson, Israel; Meshulach, Doron; Hendrickx, Eric; Ronse, Kurt

    2011-11-01

    First experimental evidence is given that a second generation blank inspection tool has missed a number of printing reticle defects caused by an imperfection of its EUV mirror, i.e., so-called multi-layer defects (ML-defects). This work continued to use a combination of blank inspection (BI), patterned mask inspection (PMI) and wafer inspection (WI) to find as many as possible printing defects on EUV reticles. The application of more advanced wafer inspection, combined with a separate repeater analysis for each of the multiple focus conditions used for exposure on the ASML Alpha Demo Tool (ADT) at IMEC, has allowed to increase the detection capability for printing ML-defects. It exploits the previous finding that ML-defects may have a through-focus printing behavior. They cause a different grade of CD impact on the pattern in their neighborhood, depending on the focus condition. Subsequent reticle review is done on the corresponding locations with both SEM (Secondary Electron Microscope) and AFM (Atomic Force Microscope). This review methodology has allowed achieving clear evidence of printing ML defects missed by this BI tool, despite of a too high nuisance rate, reported before. This establishes a next step in the investigation how essential actinic blank inspection (ABI) is. Presently it is the only known technique whose detection capability is considered independent from the presence of a (residual) distortion of the multi-layer at the top surface. This is considered an important asset for blank inspection, because the printability of a ML-defect in EUV lithography is determined by the distortion throughout the multilayer, not that at the top surface.

  3. Project CAST.

    ERIC Educational Resources Information Center

    Charles County Board of Education, La Plata, MD. Office of Special Education.

    The document outlines procedures for implementing Project CAST (Community and School Together), a community-based career education program for secondary special education students in Charles County, Maryland. Initial sections discuss the role of a learning coordinator, (including relevant travel reimbursement and mileage forms) and an overview of…

  4. Strip casting apparatus and method

    DOEpatents

    Williams, R.S.; Baker, D.F.

    1988-09-20

    Strip casting apparatus including a molten-metal-holding container and a nozzle to deposit molten metal onto a moving chill drum to directly cast continuous metallic strip. The nozzle body includes a slot bounded between a back and a front lip. The slot width exceeds about 20 times the gap distance between the nozzle and the chill drum surface. Preferably, the slot width exceeds 0.5 inch. This method of strip casting minimizes pressure drop, insuring better metal-to-chill-drum contact which promotes heat transfer and results in a better quality metallic strip. 6 figs.

  5. Strip casting apparatus and method

    DOEpatents

    Williams, Robert S.; Baker, Donald F.

    1988-01-01

    Strip casting apparatus including a molten-metal-holding container and a nozzle to deposit molten metal onto a moving chill drum to directly cast continuous metallic strip. The nozzle body includes a slot bounded between a back and a front lip. The slot width exceeds about 20 times the gap distance between the nozzle and the chill drum surface. Preferably, the slot width exceeds 0.5 inch. This method of strip casting minimizes pressure drop, insuring better metal-to-chill-drum contact which promotes heat transfer and results in a better quality metallic strip.

  6. The Concurrent Validity of the Correctional Officers' Interest Blank.

    ERIC Educational Resources Information Center

    Sevy, Bruce A.

    1988-01-01

    Available data yields an estimated validity of .27 for the Corrections Officer Interest Blank (COIB) as a predictor of job performance of corrections officers. The COIB is only weakly related to the job performance of juvenile counselors and has no relationship to the performance of probation officers. (JOW)

  7. [Dangerousness of blank fright guns and salute rifles].

    PubMed

    Schöning, R; Krause, D; Lichtenberg, W; Schmidt, U; Effenberger, O

    1997-01-01

    According to the German law salute-fire guns altered weapons with a barrel length of more than 60 cm. They have inside the barrel special constructions, which are guiding the gunshot residues under high pressure to the muzzle. Therefore they own an high potential of injury, like blank-cartridge guns with short barrels. PMID:9313063

  8. Analysis of heat transfer during quenching of a gear blank

    SciTech Connect

    Aceves, S M; Sahai, V

    1999-03-01

    This paper presents experimental and numerical results for the quench of a gear blank in agitated and stagnant oil. Heat transfer within the gear blank is analyzed with a whole domain-optimizer technique inverse solution method, to calculate the time history at every point in the gear blank. The development of this procedure represents the first stage in an overall analysis of the quench process that will later include material phase transformations and deformation. The paper presents ten variations in setting up the inverse problem, to analyze which combination of independent variables and decision variables results in the best match between experimental and numerical results. The results indicate that dividing the boundary of the gear blank into four zones and assigning a fixed heat transfer coefficient or heat flux to each zone yields an average RMS error (average difference between experimental and numerical results) of the order of 40 K. This error can be reduced by either increasing the number of zones, by reducing the number of thermocouples being matched, or by allowing the heat transfer or heat flux to vary within the zones. Of these possibilities, variation of heat transfer within the zones gives the best improvement in the quality of the match for the amount of extra effort required to run the problem.

  9. [Morphologic detection of Bacillus cereus in blank cartridges].

    PubMed

    Rothschild, M A; Mülling, C

    1998-01-01

    Wound infections after gunshot wounds from live ammunition can produce serious complications. It is well known that projectiles per se are neither sterile nor does their firing cause sterilization. The germs on the surface of a projectile enter the body together with the projectile and are thus introduced into the wound together with skin bacteria. However it is less known that wound infections can occur in wounds caused by the gas jet from blank ammunition (mainly from shots at very close range). In such ammunition without a projectile, the propellant particles are usually contaminated with bacteria which find their way into the wound together with skin germs. In previous investigations, we have microbiologically detected the species Bacillus cereus in the propellant of blank cartridges. In the present study, we have applied scanning electron microscopic methods to find out which areas of the blank cartridges are colonized by these bacteria. For this purpose 20 blank cartridges, each from 4 different manufacturers, were electronmicroscopically examined. B. cereus only found on the surface of intact nitrocellulose particles but not in the interior of broken prepared propellant particles. Bacterial structures were not morphologically identified on black powder particles. PMID:9701752

  10. Grammatical Categories in Robert Frost's Blank Verse: A Quantitative Analysis.

    ERIC Educational Resources Information Center

    Lyford, Roland Hazen

    Structural linguistic techniques were utilized to categorize the grammatical elements employed by Robert Frost in 46 blank-verse poems. Nineteen main grammatical categories and 26 verb sub-categories based on distinctive selection criteria were devised to examine the range and distribution of Frost's grammatical patterns. Five control poems by E.…

  11. Casting methods

    DOEpatents

    Marsden, Kenneth C.; Meyer, Mitchell K.; Grover, Blair K.; Fielding, Randall S.; Wolfensberger, Billy W.

    2012-12-18

    A casting device includes a covered crucible having a top opening and a bottom orifice, a lid covering the top opening, a stopper rod sealing the bottom orifice, and a reusable mold having at least one chamber, a top end of the chamber being open to and positioned below the bottom orifice and a vacuum tap into the chamber being below the top end of the chamber. A casting method includes charging a crucible with a solid material and covering the crucible, heating the crucible, melting the material, evacuating a chamber of a mold to less than 1 atm absolute through a vacuum tap into the chamber, draining the melted material into the evacuated chamber, solidifying the material in the chamber, and removing the solidified material from the chamber without damaging the chamber.

  12. CASTING APPARATUS

    DOEpatents

    Gray, C.F.; Thompson, R.H.

    1958-09-23

    An apparatus is described for casting small quantities of uranlum. It consists of a crucible having a hole in the bottom with a mold positioned below. A vertical rcd passes through the hole in the crucible and has at its upper end a piercing head adapted to break the oxide skin encasing a molten uranium body. An air tight cylinder surrounds the crucible and mold, and is arranged to be evacuated.

  13. Emulsion based cast booster - a priming system

    SciTech Connect

    Gupta, R.N.; Mishra, A.K.

    2005-07-01

    This paper explores the potential of emulsion based cast booster to be used as primer to initiate bulk delivered emulsion explosives used in mines. An attempt has been made for comparative study between conventional cast booster and emulsion based cast booster in terms of the initiation process developed and their capability to develop and maintain the stable detonation process in the column explosives. The study has been conducted using a continuous velocity of detonation (VOD) measuring instrument. During this study three blasts have been monitored. In each blast two holes have been selected for study, the first hole being initiated with conventional cast booster while the other one with emulsion based cast booster. The findings of the study advocates that emulsion based cast booster is capable of efficient priming of bulk delivered column explosive with stable detonation process in the column. Further, the booster had advantages over the conventional PETN/TNT based cast booster. 5 refs., 2 figs., 1 tab., 1 photo.

  14. Manufacture of Φ1.2m reaction bonded silicon carbide mirror blank CFID

    NASA Astrophysics Data System (ADS)

    Zhang, Ge; Zhao, Rucheng; Zhao, Wenxing; Bao, Jianxun

    2010-05-01

    Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion, high stiffness, fine optical quality and dimensional stability, make SiC an ideal material for large space born telescope. Since ten years Changchun institute optics, fine mechanics and physics (CIOMP) has developed reaction bonded SiC (RB-SiC) technology for space application, and can fabricate RB-SiC mirror with scale less than 1.0 meter for telescope. The green body is prepared with gel-casting method which is an attractive new ceramic forming process for making high-quality, complex-shaped ceramic parts. And then unmolding, drying, binder burning out, reacting bonded, the RB-SiC can be obtained. But with the development of space-born or ground telescope, the scale of primary mirror has exceeded 1.0 meter. So CIOMP has developed an assembly technique which called novel reaction-formed joint technology for larger RB-SiC mirror blank. The steps include joining of green bodies with mixture comprised of SiC particles and phenolic resin etc, firing, machining and sintering. Joining the Φ1.2 meter RB-SiC mirror blank by the novel reaction-formed joint technology. And testing the welding layer's performance, the results show that the thickness of 54-77μm, the microstructure and thermal property can be comparable to the substrate and the mechanical property are excellent in bending strength of 307MPa.

  15. Strip casting with fluxing agent applied to casting roll

    DOEpatents

    Williams, Robert S.; O'Malley, Ronald J.; Sussman, Richard C.

    1997-01-01

    A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). A preferred flux is boron oxide having a melting point of about 550.degree. C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll.

  16. Strip casting with fluxing agent applied to casting roll

    DOEpatents

    Williams, R.S.; O`Malley, R.J.; Sussman, R.C.

    1997-07-29

    A strip caster for producing a continuous strip includes a tundish for containing a melt, a pair of horizontally disposed water cooled casting rolls and devices for electrostatically coating the outer peripheral chill surfaces of the casting rolls with a powder flux material. The casting rolls are juxtaposed relative to one another for forming a pouting basin for receiving the melt through a teeming tube thereby establishing a meniscus between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line to a sealing chamber. A preferred flux is boron oxide having a melting point of about 550 C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll. 3 figs.

  17. OVERVIEW LOOKING SOUTH OF CONTAINMENT SYSTEM (TOP), SLAB CASTING MACHINE ...

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

    OVERVIEW LOOKING SOUTH OF CONTAINMENT SYSTEM (TOP), SLAB CASTING MACHINE AND RUN OUT WITH TRAVELING TORCH. MACHINE IS CASTING IN TWIN MOLD. - U.S. Steel, Fairfield Works, Continuous Caster, Fairfield, Jefferson County, AL

  18. Cast aluminum denture base.

    PubMed

    Barco, M T; Dembert, M L

    1987-08-01

    The laboratory procedures for a cast aluminum base denture have been presented. If an induction casting machine is not available, the "two-oven technique" works well, provided the casting arm is kept spinning manually for 4 minutes after casting. If laboratory procedures are executed precisely and with care, the aluminum base denture can be cast with good results. PMID:3305884

  19. Production of EUV mask blanks with low killer defects

    NASA Astrophysics Data System (ADS)

    Antohe, Alin O.; Kearney, Patrick; Godwin, Milton; He, Long; John Kadaksham, Arun; Goodwin, Frank; Weaver, Al; Hayes, Alan; Trigg, Steve

    2014-04-01

    For full commercialization, extreme ultraviolet lithography (EUVL) technology requires the availability of EUV mask blanks that are free of defects. This remains one of the main impediments to the implementation of EUV at the 22 nm node and beyond. Consensus is building that a few small defects can be mitigated during mask patterning, but defects over 100 nm (SiO2 equivalent) in size are considered potential "killer" defects or defects large enough that the mask blank would not be usable. The current defect performance of the ion beam sputter deposition (IBD) tool will be discussed and the progress achieved to date in the reduction of large size defects will be summarized, including a description of the main sources of defects and their composition.

  20. Three cases of death caused by shots from blank cartridge.

    PubMed

    Zdravkovic, Miodrag; Milic, Miroslav; Stojanovic, Miroslav; Kostov, Milos

    2009-12-01

    The authors describe 3 cases of lethal injuries caused by 7.62 mm blank cartridge shots from military automatic rifle of domestic origin (AK 47, 7.62 mm). In 1 case, the cartridge was fired from a weapon that had been leaned on the head, with subsequent destruction of brain, and in other 2 cases, the weapon had been leaned on the chests, which led to destruction of heart parts. The injuries were caused by the action of striking wave of gunpowder explosion, the air blast type. The cases demonstrate that the gas pressure from the exploding propellant of blank cartridge is powerful enough to penetrate the thoracic wall and the skull. PMID:19901805

  1. FSW of Aluminum Tailor Welded Blanks across Machine Platforms

    SciTech Connect

    Hovanski, Yuri; Upadhyay, Piyush; Carlson, Blair; Szymanski, Robert; Luzanski, Tom; Marshall, Dustin

    2015-02-16

    Development and characterization of friction stir welded aluminum tailor welded blanks was successfully carried out on three separate machine platforms. Each was a commercially available, gantry style, multi-axis machine designed specifically for friction stir welding. Weld parameters were developed to support high volume production of dissimilar thickness aluminum tailor welded blanks at speeds of 3 m/min and greater. Parameters originally developed on an ultra-high stiffness servo driven machine where first transferred to a high stiffness servo-hydraulic friction stir welding machine, and subsequently transferred to a purpose built machine designed to accommodate thin sheet aluminum welding. The inherent beam stiffness, bearing compliance, and control system for each machine were distinctly unique, which posed specific challenges in transferring welding parameters across machine platforms. This work documents the challenges imposed by successfully transferring weld parameters from machine to machine, produced from different manufacturers and with unique control systems and interfaces.

  2. Stressed mirror polishing: finite element simulation of mirror blank deformation

    NASA Astrophysics Data System (ADS)

    Han, Yu; Lu, Lihong

    2014-08-01

    The theoretical principle of Stressed Mirror Polishing (SMP) is introduced, including the representation method of elastic deformation, the formulations of discrete bending moment and shearing force. A Finite Element Analysis (FEA) simulation model of has been set up by ANSYS software. The warping facility in this model is consisted of 36 aluminum alloy arms equally distribute on the ambit of mirror blank. Two forces are applied on each arm to provide bending moment and shearing force. Taking type 82 segment of Thirty Meters Telescope (TMT) primary mirror for example, a FEA simulation of mirror blank deformation has been performed. Simulation result shows that, the deformation error is 33μm PV. The theoretical deformation PV value is 205μm and the simulation deformation PV value is 172μm, converging rate reaches to 0.84 in a single warping cycle. After three or four warping cycles, the residue error may converge into 1μm.

  3. Modification methods of blank pistols in Turkey in 2006.

    PubMed

    Saribey, Aylin Yalçin; Tarimci, Celik

    2009-05-01

    This study describes the modification methods of blank cartridge firing pistols in Turkey. We have examined cases submitted to the Aydin Regional Criminal Laboratory of Turkey in 2006. In total, 95 modified pistols and 300 modified cartridges were examined. The blank cartridge firing pistols are guns which look similar to "real" pistols, however, there are blockages in their barrel in order to prevent the discharge of a bullet. However, as a result of simple modifications, these pistols can be easily converted into "real" firearms. Studied modification methods are removing the obstruction from the barrel, removing the partial obstruction from the barrel, sleeving a smaller diameter tube into the original barrel, using a replacement barrel, and rifling the original barrel. Special cartridges for these modified pistols are also produced. These modified pistols and cartridges were evaluated in respect of the converting methods. PMID:19302384

  4. Volume MLS ray casting.

    PubMed

    Ledergerber, Christian; Guennebaud, Gaël; Meyer, Miriah; Bächer, Moritz; Pfister, Hanspeter

    2008-01-01

    The method of Moving Least Squares (MLS) is a popular framework for reconstructing continuous functions from scattered data due to its rich mathematical properties and well-understood theoretical foundations. This paper applies MLS to volume rendering, providing a unified mathematical framework for ray casting of scalar data stored over regular as well as irregular grids. We use the MLS reconstruction to render smooth isosurfaces and to compute accurate derivatives for high-quality shading effects. We also present a novel, adaptive preintegration scheme to improve the efficiency of the ray casting algorithm by reducing the overall number of function evaluations, and an efficient implementation of our framework exploiting modern graphics hardware. The resulting system enables high-quality volume integration and shaded isosurface rendering for regular and irregular volume data. PMID:18988986

  5. Advances in Low-Defect Multilayers for EUVL Mask Blanks

    SciTech Connect

    Folta, J A; Davidson, J C; Larson, C C; Walton, C C; Kearney, P A

    2002-04-15

    Low-defect multilayer coatings are required to fabricate mask blanks for Extreme Ultraviolet Lithography (EUVL). The mask blanks consist of high reflectance E W multilayers on low thermal expansion substrates. A defect density of 0.0025 printable defects/cm{sup 2} for both the mask substrate and the multilayer is required to provide a mask blank yield of 60%. Current low defect multilayer coating technology allows repeated coating-added defect levels of 0.05/cm{sup 2} for defects greater than 90 nm polystyrene latex sphere (PSL) equivalent size for lots of 20 substrates. Extended clean operation of the coating system at levels below 0.08/cm{sup 2} for 3 months of operation has also been achieved. Two substrates with zero added defects in the quality area have been fabricated, providing an existence proof that ultra low defect coatings are possible. Increasing the ion source-to-target distance from 410 to 560 mm to reduce undesired coating of the ion source caused the defect density to increase to 0.2/cm{sup 2}. Deposition and etching diagnostic witness substrates and deposition pinhole cameras showed a much higher level of ion beam spillover (ions missing the sputter target) than expected. Future work will quantify beam spillover, and test designs to reduce spillover, if it is confirmed to be the cause of the increased defect level. The LDD system will also be upgraded to allow clean coating of standard format mask substrates. The upgrade will confirm that the low defect process developed on Si wafers is compatible with the standard mask format 152 mm square substrates, and will provide a clean supply of EUVL mask blanks needed to support development of EUVL mask patterning processes and clean mask handling technologies.

  6. The Problems of Mechanical Treatment of Leucosapphire Blanks

    NASA Astrophysics Data System (ADS)

    Petreshin, D. I.; Handozhko, A. V.; Protasev, V. B.; Fedonin, O. N.; Bizykina, N. A.; Shukin, D. Y.

    2016-04-01

    The problems of the technology of mechanical treatment of hard crystal materials, particularly leucosapphires and their possible solutions, are discovered. General questions of the project works, solutions of accurate basic tasks and secure fixation of the blanks or tooling backup of the work technology are considered. The results of experimental studies of the diamond tool dressing and their efficiency evolution results are provided. Some recommendations on the technological process development are worked out.

  7. Sixty Years of Casting Research

    NASA Astrophysics Data System (ADS)

    Campbell, John

    2015-11-01

    The 60 years of solidification research since the publication of Chalmer's constitutional undercooling in 1953 has been a dramatic advance of understanding which has and continues to be an inspiration. In contrast, 60 years of casting research has seen mixed fortunes. One of its success stories relates to improvements in inoculation of gray irons, and another to the discovery of spheroidal graphite iron, although both of these can be classified as metallurgical rather than casting advances. It is suggested that true casting advances have dated from the author's lab in 1992 when a critical surface turbulence condition was defined for the first time. These last 20 years have seen the surface entrainment issues of castings developed to a sufficient sophistication to revolutionize the performance of light alloy and steel foundries. However, there is still a long way to go, with large sections of the steel and Ni-base casting industries still in denial that casting defects are important or even exist. The result has been that special ingots are still cast poorly, and shaped casting operations have suffered massive losses. For secondary melted and cast materials, electro-slag remelting has the potential to be much superior to expensive vacuum arc remelting, which has cost our aerospace and defense industries dearly over the years. This failure to address and upgrade our processing of liquid metals is a serious concern, since the principle entrainment defect, the bifilm, is seen as the principle initiator of cracks in metals; in general, bifilms are the Griffith cracks that initiate failures by cracking. A new generation of crack resistant metals and engineering structures can now be envisaged.

  8. The Energy Savings in Reroll Casting From Primary Metal

    NASA Astrophysics Data System (ADS)

    Evans, J. F.; Fitzpatrick, N. P.

    1981-11-01

    Recent developments in the continuous casting of strip by belt casting, associated with the primary production of aluminum, offer substantial advantages in energy saving, through the direct conversion of molten metal into strip and through the reduction of melt loss. The total energy content (electrical and thermal) of the continuous casting route is compared to that involved in the conventional ingot casting and hot-rolling route for a typical semi-fabricated product.

  9. Photomask blanks enhancement for the laser reticle writer

    NASA Astrophysics Data System (ADS)

    Kobayashi, Hideo; Asakawa, Keishi; Yokoya, Yasunori

    1995-07-01

    The laser writer (CORE) has come to the front for advanced reticle fabrication so that photomask blanks enhancement is much more to be desired for the application. We have investigated novel techniques to bring out photomask blanks potential to expand process windows for the laser writer application, which included optimization of resist coating thickness by studying standing wave effect, optimization of soft-baking by studying resist behavior to soft-baking temperature, and optimization of pretreatment by studying resist adhesion characteristic to chromium oxide based film and molybdenum silicide based film. We have also explored very basic features of several resists in a comparison between the most popular OCG-895i and new candidates under an optimized coating thickness and soft-baking temperature respectively for each resist. This paper describes details of our findings on novel techniques for photomask blanks enhancement, and a comparison result of several resists in very basic features, in order to expand process windows to meet critical dimension performance requirements of advanced reticle fabrication by the laser writer.

  10. Fatal cranial shot by blank cartridge gun: two suicide cases.

    PubMed

    Buyuk, Yalcin; Cagdir, Sadi; Avsar, Abdullah; Duman, Gokce U; Melez, D Oguzhan; Sahin, Feyzi

    2009-08-01

    Blank firing pistols are generally considered to be harmless and these guns are not accepted as being firearms in most countries. Due to lack of legal regulations these guns are easily purchased by anyone aged over 18 years. Reports of serious injuries and even fatalities due to these guns are increasing in the literature. These guns when modified or even unmodified can cause serious and potentially fatal injuries. Without doing any changes to the barrel, using blank or tear gas cartridges, firing at contact range can cause penetration of gas into the body including bone originated from gun powder. We report two suicide cases shooting themselves at temporal region with a blank cartridge gun at contact range. There was no foreign body on radiological examination and there was no trajectory of a bullet inside the brain. In both cases the wound was at the right temporal region and there was defect at temporal bone. There was circular soot around this bone defect. The injury of the brain tissue was localized at the level of the defect but there was widespread subarachnoidal bleeding. We discussed the potential danger of these guns and stressed the need of legal regulations concerning these guns. PMID:19573850

  11. Radar interference blanking in radio astronomy using a Kalman tracker

    NASA Astrophysics Data System (ADS)

    Dong, W.; Jeffs, B. D.; Fisher, J. R.

    2005-06-01

    Radio astronomical observations of highly Doppler shifted spectral lines of neutral hydrogen and the hydroxyl molecule must often be made at frequencies allocated to pulsed air surveillance radar in the 1215-1350 MHz frequency range. The Green Bank telescope (GBT) and many other observatories must deal with these terrestrial signals. Even when strong radar fixed clutter echoes are removed, there are still weaker aircraft echoes present which can corrupt the data. We present an algorithm which improves aircraft echo blanking using a Kalman filter tracker to follow the path of a sequence of echoes observed on successive radar antenna sweeps. Aircraft tracks can be used to predict regions (in bearing and range) for the next expected echoes, even before they are detected. These data can then be blanked in real time without waiting for the pulse peak to arrive. Additionally, we briefly suggest an approach for a new Bayesian algorithm which combines tracker and pulse detector operations to enable more sensitive weak pulse detection. Examples are presented for Kalman tracking and radar transmission blanking using real observations at the GBT.

  12. Steel castings by the electroslag casting technique

    NASA Astrophysics Data System (ADS)

    Sikka, V. K.; Mitchell, A.

    1984-10-01

    Electroslag casting facilities in Canada and the United States were reviewed. Several value body castings of 2 1/4 Cr-1 Mo, 9 Cr-1 Mo, and 18% Cr-8% Ni (Mo) steels were made at the University of British Columbia facility. These castings were examined for surface finish, chemical segregation, and macrostructure in the as-cast condition and after various heat treatments. Castings were subjected to tensile, charpy impact, and creep testing. Results of these tests were compared with similar data on wrought material and where applicable, with data on sand castings.

  13. Steel castings by the electroslag casting technique

    SciTech Connect

    Sikka, V.K.; Mitchell, A.

    1984-10-01

    Electroslag casting facilities in Canada and the United States were reviewed. Several valve body castings of 2 1/4 Cr-1 Mo, 9 Cr-1 Mo, and 18% Cr-8% Ni(Mo) steels were made at the University of British Columbia facility. These castings were examined for surface finish, chemical segregation, and macrostructure in the as-cast condition and after various heat treatments. Castings were subjected to tensile, Charpy impact, and creep testing. Results of these tests were compared with similar data on wrought material and, where applicable, with data on sand castings. 22 figures.

  14. Influence of Anisotropy Properties in Finite Element Optimization of Blank Shape Using NURBS Surfaces

    SciTech Connect

    Padmanabhan, R.; Oliveira, M. C.; Baptista, A. J.; Menezes, L. F.; Alves, J. L.

    2007-04-07

    Sheet metal forming is a complex process controlled by process parameters and material properties of the blank sheet. The initial anisotropy has influence on the determination of optimal blank shape because it governs the material flow. In this paper, the influence of the initial anisotropy, in achieving an optimal blank shape, is analyzed using mild steel (DC06) blank sheet and two different tool geometries: circular and rectangular cup. The numerical method is based on the initial NURBS surface used to produce the mesh that models the blank and the resulting flange geometry of the deformed part. Different rolling direction orientations were considered in the blanks for deep drawing to investigate their effect on the blank shape optimization procedure. From the numerical study it is evident that the described method is sensitive to the initial anisotropy in the material and can produce optimal initial blank shape within few iterations.

  15. Casting defects in low-pressure die-cast aluminum alloy wheels

    NASA Astrophysics Data System (ADS)

    Zhang, B.; Cockcroft, S. L.; Maijer, D. M.; Zhu, J. D.; Phillion, A. B.

    2005-11-01

    Defects in automotive aluminum alloy casting continue to challenge metallurgists and production engineers as greater emphasis is placed on product quality and production cost. A range of casting-related defects found in low-pressure die-cast aluminum wheels were examined metallographically in samples taken from several industrial wheel-casting facilities. The defects examined include macro- and micro- porosity, entrained oxide films, and exogenous oxide inclusions. Particular emphasis is placed on the impact of these defects with respect to the three main casting-related criteria by which automotive wheel quality are judged: wheel cosmetics, air-tightness, and wheel mechanical performance.

  16. NHEXAS PHASE I ARIZONA STUDY--QA ANALYTICAL RESULTS FOR METALS IN BLANK SAMPLES

    EPA Science Inventory

    The Metals in Blank Samples data set contains the analytical results of measurements of up to 27 metals in 82 blank samples from 26 households. Measurements were made in blank samples of dust, indoor and outdoor air, personal air, food, beverages, blood, urine, and dermal wipe r...

  17. 21 CFR 880.6185 - Cast cover.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cast cover. 880.6185 Section 880.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Miscellaneous Devices § 880.6185 Cast cover. (a) Identification. A...

  18. Evaluation of alternative capping layers for EUVL mask ML blank

    NASA Astrophysics Data System (ADS)

    Yan, Pei-yang; Spiller, Eberhard; Gullikson, Eric; Hill, Shannon

    2005-11-01

    The standard silicon (Si) capping layer used for extreme ultra-violet lithography (EUVL) multilayer (ML) mask blanks has some shortcomings, such as low oxidation resistance, low chemical resistance, low etch selectivity in either the SiO2 buffer layer etch to the capping layer or the absorber etch (e.g., TaN) to the capping layer. These performance and process issues with Si capped ML mask blank will reduce the mask lifetime and require tighter process control during EUVL mask fabrication. Alternative capping materials have been investigated for both EUVL optics and for mask applications.1-5 It has been initially demonstrated that Ru capping layers have high oxidation resistance and high mask process margin as compared to Si ML cap. In this paper, we will present a detailed evaluation of Ru and ion beam deposited (IBD) diamond-like-carbon (DLC) for EUVL mask application. Performance evaluations of the DLC mask blank capping layer and Ru capping layer were made in the area of reflectivity performance, shelf-life, and EUV exposure stability. It has been shown that EUV exposure induced capping layer change depends upon the exposure conditions. However, we found that as long as the induced relative change in the ML cap material are the same (e.g., the same amount of oxidation), regardless of exposure time and exposure conditions, the resulting reflectivity change is about the same. In the case of the two capping layer materials we evaluated, the capping surface reaction with active oxygen is the primary cause for the reflectivity degradation.

  19. Automatic classification and accurate size measurement of blank mask defects

    NASA Astrophysics Data System (ADS)

    Bhamidipati, Samir; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

    2015-07-01

    A blank mask and its preparation stages, such as cleaning or resist coating, play an important role in the eventual yield obtained by using it. Blank mask defects' impact analysis directly depends on the amount of available information such as the number of defects observed, their accurate locations and sizes. Mask usability qualification at the start of the preparation process, is crudely based on number of defects. Similarly, defect information such as size is sought to estimate eventual defect printability on the wafer. Tracking of defect characteristics, specifically size and shape, across multiple stages, can further be indicative of process related information such as cleaning or coating process efficiencies. At the first level, inspection machines address the requirement of defect characterization by detecting and reporting relevant defect information. The analysis of this information though is still largely a manual process. With advancing technology nodes and reducing half-pitch sizes, a large number of defects are observed; and the detailed knowledge associated, make manual defect review process an arduous task, in addition to adding sensitivity to human errors. Cases where defect information reported by inspection machine is not sufficient, mask shops rely on other tools. Use of CDSEM tools is one such option. However, these additional steps translate into increased costs. Calibre NxDAT based MDPAutoClassify tool provides an automated software alternative to the manual defect review process. Working on defect images generated by inspection machines, the tool extracts and reports additional information such as defect location, useful for defect avoidance[4][5]; defect size, useful in estimating defect printability; and, defect nature e.g. particle, scratch, resist void, etc., useful for process monitoring. The tool makes use of smart and elaborate post-processing algorithms to achieve this. Their elaborateness is a consequence of the variety and

  20. Method and apparatus for inspecting an EUV mask blank

    DOEpatents

    Goldberg, Kenneth A.

    2005-11-08

    An apparatus and method for at-wavelength EUV mask-blank characterization for inspection of moderate and low spatial frequency coating uniformity using a synchrotron or other source of EUV light. The apparatus provides for rapid, non-destruction, non-contact, at-wavelength qualification of large mask areas, and can be self-calibrating or be calibrated to well-characterized reference samples. It can further check for spatial variation of mask reflectivity or for global differences among masks. The apparatus and method is particularly suited for inspection of coating uniformity and quality and can detect defects in the order of 50 .mu.m and above.

  1. Thin Wall Iron Castings

    SciTech Connect

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  2. 21 CFR 888.5960 - Cast removal instrument.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cast removal instrument. 888.5960 Section 888.5960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... patient. This generic type of device includes the electric cast cutter and cast vacuum. (b)...

  3. 21 CFR 888.5960 - Cast removal instrument.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cast removal instrument. 888.5960 Section 888.5960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... patient. This generic type of device includes the electric cast cutter and cast vacuum. (b)...

  4. 21 CFR 888.5960 - Cast removal instrument.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cast removal instrument. 888.5960 Section 888.5960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... patient. This generic type of device includes the electric cast cutter and cast vacuum. (b)...

  5. 21 CFR 888.5960 - Cast removal instrument.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cast removal instrument. 888.5960 Section 888.5960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... patient. This generic type of device includes the electric cast cutter and cast vacuum. (b)...

  6. 21 CFR 888.5960 - Cast removal instrument.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cast removal instrument. 888.5960 Section 888.5960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... patient. This generic type of device includes the electric cast cutter and cast vacuum. (b)...

  7. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet...

  8. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet...

  9. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet...

  10. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet...

  11. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet...

  12. Understanding the ion beam in EUV mask blank production

    NASA Astrophysics Data System (ADS)

    Kearney, Patrick; Jindal, Vibhu; Weaver, Alfred; Teora, Pat; Sporre, John; Ruzic, David; Goodwin, Frank

    2012-03-01

    One of the major technical hurdles to be overcome before EUV lithography can enter high volume manufacturing is the amount of defects in EUV mask blanks, many of which occur during the EUV reflector deposition process. The technology currently used to deposit this reflector is ion beam sputter deposition. Understanding the properties of the ion beam and the nature of the plasma in the deposition chamber is therefore critical to understanding defect production mechanisms and subsequently eliminating them. In this work, we have studied how the source parameters influence ion beam divergence, its footprint on the target, and the amount of beam that misses the target and hits the shielding. By optimizing the source parameters, we can modulate certain target- and shield-specific defect types. We have compared our data with models of source performance and found general agreement, enabling the theory to be fine-tuned based on the results of the measurements. Models are being developed to better describe actual source performance. We have also investigated the plasma conditions the ion beam creates in the tool, which is crucial to understanding the transport of defects from their source to the mask. A well characterized ion beam and plasma will lead to process and tool changes that will ultimately reduce defect levels in EUV mask blanks.

  13. Performance in practical use of actinic EUVL mask blank inspection

    NASA Astrophysics Data System (ADS)

    Yamane, Takeshi; Kim, Yongdae; Takagi, Noriaki; Terasawa, Tsuneo; Ino, Tomohisa; Suzuki, Tomohiro; Miyai, Hiroki; Takehisa, Kiwamu; Kusunose, Haruhiko

    2014-07-01

    A high-volume manufacturing (HVM) actinic blank inspection (ABI) prototype has been developed, of which the inspection capability for a native defect was evaluated. An analysis of defect signal intensity (DSI) analysis showed that the DSI varied as a result of mask surface roughness. Operating the ABI under a review mode reduced that variation by 71 %, and therefore this operation was made available for precise DSI evaluation. The result also indicated that the defect capture rate was influenced by the DSI variation caused by mask surface roughness. A mask blank was inspected three times by the HVM ABI prototype, and impact of the detected native defects on wafer CD was evaluated. There was observed a pronounced relationship between the DSI and wafer CD; and this means that the ABI tool could detect wafer printable defects. Using the total DSI variation, the capture rate of the smallest defect critical for 16 nm node was estimated to be 93.2 %. This means that most of the critical defects for 16 nm node can be detected with the HVM ABI prototype.

  14. Casting propellant in rocket engine

    NASA Technical Reports Server (NTRS)

    Roach, J. E.; Froehling, S. C. (Inventor)

    1976-01-01

    A method is described for casting a solid propellant in the casing of a rocket engine having a continuous wall with a single opening which is formed by leaves of a material which melt at a temperature of the propellant and with curved edges concentric to the curvature of the spherical casing. The leaves are inserted into the spherical casing through the opening forming a core having a greater width than the width of the single opening and with curved peripheral edges. The cast propellant forms a solid mass and then heated to melt the leaves and provide a central opening with radial projecting flutes.

  15. Defects caused by blank masks and repair solution with nanomachining for 20nm node

    NASA Astrophysics Data System (ADS)

    Lee, HyeMi; Kim, ByungJu; Kim, MunSik; Jung, HoYong; Kim, Sang Pyo; Yim, DongGyu

    2014-09-01

    As the number of masks per wafer product set is increasing and low k1 lithography requires tight mask specifications, the patterning process below sub 20nm tech. node for critical layers will be much more expensive compared with previous tech. generations. Besides, the improved resolution and the zero defect level are necessary to meet tighter specifications on a mask and these resulted in the increased the blank mask price as well as the mask fabrication cost. Unfortunately, in spite of expensive price of blank masks, the certain number of defects on the blank mask is transformed into the mask defects and its ratio is increased. But using high quality blank mask is not a good idea to avoid defects on the blank mask because the price of a blank mask is proportional to specifications related to defect level. Furthermore, particular defects generated from the specific process during manufacturing a blank mask are detected as a smaller defect than real size by blank inspection tools because of its physical properties. As a result, it is almost impossible to prevent defects caused by blank masks during the mask manufacturing. In this paper, blank defect types which is evolved into mask defects and its unique characteristics are observed. Also, the repair issues are reviewed such as the pattern damage according to the defect types and the repair solution is suggested to satisfy the AIMS (Arial Image Measurement System) specification using a nanomachining tool.

  16. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--QA ANALYTICAL RESULTS FOR METALS IN BLANK SAMPLES

    EPA Science Inventory

    The Metals in Blank Samples data set contains the analytical results of measurements of up to 27 metals in 52 blank samples. Measurements were made in blank samples of dust, indoor air, food, water, and dermal wipe residue. Blank samples were used to assess the potential for sa...

  17. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--QA ANALYTICAL RESULTS FOR PESTICIDES IN BLANK SAMPLES

    EPA Science Inventory

    The Pesticides in Blank Samples data set contains the analytical results of measurements of up to 20 pesticides in 34 blank samples. Measurements were made in blank samples of dust, indoor air, food, water, and dermal wipe residue. Blank samples were used to assess the potentia...

  18. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--QA ANALYTICAL RESULTS FOR VOCS IN BLANK SAMPLES

    EPA Science Inventory

    The VOCs in Blank Samples data set contains the analytical results of measurements of up to 47 volatile organic compounds (VOCs) in 24 blank samples. Measurements were made in blank samples of indoor air, outdoor air, and water. Blank samples were used to assess the potential f...

  19. Understanding EUV mask blank surface roughness induced LWR and associated roughness requirement

    SciTech Connect

    Yan, Pei-Yang; Zhang, Guojing; Gullickson, Eric M.; Goldberg, Kenneth A.; Benk, Markus P.

    2015-03-01

    Extreme ultraviolet lithography (EUVL) mask multi-layer (ML) blank surface roughness specification historically comes from blank defect inspection tool requirement. Later, new concerns on ML surface roughness induced wafer pattern line width roughness (LWR) arise. In this paper, we have studied wafer level pattern LWR as a function of EUVL mask surface roughness via High-NA Actinic Reticle Review Tool. We found that the blank surface roughness induced LWR at current blank roughness level is in the order of 0.5nm 3σ for NA=0.42 at the best focus. At defocus of ±40nm, the corresponding LWR will be 0.2nm higher. Further reducing EUVL mask blank surface roughness will increase the blank cost with limited benefit in improving the pattern LWR, provided that the intrinsic resist LWR is in the order of 1nm and above.

  20. The present status of dental titanium casting

    NASA Astrophysics Data System (ADS)

    Okabe, Toru; Ohkubo, Chikahiro; Watanabe, Ikuya; Okuno, Osamu; Takada, Yukyo

    1998-09-01

    Experimentation in all aspects of titanium casting at universities and industries throughout the world for the last 20 years has made titanium and titanium-alloy casting nearly feasible for fabricating sound cast dental prostheses, including crowns, inlays, and partial and complete dentures. Titanium casting in dentistry has now almost reached the stage where it can seriously be considered as a new method to compete with dental casting using conventional noble and base-metal alloys. More than anything else, the strength of titanium’s appeal lies in its excellent biocompatibility, coupled with its comparatively low price and abundant supply. Research efforts to overcome some problems associated with this method, including studies on the development of new titanium alloys suitable for dental use, will continue at many research sites internationally.

  1. Cool Cast Facts

    MedlinePlus

    ... outer layer is usually made of plaster or fiberglass. Fiberglass casts are made of fiberglass, which is a plastic that can be shaped. Fiberglass casts come in many different colors — if you' ...

  2. Clean cast steel technology. Final report

    SciTech Connect

    Bates, C.E.; Griffin, J.A.

    1998-06-01

    This report documents the results obtained from the Clean Cast Steel Technology Program financially supported by the DOE Metal Casting Competitiveness Research Program and industry. The primary objective of this program is to develop technology for delivering steel free of oxide macroinclusions to mold cavities. The overall objective is to improve the quality of cast steel by developing and demonstrating the technology for substantially reducing surface and sub-surface oxide inclusions. Two approaches are discussed here. A total of 23 castings were produced by submerge pouring along with sixty conventionally poured castings. The submerged poured castings contained, on average, 96% fewer observable surface inclusions (11.9 vs 0.4) compared to the conventionally poured cast parts. The variation in the population of surface inclusions also decreased by 88% from 5.5 to 0.7. The machinability of the casting was also improved by submerged pouring. The submerge poured castings required fewer cutting tool changes and less operator intervention during machining. Subsequent to these trials, the foundry has decided to purchase more shrouds for continued experimentation on other problem castings where submerge pouring is possible. An examination of melting and pouring practices in four foundries has been carried out. Three of the four foundries showed significant improvement in casting quality by manipulating the melting practice. These melting practice variables can be grouped into two separate categories. The first category is the pouring and filling practice. The second category concerns the concentration of oxidizable elements contained in the steel. Silicon, manganese, and aluminum concentrations were important factors in all four foundries. Clean heats can consistently be produced through improved melting practice and reducing exposure of the steel to atmospheric oxygen during pouring and filling.

  3. LLNL casting technology

    SciTech Connect

    Shapiro, A.B.; Comfort, W.J. III

    1994-01-01

    Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US compentiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the leverage for LLNL to collaborate with industrial partners to share this advanced casting expertise and technology. At the same time, collaboration with industrial partners provides LLNL technologists with broader insights into casting industry issues, casting process data, and the collective, experience of industry experts. Casting R&D is also an excellent example of dual-use technology; it is the cornerstone for increasing US industrial competitiveness and minimizing waste nuclear material in weapon component production. Annual funding for casting projects at LLNL is $10M, which represents 1% of the total LLNL budget. Metal casting accounts for about 80% of the funding. Funding is nearly equally divided between development directed toward US industrial competitiveness and weapon component casting.

  4. LLNL casting technology

    NASA Astrophysics Data System (ADS)

    Shapiro, A. B.; Comfort, W. J., III

    1994-01-01

    Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US competiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the leverage for LLNL to collaborate with industrial partners to share this advanced casting expertise and technology. At the same time, collaboration with industrial partners provides LLNL technologists with broader insights into casting industry issues, casting process data, and the collective experience of industry experts. Casting R&D is also an excellent example of dual-use technology; it is the cornerstone for increasing US industrial competitiveness and minimizing waste nuclear material in weapon component production. Annual funding for casting projects at LLNL is $10M, which represents 1% of the total LLNL budget. Metal casting accounts for about 80% of the funding. Funding is nearly equally divided between development directed toward US industrial competitiveness and weapon component casting.

  5. Caste in 21st Century India: Competing Narratives

    PubMed Central

    Desai, Sonalde; Dubey, Amaresh

    2012-01-01

    Recent debates regarding inclusion of caste in 2011 Census have raised questions about whether caste still matters in modern India. Ethnographic studies of the mid-20th century identified a variety of dimensions along which caste differentiation occurs. At the same time, whether this differentiation translates into hierarchy remains a contentious issue as does the persistence of caste, given the economic changes of the past two decades. Using data from a nationally representative survey of 41,554 households conducted in 2005, this paper examines the relationship between social background and different dimensions of well-being. The results suggest continued persistence of caste disparities in education, income and social networks. PMID:22736803

  6. Evaluation of electroslag castings

    SciTech Connect

    Judkins, R.R.; Sikka, V.K.

    1985-01-01

    Results of evaluations of electroslag castings of ferritic (2-1/4 Cr-1 Mo and 9 Cr-1 Mo) and austenitic (CF8M or type 316) steels are presented. The castings have been characterized for surface finish, cracking, solidification structure, chemical composition, hardness, ferrite distribution, tensile properties, Charpy impact properties, and creep properties. Pertinent data are compared with equivalent data for sand castings and wrought products of the same materials. Based on the results of these studies, the properties of electroslag castings compare favorably with those of sand castings and wrought materials.

  7. Mind-blanking: when the mind goes away

    PubMed Central

    Ward, Adrian F.; Wegner, Daniel M.

    2013-01-01

    People often feel like their minds and their bodies are in different places. Far from an exotic experience, this phenomenon seems to be a ubiquitous facet of human life (e.g., Killingsworth and Gilbert, 2010). Many times, people's minds seem to go “somewhere else”—attention becomes disconnected from perception, and people's minds wander to times and places removed from the current environment (e.g., Schooler et al., 2004). At other times, however, people's minds may seem to go nowhere at all—they simply disappear. This mental state—mind-blanking—may represent an extreme decoupling of perception and attention, one in which attention fails to bring any stimuli into conscious awareness. In the present research, we outline the properties of mind-blanking, differentiating this mental state from other mental states in terms of phenomenological experience, behavioral outcomes, and underlying cognitive processes. Seven experiments suggest that when the mind seems to disappear, there are times when we have simply failed to monitor its whereabouts—and there are times when it is actually gone. PMID:24098287

  8. Advances in aluminum casting technology

    SciTech Connect

    Tiryakioglu, M.; Campbell, J.

    1998-01-01

    This symposium focuses on the improvements of aluminum casting quality and reliability through a better understanding of processes and process variables, and explores the latest innovations in casting-process design that allow increasing use of the castings to replace complex assemblies and heavy steel and cast-iron components in aerospace and automotive applications. Presented are 35 papers by international experts in the various aspects of the subject. The contents include: Semisolid casting; Computer-aided designing of molds and castings; Casting-process modeling; Aluminum-matrix composite castings; HIPing of castings; Progress in the US car project; Die casting and die design; and Solidification and properties.

  9. Optimisation of the blank shape for micro deep drawing of rectangular parts

    SciTech Connect

    Hu Zhenyu; Vollertsen, Frank

    2011-05-04

    In this investigation the blank shape for micro deep drawing of rectangular parts was for the first time optimized using FEM method with consideration of the real process conditions in micro forming, i.e. the coefficient of friction and the flow curves of thin foils. The acquired optimized blank shape was then validated by applying it to experiments. For both numerical and experimental investigations a punch with a section of 2x1 mm{sup 2} was used. Aluminum Al99.5 with a sheet thickness of 20 {mu}m was used as blank material in this investigation. A flange free drawn part was successfully obtained from experiment using the blank shape and blank holder force optimized using FEM.

  10. High Speed Surface Micro-Polishing for Spurious Reduction of Small Quartz Crystal Blanks

    NASA Astrophysics Data System (ADS)

    Hatsuzawa, Takeshi; Hamano, Hisashi; Saito, Masashi; Yanagida, Yasuko

    Surface polishing is required for small crystal blanks to eliminate frequency spurious generated by the infinite rectangular shape. From the productivity viewpoint, bi-convex or plano-cylindrical surface are generally used to realize the energy trapping at the central part of the blanks. So far barrel polishing is the common fabrication technology to obtain bi-convex surface, however, the surface is finished insufficiently and fabrication process takes longer time as the blank size becomes small. To solve this difficulty, two types of new surface micro-polishing mechanisms with fixed abrasive and arrayed blank arrangement are experimentally examined to obtain plano-cylindrical surface. The fastest finishing time of 10 s for a blank is achieved together with the spurious elimination.

  11. Low-defect reflective mask blanks for extreme ultraviolet lithography

    SciTech Connect

    Burkhart, S C; Cerjarn, C; Kearney, P; Mirkarimi, P; Walton, C; Ray-Chaudhuri, A

    1999-03-11

    Extreme Ultraviolet Lithgraphy (EUVL) is an emerging technology for fabrication of sub-100 nm feature sizes on silicon, following the SIA roadmap well into the 21st century. The specific EUVL system described is a scanned, projection lithography system with a 4:1 reduction, using a laser plasma EUV source. The mask and all of the system optics are reflective, multilayer mirrors which function in the extreme ultraviolet at 13.4 nm wavelength. Since the masks are imaged to the wafer exposure plane, mask defects greater than 80% of the exposure plane CD (for 4:1 reduction) will in many cases render the mask useless, whereas intervening optics can have defects which are not a printing problem. For the 100 nm node, we must reduce defects to less than 0.01/cm² @ 80nm or larger to obtain acceptable mask production yields. We have succeeded in reducing the defects to less than 0.1/cm² for defects larger than 130 nm detected by visible light inspection tools, however our program goal is to achieve 0.01/cm² in the near future. More importantly though, we plan to have a detailed understanding of defect origination and the effect on multilayer growth in order to mitigate defects below the 10-2/cm² level on the next generation of mask blank deposition systems. In this paper we will discuss issues and results from the ion-beam multilayer deposition tool, details of the defect detection and characterization facility, and progress on defect printability modeling.

  12. Numerical Simulation of Blanking Process over a Wide Range of Clearances

    NASA Astrophysics Data System (ADS)

    Takata, Yusuke; Hirota, Kenji

    A number of special blanking processes are available for producing fine cut edges and blanking with a negative clearance is one of them. The aim of this study is to elucidate the mechanism of precision blanking with a negative clearance by using finite element method. Experiments were performed for two kinds of aluminum sheets over a wide range of clearances between -30 and 20 percent of the sheet thickness. Fine blanked products with no fractured zone were obtained in the case with negatively large clearances, while fractured zone appeared on the cut edge by conventional blanking. Corresponding simulations were carried out by using the Ayada's and the Jeong's criterion to predict ductile fracture initiation. Numerical results with both criteria agreed well with the experimental results except a few cases accompanied by secondary shear. The difference in blanking mechanism between the positive and the negative clearance blanking was explained by the variation of the damage value; it reached the threshold value for positive clearances, while it was kept low and never exceeded the threshold for negatively large clearances.

  13. SLIP CASTING METHOD

    DOEpatents

    Allison, A.G.

    1959-09-01

    S>A process is described for preparing a magnesium oxide slip casting slurry which when used in conjunction with standard casting techniques results in a very strong "green" slip casting and a fired piece of very close dimensional tolerance. The process involves aging an aqueous magnestum oxide slurry, having a basic pH value, until it attains a specified critical viscosity at which time a deflocculating agent is added without upsetting the basic pH value.

  14. A Study of Forming Force in the Fine-blanking Process Using the Theoretical Predication and Experimental Approach

    NASA Astrophysics Data System (ADS)

    Elyasi, Majid; Daeizadeh, Vahid

    2011-01-01

    In the fine-blanking process, a smooth cut surface over almost the entire thickness of the material and high degree of dimensional accuracy are produced Previous research on fine-blanking was carried out mainly to develop this technology and clarify its mechanism In this paper the effect of the shape of the workpiece, material tensile strength and initial blank thickness on forming force in fine-blanking process was studied by theoretical formulation and experimental approach The theoretical formulation was used as a tool to carry out the predication of fine-blanking force The obtained results indicated that by increasing the shape of the workpiece the forces in fine-blanking process is increased Also, by increasing the initial blank thickness and the material tensile strength, the forces in fine-blanking process is increased

  15. 76 FR 14697 - Aleris Blanking and Rim Products, Inc., a Division of Aleris International, Inc., Terre Haute, IN...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ... the Federal Register on March 2, 2010 (75 FR 9436-9437). The workers produce aluminum blanks and hoops... Employment and Training Administration Aleris Blanking and Rim Products, Inc., a Division of Aleris... Blanking and Rim Products, Inc., a division of Aleris International, Inc., Terre Haute, Indiana, who...

  16. Improved confidence intervals when the sample is counted an integer times longer than the blank.

    PubMed

    Potter, William Edward; Strzelczyk, Jadwiga Jodi

    2011-05-01

    Past computer solutions for confidence intervals in paired counting are extended to the case where the ratio of the sample count time to the blank count time is taken to be an integer, IRR. Previously, confidence intervals have been named Neyman-Pearson confidence intervals; more correctly they should have been named Neyman confidence intervals or simply confidence intervals. The technique utilized mimics a technique used by Pearson and Hartley to tabulate confidence intervals for the expected value of the discrete Poisson and Binomial distributions. The blank count and the contribution of the sample to the gross count are assumed to be Poisson distributed. The expected value of the blank count, in the sample count time, is assumed known. The net count, OC, is taken to be the gross count minus the product of IRR with the blank count. The probability density function (PDF) for the net count can be determined in a straightforward manner. PMID:21451310

  17. Numerical and experimental analysis on the formability of tailor welded blanks based on digital image correlation

    NASA Astrophysics Data System (ADS)

    Li, Yanhua; Lin, Jianping; Guo, Ruiquan

    2013-12-01

    Formability of tailor welded blanks (TWBs) and control of blank deformation during stamping is always a challenge for manufacturing designers due to different properties or thicknesses of the blanks. The plastic deformation capacity of TWBs is reduced even when the material and thickness are the same. Same material same gauge TWBs (SMSG- TWBs) are now widely applied to mass production of automobile components for raising the utilization ratio of materials and expanding the dimension of steel coil. The aim of this work is to investigate the formability of SMSG-TWBs by both numerical and experimental approaches. Local constitutive properties of laser welded beads are determined by tensile tests with the aid of digital image correlation (DIC). Based on these mechanical properties, the formability of TWBs and monolithic blank are evaluated by performing Erichsen cupping tests numerically and experimentally. The influence of weld on strain distribution is discussed as well. Comparisons with the experimental results showed general agreement.

  18. Casting Footprints for Eternity

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Apollo 11 Astronaut Buzz Aldrin has his footprints casted during the dedication ceremony of the rocket fountain at Building 4200 at Marshall Space Flight Center. The casts of Aldrin's footprints will be placed in the newly constructed Von Braun courtyard representing the accomplishments of the Apollo 11 lunar landing.

  19. Attenuated phase-shift mask (PSM) blanks for flat panel display

    NASA Astrophysics Data System (ADS)

    Kageyama, Kagehiro; Mochizuki, Satoru; Yamakawa, Hiroyuki; Uchida, Shigeru

    2015-10-01

    The fine pattern exposure techniques are required for Flat Panel display applications as smart phone, tablet PC recently. The attenuated phase shift masks (PSM) are being used for ArF and KrF photomask lithography technique for high end pattern Semiconductor applications. We developed CrOx based large size PSM blanks that has good uniformity on optical characteristics for FPD applications. We report the basic optical characteristics and uniformity, stability data of large sized CrOx PSM blanks.

  20. Effect of the atrial blanking time on the detection of atrial fibrillation in dual chamber pacing.

    PubMed

    Nowak, B; Kracker, S; Rippin, G; Horstick, G; Vincent, A; Geil, S; Himmrich, E; Meyer, J

    2001-04-01

    Patients with paroxysmal atrial fibrillation (PAF) and dual chamber pacemakers frequently have short postventricular atrial blanking times and sensitive atrial sensing thresholds used to provide reliable detection and mode switching during AF. However, short atrial blanking times increase the risk of atrial sensing of ventricular far-field signals. We evaluated if the length of the atrial blanking time influences the detection of AF. The study included ten patients with a VDDR (n = 7) or DDDR system (n = 3), who presented with AF at 18 follow-up visits. Bipolar atrial sensing was programmed to the most sensitive value. Atrial blanking times were programmed from 100 to 200 ms in 25-ms steps in each patient. Using marker annotation, the following parameters were measured at ten consecutive ventricular beats: VAF = the interval between ventricular stimulus and first sensing of AF; AFS = the number of atrial-sensed events between two ventricular events; and XAF = the interpolated number of atrial-sensed events during atrial blanking time. The intervals between ventricular events and between atrial-sensed event markers showed no significant differences for the five blanking times tested. There was no significant influence of the atrial blanking time onto the measured parameters (least square means +/- standard error) with VAF between 281 +/- 12 and 300 +/- 12 ms (P = NS), AFs between 3.4 +/- 0.2 and 3.6 +/- 0.2 beats (P = NS) and XAF between 1.84 +/- 0.12 and 2.03 +/- 0.12 beats (P = NS). At ventricular rates < 100/min, the atrial sensing of AF in dual chamber pacemakers demonstrated no evidence for deterioration by an increase of the atrial blanking time from 100 to 200 ms. Thus, the risk of ventricular far-field sensing may be reduced without compromising atrial sensing. PMID:11341088

  1. 40 CFR 53.58 - Operational field precision and blank test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... section 6 of 40 CFR part 50, appendix L, conditioned and preweighed as required by section 8 of 40 CFR... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Operational field precision and blank... Methods for PM2.5 or PM10â2.5 § 53.58 Operational field precision and blank test. (a) Overview. This...

  2. Research on flow mechanism of material for spur gear in closed extruding fine blanking process

    NASA Astrophysics Data System (ADS)

    Deng, Ming; Liu, Lu-zhou

    2013-05-01

    The finite element method (FEM) is applied to analyze closed extruding fine blanking gear. The reason of engendering corner collapse is the friction between blank and die. Meanwhile, this paper analyzes effects of various counterpunch forces on the flow characteristics, obtains the fiber distribution on different sections of the gear. The effects of counterpunch forces on material flow characteristics in deformation zone and the swirling flow in scrap are also obtained.

  3. Estimation of Thermal Contact Conductance between Blank and Tool Surface in Hot Stamping Process

    NASA Astrophysics Data System (ADS)

    Taha, Zahari; Hanafiah Shaharudin, M. A.

    2016-02-01

    In hot stamping, the determination of the thermal contact conductance values between the blank and tool surface during the process is crucial for the purpose of simulating the blank rapid cooling inside the tool using finite element analysis (FEA). The thermal contact conductance value represents the coefficient of the heat transfer at the surface of two solid bodies in contact and is known to be influenced greatly by the applied pressure. In order to estimate the value and its dependency on applied pressure, the process of hot stamping was replicated and simplified into a process of compression of heated flat blank in between the tool at different applied pressure. The temperature of the blank and tool surface were measured by means of thermocouples installed inside the tool. Based on the measured temperature, the thermal contact conductance between the surfaces was calculated using Newton's cooling law equation. The calculated value was then used to simulate the blank cooling inside the tool using FEA commercial software. This paper describes an experimental approach to estimate the thermal contact conductance between a blank made of Boron Steel (USIBOR 1500) and tool made of Tool Steel (STAVAX). Its dependency on applied pressure is also studied and the experimental results were then compared with FEA simulations.

  4. SEMATECH produces defect-free EUV mask blanks: defect yield and immediate challenges

    NASA Astrophysics Data System (ADS)

    Antohe, Alin O.; Balachandran, Dave; He, Long; Kearney, Patrick; Karumuri, Anil; Goodwin, Frank; Cummings, Kevin

    2015-03-01

    Availability of defect-free reflective mask has been one of the most critical challenges to extreme ultraviolet lithography (EUVL). To mitigate the risk, significant progress has been made on defect detection, pattern shifting, and defect repair. Clearly such mitigation strategies are based on the assumption that defect counts and sizes from incoming mask blanks must be below practical levels depending on mask specifics. The leading industry consensus for early mask product development is that there should be no defects greater than 80 nm in the quality area, 132 mm x 132 mm. In addition less than 10 defects smaller than 80 nm may be mitigable. SEMATECH has been focused on EUV mask blank defect reduction using Veeco Nexus TM IBD platform, the industry standard for mask blank production, and assessing if IBD technology can be evolved to a manufacturing solution. SEMATECH has recently announced a breakthrough reduction of defects in the mask blank deposition process resulting in the production of two defect-free EUV mask blanks at 54 nm inspection sensitivity (SiO2 equivalent). This paper will discuss the dramatic reduction of baseline EUV mask blank defects, review the current deposition process run and compare results with previous process runs. Likely causes of remaining defects will be discussed based on analyses as characterized by their compositions and whether defects are embedded in the multilayer stack or non-embedded.

  5. Improvement of defect mitigation with EUV actinic blank inspection prototype for 16 nm hp

    NASA Astrophysics Data System (ADS)

    Murachi, Tetsunori; Amano, Tsuyoshi; Suzuki, Tomohiro; Miyai, Hiroki

    2014-04-01

    A major challenge for extreme ultraviolet lithography (EUVL) is avoiding defects in the fabrication of multilayered (ML) mask blanks. Substrate defects and adders during ML coating are responsible for ML defects which causes changes on phase and amplitude of EUV light. ML defects must be identified by inspection prior to absorber patterning in order to reduce the effects of ML defects via covering them with patterns to permit the use of fewer ML defect blanks. Fiducial marks (FMs) on ML blanks can be used for mask alignment and to accurately and precisely determine the locations of ML defects. In this study, we fabricated an FM mask by resist exposure using an e-beam writer and etching. Then, we inspected FMs and ML defects with an EUV actinic full-field mask blank inspection tool developed by EIDEC-LaserTec (LT ABI). Next, we evaluated the ML defect location accuracy on the mask based on FMs of several line depths by deriving center position of FMs and defects with Lorentz, Gaussian fitting and center-of-mass calculation. Here, we explain the estimation of defect location accuracy using FMs and the LT ABI, and discuss the defect numbers which can be covered by absorber patterns. Fewer than 19 defects per blank should be required for EUV blanks to cover ML defects with patterns.

  6. 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

  7. Japanese R&D on new cast alloys and materials

    SciTech Connect

    Hayden, H.W.

    1996-05-01

    On the basis of observations of the JTEC team, it appears that Japanese universities and research institutes are leading long-term R&D thrusts for development of new materials casting technologies. Significant efforts include amorphous metals, intermetallics, application of MHD in continuous casting of steel, and energy efficient furnace technology. Industrial R&D seems focused more on process improvements than on new product technologies, but significant efforts in new cast materials included cast metal matrix composites, materials substitutions for thinner wall products, and advanced ceramic products for foundry industry applications.

  8. Impact of the analytical blank in the uncertainty evaluation of the copper content in waters by flame atomic absorption spectrometry.

    PubMed

    de Oliveira, Elcio Cruz; Monteiro, Maria Inês Couto; Pontes, Fernanda Veronesi Marinho; de Almeida, Marcelo Dominguez; Carneiro, Manuel Castro; da Silva, Lílian Irene Dias; Alcover Neto, Arnaldo

    2012-01-01

    Chemical analysts use analytical blanks in their analyses, but seldom is this source of uncertainty evaluated. Generally, there is great confusion. Although the numerical value of the blank, in some situations, can be negligible, its source of uncertainty cannot be. This article discusses the uncertainty contribution of the analytical blank using a numerical example of the copper content in waters by flame atomic absorption spectrometry. The results indicate that the uncertainties of the analytical blank can contribute up to 50% when the blank sample is considered in this analysis, confirming its high impact. This effect can be primarily observed where the analyte concentration approaches the lower range of the analytical curve. Even so, the blank is not always computed. Therefore, the relevance of the analytical blank can be confirmed by uncertainty evaluation. PMID:22649945

  9. Solvent casting flow from slot die

    NASA Astrophysics Data System (ADS)

    Lee, Semi; Nam, Jaewook

    2015-11-01

    A continuous solvent casting method using a slot die can precisely control the film thickness by adjusting the operating conditions, such as the belt speed and pumping rate, not the liquid property. Therefore, it is a suitable method for high precision continuous film production. In this particular method, the dope, or casting solution, is pumped through the feed slot to form a short curtain between the die and the moving belt. Although this method is widely used in producing films for various applications, it is difficult to find indepth analyses of such flow. In this study, we developed a finite element computational model for the steady-state two-dimensional sovent casting flow from the slot die. The effect of die configurations, rheological properties and operating conditions on the behavior and shape of the gas/liquid interfaces and the location of the dynamic contact line, which is the place where the dope meets the moving belt, were investigated.

  10. INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' ...

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

    INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' PIPE OPERATOR SPRAYING A POWDER TO HELP SOLIDIFY THE PIPE BEING CENTRIFUGALLY CAST. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  11. Clean Metal Casting

    SciTech Connect

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The objective of this project is to develop a technology for clean metal processing that is capable of consistently providing a metal cleanliness level that is fit for a given application. The program has five tasks: Development of melt cleanliness assessment technology, development of melt contamination avoidance technology, development of high temperature phase separation technology, establishment of a correlation between the level of melt cleanliness and as cast mechanical properties, and transfer of technology to the industrial sector. Within the context of the first task, WPI has developed a standardized Reduced Pressure Test that has been endorsed by AFS as a recommended practice. In addition, within the context of task1, WPI has developed a melt cleanliness sensor based on the principles of electromagnetic separation. An industrial partner is commercializing the sensor. Within the context of the second task, WPI has developed environmentally friendly fluxes that do not contain fluorine. Within the context of the third task, WPI modeled the process of rotary degassing and verified the model predictions with experimental data. This model may be used to optimize the performance of industrial rotary degassers. Within the context of the fourth task, WPI has correlated the level of melt cleanliness at various foundries, including a sand casting foundry, a permanent mold casting foundry, and a die casting foundry, to the casting process and the resultant mechanical properties. This is useful in tailoring the melt cleansing operations at foundries to the particular casting process and the desired properties of cast components.

  12. Casting in Sport

    PubMed Central

    DeCarlo, Mark; Malone, Kathy; Darmelio, John; Rettig, Arthur

    1994-01-01

    Attempts by sports medicine professionals to return high school athletes with hand and wrist injuries to competition quickly and safely have been the source of confusion and debate on many playing fields around the country. In addition to the differing views regarding the appropriateness of playing cast usage in high school football, a debate exists among sports medicine professionals as to which material is best suited for playing cast construction. Materials used in playing cast construction should be hard enough to provide sufficient stabilization to the injured area and include adequate padding to absorb blunt impact forces. The purpose of the biomechanical portion of this investigation was to attempt to determine the most appropriate materials for use in constructing playing casts for the hand and wrist by assessing different materials for: 1) hardness using a Shore durometer, and 2) ability to absorb impact using a force platform. Results revealed that RTV11 and Scotchcast were the “least hard” of the underlying casting materials and that Temper Stick foam greatly increased the ability of RTV11 to absorb impact. Assessment of the mechanical properties of playing cast materials and review of current developments in high school football rules are used to aid practitioners in choosing the most appropriate materials for playing cast construction. ImagesFig 1.Fig 2.Fig 3. PMID:16558257

  13. CASTING METHOD AND APPARATUS

    DOEpatents

    Gray, C.F.; Thompson, R.H.

    1958-10-01

    An improved apparatus for the melting and casting of uranium is described. A vacuum chamber is positioned over the casting mold and connected thereto, and a rod to pierce the oxide skin of the molten uranium is fitted into the bottom of the melting chamber. The entire apparatus is surrounded by a jacket, and operations are conducted under a vacuum. The improvement in this apparatus lies in the fact that the top of the melting chamber is fitted with a plunger which allows squeezing of the oxide skin to force out any molten uranium remaining after the skin has been broken and the molten charge has been cast.

  14. CENTRIFUGAL CASTING MACHINE

    DOEpatents

    Shuck, A.B.

    1958-04-01

    A device is described that is specifically designed to cast uraniumn fuel rods in a vacuunn, in order to obtain flawless, nonoxidized castings which subsequently require a maximum of machining or wastage of the expensive processed material. A chamber surrounded with heating elements is connected to the molds, and the entire apparatus is housed in an airtight container. A charge of uranium is placed in the chamber, heated, then is allowed to flow into the molds While being rotated. Water circulating through passages in the molds chills the casting to form a fine grained fuel rod in nearly finished form.

  15. Edge Length and Surface Area of a Blank: Experimental Assessment of Measures, Size Predictions and Utility

    PubMed Central

    Dogandžić, Tamara; Braun, David R.; McPherron, Shannon P.

    2015-01-01

    Blank size and form represent one of the main sources of variation in lithic assemblages. They reflect economic properties of blanks and factors such as efficiency and use life. These properties require reliable measures of size, namely edge length and surface area. These measures, however, are not easily captured with calipers. Most attempts to quantify these features employ estimates; however, the efficacy of these estimations for measuring critical features such as blank surface area and edge length has never been properly evaluated. In addition, these parameters are even more difficult to acquire for retouched implements as their original size and hence indication of their previous utility have been lost. It has been suggested, in controlled experimental conditions, that two platform variables, platform thickness and exterior platform angle, are crucial in determining blank size and shape meaning that knappers can control the interaction between size and efficiency by selecting specific core angles and controlling where fracture is initiated. The robustness of these models has rarely been tested and confirmed in context other than controlled experiments. In this paper, we evaluate which currently employed caliper measurement methods result in the highest accuracy of size estimations of blanks, and we evaluate how platform variables can be used to indirectly infer aspects of size on retouched artifacts. Furthermore, we investigate measures of different platform management strategies that control the shape and size of artifacts. To investigate these questions, we created an experimental lithic assemblage, we digitized images to calculate 2D surface area and edge length, which are used as a point of comparison for the caliper measurements and additional analyses. The analysis of aspects of size determinations and the utility of blanks contributes to our understanding of the technological strategies of prehistoric knappers and what economic decisions they made

  16. 40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the zinc... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The provisions of...

  17. 40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the zinc... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The provisions of...

  18. 21 CFR 888.5980 - Manual cast application and removal instrument.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual cast application and removal instrument... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5980 Manual cast application and removal instrument. (a) Identification. A manual cast application and removal instrument is...

  19. Tundish Technology for Casting Clean Steel: A Review

    NASA Astrophysics Data System (ADS)

    Sahai, Yogeshwar

    2016-03-01

    With increasing demand of high-quality clean steel, cleanliness is of paramount importance in steel production and casting. Tundish plays an important role in controlling the continuously cast steel quality as it links a batch vessel, ladle, to a continuous casting mold. Tundish is also the last vessel in which metal flows before solidifying in mold. For controlling the quality of steel, flow and temperature control of the melt are critical, and these are presented in this paper. Use of proper flux, design of flow control devices, and gas injection in tundish become important factors in casting clean steel. Recycling of hot tundish, centrifugal flow tundish, H-shaped tundish, etc. are some of the developments which were implemented to cast clean steel and these are discussed.

  20. Tundish Technology for Casting Clean Steel: A Review

    NASA Astrophysics Data System (ADS)

    Sahai, Yogeshwar

    2016-08-01

    With increasing demand of high-quality clean steel, cleanliness is of paramount importance in steel production and casting. Tundish plays an important role in controlling the continuously cast steel quality as it links a batch vessel, ladle, to a continuous casting mold. Tundish is also the last vessel in which metal flows before solidifying in mold. For controlling the quality of steel, flow and temperature control of the melt are critical, and these are presented in this paper. Use of proper flux, design of flow control devices, and gas injection in tundish become important factors in casting clean steel. Recycling of hot tundish, centrifugal flow tundish, H-shaped tundish, etc. are some of the developments which were implemented to cast clean steel and these are discussed.

  1. MOLDS FOR CASTING PLUTONIUM

    DOEpatents

    Anderson, J.W.; Miley, F.; Pritchard, W.C.

    1962-02-27

    A coated mold for casting plutonium comprises a mold base portion of a material which remains solid and stable at temperatures as high as the pouring temperature of the metal to be cast and having a thin coating of the order of 0.005 inch thick on the interior thereof. The coating is composed of finely divided calcium fluoride having a particle size of about 149 microns. (AEC)

  2. Method of casting aerogels

    DOEpatents

    Poco, J.F.

    1993-09-07

    The invention describes a method for making monolithic castings of transparent silica aerogel with densities in the range from 0.001 g/cm[sup 3] to 0.6 g/cm[sup 3]. Various shapes of aerogels are cast in flexible polymer molds which facilitate removal and eliminate irregular surfaces. Mold dimensions are preselected to account for shrinkage of aerogel which occurs during the drying step of supercritical extraction of solvent. 2 figures.

  3. Method of casting aerogels

    DOEpatents

    Poco, John F.

    1993-01-01

    The invention describes a method for making monolithic castings of transparent silica aerogel with densities in the range from 0.001 g/cm.sup.3 to 0.6 g/cm.sup.3. Various shapes of aerogels are cast in flexible polymer molds which facilitate removal and eliminate irregular surfaces. Mold dimensions are preselected to account for shrinkage of alcogel which occurs during the drying step of supercritical extraction of solvent.

  4. Casting Characteristics of Aluminum Die Casting Alloys

    SciTech Connect

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.

  5. A Winning Cast

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Howmet Research Corporation was the first to commercialize an innovative cast metal technology developed at Auburn University, Auburn, Alabama. With funding assistance from NASA's Marshall Space Flight Center, Auburn University's Solidification Design Center (a NASA Commercial Space Center), developed accurate nickel-based superalloy data for casting molten metals. Through a contract agreement, Howmet used the data to develop computer model predictions of molten metals and molding materials in cast metal manufacturing. Howmet Metal Mold (HMM), part of Howmet Corporation Specialty Products, of Whitehall, Michigan, utilizes metal molds to manufacture net shape castings in various alloys and amorphous metal (metallic glass). By implementing the thermophysical property data from by Auburn researchers, Howmet employs its newly developed computer model predictions to offer customers high-quality, low-cost, products with significantly improved mechanical properties. Components fabricated with this new process replace components originally made from forgings or billet. Compared with products manufactured through traditional casting methods, Howmet's computer-modeled castings come out on top.

  6. On the Determination of the Blank Shape Contour for Thin Precision Parts Obtained by Stamping

    NASA Astrophysics Data System (ADS)

    Azaouzi, M.; Delamézière, A.; Naceur, H.; Sibaud, D.; Batoz, J. L.; Belouettar, S.

    2007-05-01

    The present study deals with the "automatic" determination of the initial blank shape contour for 3D thin metallic precision parts obtained by stamping, knowing the 3D CAD geometry of the final part (the desired product). The forming process can involve several steps presented in this paper that consists in applying a heuristic method of optimization to find out the initial blank shape of thin precision metallic part in order to obtain a final part, with a required 3D geometry (specified). The purpose of the present approach is to replace the experimental trial and error optimization method used currently, which is expensive and time consuming. The principle of the "heuristic" optimization method is to first estimate the blank shape using the Inverse Approach, then to compensate the shape error calculated in each node of the blank contour. The "heuristic" optimization loop is done using a precise incremental code (Abaqus Explicit or Stampack) and, the iterations loop is stopped when the shape errors are within some initially fixed tolerances. The method is tested in the case of a special stamping process where the parts are pressed in one or more steps using a manual press, without blank holder and by the mean of tools having complex shape. The sensitivities of the process parameters regarding the optimal solution are investigated.

  7. Deep blank-field catalogue for medium- and large-sized telescopes

    NASA Astrophysics Data System (ADS)

    Jiménez Esteban, F. M.; Cabrera Lavers, A.; Cardiel, N.; Alacid, J. M.

    2012-11-01

    The observation of blank fields, defined as regions of the sky that are devoid of stars down to a given threshold magnitude, constitutes one of the most relevant calibration procedures required for the proper reduction of astronomical data obtained following typical observing strategies. In this work, we have used Delaunay triangulation to search for deep blank fields throughout the whole sky, with a minimum size of 10 arcmin in diameter and an increasing threshold magnitude from 15 to 18 in the R band of the USNO-B Catalog of the United States Naval Observatory. The result is a catalogue with the deepest blank fields known so far. A short sample of these regions has been tested with the 10.4-m Gran Telescopio Canarias, and it has been shown to be extremely useful for medium- and large-sized telescopes. Because some of the regions found could also be suitable for new extragalactic studies, we have estimated the galactic extinction in the direction of each deep blank field. This catalogue is accessible through the virtual observatory tool TESELA, and the user can retrieve - and visualize using ALADIN - the deep blank fields available near a given position in the sky.

  8. Salvaged castings and methods of salvaging castings with defective cast cooling bumps

    DOEpatents

    Johnson, Robert Alan; Schaeffer, Jon Conrad; Lee, Ching-Pang; Abuaf, Nesim; Hasz, Wayne Charles

    2002-01-01

    Castings for gas turbine parts exposed on one side to a high-temperature fluid medium have cast-in bumps on an opposite cooling surface side to enhance heat transfer. Areas on the cooling surface having defectively cast bumps, i.e., missing or partially formed bumps during casting, are coated with a braze alloy and cooling enhancement material to salvage the part.

  9. Steel castings by the electroslag casting technique. [CF8M

    SciTech Connect

    Sikka, V.K.; Mitchell, A.

    1984-01-01

    ELectroslag casting facilities in Canada and the United States were reviewed. Several valve body castings of 2-1/4 Cr-1 Mo, 9 Cr-1 Mo, and 18% Cr-8% Ni(Mo) steels were made at the University of British Columbia facility. These castings were examined for surface finish, chemical segregation, and macrostructure in the as-cast condition and after various heat treatments. Castings were subjected to tensile, Charpy impact, and creep testing. Results of these tests were compared with similar data on wrought material and sand castings.

  10. Fatigue of die cast zinc alloys

    SciTech Connect

    Schrems, K.K.; Dogan, O.N.; Goodwin, F.E.

    2006-04-01

    The rotating bending fatigue limit of die cast zinc alloy 2, alloy 3, alloy 5, AcuZinc 5, and ZA-8 were determined as a part of an on-going program by ILZRO into the mechanical properties of die cast zinc. The stress-life (S-N) curves of alloys 3, 5, AcuZinc 5, and ZA-8 were determined previously. This presentation reports the results of the S-N curve for Alloy 2 and the calculated fatigue limits for all five alloys. During the previous stress-life testing, the samples were stopped at 10 million cycles and the fatigue limit for alloy 3, alloy 5, and AcuZinc 5 appeared to be higher and the fatigue limit for ZA-8 appeared to be lower than the values reported in the literature. This was further investigated in alloy 5 and ZA-8 by testing continuous cast bulk alloy 5 and ZA-8.

  11. Enhanced procedural blank control for organic geochemical studies of critical sample material.

    PubMed

    Leider, A; Schumacher, T C; Hallmann, C

    2016-09-01

    Organic contamination of sedimentary rocks can produce artefacts in studies of hydrocarbon composition, and this can have significant negative consequences for interpretations of the geobiological record. False positives - that is cases of non-syngenetic hydrocarbon biomarkers - are common in Precambrian studies, and significant challenges persist despite the intensive effort devoted to these studies. Efforts to standardize the 'burden of proof' for distinguishing between contamination and syngenetic material have to date failed to yield a simple or universal protocol, yet the need remains great, as both bitumen-lean rocks and bitumen-rich samples can be vulnerable to the accumulation of false-positive signals. In an effort to determine the best approach to quality control, we tested the capability of different blank materials to collect ambient contamination by assessing their capacity to adsorb hydrocarbons during storage in plastic bags and found that commonly used Quartz sand does not provide an adequate measure of storage- or laboratory-induced contamination. Brick blanks, having the advantage that they can parallel rock samples even during the sawing process, are characterized by similar poor adsorption properties. Primarily steered by mineralogy, organic carbon content and surface area, model-black shales can adsorb up to 20 times more contaminants than sand blanks and up to 200 times more contaminants than organic-free model-carbonates. This observation provides an explanation for reports and observations of seemingly systematic stratigraphic variation of contaminants, but mostly should raise awareness for the evaluation of procedural blanks, in particular of sample-to-blank ratios, when studying bitumen-lean rock samples of varying lithologies. Additionally, differences between the hydrocarbon profiles in plastic bags and the hydrocarbon signatures transferred to blank materials emphasize difficulties in the unequivocal detection of contamination sources

  12. Mercury Deposition Network Site Operator Training for the System Blank and Blind Audit Programs

    USGS Publications Warehouse

    Wetherbee, Gregory A.; Lehmann, Christopher M.B.

    2008-01-01

    The U.S. Geological Survey operates the external quality assurance project for the National Atmospheric Deposition Program/Mercury Deposition Network. The project includes the system blank and blind audit programs for assessment of total mercury concentration data quality for wet-deposition samples. This presentation was prepared to train new site operators and to refresh experienced site operators to successfully process and submit system blank and blind audit samples for chemical analysis. Analytical results are used to estimate chemical stability and contamination levels of National Atmospheric Deposition Program/Mercury Deposition Network samples and to evaluate laboratory variability and bias.

  13. CAST FLOOR WITH VIEW OF TORPEDO LADLE (BENEATH CAST FLOOR) ...

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

    CAST FLOOR WITH VIEW OF TORPEDO LADLE (BENEATH CAST FLOOR) AND KEEPERS OF THE CAST HOUSE FLOOR, S.L. KIMBROUGH AND DAVID HOLMES. - U.S. Steel, Fairfield Works, Blast Furnace No. 8, North of Valley Road, West of Ensley-Pleasant Grove Road, Fairfield, Jefferson County, AL

  14. Prediction of Grades and Satisfaction Using the Strong Vocational Interest Blank.

    ERIC Educational Resources Information Center

    Welch, Thomas Alfred

    Research was undertaken to investigate improving selection criteria for several curricula at the Naval Postgraduate School using the Strong Vocational Interest Blank and a biographical questionnaire as indicators of academic success and satisfaction with curriculum and future assignments. The seven curricula investigated were merged into three…

  15. Use of Monocrystalline Silicon as Tool Material for Highly Accurate Blanking of Thin Metal Foils

    SciTech Connect

    Hildering, Sven; Engel, Ulf; Merklein, Marion

    2011-05-04

    The trend towards miniaturisation of metallic mass production components combined with increased component functionality is still unbroken. Manufacturing these components by forming and blanking offers economical and ecological advantages combined with the needed accuracy. The complexity of producing tools with geometries below 50 {mu}m by conventional manufacturing methods becomes disproportional higher. Expensive serial finishing operations are required to achieve an adequate surface roughness combined with accurate geometry details. A novel approach for producing such tools is the use of advanced etching technologies for monocrystalline silicon that are well-established in the microsystems technology. High-precision vertical geometries with a width down to 5 {mu}m are possible. The present study shows a novel concept using this potential for the blanking of thin copper foils with monocrystallline silicon as a tool material. A self-contained machine-tool with compact outer dimensions was designed to avoid tensile stresses in the brittle silicon punch by an accurate, careful alignment of the punch, die and metal foil. A microscopic analysis of the monocrystalline silicon punch shows appropriate properties regarding flank angle, edge geometry and surface quality for the blanking process. Using a monocrystalline silicon punch with a width of 70 {mu}m blanking experiments on as-rolled copper foils with a thickness of 20 {mu}m demonstrate the general applicability of this material for micro production processes.

  16. Enabling high speed friction stir welding of aluminum tailor welded blanks

    NASA Astrophysics Data System (ADS)

    Hovanski, Yuri

    Current welding technologies for production of aluminum tailor-welded blanks (TWBs) are utilized in low-volume and niche applications, and have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high-volumes. While friction stir welding (FSW) has traditionally been applied at linear velocities less than one meter per minute, high volume production applications demand the process be extended to higher velocities more amenable to cost sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low to moderate welding velocities do not directly translate to high speed linear friction stir welding. Therefore, in order to facilitate production of high volume aluminum FSW components, parameters were developed with a minimum welding velocity of three meters per minute. With an emphasis on weld quality, welded blanks were evaluated for post-weld formability using a combination of numerical and experimental methods. Evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum tailor-welded blanks, which provided validation of the numerical and experimental analysis of laboratory scale tests.

  17. Fill in the Blank: Culture Jamming and the Advertising of Agency

    ERIC Educational Resources Information Center

    Lambert-Beatty, Carrie

    2010-01-01

    This article is a review on billboard liberation and some other projects that develop the idea of talking back or over advertising in a playful and youthful way. In one of them, Ji Lee's Bubble Project, an artist places blank thought-bubble stickers on street advertisements and waits to see what people write on them, completing the work of art and…

  18. Is ''BLANK'' a Suitable Neutral Prime for Event-Related Potential Experiments?

    ERIC Educational Resources Information Center

    Dien, Joseph; Franklin, Michael S.; May, Christopher J.

    2006-01-01

    We report an experiment that evaluates whether "BLANK" or an unrelated prime is a more suitable baseline for assessing priming for an ERP study. Sixteen subjects performed a lexical decision task with a 1 s prime-target stimulus onset asynchrony. Increased amplitude for the N400 was observed for targets in the unrelated prime condition whereas…

  19. Avoiding the Blank Stare: Teacher Training with the Gradual Release of Responsibility in Mind

    ERIC Educational Resources Information Center

    Clark, Sandra

    2014-01-01

    Most teachers have experienced the "blank stare" when after teaching a lesson implementing all their best strategies using their best language-learning English and at the moment of releasing responsibility--that is, moving from the teacher's responsibility to prepare students for the task to their responsibility to carry it out--the…

  20. Method for casting polyethylene pipe

    NASA Technical Reports Server (NTRS)

    Elam, R. M., Jr.

    1973-01-01

    Short lengths of 7-cm ID polyethylene pipe are cast in a mold which has a core made of room-temperature-vulcanizable (RTV) silicone. Core expands during casting and shrinks on cooling to allow for contraction of the polyethylene.

  1. Seismic blanking zones in the deep-water Ullung Basin, East Sea of Korea.

    NASA Astrophysics Data System (ADS)

    Ryu, Byong-Jae; Riedel, Michael; Yoo, Dong-Geun

    2015-04-01

    A total 12366.395 L.km of 2D multichannel seismic data were acquired by the Korea Institute of Geoscience and Mineral Resources (KIGAM) for detecting and mapping seismic indicators for the presence of gas hydrate in the deep-water Ulleung Basin, East Sea of Korea. The seismic data were acquired using Trilogy System of Geco-Prakla, Bolt Air-gun System onboard the R/V TAMHAE II of KIGAM during the years of 2000 to 2004. The seismic faices of shallow sediments were also analyzed to understand the sedimentary strata developed in the basin. Seismic data were processed to define gas hydrate indicators such as bottom simulating reflectors (BSRs) and seismic blank zones. The BSR was identified by (a) its polarity opposite to the seafloor, (b) its seafloor-parallel reflection behavior, and (c) its occurrence at a sub-bottom depth corresponding to the expected base of gas hydrate stability zone, on heat flow and other thermal data for the region and on seismic velocity data. The seismic velocity analysis was also conducted for determining the velocity deviation effect of high-velocity gas hydrate and underlying low-velocity free gas. The BSRs occur mainly in the southern part of the basin where mass transport deposits are widely occurring. A number of vertical to sub-vertical seismic blanking zones were identified in the basin. The blanking zones are near-vertical broad chimney-like structures of reduced seismic reflectivity. They may be formed by gas and/or fluid upwelling through fractures and faults. Many of the blanking zones show apparent velocity pull-up effects of sediment layering structures that are interpreted to be a result of higher velocity gas hydrate. The presence of substantial amounts of gas hydrate in the blank zones were first found by piston coring in 2007, and subsequently confirmed by two deep-drilling expeditions in 2007 and 2010. Most of the blanking zones occur in well-bedded turbidite/hemi-pelagic sediments in the northern deep basin. The

  2. Influence of Refiner in ZA-12 Alloys During Centrifugal Casting Process

    NASA Astrophysics Data System (ADS)

    Jyothi, P. N.; Shailesh, Rao A.; Jagath, M. C.; Channakeshavalu, K.

    2014-05-01

    The behavior of the molten melt plays a predominant role in determining the quality cast product. In continuous casting, addition of refiner 1% (Al+Ti+B2) onto the molten metal increases its mechanical properties as a result of the nucleation within the process. In this article, the effect of refiners in the centrifugal casting process was studied. Eutectic ZA-12 alloys were taken for our experiment and cast at various rotational speeds (400 rpm, 600 rpm, and 800 rpm) with and without the addition of refiners. Rather than increase in the solidification rate as in continuous casting, these refiners diminish the solidification rate, which in turn forms an irregular-shaped cast tube. The microstructure and hardness for the entire cast specimen were discussed finally.

  3. Casting Of Multilayer Ceramic Tapes

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr.

    1991-01-01

    Procedure for casting thin, multilayer ceramic membranes, commonly called tapes, involves centrifugal casting at accelerations of 1,800 to 2,000 times normal gravitational acceleration. Layers of tape cast one at a time on top of any previous layer or layers. Each layer cast from slurry of ground ceramic suspended in mixture of solvents, binders, and other components. Used in capacitors, fuel cells, and electrolytic separation of oxygen from air.

  4. Blank corrections for ramped pyrolysis radiocarbon dating of sedimentary and soil organic carbon.

    PubMed

    Fernandez, Alvaro; Santos, Guaciara M; Williams, Elizabeth K; Pendergraft, Matthew A; Vetter, Lael; Rosenheim, Brad E

    2014-12-16

    Ramped pyrolysis (RP) targets distinct components of soil and sedimentary organic carbon based on their thermochemical stabilities and allows the determination of the full spectrum of radiocarbon ((14)C) ages present in a soil or sediment sample. Extending the method into realms where more precise ages are needed or where smaller samples need to be measured involves better understanding of the blank contamination associated with the method. Here, we use a compiled data set of RP measurements of samples of known age to evaluate the mass of the carbon blank and its associated (14)C signature, and to assess the performance of the RP system. We estimate blank contamination during RP using two methods, the modern-dead and the isotope dilution method. Our results indicate that during one complete RP run samples are contaminated by 8.8 ± 4.4 μg (time-dependent) of modern carbon (MC, fM ∼ 1) and 4.1 ± 5.5 μg (time-independent) of dead carbon (DC, fM ∼ 0). We find that the modern-dead method provides more accurate estimates of uncertainties in blank contamination; therefore, the isotope dilution method should be used with caution when the variability of the blank is high. Additionally, we show that RP can routinely produce accurate (14)C dates with precisions ∼100 (14)C years for materials deposited in the last 10,000 years and ∼300 (14)C years for carbon with (14)C ages of up to 20,000 years. PMID:25375178

  5. Mix/Cast Contamination Control

    NASA Technical Reports Server (NTRS)

    Wallentine, M.

    2005-01-01

    Presented is a training handbook for Mix/Cast Contamination Control; a part of a series of training courses to qualify access to Mix/Cast facilities. Contents: List Contamination Control Requirements; Identify foreign objects debris (FOD), Control Areas and their guidelines; Describe environmental monitoring; List Contamination Control Initiatives; Describe concern for Controlled Materials; Identify FOD Controlled Areas in Mix/Cast.

  6. Casting and Angling.

    ERIC Educational Resources Information Center

    Little, Mildred J.; Bunting, Camille

    The self-contained packet contains background information, lesson plans, 15 transparency and student handout masters, drills and games, 2 objective examinations, and references for teaching a 15-day unit on casting and angling to junior high and senior high school students, either as part of a regular physical education program or as a club…

  7. Extrusion cast explosive

    DOEpatents

    Scribner, Kenneth J.

    1985-01-01

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants.

  8. ShakeCast Manual

    USGS Publications Warehouse

    Lin, Kuo-Wan; Wald, David J.

    2008-01-01

    ShakeCast is a freely available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users? facilities, and generates potential damage assessment notifications, facility damage maps, and other Web-based products for emergency managers and responders.

  9. Hair Casts or Pseudonits

    PubMed Central

    França, Katlein; Villa, Ricardo Tadeu; Silva, Isabella Rezende; de Carvalho, Cristine Almeida; Bedin, Valcinir

    2011-01-01

    Hair casts or pseudonits are thin, elongated, cylindrical concretions that encircle the hair shaft and can be easily dislodged. A case of pseudonits in a 9-year-old girl is reported. Though not unusual, false diagnoses are common. PMID:22223977

  10. Casting and Angling.

    ERIC Educational Resources Information Center

    Smith, Julian W.

    As part of a series of books and pamphlets on outdoor education, this manual consists of easy-to-follow instructions for fishing activities dealing with casting and angling. The manual may be used as a part of the regular physical education program in schools and colleges or as a club activity for the accomplished weekend fisherman or the…

  11. Evaluation of an improved centrifugal casting machine.

    PubMed

    Donovan, T E; White, L E

    1985-05-01

    A Type III gold alloy, a silver-palladium alloy, and a base metal alloy were cast in two different centrifugal casting machines. With the number of complete cast mesh squares as an indicator of castability, the Airspin casting machine produced superior castings with all three alloys. The base metal alloy produced the greatest number of complete squares with both casting machines. PMID:3889295

  12. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--QA ANALYTICAL RESULTS FOR PAHS IN BLANK SAMPLES

    EPA Science Inventory

    The PAHs in Blanks data set contains the analytical results for measurements of up to 26 polynuclear aromatic hydrocarbons (PAHs) in 27 blank samples of indoor air, outdoor air, and food. The PAHs of interest include Anthracene (CAS # 120-12-7), Benzo(ghi)pyrelene (CAS# 191-24-2...

  13. Computer cast blast modelling

    SciTech Connect

    Chung, S.; McGill, M.; Preece, D.S.

    1994-07-01

    Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than normal is required plus an initiation technique designed to produce a much greater degree of horizontal muck movement. This paper compares two blast models known as DMC (Distinct Motion Code) and SABREX (Scientific Approach to Breaking Rock with Explosives). DMC, applies discrete spherical elements interacted with the flow of explosive gases and the explicit time integration to track particle motion resulting from a blast. The input to this model includes multi-layer rock properties, and both loading geometry and explosives equation-of-state parameters. It enables the user to have a wide range of control over drill pattern and explosive loading design parameters. SABREX assumes that heave process is controlled by the explosive gases which determines the velocity and time of initial movement of blocks within the burden, and then tracks the motion of the blocks until they come to a rest. In order to reduce computing time, the in-flight collisions of blocks are not considered and the motion of the first row is made to limit the motion of subsequent rows. Although modelling a blast is a complex task, the DMC can perform a blast simulation in 0.5 hours on the SUN SPARCstation 10--41 while the new SABREX 3.5 produces results of a cast blast in ten seconds on a 486-PC computer. Predicted percentage of cast and face velocities from both computer codes compare well with the measured results from a full scale cast blast.

  14. Bioinspired Design: Magnetic Freeze Casting

    NASA Astrophysics Data System (ADS)

    Porter, Michael Martin

    Nature is the ultimate experimental scientist, having billions of years of evolution to design, test, and adapt a variety of multifunctional systems for a plethora of diverse applications. Next-generation materials that draw inspiration from the structure-property-function relationships of natural biological materials have led to many high-performance structural materials with hybrid, hierarchical architectures that fit form to function. In this dissertation, a novel materials processing method, magnetic freeze casting, is introduced to develop porous scaffolds and hybrid composites with micro-architectures that emulate bone, abalone nacre, and other hard biological materials. This method uses ice as a template to form ceramic-based materials with continuously, interconnected microstructures and magnetic fields to control the alignment of these structures in multiple directions. The resulting materials have anisotropic properties with enhanced mechanical performance that have potential applications as bone implants or lightweight structural composites, among others.

  15. Summary and evaluation of pesticides in field blanks collected for the National Water-Quality Assessment Program, 1992-95

    USGS Publications Warehouse

    Martin, Jeffrey D.; Gilliom, Robert J.; Schertz, Terry L.

    1999-01-01

    Field blanks are quality-control samples used to assess contamination in environmental water samples. Contamination is the unintentional introduction of a chemical (pesticides in this instance) into an environmental water sample from sources such as inadequately cleaned equipment, dirty hands, dust, rain, or fumes. Contamination causes a positive bias in analytical measurements that may need to be considered in the analysis and interpretation of the environmental data. Estimates of pesticide contamination in environmental water samples collected for the National Water-Quality Assessment (NAWQA) Program are used to qualify, where needed, interpretations of the occurrence and distribution of pesticides in the surface and ground waters of the United States. Field blanks collected from 1992 to 1995 as part of the NAWAQA Program were analyzed for 88 pesticides and pesticide metabolites. Of 47 pesticides determined by gas chromatography/mass spectrometry, 23 were detected at least once in 175 surfacewater field blanks and 15 were detected at least once in 145 ground-water field blanks. The most frequently detected pesticides in surface-water field blanks were atrazine (in 10.9 percent of blanks), simazine (9.1 percent), and metolachlor (4.6 percent). The most frequently detected pesticides in ground-water field blanks were p,p?-DDE (4.1 percent) and atrazine (2.8 percent). The maximum pesticide concentration detected by gas chromatography/ mass spectrometry in a surfacewater field blank was 0.120 microgram per liter (mg/L) for pronamide; the maximum concentration detected in a ground-water field blank was 0.013 mg/L for chlorpyrifos and prometon. Of 41 pesticides determined by high-performance liquid chromatography, diuron and 2,4-D were detected once in 109 surface-water field blanks and bromacil, diuron, and fenuron were detected once in 104 ground-water field blanks. Except for a detection of 2,4-D at 0.230 mg/L, the detectable concentrations of these pesticides were

  16. Precision cast vs. wrought superalloys

    NASA Technical Reports Server (NTRS)

    Tien, J. K.; Borofka, J. C.; Casey, M. E.

    1986-01-01

    While cast polycrystalline superalloys recommend themselves in virtue of better 'buy-to-fly' ratios and higher strengthening gamma-prime volume fractions than those of wrought superalloys, the expansion of their use into such critical superalloy applications as gas turbine hot section components has been slowed by insufficient casting process opportunities for microstructural control. Attention is presently drawn, however, to casting process developments facilitating the production of defect-tolerant superalloy castings having improved fracture reliability. Integrally bladed turbine wheel and thin-walled turbine exhaust case near-net-shape castings have been produced by these means.

  17. Quartz sand as "blank" compound in rehabilitation experience of industrial barren

    NASA Astrophysics Data System (ADS)

    Gorbacheva, T. T.; Ivanova, L. A.; Kikuchi, R.; Gerardo, R.

    2010-05-01

    During 2008 the field test was performed near the smelter complex Monchegorsk (67°51'N, 32°48'E) to estimate suitability of innovate method for site remediation in severe conditions such as in industrial barren. The method is based on cultivation of perennial grasses using hydroponics with thermally inflated vermiculite from local deposit (Kovdor) followed by rolled lawn placement on very contaminated sites near Monchegorsk. Growing in very contaminated ground resulted in 50% rolled lawn surface loss during first year but with biodiversity maintenance. Field experiment was carried out in three variants (1- mineral ground - flat site; 2- mineral ground- slope sites; 3- organogenic ground - flat site in depression in five replicates. More comprehensive results were received for mineral ground due to better natural washing compared to organogenic ground. In all variants we observed secondary roots formation. It seems obvious that plant roots choose the best zones of soils to grow, and that they avoided toxic zones. Observations continued during 2009 to follow freezing influence and nutrient loss rate. We observed grass survival of about 20-30% during second year of field test but grass roots proliferated very slowly in contaminated ground. Affinity to the ground is one of most important estimate of rolled lawn efficiency for grass cover creation. One of possible measure to improve rolled lawn affinity is to establish additional permeable barrier for grass roots isolation from toxic ground. Simultaneously with rolled lawn placement litterbag experiment was carried out with quartz sand as filling. Quartz was chosen as blank compound and as possible material for permeable barrier creation. Original quartz have some initial nutritional status: pH 6.87, available forms of K 1.9 mg g-1, Ca 9.5 mg g-1, Mg 2.8 mg g-1, P 0.4 mg g-1. There was both increasing and decreasing of quartz nutritional status during 2008-2009 period. Besides quartz is recognized to be some barrier

  18. AMCC casting development, volume 2

    NASA Technical Reports Server (NTRS)

    1995-01-01

    PCC successfully cast and performed nondestructive testing, FPI and x-ray, on seventeen AMCC castings. Destructive testing, lab analysis and chemical milling, was performed on eleven of the castings and the remaining six castings were shipped to NASA or Aerojet. Two of the six castings shipped, lots 015 and 016, were fully processed per blueprint requirements. PCC has fully developed the gating and processing parameters of this part and feels the part could be implemented into production, after four more castings have been completed to ensure the repeatability of the process. The AMCC casting has been a technically challenging part due to its size, configuration, and alloy type. The height and weight of the wax pattern assembly necessitated the development of a hollow gating system to ensure structural integrity of the shell throughout the investment process. The complexity in the jacket area of the casting required the development of an innovative casting technology that PCC has termed 'TGC' or thermal gradient control. This method of setting up thermal gradients in the casting during solidification represents a significant process improvement for PCC and has been successfully implemented on other programs. The alloy, JBK75, is a relatively new alloy in the investment casting arena and required our engineering staff to learn the gating, processing, and dimensional characteristics of the material.

  19. A Rapid and Portable DIC Analysis for Aquatic Systems: Rise of the Blanks.

    NASA Astrophysics Data System (ADS)

    Olack, G.; Pfister, C. A.; Wootton, J. T.; Colman, A. S.

    2015-12-01

    Dissolved inorganic carbon analysis, in both fresh water and marine systems, can help determine carbon sources, sinks and flows through an ecosystem (Apongwa et al. 2013). Methods to measure DIC with small quantities in situ are becoming more important as the need for DIC estimation increases across aquatic ecosystems. Recently a number of papers have measured both δ13CVPDB and concentrations by injecting a relatively small amount of sample, e.g. 1 to 2 mL, into prepared sample tubes and then analyzing the headspace gas (Spötl 2004, Torres et al. 2005, Assayag et al. 2006). The initial sampling can be done in the field and samples are stable for weeks to months (Capasso et al. 2005, Taipale and Sonninen 2009) prior to analysis. However, CO2 gas samples can have a contaminant interfering with measurements when concentrations are low, e.g. 0.04% CO2 (Knohl et al. 2004), though the effect can be negligible at higher concentrations, e.g. 1% (Spötl 2005). We investigate fitting a blank correction to a suite of standards to quantify the contamination and more accurately measure the DIC concentration and isotopic values. We examined 6 and 18 month time points, using the suite of standards with δ13CVPDB of 18.69, -2.69 and -16.86 ‰, 2 to 3 mM concentration range. Fitting the blank correction allows us to detect the blank in the 6 month time point. The blank only has a minor effect on the -2.69 and -16.86 ‰ standards, <0.1 ‰, but a significant one for the 18.69 ‰ standard, ~0.4 ‰. Samples run ca. 2 mM in the range of 0 ‰ only see a blank effect in the range of 0.15 ‰, but samples run at < 1 mM show potential shifts of up to 0.8 ‰. The 18 month test showed the tubes are under vacuum—apparently the He diffuses thru the chlorobutyl rubber septa. Those samples can still be analyzed, either by charging them with He so they will not be under vacuum, or running as is and letting the vacuum in the tubes draw in air during the analysis. After correcting for the

  20. Blank Slate

    ERIC Educational Resources Information Center

    Webber-Thrush, Diane

    2011-01-01

    Ullysses Tucker likes a good challenge. After spending the first 20 years of his career working in media, he entered the development profession in 2000. He worked for the State University of New York Plattsburgh, New Jersey's Montclair State University, Louisiana's Grambling State University, and Western Illinois University before joining London…

  1. Melting and casting of FeAl-based cast alloy

    SciTech Connect

    Sikka, V.K.; Wilkening, D.; Liebetrau, J.; Mackey, B.

    1998-11-01

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

  2. Printability of native blank defects and programmed defects and their stack structures

    NASA Astrophysics Data System (ADS)

    Kwon, Hyuk Joo; Harris-Jones, Jenah; Teki, Ranganath; Cordes, Aaron; Nakajima, Toshio; Mochi, Iacopo; Goldberg, Kenneth A.; Yamaguchi, Yuya; Kinoshita, Hiroo

    2011-11-01

    We describe the characterization of native phase defects in the manufacturing of extreme ultraviolet (EUV) mask blanks using the state-of-the-art mask metrology equipment in SEMATECH's Mask Blank Development Center (MBDC). We used commercially available quartz substrates and deposited Mo/Si multilayers on the substrates to characterize phase defects. We also prepared programmed defects of various dimensions using e-beam patterning technology on which multilayers were deposited. Transmission electron microscopy (TEM) was used to study multilayer profile changes, while SEMATECH's actinic inspection tool (AIT) was used to image defects and predict their printability. Defect images at different focal depths of the AIT are correlated to TEM cross sections and atomic force microscopy (AFM) dimensions. The printability of native and programmed defects was also investigated.

  3. Amplitude blanking related to the pore-filling of gas hydrate in sediments

    USGS Publications Warehouse

    Lee, M.W.; Dillon, William P.

    2001-01-01

    Seismic indicators of gas-hydrate-bearing sediments include elevated interval velocities and amplitude reduction of seismic reflections owing to the presence of gas hydrate in the sediment's pore spaces. However, large amplitude blanking with relatively low interval velocities observed at the Blake Ridge has been enigmatic because realistic seismic models were absent to explain the observation. This study proposes models in which the gas hydrate concentrations vary in proportion to the porosity. Where gas hydrate concentrations are greater in more porous media, a significant amplitude blanking can be achieved with relatively low interval velocity. Depending on the amount of gas hydrate concentration in the pore space, reflection amplitudes from hydrate-bearing sediments can be much less, less or greater than those from corresponding non-hydrate-bearing sediments.

  4. Numerical simulation of fine blanking process using fully coupled advanced constitutive equations with ductile damage

    NASA Astrophysics Data System (ADS)

    Labergere, C.; Saanouni, K.; Benafia, S.; Galmiche, J.; Sulaiman, H.

    2013-05-01

    This paper presents the modelling and adaptive numerical simulation of the fine blanking process. Thermodynamically-consistent constitutive equations, strongly coupled with ductile damage, together with specific boundary conditions (particular command of forces on blank holder and counterpunch) are presented. This model is implemented into ABAQUS/EXPLICIT using the Vumat user subroutine and connected with an adaptive 2D remeshing procedure. The different material parameters are identified for the steel S600MC using experimental tensile tests conducted until the final fracture. A parametric study aiming to examine the sensitivity of the process parameters (die radius, clearance die/punch) to the punch force and fracture surfaces topology (convex zone, sheared zone, fracture zone and the burr).

  5. Fill in the blank: culture jamming and the advertising of agency.

    PubMed

    Lambert-Beatty, Carrie

    2010-01-01

    This article is a review on billboard liberation and some other proj-ects that develop the idea of talking back or over advertising in a playful and youthful way. In one of them, Ji Lee's Bubble Project, an artist places blank thought-bubble stickers on street advertisements and waits to see what people write on them, completing the work of art and transgression. In other initiative, blank pages with the word God were placed around the city in place of advertising, inviting people to complete the prayer/complaint and to participate in a Suggestion Box, a project that collected "suggestions" from people out in the street. A review of playful and youthful ways to "rebel" against the impositions of powers like media and advertising. PMID:20391621

  6. A Novel Approach to the Determination of Forming Limit Diagrams for Tailor-Welded Blanks

    NASA Astrophysics Data System (ADS)

    Mamusi, Hossein; Masoumi, Abolfazl; Hashemi, Ramin; Mahdavinejad, Ramazanali

    2013-11-01

    This paper presents the results of simulated hemispherical die stretching of laser-welded, low carbon steel (ST12 and ST14) blanks of various thicknesses. The simulations were designed to produce forming limit diagrams (FLDs) for the tailor-welded blanks. Multiple criteria, including the second time derivatives of major strain, thickness strain, and equivalent plastic strain extracted from the strain history of simulations, were used to accurately detect the start of necking in FLDs. This is to say that necking starts when the second derivative of the thickness strain, major strain or plastic strain reaches its maximum value. Knowing the onset of necking, one can measure the major and minor strains at the critical area and produce the corresponding FLD. Results from the proposed method and those from experimental tests are compared to demonstrate the efficiency of the proposed method.

  7. Method for fabricating an ultra-low expansion mask blank having a crystalline silicon layer

    DOEpatents

    Cardinale, Gregory F.

    2002-01-01

    A method for fabricating masks for extreme ultraviolet lithography (EUVL) using Ultra-Low Expansion (ULE) substrates and crystalline silicon. ULE substrates are required for the necessary thermal management in EUVL mask blanks, and defect detection and classification have been obtained using crystalline silicon substrate materials. Thus, this method provides the advantages for both the ULE substrate and the crystalline silicon in an Extreme Ultra-Violet (EUV) mask blank. The method is carried out by bonding a crystalline silicon wafer or member to a ULE wafer or substrate and thinning the silicon to produce a 5-10 .mu.m thick crystalline silicon layer on the surface of the ULE substrate. The thinning of the crystalline silicon may be carried out, for example, by chemical mechanical polishing and if necessary or desired, oxidizing the silicon followed by etching to the desired thickness of the silicon.

  8. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-11-26

    Disclosed is an improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  9. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-01-29

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  10. Computer cast blast modelling

    SciTech Connect

    Chung, S.; McGill, M.; Preece, D.S.

    1994-12-31

    Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. This paper compares two blast models known as DMC (Distinct Motion Code) and SABREX (Scientific Approach to Breaking Rock with Explosives). DMC applies discrete spherical elements interacted with the flow of explosive gases and the explicit time integration to track particle motion resulting from a blast. The input to this model includes multi-layer rock properties, and both loading geometry and explosives equation-of-state parameters. It enables the user to have a wide range of control over drill pattern and explosive loading design parameters. SABREX assumes that heave process is controlled by the explosive gases which determines the velocity and time of initial movement of blocks within the burden, and then tracks the motion of the blocks until they come to a rest. In order to reduce computing time, the in-flight collisions of blocks are not considered and the motion of the first row is made to limit the motion of subsequent rows. Although modelling a blast is a complex task, the advance in computer technology has increased the computing power of small work stations as well as PC (personal computers) to permit a much shorter turn-around time for complex computations. The DMC can perform a blast simulation in 0.5 hours on the SUN SPARC station 10-41 while the new SABREX 3.5 produces results of a cast blast in ten seconds on a 486-PC. Predicted percentage of cast and face velocities from both computer codes compare well with the measured results from a full scale cast blast.

  11. USGS ShakeCast

    USGS Publications Warehouse

    Wald, David; Lin, Kuo-Wan

    2007-01-01

    Automating, Simplifying, and Improving the Use of ShakeMap for Post-Earthquake Decisionmaking and Response. ShakeCast is a freely available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users facilities, and generates potential damage assessment notifications, facility damage maps, and other Web-based products for emergency managers and responders.

  12. [Casting faults and structural studies on bonded alloys comparing centrifugal castings and vacuum pressure castings].

    PubMed

    Fuchs, P; Küfmann, W

    1978-07-01

    The casting processes in use today such as centrifugal casting and vacuum pressure casting were compared with one another. An effort was made to answer the question whether the occurrence of shrink cavities and the mean diameter of the grain of the alloy is dependent on the method of casting. 80 crowns were made by both processes from the baked alloys Degudent Universal, Degudent N and the trial alloy 4437 of the firm Degusa. Slice sections were examined for macro and micro-porosity and the structural appearance was evaluated by linear analysis. Statistical analysis showed that casting faults and casting structure is independent of the method used and their causes must be found in the conditions of casting and the composition of the alloy. PMID:352670

  13. Formability Analysis of Diode-Laser-Welded Tailored Blanks of Advanced High-Strength Steel Sheets

    NASA Astrophysics Data System (ADS)

    Panda, S. K.; Baltazar Hernandez, V. H.; Kuntz, M. L.; Zhou, Y.

    2009-08-01

    Currently, advances due to tailored blanking can be enhanced by the development of new grades of advanced high-strength steels (HSSs), for the further weight reduction and structural improvement of automotive components. In the present work, diode laser welds of three different grades of advanced high-strength dual-phase (DP) steel sheets (with tensile strengths of 980, 800, and 450 MPa) to high-strength low-alloy (HSLA) material were fabricated by applying the proper welding parameters. Formability in terms of Hecker’s limiting dome height (LDH), the strain distribution on the hemispherical dome surface, the weld line movement during deformation, and the load-bearing capacity during the stretch forming of these different laser-welded blanks were compared. Finite element (FE) analysis of the LDH tests of both the parent metals and laser-welded blanks was done using the commercially available software package LS-DYNA (Livermore Software Technology Corporation, Livermore, CA); the results compared well with the experimental data. It was also found that the LDH was not affected by the soft zone or weld zone properties; it decreased, however, with an increase in a nondimensional parameter, the “strength ratio” (SR). The weld line movement during stretch forming is an indication of nonuniform deformation resulting in a decrease in the LDH. In all the dissimilar weldments, fracture took place on the HSLA side, but the fracture location shifted to near the weld line (at the pole) in tailor-welded blanks (TWBs) of a higher strength ratio.

  14. Experimental and Numerical Investigations of Constraint Effect on Deformation Behavior of Tailor-Welded Blanks

    NASA Astrophysics Data System (ADS)

    Li, Yanhua; Lin, Jianping

    2015-08-01

    Tailor-welded blanks (TWBs) have been considered as a productive sheet forming method in automotive industries. However, formability of TWBs is reduced due to different properties or thicknesses of the blanks and is a challenge for manufacturing designers. The plastic capacity of TWBs is decreased even when the material and thickness are the same. The constraint effect of the laser weld (including weld and heat-affected zone) material in the forming process of similar TWBs is a key problem to be solved in the research, development and application of thin-sheet TWBs. In this paper, uniaxial tensile tests with full-field strain measurement by digital image correlation and Erichsen tests are performed to investigate the constraint effect on deformation behavior and explore the mechanism of decreasing formability of similar TWBs. In addition, finite element models are conducted under ABAQUS code to further reveal the phenomenal behavior of the constraint effect. The results of the base material and welded blanks are compared for characterizing the differences. Furthermore, in order to better understand this mechanism, theoretical and numerical investigations are employed and compared to interpret the constraint effect of laser weld on the deformation behavior of TWBs. An index is proposed to quantify the constraint effect. Results show that the constraint effect of laser weld appears in both stretch forming and drawing of TWBs. Strain paths are approaching the plane strain condition as compared to the monolithic blank due to the constraint effect. Constraint effect is a major factor affecting the formability of TWBs when the failure occurs away from the weld seam.

  15. Casting larger polycrystalline silicon ingots

    SciTech Connect

    Wohlgemuth, J.; Tomlinson, T.; Cliber, J.; Shea, S.; Narayanan, M.

    1995-08-01

    Solarex has developed and patented a directional solidification casting process specifically designed for photovoltaics. In this process, silicon feedstock is melted in a ceramic crucible and solidified into a large grained semicrystalline silicon ingot. In-house manufacture of low cost, high purity ceramics is a key to the low cost fabrication of Solarex polycrystalline wafers. The casting process is performed in Solarex designed casting stations. The casting operation is computer controlled. There are no moving parts (except for the loading and unloading) so the growth process proceeds with virtually no operator intervention Today Solarex casting stations are used to produce ingots from which 4 bricks, each 11.4 cm by 11.4 cm in cross section, are cut. The stations themselves are physically capable of holding larger ingots, that would yield either: 4 bricks, 15 cm by 15 an; or 9 bricks, 11.4 cm by 11.4 an in cross-section. One of the tasks in the Solarex Cast Polycrystalline Silicon PVMaT Program is to design and modify one of the castings stations to cast these larger ingots. If successful, this effort will increase the production capacity of Solarex`s casting stations by 73% and reduce the labor content for casting by an equivalent percentage.

  16. Study Of Various Initial Blank Shapes To Minimize The Earing In The Different Shaped Formed Parts Using Finite Element Analysis

    SciTech Connect

    Desai, Sharvari G.; Date, P P.; Pardeshi, R. H.

    2005-08-05

    In deep drawing process planar anisotropy is found to be a major problem. A high planar anisotropy causes earing in the formed cup (formation of wavy edge at the top). In this paper anisotropic behavior of stainless steel sheet is studied for drawn rectangular, circular and octagonal shaped parts. Finite element based simulation software PAMSTAMP2G is used to simulate the forming of the octagonal deep drawn cup. It is well known that the blank shape and size greatly affects the strain distribution in deep drawing process. Earing is a major problem due to highly anisotropic behavior of the selected material. To optimize the initial blank shape to minimize earing, the flow of material was observed at various steps during the forming and accordingly blank shapes were modified. Four blank shapes were considered to minimize earing for the forming of octagonal product. Finally a circular blank was used for forming of the octagonal part which gave minimum earing. The thickness strain distribution for circular shaped blank is better as compared to other blank shapes.

  17. Predetermined Flake Production at the Lower/Middle Paleolithic Boundary: Yabrudian Scraper-Blank Technology

    PubMed Central

    Shimelmitz, Ron; Kuhn, Steven L.; Ronen, Avraham; Weinstein-Evron, Mina

    2014-01-01

    While predetermined débitage technologies are recognized beginning with the middle Acheulian, the Middle Paleolithic is usually associated with a sharp increase in their use. A study of scraper-blank technology from three Yabrudian assemblages retrieved from the early part of the Acheulo-Yabrudian complex of Tabun Cave (ca. 415–320 kyr) demonstrates a calculated and preplanned production, even if it does not show the same complexity and elaboration as in the Levallois technology. These scraper dominated assemblages show an organization of production based on an intensive use of predetermination blank technology already in place at the end of the Lower Paleolithic of the Levant. These results provide a novel perspective on the differences and similarities between the Lower and Middle Paleolithic industries. We suggest that there was a change in the paradigm in the way hominins exploited stone tools: in many Middle Paleolithic assemblages the potential of the stone tools for hafting was a central feature, in the Lower Paleolithic ergonometric considerations of manual prehension were central to the design of blanks and tools. PMID:25192429

  18. High-Speed Friction-Stir Welding to Enable Aluminum Tailor-Welded Blanks

    NASA Astrophysics Data System (ADS)

    Hovanski, Yuri; Upadhyay, Piyush; Carsley, John; Luzanski, Tom; Carlson, Blair; Eisenmenger, Mark; Soulami, Ayoub; Marshall, Dustin; Landino, Brandon; Hartfield-Wunsch, Susan

    2015-05-01

    Current welding technologies for production of aluminum tailor-welded blanks (TWBs) are utilized in low-volume and niche applications, and they have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high volumes. While friction-stir welding (FSW) has been traditionally applied at linear velocities less than 1 m/min, high-volume production applications demand the process be extended to higher velocities more amenable to cost-sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low-to-moderate welding velocities do not directly translate to high-speed linear FSW. Therefore, to facilitate production of high-volume aluminum FSW components, parameters were developed with a minimum welding velocity of 3 m/min. With an emphasis on weld quality, welded blanks were evaluated for postweld formability using a combination of numerical and experimental methods. An evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum TWBs, which provided validation of the numerical and experimental analysis of laboratory-scale tests.

  19. High-Speed Friction-Stir Welding To Enable Aluminum Tailor-Welded Blanks

    SciTech Connect

    Hovanski, Yuri; Upadhyay, Piyush; Carsley, John; Luzanski, Tom; Carlson, Blair; Eisenmenger, Mark; Soulami, Ayoub; Marshall, Dustin; Landino, Brandon; Hartfield-Wunsch, Susan

    2015-05-01

    Current joining technologies for automotive aluminum alloys are utilized in low-volume and niche applications, and have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high-volumes. While friction stir welding has been traditionally applied at linear velocities less than one meter per minute, high volume production applications demand the process be extended to higher velocities more amenable to cost sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low to moderate welding velocities do not directly translate to high speed linear friction stir welding. Therefore, in order to facilitate production of high volume aluminum welded components, parameters were developed with a minimum welding velocity of three meters per minute. With an emphasis on weld quality, welded blanks were evaluated for post-weld formability utilizing a combination of numerical and experimental methods. Evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum tailor-welded blanks, which provided validation of the numerical and experimental analysis of laboratory scale tests.

  20. Use of non-quadratic yield surfaces in design of optimal deep-draw blank geometry

    SciTech Connect

    Logan, R.W.

    1995-12-01

    Planar anisotropy in the deep-drawing of sheet can lead to the formation of ears in cylindrical cups and to undesirable metal flow in the blankholder in the general case. For design analysis purposes in non-linear finite-element codes, this anisotropy is characterized by the use of an appropriate yield surface which is then implemented into codes such as DYNA3D . The quadratic Hill yield surface offers a relatively straightforward implementation and can be formulated to be invariant to the coordinate system. Non-quadratic yield surfaces can provide more realistic strength or strain increment ratios, but they may not provide invariance and thus demand certain approximations. Forms due to Hosford and Badat et al. have been shown to more accurately address the earning phenomenon. in this work, use is made of these non-quadratic yield surfaces in order to determine the optimal blank shape for cups and other shapes using ferrous and other metal blank materials with planar anisotropy. The analyses are compared to previous experimental studies on non-uniform blank motion due to anisotropy and asymmetric geometry.

  1. 42 CFR 414.106 - Splints and casts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 3 2014-10-01 2014-10-01 false Splints and casts. 414.106 Section 414.106 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM (CONTINUED) PAYMENT FOR PART B MEDICAL AND OTHER HEALTH SERVICES Fee Schedules for Parenteral and Enteral Nutrition (PEN)...

  2. Development of a CFD code for casting simulation

    NASA Technical Reports Server (NTRS)

    Murph, Jesse E.

    1993-01-01

    Because of high rejection rates for large structural castings (e.g., the Space Shuttle Main Engine Alternate Turbopump Design Program), a reliable casting simulation computer code is very desirable. This code would reduce both the development time and life cycle costs by allowing accurate modeling of the entire casting process. While this code could be used for other types of castings, the most significant reductions of time and cost would probably be realized in complex investment castings, where any reduction in the number of development castings would be of significant benefit. The casting process is conveniently divided into three distinct phases: (1) mold filling, where the melt is poured or forced into the mold cavity; (2) solidification, where the melt undergoes a phase change to the solid state; and (3) cool down, where the solidified part continues to cool to ambient conditions. While these phases may appear to be separate and distinct, temporal overlaps do exist between phases (e.g., local solidification occurring during mold filling), and some phenomenological events are affected by others (e.g., residual stresses depend on solidification and cooling rates). Therefore, a reliable code must accurately model all three phases and the interactions between each. While many codes have been developed (to various stages of complexity) to model the solidification and cool down phases, only a few codes have been developed to model mold filling.

  3. A study of storage life extension for high performance chemically amplified resist coated blanks

    NASA Astrophysics Data System (ADS)

    Yang, Sin-Ju; Seo, Sung-Min; Ko, Sang-Hoon; Cha, Han-Sun; Kang, Geung-Won; Nam, Kee-Soo; Seo, Woong-Won; Jung, Woo-Kyun; Cho, Hyun-Kyoon; Kim, Jin-Min; Choi, Sang-Soo

    2005-06-01

    The importance of advanced e-beam writing system and chemically amplified resist (CAR) coated blank is increasing gradually in high-end grade photomask manufacture according to CD embodiment of 90 nm and beyond technology node requiring because of the shrinkage of design rule in the semiconductor industry. However, many studies have been reported that CAR has several troubles and especially, CAR sensitivity change is occurred by airborne molecular contamination (AMC). So, the storage life of CAR coated blank is shortened. This problem may cause the difficulty of high-end grade photomask manufacture because it is hard to secure stable mean to target (MTT) and CD uniformity by sensitivity change, T-top profile and footing profile. Therefore, the purpose of this paper is to investigate the storage life extension for high performance CAR coated blank through improvement of the packing materials. Firstly, a variety of packing materials were collected and the selected packing materials were analyzed by Automatic Thermal Desorption Gas Chromatograph/Mass Spectrometer (ATD GC/MS) and Ion Chromatograph (IC) to examine AMC generated from the packing materials. As a result, molecular condensables such as alcohols, hydrocarbons and fatty acids were detected and molecular acids and molecular bases those are NH4+, Cl-, NOx- and SOx- were also detected from the packing materials, respectively. From the above results, we selected the best packing materials which generated the least AMC and the worst packing materials which generated the most AMC. Additionally, we verified photomask process with CAR coated blanks which were packed with those packing materials with post coating delay (PCD) by 50 kV e-beam writing system. In consequence, dose to clear (DTC) showed 4.6 μC/cm2 at 0 day PCD for both of the best and the worst packing materials of CAR coated blank. After 90 days PCD, DTC variation was only 0.4 μC/cm2 for the best packing materials, but DTC variation of 4.0 μC/cm2

  4. High density tape casting system

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr. (Inventor)

    1989-01-01

    A system is provided for casting thin sheets (or tapes) of particles bound together, that are used for oxygen membranes and other applications, which enables the particles to be cast at a high packing density in a tape of uniform thickness. A slurry contains the particles, a binder, and a solvent, and is cast against the inside walls of a rotating chamber. Prior to spraying the slurry against the chamber walls, a solvent is applied to a container. The solvent evaporates to saturate the chamber with solvent vapor. Only then is the slurry cast. As a result, the slurry remains fluid long enough to spread evenly over the casting surface formed by the chamber, and for the slurry particles to become densely packed. Only then is the chamber vented to remove solvent, so the slurry can dry. The major novel feature is applying solvent vapor to a rotating chamber before casting slurry against the chamber walls.

  5. Cast dielectric composite linear accelerator

    DOEpatents

    Sanders, David M.; Sampayan, Stephen; Slenes, Kirk; Stoller, H. M.

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  6. Replacing London's cast iron mains

    SciTech Connect

    Thorne, A. ); Mathews, P. )

    1992-07-01

    This paper discusses the cast iron gas distribution systems that exist in many cities and contains considerable amounts of pipe that vary in age from 20 to 150 years. In many ways, cast iron is an excellent material. It is inherently corrosion resistant, easy to install and cheap. However, it is also brittle and smaller diameter cast iron pipe has a relatively low beam strength. This can lead, under some circumstances, to failure without external warning, with typically a full-circumferential failure. In congested areas this can lead to serious consequences. As a result, cast iron replacement programs are a common feature in such urban gas distribution systems.

  7. Casting Equipment. Casting and Angling Skills Series. Instructor Manual.

    ERIC Educational Resources Information Center

    Staton, Robert D., Jr.

    Part of a series of self-contained instructional units designed by the Missouri Department of Conservation to teach Missourians how to use outdoor resources wisely and skillfully, the instructor manual, the first in the casting and angling series, is intended both as a reference book on casting equipment and as an introduction to the sport.…

  8. When Your Child Needs a Cast

    MedlinePlus

    ... hard bandage that's usually made of material like fiberglass or plaster. Casts keep bones in place while ... water. Plaster of Paris casts are heavier than fiberglass casts and don't hold up as well ...

  9. A numerical study on intended and unintended failure mechanisms in blanking of sandwich plates

    NASA Astrophysics Data System (ADS)

    Chen, L.; Soyarslan, C.; Tekkaya, A. E.

    2013-05-01

    Metal-polymer-metal sandwich plates are widely used in the automotive and aerospace industry. As for different applications the sandwich plates can be divided into two types. They are sound-damping laminates with a polymer core much thinner than the metallic faces and low-density laminates with a core thickness of approximately 40-60% of the total thickness. One frequent process step in production of parts made of these plates is the blanking process whose hereditary effects draw the limits of further forming stages or service performance and life; e.g. the failure of the adhesive in the thermoplastic polymer interface affects the sound-damping efficiency intensively. With this motivation, we present FE simulation of an axi-symmetric blanking process of steel/polyethylene/steel sound-damping laminates. The mechanical behavior of the metallic layers was characterized by finite strain rate independent elasto-plasticity where progressive material deterioration and fracture are given account for using continuum damage mechanics (CDM). This material model is made accessible via implementations as VUMAT subroutines for ABAQUS/Explicit. Possible failure of the thermoplastic polymer which may lead to delamination of the metallic layers is modeled using ABAQUS built-in cohesive zone elements. The results show that existing intended and unintended failure modes, e.g. blanking of the metallic and thermoplastic polymer constituents as well as failure of polymer layer under shear and compression, can be effectively studied with the proposed framework for process enhancement. As a future work, a damage coupled nonlinear visco-elastic constitutive model will be devised for the simulation of the thermoplastic layer in low-density laminates.

  10. Cone of Darkness: Finding Blank-sky Positions for Multi-object Wide-field Observations

    NASA Astrophysics Data System (ADS)

    Lorente, N. P. F.

    2014-05-01

    We present the Cone of Darkness, an application to automatically configure blank-sky positions for a series of stacked, wide-field observations, such as those carried out by the SAMI instrument on the Anglo-Australian Telescope (AAT). The Sydney-AAO Multi-object Integral field spectrograph (SAMI) uses a plug-plate to mount its 13×61 core imaging fibre bundles (hexabundles) in the optical plane at the telescope's prime focus. To make the most efficient use of each plug-plate, several observing fields are typically stacked to produce a single plate. When choosing blank-sky positions for the observations it is most effective to select these such that one set of 26 holes gives valid sky positions for all fields on the plate. However, when carried out manually this selection process is tedious and includes a significant risk of error. The Cone of Darkness software aims to provide uniform blank-sky position coverage over the field of observation, within the limits set by the distribution of target positions and the chosen input catalogs. This will then facilitate the production of the best representative median sky spectrum for use in sky subtraction. The application, written in C++, is configurable, making it usable for a range of instruments. Given the plate characteristics and the positions of target holes, the software segments the unallocated space on the plate and determines the position which best fits the uniform distribution requirement. This position is checked, for each field, against the selected catalog using a TAP ADQL search. The process is then repeated until the desired number of sky positions is attained.

  11. Lost-Soap Aluminum Casting.

    ERIC Educational Resources Information Center

    Mihalow, Paula

    1980-01-01

    Lost-wax casting in sterling silver is a costly experience for the average high school student. However, this jewelry process can be learned at no cost if scrap aluminum is used instead of silver, and soap bars are used instead of wax. This lost-soap aluminum casting process is described. (Author/KC)

  12. Particle transport in plasma systems for development of EUVL mask blanks

    NASA Astrophysics Data System (ADS)

    Stoltz, Peter; Likhanskii, Alex; Zhou, Chuandong; Jindal, Vibhu; Kearney, Patrick

    2012-11-01

    Defect transport in development of EUVL mask blanks is an important issue for the near-term of the industry. One main issue affecting transport is how the defect may charge in the presence of plasma. In some cases, plasma may act to contain defects away from the mask surface. We show simulation results of the effect of plasma on defect transport demonstrating how the formation of plasma sheathes and a plasma potential act to confine highly negatively charged particles, such as defect particles would be.

  13. Actual defect observation results of an extreme-ultraviolet blank mask by coherent diffraction imaging

    NASA Astrophysics Data System (ADS)

    Harada, Tetsuo; Hashimoto, Hiraku; Amano, Tsuyoshi; Kinoshita, Hiroo; Watanabe, Takeo

    2016-03-01

    Extreme-ultraviolet (EUV) lithography poses a number of challenges, one of which is the production of a defect-free mask. To observe the defects on an EUV mask in a quantitative phase image, we have developed a microcoherent EUV scatterometry microscope. The intensity and phase images of the defects are reconstructed using ptychography. We observe four actual defects on an EUV blank mask using the microscope. The reconstructed shapes of the actual defects correspond well to those measured by atomic force microscopy (AFM). Our microscope should therefore function as an essential review tool in characterizing defects.

  14. Comparing Laser Welding Technologies with Friction Stir Welding for Production of Aluminum Tailor-Welded Blanks

    SciTech Connect

    Hovanski, Yuri; Carsley, John; Carlson, Blair; Hartfield-Wunsch, Susan; Pilli, Siva Prasad

    2014-01-15

    A comparison of welding techniques was performed to determine the most effective method for producing aluminum tailor-welded blanks for high volume automotive applications. Aluminum sheet was joined with an emphasis on post weld formability, surface quality and weld speed. Comparative results from several laser based welding techniques along with friction stir welding are presented. The results of this study demonstrate a quantitative comparison of weld methodologies in preparing tailor-welded aluminum stampings for high volume production in the automotive industry. Evaluation of nearly a dozen welding variations ultimately led to down selecting a single process based on post-weld quality and performance.

  15. Finite Element Modeling of Transition Zone in Friction Stir Welded Tailor-Made Blanks

    SciTech Connect

    Zadpoor, Amir A.; Sinke, Jos; Benedictus, Rinze

    2007-05-17

    Finite element modeling of a prototype friction stir welded blank made of aluminum alloy 2024-T351 is considered in this paper. Feasibility of implementation of the experimentally-obtained mechanical properties of the weld nugget and heat-affected zones in FEM models is investigated. Limiting dome height test is considered as case of the study. Three different finite element models implementing different levels of the weld details are built and compared. It is shown that despite increased simulation time, implementation of the weld nugget and heat-affected zones is justified by significantly improved accuracy of the simulation results.

  16. Electroslag component casting. [Nickel aluminide

    SciTech Connect

    Sikka, V.K.

    1986-01-01

    This project is directed toward the development of electroslag-casting (ESC) technology for use in coal conversion components such as valve bodies, pump housings, and pipe fittings. The aim is also to develop a sufficient data base to permit electroslag casting to become an ASME Code-accepted process. It is also intended to transfer the ESC process technology to private industry. A total of 32 electroslag castings of 2.25Cr-1Mo, 9Cr-1Mo, type 316, and nickel aluminide were procured from four facilities for evaluation (Table 1). The most complex castings procured during this program were the valve bodies shown in Figure 2. The castings were subjected to various heat treatments (Table 2), checked for chemical composition uniformity from top to bottom, and subjected to macrostructural evaluation and mechanical properties testing. Results are discussed. 10 refs., 7 figs., 3 tabs.

  17. Relationship between casting distortion, mold filling, and interfacial heat transfer. Annual technical report, September 1997 - September 1998

    SciTech Connect

    Woodbury, K.A.; Parker, J.K.; Piwonka, T.S.; Owusu, Y.

    1998-10-22

    In the third year of this program, the final castings necessary to evaluate the effect of casting orientation and gating in silica sand lost foam were poured and measured using a CMM machine. Interfacial heat transfer and gap formation measurements continued. However, significant problems were encountered in making accurate measurements. No consistent evidence of gap formation was found in aluminum sand casting. Initial analysis yields heat transfer values below those previously reported in the literature. The program in continuing.

  18. 29 CFR 1926.703 - Requirements for cast-in-place concrete.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Requirements for cast-in-place concrete. 1926.703 Section..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.703 Requirements for cast-in-place concrete. (a) General requirements for formwork....

  19. 29 CFR 1926.703 - Requirements for cast-in-place concrete.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Requirements for cast-in-place concrete. 1926.703 Section..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.703 Requirements for cast-in-place concrete. (a) General requirements for formwork....

  20. 29 CFR 1926.703 - Requirements for cast-in-place concrete.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Requirements for cast-in-place concrete. 1926.703 Section..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.703 Requirements for cast-in-place concrete. (a) General requirements for formwork....

  1. 29 CFR 1926.703 - Requirements for cast-in-place concrete.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Requirements for cast-in-place concrete. 1926.703 Section..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.703 Requirements for cast-in-place concrete. (a) General requirements for formwork....

  2. 29 CFR 1926.703 - Requirements for cast-in-place concrete.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Requirements for cast-in-place concrete. 1926.703 Section..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.703 Requirements for cast-in-place concrete. (a) General requirements for formwork....

  3. Software Analytical Instrument for Assessment of the Process of Casting Slabs

    SciTech Connect

    Franek, Zdenek; Kavicka, Frantisek; Stetina, Josef; Masarik, Milos

    2010-06-15

    The paper describes the original proposal of ways of solution and function of the program equipment for assessment of the process of casting slabs. The program system LITIOS was developed and implemented in EVRAZ Vitkovice Steel Ostrava on the equipment of continuous casting of steel (further only ECC). This program system works on the data warehouse of technological parameters of casting and quality parameters of slabs. It enables an ECC technologist to analyze the course of casting melt and with using statistics methods to set the influence of single technological parameters on the duality of final slabs. The system also enables long term monitoring and optimization of the production.

  4. Study and application on accelerated algorithm of ray-casting

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoping; Wu, Jian; Cui, Zhiming; Ma, Jianlin

    2007-12-01

    Medical image 3D reconstruct is an important application filed for volume rendering, for it special using, it required fast interactive speed and high image quality. The ray casting algorithm (RCA) is a widely used basic volume rendering algorithm. It can get high quality image but the rendering speed is very slowly for powerful computing capacity. Due to these shortcomings and deficiencies, the accelerated ray casting algorithm is presented in this paper to improve its rendering speed and apply it to medical image 3D reconstruct. Firstly, accelerate algorithms for ray casting are fully studied and compared. Secondly, improved tri-linear interpolation technology has been selected and extended to continuous ray casting in order to reduce matrix computation by matrix transformation characteristics of re-sampling points. Then ray interval casting technology is used to reduce the number of rays. Utilizing volume data sets cropping technology that improving boundary box technique avoids the sampling in empty voxel. Finally, the synthesized accelerate algorithm has been proposed. The result shown that compare with standard ray casting algorithm, the accelerate algorithm not only improve the rendering speed but also produce the required quality images.

  5. Growth and Printability of Multilayer Phase Defects on EUV MaskBlanks

    SciTech Connect

    Liang, Ted; Ultanir, Erdem; Zhnag, Guojing; Park, Seh-Jin; Anderson, Erik; Gullikson, Eric; Naulleau, Patrick; Salmassi, Farhad; Mirkarimi, Paul; Spiller, Eberhard; Baker, Sherry

    2007-06-10

    The ability to fabricate defect-free mask blanks is a well-recognized challenge in enabling extreme ultraviolet lithography (EUVL) for semiconductor manufacturing. Both the specification and reduction of defects necessitate the understanding of their printability and how they are generated and grow during Mo-Si multilayer (ML) deposition. A ML phase defect can be depicted by its topographical profile on the surface as either a bump or pit, which is then characterized by height or depth and width. The complexity of such seemingly simple phase defects lies in the many ways they can be generated and the difficulties of measuring their physical shape/size and optical effects on printability. An effective way to study phase defects is to use a programmed defect mask (PDM) as 'model' test sample where the defects are produced with controlled growth on a ML blank and accurate placement in varying proximity to absorber patterns on the mask. This paper describes our recent study of ML phase defect printability with resist data from exposures of a ML PDM on the EUV micro-exposure tool (MET, 5X reduction with 0.3NA).

  6. Formability of Friction Stir-Welded Blanks with Different Thickness Ratios

    NASA Astrophysics Data System (ADS)

    Kolahgar, Sina; Ghaffarpour, Morteza; Habibi, Niloufar; Kokabi, Amir Hossein; Akbarzadeh, Abbas

    2016-05-01

    Welded sheets with different thicknesses are one of the interesting types of tailor-welded blanks (TWBs) that are widely used in metal-forming industries. In the present work, the formability behavior of different 1100-aluminum TWBs was studied. In this regard, the TWBs were made with different thickness ratios by using friction stir welding (FSW) at different welding rotational speeds ( ω). The thickness ratios of 1.0, 1.3, and 1.7 were investigated where the thinner sheets had 1.5 mm thick for all conditions; i.e., the volume of welded material increased when the thickness ratio increased. Macrostructural observations, mechanical investigations, and sheet-forming limit tests were conducted. The results indicate that increasing ω leads to increasing the weld nugget size up to a maximum level and welding became impossible at higher ω. Furthermore, increasing heat input during FSW, the ultimate tensile strength of welds reduced in comparison with the initial cold-worked base metal. However, the ductility improved by increasing the heat input, which produced the sound welds. Formability studies of the friction stir-welded blanks with equal thicknesses have shown that the forming ratio improves up to 2.8 times the base metal. Forming limit curves also illustrate that increasing the thickness ratio of TWB causes the formability ratio to decrease steadily. Thus, when the thickness ratio becomes 1.7, the formability of TWB decreases approximately to the thinnest base metal.

  7. Optimization of the Blank Holder Force Using the Neural Network Algorithm

    NASA Astrophysics Data System (ADS)

    Albut, A.; Ciubotaru, V.; Radu, C.; Olaru, I.

    2011-08-01

    In case of sheet metal forming the main dimensional errors are caused by the springback phenomena. The present work deals with numerical simulation related to draw bending and springback of U-shaped parts. The current paper is trying to prove out the important role of the blank holder force variation during the forming process. The Dynaform 5.6 software was used to simulate the forming process, in which the blank holder force varies linearly in four steps between 20 and 50 kN. The factorial simulations test plan was made using the Design Experts 7.0 software and 72 simulations were necessarily to cover completely the variation domain. The part obtained after each simulation is analyzed and measured to quantify the errors caused by springback. Parameters as: angle between flange and sidewall, angle between sidewall and part bottom, chamfer radius between part bottom and sidewall or chamfer radius between sidewall and flange are recorded in a data base. The initial simulations plan together with the generated data base is loaded in a neural network software called NeuroSolution 5. The presented optimization method is a good method to reduce the springback effect. The inconvenient of this method is the large number of simulations tests that must be done and the large amount of data necessarily as input for the NeuroSolution software.

  8. Technique for rapid at-wavelength inspection of extreme ultraviolet mask blanks

    SciTech Connect

    Spector, S. J.; White, D. L.; Tennant, D. M.; Ocola, L. E.; Novembre, A. E.; Peabody, M. L.; Wood, O. R. II

    1999-11-01

    We have developed two new methods for at-wavelength inspection of mask blanks for extreme-ultraviolet (EUV) lithography. In one method an EUV photoresist is applied directly to a mask blank which is then flood exposed with EUV light and partially developed. In the second method, the photoresist is applied to an EUV transparent membrane that is placed in close proximity to the mask and then exposed and developed. Both reflectivity defects and phase defects alter the exposure of the resist, resulting in mounds of resist at defect sites that can then be located by visual inspection. In the direct application method, a higher contrast resist was shown to increase the height of the mounds, thereby improving the sensitivity of the technique. In the membrane method, a holographic technique was used to reconstruct an image of the mask, revealing the presence of very small defects, approximately 0.2 {mu}m in size. The demonstrated clean transfer of phase and amplitude defects to resist features on a membrane will be important when flagging defects in an automatic inspection tool. (c) 1999 American Vacuum Society.

  9. Copper-ceramic composite coatings for steel strip casting

    SciTech Connect

    Legoux, J.G.; Dallaire, S.

    1994-12-31

    Materials in contact with solidifying steel during continuous strip casting should have high thermal conductivity, good thermal shock resistance and high inertness to liquid steel. A good ability to withstand mechanical damages could be mandatory particularly during the braking-in period. A copper-ceramic coating has been developed in order to fulfill these requirements. This coating was plasma sprayed on the rolls of a prototype twin-roll strip casting machine. As it is ductile it can withstand mechanical deformations. Being a barrier preventing reactions with liquid steel, it ensures the spreading of liquid steel over the rolls and the easy removal of the solidified strip. As a thin ceramic rich continuous layer is formed and renewed after each mechanical damage this coating possesses self-healing properties. This paper presents the development of this copper-ceramic coating in regards to the demanding service conditions of strip casting and relates its performance to its peculiar microstructure.

  10. Interface Formation During Fusion™ Casting of AA3003/AA4045 Aluminum Alloy Ingots

    NASA Astrophysics Data System (ADS)

    Di Ciano, Massimo; Caron, E. J. F. R.; Weckman, D. C.; Wells, M. A.

    2015-12-01

    Fusion™ casting is a unique Direct Chill continuous casting process whereby two different alloys can be cast simultaneously, producing a laminated ingot for rolling into clad sheet metal such as AA3003/AA4045 brazing sheet. Better understanding of the wetting and interface formation process during Fusion™ casting is required to further improve process yields and also explore use of other alloy systems for new applications. In this research, AA3003-core/AA4045-clad ingots were cast using a well-instrumented lab-scale Fusion™ casting system. As-cast Fusion™ interfaces were examined metallurgically and by mechanical testing. Computational fluid dynamic analyses of the FusionTM casts were also performed. It was shown that the liquid AA4045-clad alloy was able to successfully wet and create an oxide-free, metallurgical, and mechanically sound interface with the lightly oxidized AA3003-core shell material. Based on the results of this study, it is proposed that the bond formation process at the alloys interface during casting is a result of discrete penetration of AA4045 liquid at defects in the preexisting AA3003 oxide, dissolution of underlying AA3003 by liquid AA4045, and subsequent bridging between penetration sites. Spot exudation on the AA3003 chill cast surface due to remelting and inverse segregation may also improve the wetting and bonding process.

  11. Extended Leach Testing of Simulated LAW Cast Stone Monoliths

    SciTech Connect

    Serne, R. Jeffrey; Westsik, Joseph H.; Williams, Benjamin D.; Jung, H. B.; Wang, Guohui

    2015-07-09

    This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.

  12. Flame Sprayed Al-12Si Coatings for the Improvement of the Adhesion of Composite Casting Profiles

    NASA Astrophysics Data System (ADS)

    Voyer, Joël; Peterlechner, Christian; Noster, Ulf

    2008-12-01

    In this study, flame sprayed Al-12Si coatings were produced on the surface of inlays (aluminum profiles) of composite castings parts. The aim was to enhance the strength between the joining partners inlay and cast. Due to the high surface roughness and the presence of pores in the coatings, combined with the formation of an intermetallic phase at the interface, the adhesion of flame sprayed inlays could be enhanced by a factor of 2 compared to blank inlays and by a factor of 1.3 when compared to sand-blasted inlays. However, results also show that gaps are present, mostly at the interface between the inlays and the flame sprayed coatings, and these gaps have a negative effect on the joining strength of the composite casting parts. Therefore, optimizing the adhesion of the coating on the Al profiles via an improvement in both the sand-blasting and the flame spraying parameters would be beneficial for further enhancement of the adhesion of composite casting parts.

  13. Application of particle method to the casting process simulation

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Zulaida, Y. M.; Anzai, K.

    2012-07-01

    Casting processes involve many significant phenomena such as fluid flow, solidification, and deformation, and it is known that casting defects are strongly influenced by the phenomena. However the phenomena complexly interacts each other and it is difficult to observe them directly because the temperature of the melt and other apparatus components are quite high, and they are generally opaque; therefore, a computer simulation is expected to serve a lot of benefits to consider what happens in the processes. Recently, a particle method, which is one of fully Lagrangian methods, has attracted considerable attention. The particle methods based on Lagrangian methods involving no calculation lattice have been developed rapidly because of their applicability to multi-physics problems. In this study, we combined the fluid flow, heat transfer and solidification simulation programs, and tried to simulate various casting processes such as continuous casting, centrifugal casting and ingot making. As a result of continuous casting simulation, the powder flow could be calculated as well as the melt flow, and the subsequent shape of interface between the melt and the powder was calculated. In the centrifugal casting simulation, the mold was smoothly modeled along the shape of the real mold, and the fluid flow and the rotating mold are simulated directly. As a result, the flow of the melt dragged by the rotating mold was calculated well. The eccentric rotation and the influence of Coriolis force were also reproduced directly and naturally. For ingot making simulation, a shrinkage formation behavior was calculated and the shape of the shrinkage agreed well with the experimental result.

  14. Biomimetic Materials by Freeze Casting

    NASA Astrophysics Data System (ADS)

    Porter, Michael M.; Mckittrick, Joanna; Meyers, Marc A.

    2013-06-01

    Natural materials, such as bone and abalone nacre, exhibit exceptional mechanical properties, a product of their intricate microstructural organization. Freeze casting is a relatively simple, inexpensive, and adaptable materials processing method to form porous ceramic scaffolds with controllable microstructural features. After infiltration of a second polymeric phase, hybrid ceramic-polymer composites can be fabricated that closely resemble the architecture and mechanical performance of natural bone and nacre. Inspired by the narwhal tusk, magnetic fields applied during freeze casting can be used to further control architectural alignment, resulting in freeze-cast materials with enhanced mechanical properties.

  15. Slip-Cast Superconductive Parts

    NASA Technical Reports Server (NTRS)

    Wise, Stephanie A.; Buckley, John D.; Vasquez, Peter; Buck, Gregory M.; Hicks, Lana P.; Hooker, Matthew W.; Taylor, Theodore D.

    1993-01-01

    Complex shapes fabricated without machining. Nonaqueous slip-casting technique used to form complexly shaped parts from high-temperature superconductive materials like YBa(2)Cu(3)O(7-delta). Such parts useful in motors, vibration dampers, and bearings. In process, organic solvent used as liquid medium. Ceramic molds made by lost-wax process used instead of plaster-of-paris molds, used in aqueous slip-casting but impervious to organic solvents and cannot drain away liquid medium. Organic-solvent-based castings do not stick to ceramic molds as they do to plaster molds.

  16. Actinic detection of multilayer defects on EUV mask blanks using LPP light source and dark-field imaging

    NASA Astrophysics Data System (ADS)

    Tezuka, Yoshihiro; Ito, Masaaki; Terasawa, Tsuneo; Tomie, Toshihisa

    2004-05-01

    The development of defect-free mask blanks including inspection is one of the big challenges for the implementation of extreme ultraviolet lithography (EUVL), especially when the introduction of EUVL is rescheduled to a later technology node. Among others, inspection of multilayer coated mask blanks with no oversight of critical defects and with minimal detection of false defects is a challenging issue for providing mask blanks free of defects or with thorough characterization of any existing defects. MIRAI Project has been developing a novel actinic (at-wavelength) inspection tool for detecting critical multilayer defects using a dark-field imaging and a laser-produced plasma (LPP) light source, expecting better sensitivity and better correlation with printability. The first experimental set up is completed for proof-of-concept (POC) demonstration using 20x Schwarzschild imaging optics and a backsideilluminated CCD. An in-house LPP light source is integrated to optimally illuminate the area of interest by EUV with a wavelength of 13.5nm. For its illuminator, a multilayer-coated elliptical mirror is used to illuminate a mask blank with the EUV that is collected within a wide solid angle from the light source. The first EUV dark-field image is obtained from a mask blank with programmed multilayer defects which are manufactured by locating well-defined patterns before depositing Mo/Si multilayer on EUV mask substrate. All the fabricated multilayer defects down to 70nm in width and 3.5nm in height are detected as clear signals that are distinguishable from the background intensity arising from the scattering by the surface roughness of the multilayer-coated mask blank. We have also detected a phase defect as low as 2nm in height. False defect count was not only zero within the area of view but also statistically confirmed to be less than one within the whole area of a mask blank assuming the extrapolation of observed fluctuation of background intensity is applicable

  17. Warm Deep Drawing of Rectangular Parts of AZ31 Magnesium Alloy Sheet Adopting Variable Blank Holder Force

    NASA Astrophysics Data System (ADS)

    Ying-hong, Peng; Qun-feng, Chang; Da-yong, Li; Xiao-qin, Zeng

    2007-05-01

    AZ31 magnesium alloy sheet with good shape and formability is fabricated by warm cross rolling. Uniaxial tensile tests are conducted using a Gleeble 3500 thermal - mechanical simulator, and the mechanical properties of AZ31 magnesium alloy sheet are analyzed. A warm deep drawing process of square part is also simulated by the finite element method. The influences of blank holder force on the formability are numerically investigated. A double-action hydraulic press that can realize adjustable blank holder forces is developed and its working principle and control system are introduced. Some warm deep drawing experiments of square parts of AZ31 magnesium alloy sheet are also performed. Different variation schemes of the blank holder force with the stroke of the punch are tested, and the experiment results are compared. Results show that the suitable blank holder force variation scheme is a ladder curve with the punch stroke. Adopting the variable blank holder force technique can improve 13.2% of the drawing depth of square parts of AZ31 magnesium alloy sheet.

  18. Warm Deep Drawing of Rectangular Parts of AZ31 Magnesium Alloy Sheet Adopting Variable Blank Holder Force

    SciTech Connect

    Peng Yinghong; Chang Qunfeng; Li Dayong; Zeng Xiaoqin

    2007-05-17

    AZ31 magnesium alloy sheet with good shape and formability is fabricated by warm cross rolling. Uniaxial tensile tests are conducted using a Gleeble 3500 thermal - mechanical simulator, and the mechanical properties of AZ31 magnesium alloy sheet are analyzed. A warm deep drawing process of square part is also simulated by the finite element method. The influences of blank holder force on the formability are numerically investigated. A double-action hydraulic press that can realize adjustable blank holder forces is developed and its working principle and control system are introduced. Some warm deep drawing experiments of square parts of AZ31 magnesium alloy sheet are also performed. Different variation schemes of the blank holder force with the stroke of the punch are tested, and the experiment results are compared. Results show that the suitable blank holder force variation scheme is a ladder curve with the punch stroke. Adopting the variable blank holder force technique can improve 13.2% of the drawing depth of square parts of AZ31 magnesium alloy sheet.

  19. Genetic algorithm optimization of the forming process in case of a U-shaped part made from tailor welded blanks

    NASA Astrophysics Data System (ADS)

    Aurelian, Albut

    2013-05-01

    This paper presents an optimization method to minimize the springback phenomenon, which generate the main dimensional errors in case of sheet metal forming. The present work deals with numerical simulation related to draw bending and springback of U-shaped part made from tailor welded blanks. The base materials from tailor welded blanks have different springback behaviours, fact that must be taken in consideration in the optimisation process. The Dynaform 5.8.1 software was used to simulate the forming process, in which the blank holder is segmented in two parts in order to apply different holding force for each material. In this research the blank holder forces and the deformation speed take different numerical values. The factorial simulations test plan was made using the Design Experts 7.0 software to cover completely the variation domain. The part obtained after each simulation is analyzed and measured to quantify the errors caused by springback. Parameters as: angle between flange and sidewall, angle between sidewall and part bottom are recorded in a data base. The initial simulations plan together with the obtained results is used to understand the influence of the variable parameters on the springback behaviour of the U-shaped part made from tailor welded blanks. The gained knowledge is used to generate the objective function required by the genetic algorithm optimization method.

  20. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in... of § 23.305 at an ultimate load corresponding to a casting factor of 1.25; and (ii) The...

  1. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in... of § 23.305 at an ultimate load corresponding to a casting factor of 1.25; and (ii) The...

  2. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in... of § 23.305 at an ultimate load corresponding to a casting factor of 1.25; and (ii) The...

  3. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in... of § 23.305 at an ultimate load corresponding to a casting factor of 1.25; and (ii) The...

  4. Storage Stability and Antibacterial Activity against E. coli O157:H7 of Carvacrol in Edible Apple Films made by Two Different Casting Methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antimicrobial activities against E. coli O157:H7, as well as the stability of carvacrol, the main constituent of oregano oil, were evaluated during the preparation and storage of apple-based edible films made by two different casting methods, continuous casting and batch casting. Antimicrobial ...

  5. Investment casting design of experiment. Final report

    SciTech Connect

    Owens, R.

    1997-10-01

    Specific steps in the investment casting process were analyzed in a designed experiment. The casting`s sensitivity to changes in these process steps was experimentally determined Dimensional and radiographic inspection were used to judge the sensitivity of the casting. Thirty-six castings of different pedigrees were poured and measured. Some of the dimensional inspection was conducted during the processing. It was confirmed that wax fixturing, number of gates, gate location, pour and mold temperature, pour speed, and cooling profile all affected the radiographic quality of the casting. Gate and runner assembly techniques, number of gates, and mold temperature affect the dimensional quality of the casting.

  6. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Protecting cast-iron pipelines. 192.755 Section 192.755 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS...-iron pipelines. When an operator has knowledge that the support for a segment of a buried...

  7. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Protecting cast-iron pipelines. 192.755 Section 192.755 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS...-iron pipelines. When an operator has knowledge that the support for a segment of a buried...

  8. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Protecting cast-iron pipelines. 192.755 Section 192.755 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS...-iron pipelines. When an operator has knowledge that the support for a segment of a buried...

  9. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Protecting cast-iron pipelines. 192.755 Section 192.755 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS...-iron pipelines. When an operator has knowledge that the support for a segment of a buried...

  10. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Protecting cast-iron pipelines. 192.755 Section 192.755 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS...-iron pipelines. When an operator has knowledge that the support for a segment of a buried...

  11. Recent advances in SEMATECH's mask blank development program, the remaining technical challenges, and future outlook

    NASA Astrophysics Data System (ADS)

    Goodwin, Frank; Kearney, Patrick; Kadaksham, Arun J.; Wurm, Stefan

    2013-10-01

    film for the device. In addition to the increase in complexity of the mask, introduction of EUVL requires infrastructure development of new substrate, mask blank, and finished reticle inspection tools and techniques for handling and storage of a mask without a pellicle. This paper will highlight recent advances in the ability to produce pilot line quality EUV mask blanks to meet the near-term requirements and review the existing technology gaps which must be closed to extend the current capability to meet HVM needs. A special focus will be put on substrate and mask blank defect densities; other process and infrastructure challenges will also be discussed.

  12. The nature of urinary casts

    PubMed Central

    McQueen, E. G.

    1962-01-01

    The composition of hyaline casts has been investigated. The major constituent appears to be the urinary mucoprotein described by Tamm and Horsfall. Small amounts only of serum proteins are present. Neither the amounts excreted nor the concentration of Tamm-Horsfall protein appeared to determine the rate of cast formation. The only invariable association of hyaline cast formation was with the presence of significant amounts of serum proteins in the urine. In vitro it was found that aqueous solutions of serum albumin were particularly effective in producing precipitation of Tamm-Horsfall protein. This interaction was inhibited in normal urine but occurred to a greater extent in nephrotic urine and is suggested as the possible mechanism of hyaline cast formation. Images PMID:16810981

  13. Advanced casting: Today and tomorrow

    NASA Astrophysics Data System (ADS)

    Mietrach, D.

    The state of aluminum casting technology in terms of processes, component sizes, design and material-scientific data as well as mechanical characteristics was established during visits to foundries in the USA, Canada, France, Italy, Great Britain and the Federal Republic of Germany. Components of the primary structure of Tornado and ALPHA aircraft, (pylon, intake floor) classified according to the degree of difficulty during casting, were used to compare existing designs (riveted sheet metal and machined parts) and cast versions with regard to cost reduction and technical reliability. Visual inspection, dimensional checks, chemical composition analysis, penetrant tests, X-ray tests, metallographic investigations, and tensile tests were carried out. Cost savings of 25% and weight savings of 20% can be achieved by using castings.

  14. Casting Using A Polystyrene Pattern

    NASA Technical Reports Server (NTRS)

    Vasquez, Peter; Guenther, Bengamin; Vranas, Thomas; Veneris, Peter; Joyner, Michael

    1993-01-01

    New technique for making metal aircraft models saves significant amount of time and effort in comparison with conventional lost-wax method. Produces inexpensive, effective wind-tunnel models. Metal wind-tunnel model cast by use of polystyrene pattern.

  15. Moldless casting by laser

    NASA Astrophysics Data System (ADS)

    McLean, Marc A.; Shannon, G. J.; Steen, William M.

    1997-09-01

    The principle of laser cladding involves the use of high power carbon-dioxide lasers and powder deposition technology to provide wear and corrosion resistant surface coatings to engineering components. By injecting metal powder into a laser generated melt pool on a moving substrate a solidified metal track can be produced. Deposition of successive tracks produces a multi-layer build. Laser direct casting (LDC) utilizes a coaxial nozzle enabling consistent omnidirectional deposition to produce 3D components from a selection of metal powders. The influence of the principal process parameters over the process features namely, powder catchment efficiency, beam shape and build rates are presented with several successfully generated 3D components. Nickel, stainless steel and satellite powders were deposited at laser powders of 0.4 to 1.4 kW and speeds of 500 to 1000 mm/min achieving build rates of 3 to 9 mm3/s. Fully dense metallurgical structures have been produced with no cracking or porosity and powder catchment efficiencies up to 85% have been achieved.

  16. Metal pins fired from unmodified blank cartridge guns and very small calibre weapons--technical and wound ballistic aspects.

    PubMed

    Rabl, W; Riepert, T; Steinlechner, M

    1998-01-01

    Blank cartridge guns are generally regarded as being harmless and are not considered to be firearms in most countries. A comparison of the legal situations in Germany and Austria concerning weapons is given. There have been several reports of serious injuries and even fatalities due to these weapons. Ballistic experiments show that even unmodified blank cartridge guns and very small calibre weapons can fire wire nails and can inflict potentially fatal injuries even at distances of 50 cm. Two serious injuries inflicted by metal pins fired from a blank cartridge gun and a very small calibre weapon are reported. These cases suggest that such weapons should also be considered handguns in the legal sense. PMID:9646170

  17. Statistical investigation of a blank holder force distribution system for a multi-step deep drawing process

    NASA Astrophysics Data System (ADS)

    Tommerup, So/ren; Endelt, Benny; Nielsen, Karl Brian

    2013-12-01

    This paper investigates process control possibilities obtained from a new tool concept for adaptive blank holder force (BHF) distribution. The investigation concerns the concept's application to a multi-step deep drawing process exemplified by the NUMISHEET2014 benchmark 2: Springback of draw-redraw pan. An actuator system, where several cavities are embedded into the blank holder plate is used. By independently controlling the pressure of hydraulic fluid in these cavities, a controlled deflection of the blank holder plate surface can be achieved whereby the distribution of the BHF can be controlled. Using design of experiments, a full 3-level factorial experiments is conducted with respect to the cavity pressures, and the effects and interactions are evaluated.

  18. Experimental Investigations on Formability of Aluminum Tailor Friction Stir Welded Blanks in Deep Drawing Process

    NASA Astrophysics Data System (ADS)

    Kesharwani, R. K.; Panda, S. K.; Pal, S. K.

    2015-02-01

    In the present work, tailor friction stir welded blanks (TFSWBs) were fabricated successfully using 2.0-mm-thick AA5754-H22 and AA5052-H32 sheet metals with optimized tool design and process parameters. Taguchi L9 orthogonal array has been used to design the friction stir welding experiments, and the Grey relational analysis has been applied for the multi objective optimization in order to maximize the weld strength and total elongation reducing the surface roughness and energy consumption. The formability of the TFSWBs and parent materials was evaluated and compared in terms of limiting drawing ratio (LDR) using a conventional circular die. It was found that the formability of the TFSWBs was comparable with that of both the parent materials without failure in the weldment. A modified conical tractrix die (MCTD) was proposed to enhance the LDR of the TFSWBs. It was found that the formability was improved by 27% using the MCTD.

  19. Repair of localized defects in multilayer-coated reticle blanks for extreme ultraviolet lithography

    DOEpatents

    Stearns, Daniel G.; Sweeney, Donald W.; Mirkarimi, Paul B.

    2004-11-23

    A method is provided for repairing defects in a multilayer coating layered onto a reticle blank used in an extreme ultraviolet lithography (EUVL) system. Using high lateral spatial resolution, energy is deposited in the multilayer coating in the vicinity of the defect. This can be accomplished using a focused electron beam, focused ion beam or a focused electromagnetic radiation. The absorbed energy will cause a structural modification of the film, producing a localized change in the film thickness. The change in film thickness can be controlled with sub-nanometer accuracy by adjusting the energy dose. The lateral spatial resolution of the thickness modification is controlled by the localization of the energy deposition. The film thickness is adjusted locally to correct the perturbation of the reflected field. For example, when the structural modification is a localized film contraction, the repair of a defect consists of flattening a mound or spreading out the sides of a depression.

  20. A study of defects on EUV mask using blank inspection, patterned mask inspection, and wafer inspection

    SciTech Connect

    Huh, S.; Ren, L.; Chan, D.; Wurm, S.; Goldberg, K. A.; Mochi, I.; Nakajima, T.; Kishimoto, M.; Ahn, B.; Kang, I.; Park, J.-O.; Cho, K.; Han, S.-I.; Laursen, T.

    2010-03-12

    The availability of defect-free masks remains one of the key challenges for inserting extreme ultraviolet lithography (EUVL) into high volume manufacturing. yet link data is available for understanding native defects on real masks. In this paper, a full-field EUV mask is fabricated to investigate the printability of various defects on the mask. The printability of defects and identification of their source from mask fabrication to handling were studied using wafer inspection. The printable blank defect density excluding particles and patterns is 0.63 cm{sup 2}. Mask inspection is shown to have better sensitivity than wafer inspection. The sensitivity of wafer inspection must be improved using through-focus analysis and a different wafer stack.

  1. Actinic detection of sub-100 nm defects on extreme ultraviolet lithography mask blanks

    SciTech Connect

    Jeong, Seongtae; Johnson, Lewis; Rekawa, Seno; Walton, Chris C.; Prisbrey, Shon T.; Tejnil, Edita; Underwood, James H.; Bokor, Jeffrey; EECS Department, University of California, Berkeley, California 94720

    1999-11-01

    We present recent experimental results from a prototype actinic (operates at the 13 nm extreme ultraviolet wavelength) defect inspection system for extreme ultraviolet lithography mask blanks. The defect sensitivity of the current actinic inspection system is shown to reach 100 nm in experiments with programmed defects. A method to cross register and cross correlate between the actinic inspection system and a commercial visible-light scattering defect inspection system is also demonstrated. Thus, random, native defects identified using the visible-light tool can reliably be found and scanned by our actinic tool. We found that native defects as small as 86 nm (as classified by the visible-light tool) were detectable by the actinic tool. These results demonstrate the capability of this tool for independent defect counting experiments. (c) 1999 American Vacuum Society.

  2. [Suicidal shot in the mouth with an unmodified blank cartridge pistol].

    PubMed

    Bungardt, Nikola; Dettmeyer, Reinhard; Madea, Burkhard

    2005-01-01

    In the medicolegal literature reports of suicides with weapons designed for self-defence, especially gas pistols, are rare. We report on a suicide of a 54-year-old woman who fired a fatal shot in her mouth with an unmanipulated blank cartridge pistol, make Röhm RG 8, calibre 8 mm. The autopsy findings (lips and mucosa of the buccal vestibule without injuries, but extensive lesions of the tongue and the middle and rear third of the smooth palate) suggest that the shot was fired - as observed by a witness - with the barrel of the weapon inside the oral cavity. Both macroscopic inspection and histological investigations excluded the possibility that death was caused by an injury of the brain, in particular the brain stem. The immediate cause of death was deep aspiration of chyme with concurrent aspiration of blood. PMID:16134396

  3. Feasibility study of transmission of OTV camera control information in the video vertical blanking interval

    NASA Technical Reports Server (NTRS)

    White, Preston A., III

    1994-01-01

    The Operational Television system at Kennedy Space Center operates hundreds of video cameras, many remotely controllable, in support of the operations at the center. This study was undertaken to determine if commercial NABTS (North American Basic Teletext System) teletext transmission in the vertical blanking interval of the genlock signals distributed to the cameras could be used to send remote control commands to the cameras and the associated pan and tilt platforms. Wavelength division multiplexed fiberoptic links are being installed in the OTV system to obtain RS-250 short-haul quality. It was demonstrated that the NABTS transmission could be sent over the fiberoptic cable plant without excessive video quality degradation and that video cameras could be controlled using NABTS transmissions over multimode fiberoptic paths as long as 1.2 km.

  4. Backside defect printability for contact layer with different reticle blank material

    NASA Astrophysics Data System (ADS)

    Ning, Guoxiang; Holfeld, Christian; Fischer, Daniel; Ackmann, Paul; Holfeld, Andre; Kurth, Karin; Sczyrba, Martin; Hertzsch, Tino; Seltmann, Rolf; Ho, Angeline; GN, Fang H.

    2012-11-01

    Backside defects are out of focus during wafer exposure by the mask thickness and cannot be directly imaged on wafer. However, backside defects will induce transmission variation during wafer exposure. When the size of backside defect is larger than 200 microns, the shadow of such particles will locally change the illumination conditions of the mask patterns and may result in a long range critical dimension (CD) variation on wafer depending on numerical aperture (NA) and pupil shape. Backside defects will affect both wafer CD and critical dimension uniformity (CDU), especially for two-dimensional (2D) structures. This paper focuses on the printability of backside defects on contact layer using annular and quadrupole illumination mode, as well as using different reticle blank material. It also targets for gaining better understanding of critical sizes of backside defects on contact layer for different reticle blanks. We have designed and manufactured two test reticles with repeating patterns of 28nm and 40nm technology node of contact layers. Programmed chrome defects of varying size are placed on the backside opposite to the repeating front side patterns in order to measure the spatial variation of transmission and wafer CD. The test mask was printed on a bare silicon wafer, and the printed features measured for size by spatial sampling. We have investigated two contact layers with different illumination conditions. One is advance binary with single exposure; another is phase shift mask with double exposure. Wafer CD variation for different backside defect sizes are demonstrated for the two contact layers. The comparison between backside defect size with inter-field and intra-field CD variation is also discussed.

  5. Note: Vignetting calibration and temperature correction for casting billets.

    PubMed

    Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei; Bai, Haicheng

    2013-09-01

    A method for calibration of vignetting coefficient is proposed in this paper to solve the distortion of temperature measurement using a CCD-based pyrometer. On this basis, a hybrid temperature measurement system, which comprises of an array CCD camera with high resolution and a single spot colorimetric thermometer, is introduced to eliminate the influences of surface striped iron oxide scale, dust, and emissivity on temperature measurement for casting billets. Currently, the system has been successfully applied and verified in some continuous casting production lines. The vignetting estimation error of 0.052 and the maximum temperature measurement fluctuation of 5 °C were achieved in these measurements. PMID:24089881

  6. Titan Casts Revealing Shadow

    NASA Astrophysics Data System (ADS)

    2004-05-01

    A rare celestial event was captured by NASA's Chandra X-ray Observatory as Titan -- Saturn's largest moon and the only moon in the Solar System with a thick atmosphere -- crossed in front of the X-ray bright Crab Nebula. The X-ray shadow cast by Titan allowed astronomers to make the first X-ray measurement of the extent of its atmosphere. On January 5, 2003, Titan transited the Crab Nebula, the remnant of a supernova explosion that was observed to occur in the year 1054. Although Saturn and Titan pass within a few degrees of the Crab Nebula every 30 years, they rarely pass directly in front of it. "This may have been the first transit of the Crab Nebula by Titan since the birth of the Crab Nebula," said Koji Mori of Pennsylvania State University in University Park, and lead author on an Astrophysical Journal paper describing these results. "The next similar conjunction will take place in the year 2267, so this was truly a once in a lifetime event." Animation of Titan's Shadow on Crab Nebula Animation of Titan's Shadow on Crab Nebula Chandra's observation revealed that the diameter of the X-ray shadow cast by Titan was larger than the diameter of its solid surface. The difference in diameters gives a measurement of about 550 miles (880 kilometers) for the height of the X-ray absorbing region of Titan's atmosphere. The extent of the upper atmosphere is consistent with, or slightly (10-15%) larger, than that implied by Voyager I observations made at radio, infrared, and ultraviolet wavelengths in 1980. "Saturn was about 5% closer to the Sun in 2003, so increased solar heating of Titan may account for some of this atmospheric expansion," said Hiroshi Tsunemi of Osaka University in Japan, one of the coauthors on the paper. The X-ray brightness and extent of the Crab Nebula made it possible to study the tiny X-ray shadow cast by Titan during its transit. By using Chandra to precisely track Titan's position, astronomers were able to measure a shadow one arcsecond in

  7. Phase transformations in cast duplex stainless steels

    NASA Astrophysics Data System (ADS)

    Kim, Yoon-Jun

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as sigma (sigma) and chi (chi) can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (sigma + chi) formation were analyzed using the Johnson-Mehl-Avrami (JMA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities, a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, a was stabilized with increasing Cr addition and chi by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in

  8. Phase Transformations in Cast Duplex Stainless Steels

    SciTech Connect

    Yoon-Jun Kim

    2004-12-19

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as {sigma} and {chi} can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase ({sigma} + {chi}) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, {sigma} was stabilized with increasing Cr addition and {chi} by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in

  9. Stress distribution in a continuously cast intermetallic strip

    NASA Astrophysics Data System (ADS)

    Roy, George; Wronski, Zbignew; Sahoo, Mahi; Kiff, Dave

    Results of a study on the determination of the residual stress state in a nickel aluminide intermetallic strip by the hole drilling method (HDM) are presented. Special correlation functions that relate the relaxed surface strain and the original stresses before drilling were developed. It is shown that the HDM may be used to determine residual stresses in anisotropic materials such as intermetallic strips. The results indicate that a complex stress field develops through the thickness and across the width of the strip. However, a suitable thermomechanical treatment may be applied to redistribute the stresses before aluminide strips can be used to make engineering components.

  10. Fillability of Thin-Wall Steel Castings

    SciTech Connect

    Robert C. Voigt; Joseph Bertoletti; Andrew Kaley; Sandi Ricotta; Travis Sunday

    2002-07-30

    The use of steel components is being challenged by lighter nonferrous or cast iron components. The development of techniques for enhancing and ensuring the filability of thin-wall mold cavities is most critical for thinner wall cast steel production. The purpose of this research was to develop thin-wall casting techniques that can be used to reliably produce thin-wall castings from traditional gravity poured sand casting processes. The focus of the research was to enhance the filling behavior to prevent misrunds. Experiments were conducted to investigate the influence of various foundry variables on the filling of thin section steel castings. These variables include casting design, heat transfer, gating design, and metal fluidity. Wall thickness and pouring temperature have the greatest effect on casting fill. As wall thickness increases the volume to surface area of the casting increases, which increases the solidification time, allowing the metal to flow further in thicker sect ions. Pouring time is another significant variable affecting casting fill. Increases or decreases of 20% in the pouring time were found to have a significant effect on the filling of thin-wall production castings. Gating variables, including venting, pouring head height, and mold tilting also significantly affected thin-wall casting fill. Filters offer less turbulent, steadier flow, which is appropriate for thicker castings, but they do not enhance thin-wall casting fill.

  11. Cast adrift: Gortex cast liners allow greater patient activity.

    PubMed

    Dubowitz, Gerald; Miller, Deborah M

    2003-01-01

    Extremity fractures are a common injury, with nearly 1.5 million cases reported in the United States in 1998. Treatment often involves lengthy periods of immobilization. This report outlines the use of a Gortex cast liner by a subject who was able to engage in swimming and scuba diving during the healing process. We report that a Gortex cast liner may be considered for an active patient who is keen to return to limited activities during fracture healing. Apparently because of a lack of knowledge of their existence, physicians currently are underutilizing this method of casting in active patients. The use of Gortex liners elsewhere has been reported to have higher patient and physician satisfaction in both use and performance, with no reported detrimental effects on outcome. PMID:14518627

  12. Instant Casting Movie Theater: The Future Cast System

    NASA Astrophysics Data System (ADS)

    Maejima, Akinobu; Wemler, Shuhei; Machida, Tamotsu; Takebayashi, Masao; Morishima, Shigeo

    We have developed a visual entertainment system called “Future Cast” which enables anyone to easily participate in a pre-recorded or pre-created film as an instant CG movie star. This system provides audiences with the amazing opportunity to join the cast of a movie in real-time. The Future Cast System can automatically perform all the processes required to make this possible, from capturing participants' facial characteristics to rendering them into the movie. Our system can also be applied to any movie created using the same production process. We conducted our first experimental trial demonstration of the Future Cast System at the Mitsui-Toshiba pavilion at the 2005 World Exposition in Aichi Japan.

  13. 75 FR 9436 - Aleris Blanking and Rim Products, Inc., a Division of Aleris International, Inc., Terre Haute, IN...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... (75 FR 3932). The initial investigation resulted in a negative determination based on the findings... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Aleris Blanking and Rim Products, Inc., a Division of...

  14. Estimating surface hardening profile of blank for obtaining high drawing ratio in deep drawing process using FE analysis

    NASA Astrophysics Data System (ADS)

    Tan, C. J.; Aslian, A.; Honarvar, B.; Puborlaksono, J.; Yau, Y. H.; Chong, W. T.

    2015-12-01

    We constructed an FE axisymmetric model to simulate the effect of partially hardened blanks on increasing the limiting drawing ratio (LDR) of cylindrical cups. We partitioned an arc-shaped hard layer into the cross section of a DP590 blank. We assumed the mechanical property of the layer is equivalent to either DP980 or DP780. We verified the accuracy of the model by comparing the calculated LDR for DP590 with the one reported in the literature. The LDR for the partially hardened blank increased from 2.11 to 2.50 with a 1 mm depth of DP980 ring-shaped hard layer on the top surface of the blank. The position of the layer changed with drawing ratios. We proposed equations for estimating the inner and outer diameters of the layer, and tested its accuracy in the simulation. Although the outer diameters fitted in well with the estimated line, the inner diameters are slightly less than the estimated ones.

  15. Testing the Reliability of Delay Discounting of Ten Commodities Using the Fill-in-the-Blank Method

    ERIC Educational Resources Information Center

    Weatherly, Jeffrey N.; Derenne, Adam; Terrell, Heather K.

    2011-01-01

    Several measures of delay discounting have been shown to be reliable over periods of up to 3 months. In the present study, 115 participants completed a fill-in-the-blank (FITB) delay-discounting task on sets of 5 different commodities, 12 weeks apart. Results showed that discounting rates were not well described by a hyperbolic function but were…

  16. Design of Channel Type Indirect Blank Holder for Prevention of Wrinkling and Fracture in Hot Stamping Process

    NASA Astrophysics Data System (ADS)

    Choi, Hong-seok; Ha, Se-yoon; Cha, Seung-hoon; kang, Chung-gil; Kim, Byung-min

    2011-08-01

    The hot stamping process has been used in the automotive industry to reduce the weight of the body-in-white and to increase passenger safety via improved crashworthiness. In this study, a new form die with a simple structure that can prevent defects such as wrinkle and fracture is proposed for the manufacture of hot stamped components. The wrinkling at the flange cannot be eliminated when using a conventional form die. It is known that the initiation of wrinkling is influenced by many factors such as the mechanical properties of the sheet material, geometry of the sheet and tool, and other process parameters, including the blank holding force (BHF) and the contact conditions. In this research, channel type indirect blank holder (CIBH) is introduced to replace general blank holder for manufacturing the hot stamped center pillar. First, we investigate the tension force acting on the blank according to the channel shapes. We determine the appropriate range by comparing the tension force with the upper and lower BHFs in a conventional stamping process. We then use FE-analysis to study the influence of the slope angle and corner radius of the channel on the formability. Finally, the center pillar is manufactured using the form die with the selected channel.

  17. The Use of Application Blanks as Pre-Screening Devices in Employee Selection: An Assessment of Practices in Public Schools.

    ERIC Educational Resources Information Center

    Bredeson, Paul V.

    1988-01-01

    Reports on a study of the use of employment application blanks as prescreening devices in public school employee selection. Findings suggest two major areas for further research. The first relates to legal compliance with Equal Opportunity Employment guidelines. The second concerns information relevancy to personnel selection. (JAM)

  18. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--QA ANALYTICAL RESULTS FOR PARTICULATE MATTER IN BLANK SAMPLES

    EPA Science Inventory

    The Particulate Matter in Blank Samples data set contains the analytical results for measurements of two particle sizes in 12 samples. Filters were pre-weighed, loaded into impactors, kept unexposed in the laboratory, unloaded and post-weighed. Positive weight gains for laborat...

  19. 47 CFR 73.646 - Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal. 73.646 Section 73.646 Telecommunication FEDERAL COMMUNICATIONS... nature are subject to common carrier regulation. Licensees operating such services are required to...

  20. 47 CFR 73.646 - Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal. 73.646 Section 73.646 Telecommunication FEDERAL COMMUNICATIONS... nature are subject to common carrier regulation. Licensees operating such services are required to...

  1. 47 CFR 73.646 - Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Telecommunications Service on the Vertical Blanking Interval and in the Visual Signal. 73.646 Section 73.646 Telecommunication FEDERAL COMMUNICATIONS... nature are subject to common carrier regulation. Licensees operating such services are required to...

  2. Textures of strip cast Fe16%Cr

    SciTech Connect

    Raabe, D.; Reher, F.; Luecke, K. ); Hoelscher, M. )

    1993-07-01

    Ferritic stainless steels with a Cr content of 16% are mainly manufactured by continuous casting, hot rolling, cold rolling and final recrystallization. The recent development of the strip casting method, which provides sheets with an equivalent geometry, i.e. thickness and width as the hot rolled band, yields significant improvements in comparison to the conventional processing. The weak initial strip texture and the homogeneous microstructure through the sample thickness have shown evidence of avoiding the well known ridging phenomenon of the finally rolled and annealed product. The occurrence of ridging in conventionally processed FeCr steel has been attributed to the collective shear of grains with (hkl)<110>, i.e. [alpha]-fibre orientations, which become oriented and topologically arranged during hot rolling. In the present paper the textures of a stainless ferritic steel with 16% Cr and 0.02% C, strip casted (SC) as well as hot rolled (HR), were thus investigated. The textures were examined by measuring the four incomplete pole figures (110), (200), (112) and (103) in the back reflection mode. The orientation distribution function (ODF) was calculated by the series expansion method (1[sup max]=22). In the case of cubic crystal symmetry and orthorhombic sample symmetry an orientation can then be presented by the three Euler angles [var phi][sub 1], [var phi], [var phi][sub 2] in the reducted Euler space. Since bcc steels tend to develop characteristic fibre textures, it is favorable to present the ODFs as isointensity diagrams in [var phi][sub 1]-sections through the Eulerspace. In this work the [alpha]-fibre and the [gamma]-fibre are of major interest.

  3. Magnesium-lithium casting alloys

    NASA Technical Reports Server (NTRS)

    Latenko, V. P.; Silchenko, T. V.; Tikhonov, V. A.; Maltsev, V. P.; Korablin, V. P.

    1974-01-01

    The strength properties of magnesium-lithium alloys at room, low, and high temperatures are investigated. It is found that the alloys may have practical application at ambient temperatures up to 100 C, that negative temperatures have a favorable influence on the alloy strength, and that cyclic temperature variations have practically no effect on the strength characteristics. The influence of chemical coatings on corrosion resistance of the MgLi alloys is examined. Several facilities based on pressure casting machines, low-pressure casting machines, and magnetodynamic pumps were designed for producing MgLi alloy castings. Results were obtained for MgLi alloys reinforced with fibers having a volumetric content of 15%.

  4. Optimizing EUV mask blank cleaning processes using the Lasertec M7360

    NASA Astrophysics Data System (ADS)

    Shimomura, Takeya; Kadaksham, Arun John; House, Matt; Ma, Andy; Goodwin, Frank

    2012-03-01

    EUV lithography is considered the most promising lithography solution for the 16 nm node and beyond. As EUV light is strongly absorbed by all known materials, reflective optics are used instead of conventional transmittance optics applied to ArF and KrF lithography. The EUV mask must also need be reflective. It typically consists of a Ta-based absorber layer, Ru capping layer, Si/Mo multilayer on a low thermal expansion material (LTEM) substrate with a backside Cr-based metal coating. Because of the strong absorbance of the EUV light, a pellicle is not practical. Therefore, EUV masks must be cleaned more frequently to maintain the necessary cleanliness. This poses numerous unique challenges in cleaning processes. For example, the EUV mask integrity, including critical dimension (CD), EUV reflectivity, and absorber thickness must be kept intact during multiple cleanings throughout the mask's lifetime. Requirements of defect size for the cleaning, furthermore, are becoming tighter as semiconductor circuit design rules get smaller. According to the International Technology Roadmap For Semiconductors (ITRS), the smallest defect size that must be removed is 23 nm for the 18 nm NAND Flash node in 2013. In addition to defects on the frontside, defects on a backside also need to be minimized since they might lead overlay error due to local distortions of EUV masks on an electrostatic chuck. This paper focuses on evaluations of cleaning performances using the Lasertec M1350 and M7360 blank inspection system, which has a 71 nm and 43 nm sensitivity. The 43nm is the current best sensitivity while keeping a >90% defect capture rate. First, the cleaning performance using the standard process has been investigated. We found a mitigation of adders was a key challenge for the EUV mask cleaning. The primary source of the adders was also identified as pits. Secondly, the megasonic cleaning process has been optimized to mitigate the adders. We could successfully reduce the adders by

  5. Energy Consumption of Die Casting Operations

    SciTech Connect

    Jerald Brevick; clark Mount-Campbell; Carroll Mobley

    2004-03-15

    Molten metal processing is inherently energy intensive and roughly 25% of the cost of die-cast products can be traced to some form of energy consumption [1]. The obvious major energy requirements are for melting and holding molten alloy in preparation for casting. The proper selection and maintenance of melting and holding equipment are clearly important factors in minimizing energy consumption in die-casting operations [2]. In addition to energy consumption, furnace selection also influences metal loss due to oxidation, metal quality, and maintenance requirements. Other important factors influencing energy consumption in a die-casting facility include geographic location, alloy(s) cast, starting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting machine, related equipment (robots, trim presses), and downstream processing (machining, plating, assembly, etc.). Each of these factors also may influence the casting quality and productivity of a die-casting enterprise. In a die-casting enterprise, decisions regarding these issues are made frequently and are based on a large number of factors. Therefore, it is not surprising that energy consumption can vary significantly from one die-casting enterprise to the next, and within a single enterprise as function of time.

  6. Cementite Solidification in Cast Iron

    NASA Astrophysics Data System (ADS)

    Coronado, J. J.; Sinatora, A.; Albertin, E.

    2014-06-01

    Two hypereutectic cast irons (5.01 pct Cr and 5.19 pct V) were cast and the polished surfaces of test pieces were deep-etched and analyzed via scanning electron microscopy. The results show that graphite lamellae intersect the cementite and a thin austenite film nucleates and grows on the cementite plates. For both compositions, graphite and cementite can coexist as equilibrium phases, with the former always nucleating and growing first. The eutectic carbides grow from the austenite dendrites in a direction perpendicular to the primary plates.

  7. Casting behavior of titanium alloys in a centrifugal casting machine.

    PubMed

    Watanabe, K; Miyakawa, O; Takada, Y; Okuno, O; Okabe, T

    2003-05-01

    Since dental casting requires replication of complex shapes with great accuracy, this study examined how well some commercial titanium alloys and experimental titanium-copper alloys filled a mold cavity. The metals examined were three types of commercial dental titanium [commercially pure titanium (hereinafter noted as CP-Ti), Ti-6Al-4V (T64) and Ti-6Al-7Nb (T67)], and experimental titanium-copper alloys [3%, 5% and 10% Cu (mass %)]. The volume percentage filling the cavity was evaluated in castings prepared in a very thin perforated sheet pattern and cast in a centrifugal casting machine. The flow behavior of the molten metal was also examined using a so-called "tracer element technique." The amounts of CP-Ti and all the Ti-Cu alloys filling the cavity were similar; less T64 and T67 filled the cavity. However, the Ti-Cu alloys failed to reach the end of the cavities due to a lower fluidity compared to the other metals. A mold prepared with specially designed perforated sheets was effective at differentiating the flow behavior of the metals tested. The present technique also revealed that the more viscous Ti-Cu alloys with a wide freezing range failed to sequentially flow to the end of the cavity. PMID:12593955

  8. INTERIOR VIEW WITH CASTING MACHINE AND A 4" DUCTILE IRON ...

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

    INTERIOR VIEW WITH CASTING MACHINE AND A 4" DUCTILE IRON PIPE BEING EXTRACTED FROM CASTING MACHINE - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

  9. INTERIOR VIEW OF CASTING MACHINE WITH 4' DUCTILE IRON PIPE ...

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

    INTERIOR VIEW OF CASTING MACHINE WITH 4' DUCTILE IRON PIPE BEING WEIGHED ON SCALES AT CASTING MACHINE. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

  10. INTERIOR VIEW WITH CASTING MACHINE AND A 4' DUCTILE IRON ...

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

    INTERIOR VIEW WITH CASTING MACHINE AND A 4' DUCTILE IRON PIPE BEING CENTRIFUGALLY CAST, AS OPERATOR WATCHES TO ENSURE QUALITY. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

  11. INTERIOR VIEW WITH CASTING MACHINE COOLING A 20' IRON PIPE ...

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

    INTERIOR VIEW WITH CASTING MACHINE COOLING A 20' IRON PIPE PRIOR TO EXTRACTION FROM CASTING MACHINE. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

  12. Horizontal electromagnetic casting of thin metal sheets

    DOEpatents

    Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

    1987-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  13. Horizontal electromagnetic casting of thin metal sheets

    DOEpatents

    Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

    1988-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  14. CIR Casting System for making transtibial sockets.

    PubMed

    Wu, Yeongchi; Casanova, Hector R; Reisinger, Kim D; Smith, William K; Childress, Dudley S

    2009-03-01

    This paper describes a new casting system for transtibial socket fabrication. Like the earlier CIR Sand Casting System, the CIR Casting System is based on the 'dilatancy' principle that is similar to the packaging process for coffee beans by which loose beans become a solid mass when a vacuum is applied. The main difference from the CIR Sand Casting System is that the CIR Casting System uses light-weight, polystyrene beads in place of silica sand as the primary material for casting the negative mold. The formed negative mold can be converted into a positive sand model for modification and socket formation. With the new plaster-less casting system, the prosthetist can fabricate a transtibial prosthesis in about one hour. It reduces the set-up cost, overall weight and size of the casting system, and increases portability for service in remote areas. The System also creates minimal waste and is energy-conserving and environmentally-friendly. PMID:19235060

  15. Properties of electroslag castings: Part 1

    SciTech Connect

    Sikka, V.K.

    1984-11-01

    This part of several reports to be published on the properties of electroslag castings of 2 1/4 Cr-1 Mo, 9 Cr-1 Mo, and type 316 stainless steel describes the properties of three electroslag-cast valve bodies of type 316 stainless steel. These castings were electroslag cast at the University of British Columbia in Canada from ORNL-supplied electrodes. The castings have been characterized for surface finish, cracking, solidification structure, chemical analysis, hardness, ferrite distribution, tensile properties, Charpy impact properties, and creep properties. Tensile data on these castings were compared with the American Society of Mechanical Engineers (ASME) code minimum values for sand castings. The creep data were compared with the data on sand castings and the ASME code minimum curve for wrought material. 29 figures, 7 tables.

  16. Low thermal expansion material (LTEM) cleaning and optimization for extreme ultraviolet (EUV) blank deposition

    NASA Astrophysics Data System (ADS)

    Kadaksham, Arun J.; Teki, Ranganath; Godwin, Milton; House, Matt; Goodwin, Frank

    2013-04-01

    With the insertion of extreme ultraviolet lithography (EUVL) for high volume manufacturing (HVM) expected in the next few years, it is necessary to examine the performance of low thermal expansion materials (LTEMs) and assess industry readiness of EUV substrates. Owing to the high cost of LTEM, most of the development work so far has been done on fused silica substrates. Especially in developing cleaning technology prior to multilayer deposition, fused silica substrates have been used extensively, and defect trends and champion blank data have been reported using multilayer deposition data on fused silica substrates. In this paper, the response of LTEMs to cleaning processes prior to multilayer deposition is discussed. Cleaning processes discussed in this paper are developed using fused silica substrates and applied on LTEM substrates. The defectivity and properties of LTEM to fused silica are compared. Using the dense scan feature of the substrate inspection tool capable of detecting defects down to 35 nm SiO2 equivalent size and appropriate defect decoration techniques to decorate small defects on substrates to make them detectable, cleaning technologies that have the potential to meet high demands on LTEM for EUVL are developed and optimized.

  17. Delineating the Construct Network of the Personnel Reaction Blank: Associations with Externalizing Tendencies and Normal Personality

    PubMed Central

    Blonigen, Daniel M.; Patrick, Christopher J.; Gasperi, Marianna; Steffen, Benjamin; Ones, Deniz S.; Arvey, Richard D.; de Oliveira Baumgartl, Viviane; do Nascimento, Elizabeth

    2010-01-01

    Integrity testing has long been utilized in personnel selection to screen for tendencies toward counterproductive workplace behaviors. The construct of externalizing from the psychopathology literature represents a coherent spectrum marked by disinhibitory traits and behaviors. The present study used a sample of male and female undergraduates to examine the construct network of the Personnel Reaction Blank (PRB; Gough, Arvey, & Bradley, 2004), a measure of integrity, in relation to externalizing as well as normal-range personality constructs assessed by the Multidimensional Personality Questionnaire (MPQ; Tellegen & Waller, 2008). Results revealed moderate to strong associations between several PRB scales and externalizing, which were largely accounted for by MPQ traits subsumed by Negative Emotionality and Constraint. After accounting for MPQ traits in the prediction of externalizing, a modest predictive increment was achieved when adding the PRB scales, particularly biographical indicators from the Prosocial Background subscale. The findings highlight externalizing as a focal criterion for scale development in the integrity testing literature, and help delineate the construct network of the PRB within the domains of personality and psychopathology. PMID:21171783

  18. Preparation and characterization of Ag nanoparticle-embedded blank and ligand-anchored silica gels.

    PubMed

    Im, Hee-Jung; Lee, Byung Cheol; Yeon, Jei-Won

    2013-11-01

    Ag nanoparticles, used for halogen (especially iodine) adsorption and an evaluation of halogen behavior, were embedded in synthesized inorganic-organic hybrid gels. In particular, an irradiation method using an electron beam plays a part in introducing Ag nanoparticles to the organofunctionalized silica gels from AgNO3 solutions in a simple way at atmospheric pressure and room temperature. For preparation of the Ag nanoparticle-embedded inorganic-organic hybrid gels, ligands of ethylenediamine (NH2CH2CH2NH-, TMSen) and mercapto (HS-) functionalized three-dimensional porous SiO2 sol-gels were first synthesized through hydrolysis and condensation reactions, and Ag nanoparticles were then embedded into the ethylenediamine- and mercapto-anchored silica gels each, through electron-beam irradiation. The addition of ligands yielded larger average pore sizes than the absence of any ligand. Moreover, the ethylenediamine ligand led to looser structures and better access of the Ag nanoparticles to the ethylenediamine-anchored gel. As a result, more Ag nanoparticles were introduced into the ethylenediamine-anchored gel. The preparation and characterization of Ag nanoparticle-embedded blank and ligand-anchored silica gels are discussed in detail. PMID:24245307

  19. Velocity Interferometer blanking due to preheating in a double pulse planar experiment

    NASA Astrophysics Data System (ADS)

    Laffite, S.; Baton, S. D.; Combis, P.; Clerouin, J.; Koenig, M.; Recoules, V.; Rousseaux, C.; Videau, L.

    2014-08-01

    Optical diagnostics, such as VISAR (Velocity Interferometer System for Any Reflector) or SOP (Streaked Optical Pyrometry), have become essential in shock timing experiments. Their high precision allows for accurate measurements of shock velocities, chronometry, and brightness temperature. However, in some instances, these measurements can be compromised. In planar shock coalescence experiments recently performed at the LULI facility [Baton et al., Phys. Rev. Lett. 108, 195002 (2012)], VISAR signal loss was observed. In these experiments, a strong shock launched by a high-intensity spike catches up with a previously shock launched by an earlier, low-intensity beam. The disappearance of the VISAR signal is attributed to a preheating of the coronal plasma by x-rays generated by the high intensity spike. The signal does not disappear if the high-intensity spike starts after VISAR probe beam begins to reflect off of the first shock. The VISAR diagnostic, modeled using an assessment of the optical index in quartz, compares favorably to experimental results. This provides evidence that x-ray preheating can cause blanking of the VISAR signal in quartz.

  20. Velocity Interferometer blanking due to preheating in a double pulse planar experiment

    SciTech Connect

    Laffite, S.; Combis, P.; Clerouin, J.; Recoules, V.; Rousseaux, C.; Videau, L.; Baton, S. D.; Koenig, M.

    2014-08-15

    Optical diagnostics, such as VISAR (Velocity Interferometer System for Any Reflector) or SOP (Streaked Optical Pyrometry), have become essential in shock timing experiments. Their high precision allows for accurate measurements of shock velocities, chronometry, and brightness temperature. However, in some instances, these measurements can be compromised. In planar shock coalescence experiments recently performed at the LULI facility [Baton et al., Phys. Rev. Lett. 108, 195002 (2012)], VISAR signal loss was observed. In these experiments, a strong shock launched by a high-intensity spike catches up with a previously shock launched by an earlier, low-intensity beam. The disappearance of the VISAR signal is attributed to a preheating of the coronal plasma by x-rays generated by the high intensity spike. The signal does not disappear if the high-intensity spike starts after VISAR probe beam begins to reflect off of the first shock. The VISAR diagnostic, modeled using an assessment of the optical index in quartz, compares favorably to experimental results. This provides evidence that x-ray preheating can cause blanking of the VISAR signal in quartz.