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1

Vacuum Die Casting of Silicon Sheet for Photovoltaic Applications  

NASA Technical Reports Server (NTRS)

The development of a vacuum die-casting process for producing silicon sheet suitable for photovoltaic cells with a terrestrial efficiency greater than 12 percent and having the potential to be scaled for large quantity production is considered. The initial approach includes: (1) obtaining mechanical design parameters by using boron nitride, which has been shown to non-wetting to silicon; (2) optimizing silicon nitride material composition and coatings by sessile drop experiments; (3) testing effectiveness of fluoride salt interfacial media with a graphite mold; and (4) testing the effect of surface finish using both boron nitride and graphite. When the material and mechanical boundary conditions are established, a finalized version of the prototype assembly will be constructed and the casting variables determined.

1979-01-01

2

Application of a tungsten/tungsten-carbide film to H-13 casting dies by plasma assisted deposition  

SciTech Connect

Die casting is used extensively to produce Al, Mg and Zn alloy parts. H-13, a widely used die material, is a medium carbon steel alloy with Cr, Mo, and Si. A problem with die casting is soldering, thermal fatigue cracking, and carbon buildup which cause degradation of the casting. Application of a metallic coating to the die has been shown to increase the resistance to thermal fatigue cracking. In this study, a tungsten/tungsten carbide thin film was deposited on a casting die of H-13 die steel by a two step Plasma Source Ion Enhanced Deposition process using an argon and methane plasmas. The film was characterized using Auger Electron Spectroscopy, Scanning Electron Microscopy and Electron Dispersive Spectroscopy. The die and representative castings (from regular intervals during the lifetime of the die) were examined for evidence of soldering, thermal fatigue cracking and carbon buildup.

Horswill, N.; Jetzer, W.; Fetherston, P.; Conrad, J.R. [Univ. of Wisconsin, Madison, WI (United States)

1995-12-31

3

Thermo fatigue cracking of die casting dies  

Microsoft Academic Search

The investigation of aluminium alloy die casting die failures was done with the emphasis on thermal cracks. The aim of the study was to prolog the in-service die life by cladding with maraging steels, which would be economically beneficial. A vast analysis of thermal fatigue cracks in aluminium alloy die casting is done. Immersion test apparatus was developed, which enables

D. Klob?ar; L. Kosec; B. Kosec; J. Tušek

2010-01-01

4

Sputtered protective coatings for die casting dies  

NASA Technical Reports Server (NTRS)

This investigation determined whether selected ion beam sputtered coatings on H-13 die steel would have the potential of improving the thermal fatigue behavior of the steel used as a die in aluminum die casting. The coatings were selected to test candidate insulators and metals capable of providing protection of the die surface. The studies indicate that 1 micrometer thick W and Pt coatings reduced the thermal fatigue more than any other coating tested and are candidates to be used on a die surface to increase die life.

Mirtich, M. J.; Nieh, C. Y.; Wallace, J. F.

1981-01-01

5

Thermal stresses in aluminium alloy die casting dies  

Microsoft Academic Search

The aim of this research is to analyze the influence of Aluminium Alloy die casting parameters, die material, and die geometry on in-service tool life. An innovative immersion testing apparatus is developed, at which Aluminium Alloy die casting is simulated. It enables controlled thermal fatigue cycling. Special specimens with different edge geometry and specimens with maraging steel welds deposited by

Damjan Klob?ar; Janez Tušek

2008-01-01

6

Energy Consumption of Die Casting Operations  

SciTech Connect

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.

Jerald Brevick; clark Mount-Campbell; Carroll Mobley

2004-03-15

7

Application of TPM indicators for analyzing work time of machines used in the pressure die casting  

NASA Astrophysics Data System (ADS)

The article presents the application of total productive maintenance (TPM) to analyze the working time indicators of casting machines with particular emphasis on failures and unplanned downtime to reduce the proportion of emergency operation for preventive maintenance and diagnostics. The article presents that the influence of individual factors of complex machinery maintenance (TPM) is different and depends on the machines' modernity level. In an original way, by using correlation graphs, research findings on the impact of individual TPM factors on the castings quality were presented and interpreted. The examination results conducted for machines with varying modernity degrees allowed to determine changes within the impact of individual TPM factors depending on machine parameters. These results provide a rich source of information for the improvement processes on casting quality of the foundry industry that satisfies the automotive industry demand.

Borkowski, Stanis?aw; Czajkowska, Agnieszka; Stasiak-Betlejewska, Renata; Borade, Atul B.

2014-05-01

8

Prediction of Part Distortion in Die Casting  

SciTech Connect

The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

R. Allen Miller

2005-03-30

9

Modeling the Mechanical Performance of Die Casting Dies  

SciTech Connect

The following report covers work performed at Ohio State on modeling the mechanical performance of dies. The focus of the project was development and particularly verification of finite element techniques used to model and predict displacements and stresses in die casting dies. The work entails a major case study performed with and industrial partner on a production die and laboratory experiments performed at Ohio State.

R. Allen Miller

2004-02-27

10

Sputtered protective coatings for die casting dies  

NASA Technical Reports Server (NTRS)

Three experimental research designs investigating candidate materials and processes involved in protective die surface coating procedures by sputter deposition, using ion beam technologies, are discussed. Various pre-test results show that none of the coatings remained completely intact for 15,000 test cycles. The longest lifetime was observed for coatings such as tungsten, platinum, and molybdenum which reduced thermal fatigue, but exhibited oxidation and suppressed crack initiation only as long as the coating did not fracture. Final test results confirmed earlier findings and coatings with Pt and W proved to be the candidate materials to be used on a die surface to increase die life. In the W-coated specimens, which remained intact on the surface after thermal fatigue testing, no oxidation was found under the coating, although a few cracks formed on the surface where the coating broke down. Further research is planned.

Mirtich, M. J.; Nieh, C.-Y.; Wallace, J. F.

1981-01-01

11

Formation of defect bands in high pressure die cast magnesium alloys  

Microsoft Academic Search

Die cast magnesium components are being increasingly used worldwide because of the excellent castability and properties that magnesium alloys offer. High pressure die casting of thin-walled components is particularly suitable because of the excellent flow characteristics of molten magnesium alloys. Typical automotive applications for thin-walled castings include components such as instrument panels, steering wheels, door frames and seat frames. These

A. K Dahle; S Sannes; D. H St. John; H Westengen

2001-01-01

12

Potential Magnesium Alloys for High Temperature Die Cast Automotive Applications: A Review  

Microsoft Academic Search

Magnesium, as a lightweight construction material, has rapidly grown its applications in the automotive industry since the early 1990s. To maximize the weight reduction of vehicles by lightweight magnesium alloys in the coming years, the use of newly developed high-temperature magnesium alloys is expected to increase significantly, particularly in the powertrain applications where the creep resistance is always required. This

Henry Hu; Alfred Yu; Naiyi Li; John E. Allison

2003-01-01

13

Fatigue of die cast zinc alloys  

SciTech Connect

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.

Schrems, K.K.; Dogan, O.N.; Goodwin, F.E. (International Lead Zinc Research Organization, Inc.)

2006-04-01

14

77 FR 6587 - PHB Die Casting a Subsidiary of PHB, Inc., Including On-Site Leased Workers From Career Concepts...  

Federal Register 2010, 2011, 2012, 2013

...Administration [TA-W-64,292] PHB Die Casting a Subsidiary of PHB, Inc., Including...19, 2008, applicable to workers of PHB Die Casting, a subsidiary of PHB, Inc...workers are engaged in the production of die castings. New information shows that...

2012-02-08

15

Aging of maraging steel welds during aluminium alloy die casting  

Microsoft Academic Search

The aim of this study is to evaluate precipitation annealing of 18% Ni maraging steel repair welds during aluminium die casting and to predict the prolonged in-service tool life. The emphasis of this study is the influence of post-weld precipitation annealing heat treatment and aluminium die casting thermal cycling on metallurgical and mechanical properties. A series of specimens of 1.2344

D. Klob?ar; J. Tušek; B. Taljat; L. Kosec; M. Pleterski

2008-01-01

16

The thermal fatigue resistance of H-13 Die Steel for aluminum die casting dies  

NASA Technical Reports Server (NTRS)

The effects of welding, five selected surface coatings, and stress relieving on the thermal fatigue resistance of H-13 Die Steel for aluminum die casting dies were studied using eleven thermal fatigue specimens. Stress relieving was conducted after each 5,000 cycle interval at 1050 F for three hours. Four thermal fatigue specimens were welded with H-13 or maraging steel welding rods at ambient and elevated temperatures and subsequently, subjected to different post-weld heat treatments. Crack patterns were examined at 5,000, 10,000, and 15,000 cycles. The thermal fatigue resistance is expressed by two crack parameters which are the average maximum crack and the average cracked area. The results indicate that a significant improvement in thermal fatigue resistance over the control was obtained from the stress-relieving treatment. Small improvements were obtained from the H-13 welded specimens and from a salt bath nitrogen and carbon-surface treatment. The other surface treatments and welded specimens either did not affect or had a detrimental influence on the thermal fatigue properties of the H-13 die steel.

1982-01-01

17

Metallographic assessment of Al-12Si high-pressure die casting escalator steps.  

PubMed

A microstructural characterization study was performed on high-pressure die cast specimens extracted from escalator steps manufactured from an Al-12 wt.% Si alloy designed for structural applications. Black and white, color light optical imaging and scanning electron microscopy techniques were used to conduct the microstructural analysis. Most regions in the samples studied contained globular-rosette primary ?-Al grains surrounded by an Al-Si eutectic aggregate, while primary dendritic ?-Al grains were present in the surface layer. This dendritic microstructure was observed in the regions where the melt did not impinge directly on the die surface during cavity filling. Consequently, microstructures in the surface layer were nonuniform. Utilizing physical metallurgy principles, these results were analyzed in terms of the applied pressure and filling velocity during high-pressure die casting. The effects of these parameters on solidification at different locations of the casting are discussed. PMID:24999947

Vander Voort, George Frederic; Suárez-Peña, Beatriz; Asensio-Lozano, Juan

2014-10-01

18

Evaluation of permanent die coatings to improve the wear resistance of die casting dies. Final project report, January 1, 1995--April 30, 1997  

SciTech Connect

Die Casting dies are subject to severe service conditions during the die casting operation. While these severe conditions are necessary to achieve high production rates, they cause the dies which are commonly made of H13 die steel, to suffer frequent failures. The major die failure mechanisms are erosion or washout, Heat checking, soldering and corrosion. Due to their geometrical complexity, die casting dies are very expensive (some dies cost over a million dollars), and thus a large number of parts have to be produced by a die, to justify this cost and leverage the advantages of the die casting process (high production rates, low manpower costs). A potential increase in the die service life, thus has a significant impact on the economics of the die; casting operation. There are many ways to extend die life: developing new wear resistant die materials, developing new surface treatments including coatings, improving heat treatment of existing H13 dies, using better lubricants that can protect the die material, or modifying the die geometry and process parameters to reduce the intensity of wear. Of these the use of coatings to improve the wear resistance of the die surface has shown a lot of promise. Consequently, use of coatings in the die casting industry and their wide use to decrease die wear can improve significantly the productivity of shop operations resulting in large savings in material and energy usage.

Shivpuri, R.

1997-09-18

19

Manufacture of die casting dies by hot isostatic pressing. CRADA final report  

SciTech Connect

The reason for this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Doehler-Jarvis was to investigate the manufacture die-casting dies with internal water-cooling lines by hot-isostatic pressing (HIPing) of H13 tool steel powder. The use of HIPing will allow the near-net-shape manufacture of dies and the strategic placement of water-cooling lines during manufacture. The production of near-net-shape dies by HIPing involves the generation of HIPing diagrams, the design of the can that can be used for HIPing a die with complex details, strategic placement of water-cooling lines in the die, computer modeling to predict movement of the water lines during HIPing, and the development of strategies for placing water lines in the appropriate locations. The results presented include a literature review, particle analysis and characterization of H13 tool steel powder, and modeling of the HIPing process.

Viswanathan, S.; Ren, W.; Luk, K. [Oak Ridge National Lab., TN (United States); Brucher, H.G. [Doehler-Jarvis, Toledo, OH (United States)

1998-09-01

20

Surface morphology of a die-cast Mg alloy  

Microsoft Academic Search

We have studied the microstructure, phase composition and morphology of the intermetallic ?-phase in the surface layer of the most widespread magnesium alloy AZ91D (Mg–9 wt.% Al–1 wt.% Zn) used in pressure die casting. Auger electron spectroscopy (AES), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and optical microscopy have been applied. The surface of the AZ91D Mg alloy consists

Ya. B Unigovski; E. M Gutman

1999-01-01

21

Assessment of Computer Simulation Software and Process Data for High Pressure Die Casting of Magnesium  

SciTech Connect

Computer software for the numerical simulation of solidification and mold filling is an effective design tool for cast structural automotive magnesium components. A review of commercial software capabilities and their validation procedures was conducted. Aside form the software assessment, the program addressed five main areas: lubricant degradation, lubricant application, gate atomization, and heat transfer at metal mold interfaces. A test stand for lubricant application was designed. A sensor was used for the direct measurement of heat fluxes during lubricant application and casting solidification in graphite molds. Spray experiments were conducted using pure deionized water and commercial die lubricants. The results show that the sensor can be used with confidence for measuring heat fluxes under conditions specific to the die lube application. The data on heat flux was presented in forms suitable for use in HPDC simulation software. Severe jet breakup and atomization phenomena are likely to occur due to high gate velocities in HPDC. As a result of gate atomization, droplet flow affects the mold filling pattern, air entrapment, skin formation, and ensuing defects. Warm water analogue dies were designed for obtaining experimental data on mold filling phenomena. Data on break-up jet length, break-up pattern, velocities, and droplet size distribution were obtained experimentally and was used to develop correlations for jet break-up phenomena specific to die casting gate configurations.

Sabau, Adrian S [ORNL; Hatfield, Edward C [ORNL; Dinwiddie, Ralph Barton [ORNL; Kuwana, Kazunori [University of Kentucky; Viti, Valerio [University of Kentucky, Lexington; Hassan, Mohamed I [University of Kentucky, Lexington; Saito, Kozo [University of Kentucky

2007-09-01

22

Elevated temperature mechanical properties and microstructures of high pressure die cast magnesium AZ91 alloy cast with different section thicknesses  

Microsoft Academic Search

This paper investigates the influence of variations in the microstructure of high pressure die cast AZ91 on the elevated temperature mechanical properties of the alloy. Thinner-walled high pressure die castings show an improvement in elevated temperature strength, ductility and creep resistance. Further improvements to the creep resistance were achieved by ageing the alloy prior to creep testing. It appears that

M. S. Dargusch; M. A. Easton; S. M. Zhu; G. Wang

2009-01-01

23

High-speed machining of cast iron and alloy steels for die and mold manufacturing  

E-print Network

High-speed machining of cast iron and alloy steels for die and mold manufacturing P. Fallbo�hmer, C of cast iron and alloy steels used in die and mold manufacturing. This work covers: (a) theoretical, and PCBN. Workpiece materials investigated include H-13 at 46 HRC, P-20 at 20±40 HRC and cast iron. # 2000

Ozel, Tugrul

24

Notched bar Izod impact properties of zinc die castings  

SciTech Connect

Notched bar Izod impact testing of zinc die cast Alloy 3, Alloy 5, ZA-8, and AcuZinc 5 was performed at five temperatures between -40\\mDC and room temperature in accordance with ASTM E23 for impact testing of metallic materials. A direct comparison between ASTM D256 for impact testing of plastics and ASTM E23 was performed using continuously cast zinc specimens of Alloy 5 and ZA-8 at -40\\mDC and room temperature. There are differences in sample sizes, impact velocity, and striker geometry between the two tests. Bulk zinc tested according to ASTM E23 resulted in higher impact energies at -40\\mDC and lower impact energies at room temperature then did the same alloys when tested according to ASTM D256.

Schrems, K.K.; Dogan, O.N.; Goodwin, F.E. (International Lead Zinc Research Organization, Inc.)

2007-03-01

25

Investment cast AISI H13 tooling for automotive applications  

SciTech Connect

While many techniques exist for production of soft tooling, for die casting there is limited recent experience with cast tooling. The most common US alloy used for manufacture of die casting tooling is wrought AISI H13. If the performance of the cast material is comparable to the wrought counterpart, the use of investment cast HI 3 tooling directly from patterns made via rapid prototyping is of considerable interest. A metallurgical study of investment cast H13 was conducted to evaluate the mechanical behavior in simulated die casting applications. Variable thickness plate investment castings of AISI H13 hot work die steel were produced and characterized in the as-cast and heat-treated conditions. The characterization included light microscopy and mechanical testing. Wrought samples of standard and premium grade H13 were heat-treated and characterized similarly for comparison. Microstructural differences were observed in as-cast samples produced in different section thicknesses. Dendrite cell size and carbide morphology constituted the most prominent microstructural differences observed. After a full heat-treatment, microstructural differences between the wrought material and cast materials were slight regardless of section thickness.The mechanical properties of the cast and heat-treated material proved similar to the properties of the standard heat-treated wrought material. A thermal fatigue testing unit was to con-elate the heat checking susceptibility of H13 steel to its processing and consequent microstructural condition. Surface hardness decreased significantly with thermal cycling, and heat checking was observed in as few as 50 cycles. Thermal softening and thermal fatigue susceptibility were quantified and discussed relative to the microstructural conditions created by processing and heat-treatment. It was found that the premium grade wrought H13 steel provided the best overall resistance to heat checking.

Maguire, M.C.; Baldwin, M.D. [Sandia National Labs., Albuquerque, NM (United States); Hochanadel, P.W.; Edwards, G.R. [Colorado School of Mines, Golden, OH (United States)

1995-07-01

26

Modeling and Analysis of The Pressure Die Casting Using Response Surface Methodology  

NASA Astrophysics Data System (ADS)

Pressure die casting is successfully used in the manufacture of Aluminum alloys components for automobile and many other industries. Die casting is a process involving many process parameters having complex relationship with the quality of the cast product. Though various process parameters have influence on the quality of die cast component, major influence is seen by the die casting machine parameters and their proper settings. In the present work, non-linear regression models have been developed for making predictions and analyzing the effect of die casting machine parameters on the performance characteristics of die casting process. Design of Experiments (DOE) with Response Surface Methodology (RSM) has been used to analyze the effect of effect of input parameters and their interaction on the response and further used to develop nonlinear input-output relationships. Die casting machine parameters, namely, fast shot velocity, slow shot to fast shot change over point, intensification pressure and holding time have been considered as the input variables. The quality characteristics of the cast product were determined by porosity, hardness and surface rough roughness (output/responses). Design of experiments has been used to plan the experiments and analyze the impact of variables on the quality of casting. On the other-hand Response Surface Methodology (Central Composite Design) is utilized to develop non-linear input-output relationships (regression models). The developed regression models have been tested for their statistical adequacy through ANOVA test. The practical usefulness of these models has been tested with some test cases. These models can be used to make the predictions about different quality characteristics, for the known set of die casting machine parameters, without conducting the experiments.

Kittur, Jayant K.; Herwadkar, T. V.; Parappagoudar, M. B.

2010-10-01

27

Modeling and Analysis of The Pressure Die Casting Using Response Surface Methodology  

SciTech Connect

Pressure die casting is successfully used in the manufacture of Aluminum alloys components for automobile and many other industries. Die casting is a process involving many process parameters having complex relationship with the quality of the cast product. Though various process parameters have influence on the quality of die cast component, major influence is seen by the die casting machine parameters and their proper settings. In the present work, non-linear regression models have been developed for making predictions and analyzing the effect of die casting machine parameters on the performance characteristics of die casting process. Design of Experiments (DOE) with Response Surface Methodology (RSM) has been used to analyze the effect of effect of input parameters and their interaction on the response and further used to develop nonlinear input-output relationships. Die casting machine parameters, namely, fast shot velocity, slow shot to fast shot change over point, intensification pressure and holding time have been considered as the input variables. The quality characteristics of the cast product were determined by porosity, hardness and surface rough roughness (output/responses). Design of experiments has been used to plan the experiments and analyze the impact of variables on the quality of casting. On the other-hand Response Surface Methodology (Central Composite Design) is utilized to develop non-linear input-output relationships (regression models). The developed regression models have been tested for their statistical adequacy through ANOVA test. The practical usefulness of these models has been tested with some test cases. These models can be used to make the predictions about different quality characteristics, for the known set of die casting machine parameters, without conducting the experiments.

Kittur, Jayant K.; Herwadkar, T. V. [KLS Gogte Institute of Technology, Belgaum -590 008, Karnataka (India); Parappagoudar, M. B. [Chhatrapati Shivaji Institute of Technology, Durg (C.G)-491001 (India)

2010-10-26

28

Understanding the Relationship Between Filling Pattern and Part Quality in Die Casting  

SciTech Connect

The overall objective of this research project was to investigate phenomena involved in the filling of die cavities with molten alloy in the cold chamber die-casting process. It has long been recognized that the filling pattern of molten metal entering a die cavity influences the quality of die-cast parts. Filling pattern may be described as the progression of molten metal filling the die cavity geometry as a function of time. The location, size and geometric configuration of points of metal entry (gates), as well as the geometry of the casting cavity itself, have great influence on filling patterns. Knowledge of the anticipated filling patterns in die-castings is important for designers. Locating gates to avoid undesirable flow patterns that may entrap air in the casting is critical to casting quality - as locating vents to allow air to escape from the cavity (last places to fill). Casting quality attributes that are commonly flow related are non-fills, poor surface finish, internal porosity due to trapped air, cold shuts, cold laps, flow lines, casting skin delamination (flaking), and blistering during thermal treatment.

Jerald Brevick; R. Allen Miller

2004-03-15

29

Secondary Al-Si-Mg High-pressure Die Casting Alloys with Enhanced Ductility  

NASA Astrophysics Data System (ADS)

Al-Si-Mg-based secondary cast alloys are attractive candidates for thin-walled high-pressure die castings for applications in the transport industry. The present study investigates the effect of manganese additions at high cooling rates on microstructure, mechanical properties, and on the dominating fracture mechanisms of alloy AlSi10Mg with an elevated iron concentration. Systematic variations of the Mn content from 0.20 to 0.85 wt pct at a constant Fe content of 0.55 wt pct illustrate the key changes in type, phase fraction, and shape of the Fe-containing intermetallic phases, and the corresponding influence on the alloy's ductility. For high-pressure die casting (HPDC), an optimal range of the Mn content between 0.40 and 0.60 wt pct, equivalent to a Mn/Fe ratio of approximately 1, has been identified. At these Mn and Fe contents, the high cooling rates obtained in HPDC result in the formation of fine and homogeneously distributed ?-Al15(Fe,Mn)3Si2 phase, and crack initiation is transferred from AlFeSi intermetallics to eutectic silicon. The study interprets the microstructure-property relationship in the light of thermodynamic calculations which reveal a significant increase in undercooling of the ?-Al15(Fe,Mn)3Si2 phase with increased Mn content. It concludes that the interdependence of the well-defined Mn/Fe ratio and the high cooling rate in HPDC can generate superior ductility in secondary AlSi10Mg cast alloys.

Bösch, Dominik; Pogatscher, Stefan; Hummel, Marc; Fragner, Werner; Uggowitzer, Peter J.; Göken, Mathias; Höppel, Heinz Werner

2014-12-01

30

Modeling of microstructure evolution of magnesium alloy during the high pressure die casting process  

Microsoft Academic Search

Two important microstructure characteristics of high pressure die cast magnesium alloy are the externally solidified crystals (ESCs) and the fully divorced eutectic which form at the filling stage of the shot sleeve and at the last stage of solidification in the die cavity, respectively. Both of them have a significant influence on the mechanical properties and performance of magnesium alloy

Mengwu Wu; Shoumei Xiong

2012-01-01

31

Improving the Efficiency of Die Casting Machine Hydraulic Systems with the Retrofit of Adjustable Frequency Drives  

E-print Network

, which represents a connected electrical load of over 315 MW. DIE CASTING PROCESS The basic die casting process is very similar to the injection molding process used for fonning plastic parts. Two hardened steel mold or die halves are moved together... and a large force is exerted against them to keep the halves from separating upon injection. Molten metal is then forced, at high pressure (2-15 ksi) and velocity (100-200 fps) into the mold. The metal solidifies quickly as it comes into contact...

Ambs, L.; Kosanovic, D.; Edberg, C.

32

Distortion and Residual Stress in High-Pressure Die Castings: Simulation and Measurements  

NASA Astrophysics Data System (ADS)

Two individual high-pressure die casting geometries were developed to study the influence of process parameters and alloy composition on the distortion behavior of aluminum alloy castings. These geometries, a stress lattice and a V-shaped lid, tend to form residual stress due to a difference in wall thickness and a deliberate massive gating system. Castings were produced from two alloys: AlSi12(Fe) and AlSi10MnMg. In the experimental castings, the influence of important process parameters such as die temperature, ejection time, and cooling regime was examined. The time evolution of process temperatures was measured using thermal imaging. Subsequent to casting, distortion was measured by means of a tactile measuring device at ambient temperatures. The measured results were compared against a numerical process and stress simulations of the casting, ejection, and cooling process using the commercial finite element method software ANSYS Workbench. The heat transfer coefficients were adapted to the temperature distributions of the die, and the castings were observed by thermal imaging. A survey of the results of the comparison between simulation and experiment is given for both alloys.

Hofer, P.; Kaschnitz, E.; Schumacher, P.

2014-09-01

33

High Density Die Casting (HDDC): new frontiers in the manufacturing of heat sinks  

NASA Astrophysics Data System (ADS)

Finding a good solution for thermal management problems is every day more complex. due to the power density and the required performances. When a solution suitable for high volumes is needed. die-casting and extrusion are the most convenient technologies. However designers have to face the well-known limitations for those processes. High Density Die Casting (HDDC) is a process under advanced development. in order to overcome the extrusion and traditional die casting limits by working with alloys having much better thermal performances than the traditional die-casting process. while keeping the advantages of a flexible 3D design and a low cost for high volumes. HDDC offers the opportunity to design combining different materials (aluminium and copper. aluminium and stainless steel) obtaining a structure with zero porosity and overcoming some of die-casting limits. as shown in this paper. A dedicated process involving embedded heat pipes is currently under development in order to offer the possibility to dramatically improve the heat spreading.

Sce, Andrea; Caporale, Lorenzo

2014-07-01

34

Fatigue behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die casting  

Microsoft Academic Search

The room temperature fatigue properties of AZ91 magnesium alloy produced by high pressure die casting (HPDC) as cast, heat treated, friction stir processed (FSP) and FSP and heat treated were studied. The fatigue properties of the material were evaluated for the HPDC magnesium alloy in the as-received state and after a solution treatment at 415 °C for 2 h and an ageing

P.. Cavaliere; P. P. De Marco

2007-01-01

35

Mortality among workers in a die-casting and electroplating plant.  

PubMed

A proportional mortality and case-referent analysis of 238 deaths among hourly employees in an automobile hardware manufacturing plant was conducted. The major operations of the plant were zinc die casting and electroplating. Chemical exposure included die-casting emissions and mists from chrome and nickel plating. The chief proportional mortality finding was a significant excess of lung cancer among both white men and women. A case-referent analysis indicated a possible association between lung cancer and work in certain departments. The findings support the hypothesis of a work-related carcinogenic risk. Follow-up recommendations have been made. PMID:7330627

Silverstein, M; Mirer, F; Kotelchuck, D; Silverstein, B; Bennett, M

1981-01-01

36

Studies on Flow Characteristics at High-Pressure Die-Casting  

NASA Astrophysics Data System (ADS)

The flow and filling characteristics during injection of liquid aluminum during high-pressure die-casting is studied threefoldly: a) analytically, b) experimentally and c) numerically. A planar jet of liquid aluminum is formed at the ingate due to its small width (?O(10-3) m), its high aspect ratio (? 100) and high inlet velocity (up to 60 m/s). On the one hand, wavy disintegration of such a jet can inevitably lead to cold runs in the final casting. On the other hand, a high degree of atomization may strongly increase the porosity of the casting part. Both processes can highly reduce the mechanical stability of the product. Analytical investigations of Ohnesorge (or equivalently Weber) and Reynolds numbers show that the process of drop formation at the liquid planar free jet is dominated by atomization assuming an orifice nozzle geometry at the ingate. From a simple experimental investigation of an equivalent free jet of water, however, it is deduced that the process of drop formation can be changed to wavy disintegration by the nozzle geometry. Numerically, high-pressure die-casting is attacked by a Volume of Fluid approach. Although the drop formation at the phase interphase can not be captured by the numerical model since the drops are an order of magnitude smaller than feasible grid spacings, the global spreading of the free jet in the casting mold is well pictured by this first numerical simulation. In addition, a new approach is presented to detect cold runs at the final casting. Finally, the studies presented lead to an increased understanding of high pressure die casting and can help to improve the quality of casting products.

Schneiderbauer, S.; Pirker, S.; Chimani, C.; Kretz, R.

2012-01-01

37

Metallic Reinforcement of Direct Squeeze Die Casting Aluminum Alloys for Improved Strength and Fracture Resistance  

SciTech Connect

The utilization of aluminum die casting as enclosures where internal equipment is rotating inside of the casting and could fracture requires a strong housing to restrain the fractured parts. A typical example would be a supercharger. In case of a failure, unless adequately contained, fractured parts could injure people operating the equipment. A number of potential reinforcement materials were investigated. The initial work was conducted in sand molds to create experimental conditions that promote prolonged contact of the reinforcing material with molten aluminum. Bonding of Aluminum bronze, Cast iron, and Ni-resist inserts with various electroplated coatings and surface treatments were analyzed. Also toughening of A354 aluminum cast alloy by steel and stainless steel wire mesh with various conditions was analyzed. A practical approach to reinforcement of die cast aluminum components is to use a reinforcing steel preform. Such performs can be fabricated from steel wire mesh or perforated metal sheet by stamping or deep drawing. A hemispherical, dome shaped casting was selected in this investigation. A deep drawing die was used to fabricate the reinforcing performs. The tendency of aluminum cast enclosures to fracture could be significantly reduced by installing a wire mesh of austenitic stainless steel or a punched austenitic stainless steel sheet within the casting. The use of reinforcements made of austenitic stainless steel wire mesh or punched austenitic stainless steel sheet provided marked improvement in reducing the fragmentation of the casting. The best strengthening was obtained with austenitic stainless steel wire and with a punched stainless steel sheet without annealing this material. Somewhat lower results were obtained with the annealed punched stainless steel sheet. When the annealed 1020 steel wire mesh was used, the results were only slightly improved because of the lower mechanical properties of this unalloyed steel. The lowest results were obtained with unreinforced 356 aluminum casting. Good strength can be obtained with a sound die casting without any defects produced by squeeze casting. The use of higher pressure to produce the squeeze casting has been shown to increase the strength of a hemispherical dome casting. This dome shape casting has been produced both with and without reinforcement and tested to determine its pressure resistance under internal pressure of water. Only a slight improvement in strength could be determined because of water leaks at the seal between hemispherical dome and its flat supporting side. However, when the ability of the casting was tested under the compressive force of a plunger, the strengthening effect of wire mesh or sheet was evident. Higher loads to failure were obtained because of the reinforcement of the stainless steel wire and punched sheet. Rather than a sudden failure occurring, the reinforcement of the stainless steel wire or the punched hard stainless steel sheet held the material together and prevented any loss of the fractured casting to the surroundings. Unalloyed steel did not have the required strength or mechanical properties to increase the properties of the casting.

D. Schwam: J.F. Wallace: Y. Zhu: J.W. Ki

2004-10-01

38

Acoustic visualization of cold flakes and crack propagation in aluminum alloy die-cast plate  

Microsoft Academic Search

Acoustic images received at different depths of aluminum alloy (ADC12) die-cast plates containing coarse cold flakes were compared with microstructures at the same depth. The bright and dark regions in the acoustic images coincided with the oxide layer on the initially solidified surface of the cold flake and the body of the cold flake, respectively. These results show the ability

A. K. M. Aziz Ahamed; Hiroshi Kato; Kensuke Kageyama; Toru Komazaki

2006-01-01

39

Variability of skin thickness in an AM60B magnesium alloy die-casting  

Microsoft Academic Search

The skin thickness is investigated in regions of different solidification conditions in a die-cast AM60B magnesium alloy component. The results of several different techniques for determining the skin thickness in six different samples are compared. The hardness profile, the elemental aluminum and oxygen contents, the change in grain sizes, the change in eutectic percentage, and the onset of large ?-Mg

J. P. Weiler; J. T. Wood; R. J. Klassen; R. Berkmortel; G. Wang

2006-01-01

40

Use of Taguchi method to develop a robust design for the magnesium alloy die casting process  

Microsoft Academic Search

This study applies the Taguchi method to optimize the process parameters for the die casting of thin-walled magnesium alloy parts in computer, communications, and consumer electronics (3C) industries. The objectives of the Taguchi method for robust parameter design are to establish the optimal combination of design parameters and to reduce the variation in quality from a minimum number of experiments.

Der Ho Wu; Mao Sheng Chang

2004-01-01

41

Influence of Sludge Particles on the Tensile Properties of Die-Cast Secondary Aluminum Alloys  

NASA Astrophysics Data System (ADS)

The effects of sludge intermetallic particles on the mechanical properties of a secondary AlSi9Cu3(Fe) die-casting alloy have been studied. Different alloys have been produced by systematically varying the Fe, Mn, and Cr contents within the composition tolerance limits of the standard EN AC-46000 alloy. The microstructure shows primary ?-Al x (Fe,Mn,Cr) y Si z sludge particles, with polyhedral and star-like morphologies, although the presence of primary ?-Al5FeSi phase is also observed at the highest Fe:Mn ratio. The volume fraction of primary compounds increases as the Fe, Mn, and Cr contents increase and this can be accurately predicts from the Sludge Factor by a linear relationship. The sludge amount seems to not influence the size and the content of porosity in the die-cast material. Furthermore, the sludge factor is not a reliable parameter to describe the mechanical properties of the die-cast AlSi9Cu3(Fe) alloy, because this value does not consider the mutual interaction between the elements. In the analyzed range of composition, the design of experiment methodology and the analysis of variance have been used in order to develop a semi-empirical model that accurately predicts the mechanical properties of the die-cast AlSi9Cu3(Fe) alloys as function of Fe, Mn, and Cr concentrations.

Ferraro, Stefano; Timelli, Giulio

2014-12-01

42

Modeling of microstructure evolution of magnesium alloy during the high pressure die casting process  

NASA Astrophysics Data System (ADS)

Two important microstructure characteristics of high pressure die cast magnesium alloy are the externally solidified crystals (ESCs) and the fully divorced eutectic which form at the filling stage of the shot sleeve and at the last stage of solidification in the die cavity, respectively. Both of them have a significant influence on the mechanical properties and performance of magnesium alloy die castings. In the present paper, a numerical model based on the cellular automaton (CA) method was developed to simulate the microstructure evolution of magnesium alloy during cold-chamber high pressure die casting (HPDC) process. Modeling of dendritic growth of magnesium alloy with six-fold symmetry was achieved by defining a special neighbourhood configuration and calculating of the growth kinetics from complete solution of the transport equations. Special attention was paid to establish a nucleation model considering both of the nucleation of externally solidified crystals in the shot sleeve and the massive nucleation in the die cavity. Meanwhile, simulation of the formation of fully divorced eutectic was also taken into account in the present CA model. Validation was performed and the capability of the present model was addressed by comparing the simulated results with those obtained by experiments.

Wu, Mengwu; Xiong, Shoumei

2012-07-01

43

Outline of the Monte-Carlo strategy 'Iacta Alea est', the die is cast, is what Julius Caesar is reported by Suetonius to have  

E-print Network

Chapter 8 Outline of the Monte-Carlo strategy 'Iacta Alea est', the die is cast, is what Julius Rubicon in Northern Italy. (Twelve Ceasars)Gaius Suetonius 8.1 Introduction Monte Carlo methods of the novel fields where Monte Carlo methods have found a new field of applications, with financial

Elster, Charlotte

44

Energy Saving Melting and Revert Reduction Technology: Melting Efficiency in Die Casting Operations  

SciTech Connect

This project addressed multiple aspects of the aluminum melting and handling in die casting operations, with the objective of increasing the energy efficiency while improving the quality of the molten metal. The efficiency of melting has always played an important role in the profitability of aluminum die casting operations. Consequently, die casters need to make careful choices in selecting and operating melting equipment and procedures. The capital cost of new melting equipment with higher efficiency can sometimes be recovered relatively fast when it replaces old melting equipment with lower efficiency. Upgrades designed to improve energy efficiency of existing equipment may be well justified. Energy efficiency is however not the only factor in optimizing melting operations. Melt losses and metal quality are also very important. Selection of melting equipment has to take into consideration the specific conditions at the die casting shop such as availability of floor space, average quantity of metal used as well as the ability to supply more metal during peaks in demand. In all these cases, it is essential to make informed decisions based on the best available data.

David Schwam

2012-12-15

45

Fatigue Crack Growth Mechanisms in High-Pressure Die-Cast Magnesium Alloys  

NASA Astrophysics Data System (ADS)

Microstructure-affected micromechanisms of fatigue crack growth operating near the limit plasticity regime were experimentally identified for the four main commercial high-pressure die-cast (HPDC) magnesium alloys: AM50, AM60, AZ91, and AE44. These fatigue micromechanisms manifested by the concomitant effects of casting pores, interdendritic Al-rich solid solution layer, ?-phase particles, Mn-rich inclusions, rare earth-rich intermetallics, dendrite cell size, and surface segregation phenomena. These concomitant mechanisms clearly delineated the fatigue durability observed for the AM50, AM60, AZ91, and AE44 Mg alloys in both the low- and high-cycle fatigue regimes.

El Kadiri, Haitham; Horstemeyer, M. F.; Jordon, J. B.; Xue, Yibin

2008-01-01

46

Development of materials for the rapid manufacture of die cast tooling  

NASA Astrophysics Data System (ADS)

The focus of this research is to develop a material composition that can be processed by rapid prototyping (RP) in order to produce tooling for the die casting process. Where these rapidly produced tools will be superior to traditional tooling production methods by offering one or more of the following advantages: reduced tooling cost, shortened tooling creation time, reduced man-hours for tool creation, increased tool life, and shortened die casting cycle time. By utilizing RP's additive build process and vast material selection, there was a prospect that die cast tooling may be produced quicker and with superior material properties. To this end, the material properties that influence die life and cycle time were determined, and a list of materials that fulfill these "optimal" properties were highlighted. Physical testing was conducted in order to grade the processability of each of the material systems and to optimize the manufacturing process for the downselected material system. Sample specimens were produced and microscopy techniques were utilized to determine a number of physical properties of the material system. Additionally, a benchmark geometry was selected and die casting dies were produced from traditional tool materials (H13 steel) and techniques (machining) and from the newly developed materials and RP techniques (selective laser sintering (SLS) and laser engineered net shaping (LENS)). Once the tools were created, a die cast alloy was selected and a preset number of parts were shot into each tool. During tool creation, the manufacturing time and cost was closely monitored and an economic model was developed to compare traditional tooling to RP tooling. This model allows one to determine, in the early design stages, when it is advantageous to implement RP tooling and when traditional tooling would be best. The results of the physical testing and economic analysis has shown that RP tooling is able to achieve a number of the research objectives, namely, reduce tooling cost, shorten tooling creation time, and reduce the man-hours needed for tool creation. Though identifying the appropriate time to use RP tooling appears to be the most important aspect in achieving successful implementation.

Hardro, Peter Jason

47

Formation Mechanism of Discoloration on Die-Cast AZ91D Components Surface After Chemical Conversion  

NASA Astrophysics Data System (ADS)

A notebook (NB) computer component was manufactured from AZ91D Mg alloy by a die-casting process. After chemical conversion treatment, a discoloration was noted on the component surface. The source of this discoloration has been studied in detail by scanning electron microscopy, energy dispersive spectroscopy, and spark atomic absorption spectroscopy. The corrosion resistance was also measured by potentiodynamic polarization, hydrogen evolution and salt spray testing. The formation mechanism for the discoloration which was caused by the residue left behind by excess mold release agent sprayed during the die-casting was discussed in detail. After chemical conversion treatment, the residual-baked mold release agent was apparent on the component surface as "white ash." Consequently, it degraded seriously both the appearance and the corrosion resistance of the manufactured component.

Liu, Bao-sheng; Wei, Ying-hui; Hou, Li-feng

2013-01-01

48

Microstructural stability and creep properties of die casting Mg-4Al-4RE magnesium alloy  

SciTech Connect

The AE44 (Mg-4Al-4RE) alloy was prepared by a hot-chamber die casting method. The microstructure, microstructural stability and creep properties at 175 deg. C were investigated. The microstructure was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and the Rietveld method. The results show that die cast AE44 magnesium alloy consists of {alpha}-Mg, Al{sub 11}RE{sub 3}, Al{sub 2}RE and Al{sub 2.12}RE{sub 0.88} phases. The Al{sub 11}RE{sub 3} phase is thermally stable at 175 deg. C whereas the metastable Al{sub 2.12}RE{sub 0.88} phase undergoes a transition into the equilibrium Al{sub 2}RE phase. The alloy investigated is characterized by good creep properties at temperatures of 175 deg. C and 200 {sup o}C.

Rzychon, Tomasz, E-mail: tomasz.rzychon@polsl.pl [Silesian University of Technology, Faculty of Materials Science and Metallurgy, Krasinskiego 8, 40-019 Katowice (Poland); Kielbus, Andrzej; Cwajna, Jan [Silesian University of Technology, Faculty of Materials Science and Metallurgy, Krasinskiego 8, 40-019 Katowice (Poland); Mizera, Jaroslaw [Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

2009-10-15

49

Defect Band Characteristics in Mg-Al and Al-Si High-Pressure Die Castings  

NASA Astrophysics Data System (ADS)

Bands of positive macrosegregation and porosity commonly follow the surface contour of components produced by high-pressure die casting (HPDC). In this article, Al alloy AlSi7Mg and Mg alloys AZ91 and AM60 were cast into tensile test bars using cold-chamber (cc) HPDC. Microstructural characterization revealed that externally solidified crystals (ESCs) are not necessary for defect band formation, and that defect bands can form both near to and relatively far from any surface layer of different microstructure. The defect bands were 140 to 240 ?m thick. In addition to defect-band-related macrosegregation, the castings also contained inverse segregation and surface segregation. Defect bands are shown to have the characteristics of the dilatant shear bands reported in past rheology studies, indicating that defect bands form due to strain localization in partially solid material during the HPDC process.

Gourlay, C. M.; Laukli, H. I.; Dahle, A. K.

2007-08-01

50

Improvement of mechanical properties of aluminum die casting alloy by multi-pass friction stir processing  

Microsoft Academic Search

An improvement in the mechanical properties was accomplished due to the microstructural modification of an aluminum die casting alloy by multi-pass friction stir processing (MP-FSP), which is a solid-state microstructural modification technique using a frictional heat and stirring action. The hardness of the MP-FSP sample is about 20Hv higher than that of the base metal. The tensile strengths of the

K. Nakata; Y. G. Kim; H. Fujii; T. Tsumura; T. Komazaki

2006-01-01

51

Electroless nickel-plating on die cast magnesium alloy AZ91D  

Microsoft Academic Search

Electroless nickel-plating on die cast magnesium alloy AZ91D was investigated. Growth of the electroless nickel-plating coating was characterized using scanning electron microscopy. Corrosion resistance of the coating was evaluated by open circuit potential and potentiodynamic polarization curves in 3.5% (mass fraction) NaCl solution. The results show that plating deposition is initiated on the crevices and then spread onto primary ?

JIA Su-qiu; JIA Shu-sheng; YAO Jun

52

Characterization of Partial Squeeze and Vacuum Die Casting Process in Fabricating Automobile Parts  

Microsoft Academic Search

A functional automotive part, reaction shaft support, was fabricated by partial squeeze and vacuum die casting (PSVD) with light-weight Al-15% Si hypereutectic alloy which has good fluidity and excellent wear resistance. The effects of partial squeezing pressure and time-lag of PSVD process on the microstructure of the product were investigated. Measurement of specific gravity with the change of partial squeeze

E. S. Kim; K. W. Lim; K. H. Lee

2006-01-01

53

Cast Aluminum Alloy for High Temperature Applications  

NASA Technical Reports Server (NTRS)

Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450 F (232 C) to about 750 F (400 C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. It can be very economically produced from conventional permanent mold, sand casting or investment casting, with silicon content ranging from 6% to 18%. At high silicon levels, the alloy exhibits excellent dimensional stability, surface hardness and wear resistant properties.

Lee, Jonathan A.

2003-01-01

54

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

Code of Federal Regulations, 2012 CFR

...Applicability; description of the continuous casting subcategory. 420.60 ...MANUFACTURING POINT SOURCE CATEGORY Continuous Casting Subcategory § 420.60 Applicability; description of the continuous casting subcategory. The...

2012-07-01

55

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

Code of Federal Regulations, 2013 CFR

...Applicability; description of the continuous casting subcategory. 420.60 ...MANUFACTURING POINT SOURCE CATEGORY Continuous Casting Subcategory § 420.60 Applicability; description of the continuous casting subcategory. The...

2013-07-01

56

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

...Applicability; description of the continuous casting subcategory. 420.60 ...MANUFACTURING POINT SOURCE CATEGORY Continuous Casting Subcategory § 420.60 Applicability; description of the continuous casting subcategory. The...

2014-07-01

57

Application of Thread-Forming Fasteners in Net-Shaped Cast Holes in Lightweight Metal Alloys  

SciTech Connect

The application of thread-forming fasteners (TFFs) in net-shaped die-cast holes of lightweight metal alloys is being explored by the United States Automotive Materials Partnership (USAMP) through work at the Pacific Northwest National Laboratory (PNNL). These fasteners are being applied in drilled hole applications for general assembly which have reduced costs, reduced investment, and improved warranty while delivering better joint properties. Successful development of this idea in light-weight alloy die-cast products will expand the use of lightweight materials due to the proven benefits already achieved in existing applications. A portion of this effort has included a parametric study of the relationship between joint strength and as-cast hole geometry in aluminum alloy A380 test specimens.

Paxton, Dean M.; Dudder, Gregory J.; Charron, William A.; Cleaver, Todd H.

2006-03-12

58

Development of Advanced Coating Techniques for Highly-durable Casting Dies  

NASA Astrophysics Data System (ADS)

In order to improve the durability of aluminum die-casting molds, we applied microstructure-controlled PVD coating techniques. Single-layer and multilayer films consisting of chromium nitride (CrN) or titanium aluminum nitride (TiAlN) were prepared using an ion plating process. Structures of multilayer films were observed using transmission electron microscopy. Pin-shaped mold steel specimens coated with each of the films were soaked in the molten aluminum alloy at 953 K different periods of time, and the amount of weight loss due to erosion was evaluated. The weight losses for the multilayer CrN and TiAlN specimens were found to be less than those for the single-layer specimens. As a practical test, five specimens of core pins used in aluminum die casting of automobile parts were coated with multilayer films, and the number of maintenance operations required to remove aluminum alloy remaining on the specimen surfaces after several thousand castings was counted and compared with six control specimens (core pins treated using a commercial salt bath diffusion process). The number of maintenance operations for CrN- and TiAlN-based multilayer-coated core pins was found to be lower than for the control specimens.

Tanaka, S.; Takagi, M.; Mano, T.

2013-03-01

59

Fatigue Life Prediction in Rapid Die Casting - Preliminary Work in View of Current Research  

SciTech Connect

Numerical simulation technique as a prediction tool is slowly adopted in metal casting industry for predicting design modelling solidification analysis. The reasons for this activity is found in the need to further enhance the geometrical design and mechanical properties of the tool design and the correct prediction methodology to fulfil industrial needs. The present state of numerical simulation capabilities in rapid die casting technologies is reviewed and the failure mode mechanisms of thermal fatigue, aimed at developing a numerical simulation with a systematic design guidance for predicting the thermal cyclic loading analysis and improvement is presented along with several other methods. The economic benefits of a numerical simulation technique in die casting are limited to tool life time, mechanical properties and design guidance. The extensive computer capabilities of a numerical simulation with a systematic design guidance methodology are exploited to provide a solution for flexible design, mechanical properties and mould life time. Related research carried out worldwide by different organisations and academic institutions are discussed.

Chuan Huat Ng [Faculty of Mechanical and Manufacturing Engineering (FKMP), Kolej Universiti Teknologi Tun Hussein Onn (KUiTTHO), P.O.Box 101, 86400 Parit Raja, Batu Pahat, Johor (Malaysia); Grote, Karl-Heinrich [Institut fuer Maschinenkonstruktion, Lehrstuhl Konstruktionstechnik, Otto-von-Guericke University Magdeburg, Universitaetsplatz 2, 39106 Magdeburg (Germany); Baehr, Ruediger [Institut fuer Fertigungstechnik und Qualitaetssicherung, Ur und Umformtechnik, Otto-von-Guericke University Magdeburg, Universitaetsplatz 2, 39106 Magdeburg (Germany)

2007-05-17

60

Fatigue behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die casting  

SciTech Connect

The room temperature fatigue properties of AZ91 magnesium alloy produced by high pressure die casting (HPDC) as cast, heat treated, friction stir processed (FSP) and FSP and heat treated were studied. The fatigue properties of the material were evaluated for the HPDC magnesium alloy in the as-received state and after a solution treatment at 415 deg. C for 2 h and an ageing treatment at 220 deg. C for 4 h. The heat treatment resulted in a significant increase in the fatigue properties of the HPDC material, while no significance influence of heat treatment was recorded in the FSP condition. The morphology of fracture surfaces was examined by employing a field emission gun scanning electron microscope (FEGSEM)

Cavaliere, P. [INFM-Dept. of 'Ingegneria dell'Innovazione', Engineering Faculty, University of Lecce, Via per Arnesano, 73100, Lecce (Italy)]. E-mail: pasquale.cavaliere@unile.it; De Marco, P.P. [INFM-Dept. of 'Ingegneria dell'Innovazione', Engineering Faculty, University of Lecce, Via per Arnesano, 73100, Lecce (Italy)

2007-03-15

61

Modifying AM60B Magnesium Alloy Die Cast Surfaces by Friction Stir Processing  

Microsoft Academic Search

These experiments were done to evaluate the feasibility of locally modifying the surface properties of magnesium alloys with friction-stir processing. The magnesium alloy used for the study was high-pressure die-cast AM60B, nominally Mg-6Al-0.13 Mn (wt. %). Friction-stir passes were made with a translation speed of 1.7 mm\\/s using tool-rotation speeds of 1,250 rpm or 2,500 rpm. Stir passes with good

Michael L Santella; Zhili Feng; Cassandra Degen; Tsung-Yu Pan

2006-01-01

62

Flow analysis and validation of numerical modelling for a thin walled high pressure die casting using SPH  

NASA Astrophysics Data System (ADS)

High pressure die casting (HPDC) is an important process for high throughput manufacturing of complex shaped metallic components. The flow involves significant fragmentation and spray formation as the high pressure liquid jets into the die from the gate system. An important class of die cast components is one with large areas of thin walls. An example of this is the chassis of the laptop computer. Computational modelling provides an opportunity to both better understand the filling process and to optimize the runner, gates, flash overs and venting systems for the die. SPH has previously been found to be very suitable for predicting HPDC for bulkier automotive components. The modelling challenges arising from the very thin sections and the many flow paths in a laptop chassis require careful validation. A water analogue experiment is used to validate the predictions of the SPH model for this representative thin walled casting. SPH predictions are used to understand and characterise the filling process. Finally, comparison of flow lines visible in an etched finished casting with the high speed flow paths in the final filled SPH model show very strong agreement. Together these demonstrate that such an SPH model is able to capture substantial detail from both the water analogue system and the actual casting process and is very suitable for simulating these types of complex thin walled castings.

Cleary, Paul W.; Savage, Gary; Ha, Joseph; Prakash, Mahesh

2014-09-01

63

40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.  

Code of Federal Regulations, 2012 CFR

...Applicability; description of the aluminum casting subcategory. 464.10...AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The...

2012-07-01

64

40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.  

Code of Federal Regulations, 2011 CFR

...Applicability; description of the aluminum casting subcategory. 464.10...AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The...

2011-07-01

65

40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.  

...Applicability; description of the aluminum casting subcategory. 464.10...AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The...

2014-07-01

66

40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the aluminum casting subcategory. 464.10...AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The...

2013-07-01

67

40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the aluminum casting subcategory. 464.10...AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The...

2010-07-01

68

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

Code of Federal Regulations, 2013 CFR

...false Applicability; description of the zinc casting subcategory. 464.40 Section...MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The...

2013-07-01

69

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

Code of Federal Regulations, 2012 CFR

...false Applicability; description of the zinc casting subcategory. 464.40 Section...MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The...

2012-07-01

70

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

...false Applicability; description of the zinc casting subcategory. 464.40 Section...MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The...

2014-07-01

71

40 CFR 464.20 - Applicability; description of the copper casting subcategory.  

... Applicability; description of the copper casting subcategory. 464.20 Section...MOLDING AND CASTING POINT SOURCE CATEGORY Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory. The...

2014-07-01

72

MACHINING ELIMINATION THROUGH APPLICATION OF THREAD FORMING FASTENERS IN NET SHAPED CAST HOLES  

SciTech Connect

The ultimate objective of this work was to eliminate approximately 30% of the machining performed in typical automotive engine and transmission plants by using thread forming fasteners in as-cast holes of aluminum and magnesium cast components. The primary issues at the source of engineers���������������¢�������������������������������� reluctance to implementing thread forming fasteners in lightweight castings are: * Little proof of consistency of clamp load vs. input torque in either aluminum or magnesium castings. * No known data to understand the effect on consistency of clamp load as casting dies wear. The clamp load consistency concern is founded in the fact that a portion of the input torque used to create clamp load is also used to create threads. The torque used for thread forming may not be consistent due to variations in casting material, hole size and shape due to tooling wear and process variation (thermal and mechanical). There is little data available to understand the magnitude of this concern or to form the basis of potential solutions if the range of clamp load variation is very high (> +/- 30%). The range of variation that can be expected in as-cast hole size and shape over the full life cycle of a high pressure die casting die was established in previous work completed by Pacific Northwest National Laboratory, (PNNL). This established range of variation was captured in a set of 12 cast bosses by designing core pins at the size and draft angles identified in the sited previous work. The cast bosses were cut into ���������������¢��������������������������������nuts���������������¢������������������������������� that could be used in the Ford Fastener Laboratory test-cell to measure clamp load when a thread forming fastener was driven into a cast nut. There were two sets of experiments run. First, a series of cast aluminum nuts were made reflecting the range of shape and size variations to be expected over the life cycle of a die casting die. Taptite thread forming fasteners, (a widely used thread forming fastener suitable for aluminum applications), were driven into the various cored, as-cast nuts at a constant input torque and resulting clamp loads were recorded continuously. The clamp load data was used to determine the range of clamp loads to be expected. The bolts were driven to failure. The clamp load corresponding to the target input of 18.5 Nm was recorded for each fastener. In a like fashion, a second set of experiments were run with cast magnesium nuts and ALtracs thread forming fasteners, (a widely used thread forming fastener suitable for magnesium applications). Again all clamp loads were recorded and analyzed similarly to the Taptites in aluminum cast nuts. Results from previous work performed on the same test cell for a Battelle project using standard M8 bolts into standard M8 nuts were included as a comparator for a standard bolt and nut application. The results for the thread forming fasteners in aluminum cast holes were well within industry expectations of +/- 30% for out of the box and robustness range te

Cleaver, Ryan J.; Cleaver, Todd H.; Talbott, Richard

2012-05-02

73

An evaluation of direct pressure sensors for monitoring the aluminum die casting process  

SciTech Connect

This study was conducted as part of the US Department of Energy (DOE) sponsored project Die Cavity Instrumentation. One objective of that project was to evaluate thermal, pressure, and gas flow process monitoring sensors in or near the die cavity as a means of securing improved process monitoring and control and better resultant part quality. The objectives of this thesis are to (1) evaluate a direct cavity pressure sensor in a controlled production campaign at the GM Casting Advanced Development Center (CADC) at Bedford, Indiana; and (2) develop correlations between sensor responses and product quality in terms of the casting weight, volume, and density. A direct quartz-based pressure sensor developed and marked by Kistler Instrument Corp. was acquired for evaluating as an in-cavity liquid metal pressure sensor. This pressure sensor is designed for use up to 700 C and 2,000 bars (29,000 psi). It has a pressure overload capacity up to 2,500 bars (36,250 psi).

Zhang, X.

1997-12-31

74

Modifying AM60B Magnesium Alloy Die Cast Surfaces by Friction Stir Processing  

SciTech Connect

These experiments were done to evaluate the feasibility of locally modifying the surface properties of magnesium alloys with friction-stir processing. The magnesium alloy used for the study was high-pressure die-cast AM60B, nominally Mg-6Al-0.13 Mn (wt. %). Friction-stir passes were made with a translation speed of 1.7 mm/s using tool-rotation speeds of 1,250 rpm or 2,500 rpm. Stir passes with good appearance were obtained under both conditions. In some cases up to five passes were overlapped on a single bar to produce stir zones with cross-sectional dimensions of about 1.5 mm x 10 mm. Metallographic examinations indicated that the stir zones were largely comprised of a magnesium solid solution with equiaxed grains on the order of 5-10 {micro}m in size. Hardness mapping showed that the stir zones experienced increases of 16-25% compared to the as-cast metal. Room-temperature testing showed that, compared to the cast metal, the stir zones had flow stresses nearly 20% higher with about twice the tensile elongation.

Santella, Michael L [ORNL; Feng, Zhili [ORNL; Degen, Cassandra [South Dakota School of Mines and Technology; Pan, Dr. Tsung-Yu [Ford Motor Company

2006-01-01

75

Fabrication process analysis and experimental verification for aluminum bipolar plates in fuel cells by vacuum die-casting  

NASA Astrophysics Data System (ADS)

There are various methods for the fabrication of bipolar plates, but these are still limited to machining and stamping processes. High-pressure die casting (HPDC) is an ideal process for the manufacture of bipolar plates This study aims to investigate the formability of bipolar plates for polymer electrolyte membrane fuel cells (PEMFCs) fabricated by vacuum HPDC of an Al-Mg alloy (ALDC6). The cavity of the mold consisted of a thin-walled plate (200 mm × 200 mm × 0.8 mm) with a layer of serpentine channel (50 mm × 50 mm). The location and direction of the channel in the final mold design was determined by computational simulation (MAGMA soft). In addition, simulation results for different conditions of plunger stroke control were compared to those from actual die-casting experiments. Under a vacuum pressure of 35 kPa and for injection speeds of 0.3 and 2.5 m s-1 in the low and high speed regions, respectively, the samples had few casting defects. In addition, the hardness was higher and porosity in microstructure was less than those of the samples made under other injection speed conditions. In case of thin-walled plates, vacuum die casting is beneficial in terms of formability compared to conventional die casting.

Jin, Chul Kyu; Kang, Chung Gil

2011-10-01

76

Application of Thread-Forming Fasteners in Net-Shaped Cast Holes in Lightweight Metal Alloys  

Microsoft Academic Search

The application of thread-forming fasteners (TFFs) in net-shaped die-cast holes of lightweight metal alloys is being explored by the United States Automotive Materials Partnership (USAMP) through work at the Pacific Northwest National Laboratory (PNNL). These fasteners are being applied in drilled hole applications for general assembly which have reduced costs, reduced investment, and improved warranty while delivering better joint properties.

Dean M. Paxton; Gregory J. Dudder; William A. Charron; Todd H. Cleaver

2006-01-01

77

Improved design and durability of aluminum die casting horizontal shot sleeves  

NASA Astrophysics Data System (ADS)

The design and performance of shot sleeves is critical in meeting the engineering requirements of aluminum die cast parts. Improvement in shot sleeve materials have a major impact on dimensional stability, reproducibility and quality of the product. This investigation was undertaken in order to improve the life of aluminum die casting horizontal shot sleeves. Preliminary pin tests were run to evaluate the soldering, wash-out and thermal fatigue behavior of commercially available materials and coatings. An experimental rig was designed and constructed for shot sleeve configuration evaluation. Fabrication and testing of experimental shot sleeves was based upon preliminary results and manufacturing costs. Three shot sleeve designs and materials were compared to a reference nitrided H13 sleeve. Nitrided H13 is the preferred material for aluminum die casting shot sleeves because of wear resistance, strength and relative good soldering and wash-out resistance. The study was directed towards damage evaluation on the area under the pouring hole. This area is the most susceptible to damage because of high temperatures and impingement of molten aluminum. The results of this study showed that tungsten and molybdenum had the least amount of soldering and wash-out damage, and the best thermal fatigue resistance. Low solubility in molten aluminum and stability of intermetallic layers are main factors that determine the soldering and wash-out behavior. Thermal conductivity and thermal expansion coefficient directly influence thermal fatigue behavior. TiAlN nanolayered coating was chosen as the material with the best damage resistance among several commercial PVD coatings, because of relatively large thickness and simple deposition conditions. The results show that molybdenum thermal sprayed coating provided the best protection against damage under the pouring hole. Improved bonding is however required for life extension of the coating. TiAlN PVD coating applied on H13 nitrided substrate performed very well as long as the coating was maintained. Nitrided H13 sleeve showed extensive damage that occurred as early as 200 cycles. The nitrided layer only slowed down the diffusion process and dissolution took place at a higher rate as soon as the layer wore off. Stellite 6 sleeve also showed considerable wear under the action of molten aluminum.

Birceanu, Sebastian

78

21 CFR 888.5980 - Manual cast application and removal instrument.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Manual cast application and removal instrument...Surgical Devices § 888.5980 Manual cast application and removal instrument. (a) Identification. A manual cast application and removal...

2013-04-01

79

21 CFR 888.5980 - Manual cast application and removal instrument.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Manual cast application and removal instrument...Surgical Devices § 888.5980 Manual cast application and removal instrument. (a) Identification. A manual cast application and removal...

2011-04-01

80

The study of flow pattern and phase-change problem in die casting process  

NASA Technical Reports Server (NTRS)

The flow pattern and solidification phenomena in die casting process have been investigated in the first phase study. The flow pattern in filling process is predicted by using a VOF (volume of fluid) method. A good agreement with experimental observation is obtained for filling the water into a die cavity with different gate geometry and with an obstacle in the cavity. An enthalpy method has been applied to solve the solidification problem. By treating the latent heat implicitly into the enthalpy instead of explicitly into the source term, the CPU time can be reduced at least 20 times. The effect of material properties on solidification fronts is tested. It concludes that the dependence of properties on temperature is significant. The influence of the natural convection over the diffusion has also been studied. The result shows that the liquid metal solidification phenomena is diffusion dominant, and the natural convection can affect the shape of the interface. In the second phase study, the filling and solidification processes will be considered simultaneously.

Wang, T. S.; Wei, H.; Chen, Y. S.; Shang, H. M.

1996-01-01

81

Low-Cycle Fatigue Behavior of Die-Cast Mg Alloys AZ91 and AM60  

NASA Astrophysics Data System (ADS)

The influence of microstructure and artificial aging response (T6) on the low-cycle fatigue behavior of super vacuum die-cast (SVDC) AZ91 and AM60 has been investigated. Fatigue lifetimes were determined from the total strain-controlled fatigue tests for strain amplitudes of 0.2 pct, 0.4 pct, 0.6 pct, 0.8 pct, and 1.0 pct under fully reversed loading at a frequency of 5 Hz. Cyclic stress-strain behavior was determined using an incremental step test (IST) and compared with the more traditional constant amplitude test. Two locations in a prototype casting were investigated to examine the role of microstructure and porosity on fatigue behavior. At all total strain amplitudes microstructure refinement had a negligible impact on fatigue life because of significant levels of porosity. AM60 showed an improvement in fatigue life at higher strain amplitudes when compared with AZ91 because of higher ductility. T6 heat treatment had no impact on fatigue life. Cyclic stress-strain behavior obtained via the incremental step test varied from constant amplitude test results due to load history effects. The constant amplitude test is believed to be the more accurate test method. In general, larger initiation pores led to shorter fatigue life. The fatigue life of AZ91 was more sensitive to initiation pore size and pore location than AM60 at the lowest tested strain amplitude of 0.2 pct. Fatigue crack paths did not favor any specific phase, interdentritic structure or eutectic structure. A multistage fatigue (MSF) model showed good correlation to the experimental strain-life results. The MSF model reinforced the dominant role of inclusion (pore) size on the scatter in fatigue life.

Rettberg, Luke H.; Jordon, J. Brian; Horstemeyer, Mark F.; Jones, J. Wayne

2012-07-01

82

40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.  

...Applicability; description of the cast iron basis material subcategory. 466.20...PORCELAIN ENAMELING POINT SOURCE CATEGORY Cast Iron Basis Material Subcategory § 466.20 Applicability; description of the cast iron basis material subcategory....

2014-07-01

83

40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the cast iron basis material subcategory. 466.20...PORCELAIN ENAMELING POINT SOURCE CATEGORY Cast Iron Basis Material Subcategory § 466.20 Applicability; description of the cast iron basis material subcategory....

2013-07-01

84

40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the cast iron basis material subcategory. 466.20...PORCELAIN ENAMELING POINT SOURCE CATEGORY Cast Iron Basis Material Subcategory § 466.20 Applicability; description of the cast iron basis material subcategory....

2010-07-01

85

40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.  

Code of Federal Regulations, 2011 CFR

...Applicability; description of the cast iron basis material subcategory. 466.20...PORCELAIN ENAMELING POINT SOURCE CATEGORY Cast Iron Basis Material Subcategory § 466.20 Applicability; description of the cast iron basis material subcategory....

2011-07-01

86

40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.  

Code of Federal Regulations, 2012 CFR

...Applicability; description of the cast iron basis material subcategory. 466.20...PORCELAIN ENAMELING POINT SOURCE CATEGORY Cast Iron Basis Material Subcategory § 466.20 Applicability; description of the cast iron basis material subcategory....

2012-07-01

87

Improved Life of Die Casting Dies of H13 Steel by Attaining Improved Mechanical Properties and Distortion Control During Heat Treatment  

SciTech Connect

The ultimate goal of this project is to increase die casting die life by using fast enough quenching rates to obtain good toughness and fatigue resistance in premium grade H-13 steel dies. The main tasks of the project were to compile a database on physical and mechanical properties of H-13; conduct gas quenching experiments to determine cooling rates of dies in difference vacuum furnaces; measure the as-quenched distortion of dies and the residual stresses; generate finite element analysis models to predict cooling rates, distortion, and residual stress of gas quenched dies; and establish rules and create PC-based expert system for prediction of cooling rates, distortion, and residual stress in vacuum/gas quenched H-13 dies. Cooling curves during gas quenching of H-13 blocks and die shapes have been measured under a variety of gas pressure. Dimensional changes caused by the gas quenching processes have been determined by accurate mapping of all surfaces with coordinate measuring machines before and after the quench. Residual stresses were determined by the ASTM E837 hole-drilling strain gage method. To facilitate the computer modeling work, a comprehensive database of H-13 mechanical and physical properties has been compiled. Finite element analysis of the heat treated shapes has been conducted using the TRAST/ABAQUS codes. There is a good fit between the predicted and measured distortion contours. However, the magnitude of the predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required before it can be used to predict distortion and residual stress in a quantitative manner. This last step is a prerequisite to generating rules for a reliable expert system.

J. F. Wallace; D. Schwam

1998-10-01

88

Calibrating material parameters to model the thin-walled components made of die cast AM60B magnesium alloy  

Microsoft Academic Search

As a novel lightweight metal, die cast AM60B magnesium alloy continues to be considered as a potential replacement for steel in certain automotive components. However, proper numerical model representing this alloy has not yet been fully explored. Thus, an optimisation methodology was developed to calibrate the material parameters needed for four available material laws, namely, MAT_99, MAT_81, MAT_24 and MAT_107

Feng Zhu; Clifford C. Chou; King H. Yang; Xiaoming Chen; David Wagner; Sukhi Bilkhu; Alan Luo

2012-01-01

89

Influence of Electrolytic Plasma Oxidation Coating on Tensile Behavior of Die-Cast AM50 Alloy Subjected to Salt Corrosion  

Microsoft Academic Search

Three different thickness ceramic coatings were deposited on die-cast AM50 magnesium alloy in KOH and NaAlO2 solution using electrolytic plasma oxidation (EPO) technology for corrosion prevention. Immersion corrosion tests were carried out in 3.5% NaCl solution for 336 hours to investigate the effect of coating thicknesses on tensile and fracture behaviors of the coated AM50 alloys. The results show that

Lihong Han; Xueyuan Nie; Peng Zhang; Qiang Zhang; Henry Hu

2009-01-01

90

Advanced Pattern Material for Investment Casting Applications  

SciTech Connect

Cleveland Tool and Machine (CTM) of Cleveland, Ohio in conjunction with Harrington Product Development Center (HPDC) of Cincinnati, Ohio have developed an advanced, dimensionally accurate, temperature-stable, energy-efficient and cost-effective material and process to manufacture patterns for the investment casting industry. In the proposed technology, FOPAT (aFOam PATtern material) has been developed which is especially compatible with the investment casting process and offers the following advantages: increased dimensional accuracy; increased temperature stability; lower cost per pattern; less energy consumption per pattern; decreased cost of pattern making equipment; decreased tooling cost; increased casting yield. The present method for investment casting is "the lost wax" process, which is exactly that, the use of wax as a pattern material, which is then melted out or "lost" from the ceramic shell. The molten metal is then poured into the ceramic shell to produce a metal casting. This process goes back thousands of years and while there have been improvements in the wax and processing technology, the material is basically the same, wax. The proposed technology is based upon an established industrial process of "Reaction Injection Molding" (RIM) where two components react when mixed and then "molded" to form a part. The proposed technology has been modified and improved with the needs of investment casting in mind. A proprietary mix of components has been formulated which react and expand to form a foam-like product. The result is an investment casting pattern with smooth surface finish and excellent dimensional predictability along with the other key benefits listed above.

F. Douglas Neece Neil Chaudhry

2006-02-08

91

[Application to dental casting machine of the rapid heating infrared image furnace (author's transl)].  

PubMed

The authors tried to manufacture a casting machine in dentistry by application of the infrared image furnace with a high heating speed and an easy control of a heating temperature. This machine melts an alloy in a carbon crucible set in the furnace, held in the horizontal position. Then, the furnace is turned to the vertical position to drop a melted alloy on the casting mold, and the alloy is cast in the mold by the pressure of Argon gas. The functions of trial casting machine were follows. 1. The trial casting machine was capable of heating to 1250 degrees C within one minute under 4 kW electric power. 2. The castability of the 20% Au-Pd-Ag commercial alloy cast in all casting conditions by the trial casting machine was higher than that of Thermotrol D-2 automatic centrifugal casting machine. 3. Castings of the trial casting machine showed higher tensile strength and elongation than those of the centrifugal casting machine, and the deviation of values got by the trial casting machine was small. In particular, some casting of the trial casting machine showed three times or over elongation values as compared with those of the centrifugal casting machine. 4. When casting conditions (casting temperature, casting pressure) of the trial casting machine changed, the physical properties of castings did not change so much. However, when the mold was not prevented from heating by the furnace in casting, the elongation of castings increased. PMID:7017037

Etchu, Y; Noguchi, H

1980-10-01

92

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

Code of Federal Regulations, 2011 CFR

...POINT SOURCE CATEGORY Continuous Casting Subcategory § 420.60 Applicability; description of the continuous casting subcategory. The provisions...treatment works resulting from the continous casting of molten steel into...

2011-07-01

93

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

Code of Federal Regulations, 2010 CFR

...POINT SOURCE CATEGORY Continuous Casting Subcategory § 420.60 Applicability; description of the continuous casting subcategory. The provisions...treatment works resulting from the continous casting of molten steel into...

2010-07-01

94

An application of advanced control to steel casting  

Microsoft Academic Search

Accurate control of the ferro-static head in continuous casting is believed to be a key factor in improving the quality of the cast product. This paper describes an application of advanced control, that resulted in a complete re-commissioning of the investigated mould level control system. Careful physical modelling identified smooth as well as non-smooth nonlinearities in the process. The paper

S. F. Graebe; G. C. Goodwin; M. R. West; P. Stepien

1994-01-01

95

The molding analysis of automobile parts using the die-casting system  

Microsoft Academic Search

The casting defects that are caused by molten metal were cold shut formation, entrapment of air, gas, and inclusion. But the control of casting defects has been based on the experience of the foundry engineers. In this paper, computer simulations have been carried out to analyze the flow of molten metal. The quantitative analyses which proposed effective mold designs were

B. S. Sung; I. S. Kim

2008-01-01

96

Development of a 3D Filling Model of Low-Pressure Die-Cast Aluminum Alloy Wheels  

NASA Astrophysics Data System (ADS)

A two-phase computational fluid dynamics model of the low-pressure die-cast process for the production of A356 aluminum alloy wheels has been developed to predict the flow conditions during die filling. The filling model represents a 36-deg section of a production wheel, and was developed within the commercial finite-volume package, ANSYS CFX, assuming isothermal conditions. To fully understand the behavior of the free surface, a novel technique was developed to approximate the vent resistances as they impact on the development of a backpressure within the die cavity. The filling model was first validated against experimental data, and then was used to investigate the effects of venting conditions and pressure curves during die filling. It was found that vent resistance and vent location strongly affected die filling time, free surface topography, and air entrainment for a given pressure fill-curve. With regard to the pressure curve, the model revealed a strong relation between the pressure curve and the flow behavior in the hub, which is an area prone to defect formation.

Duan, Jianglan; Maijer, Daan; Cockcroft, Steve; Reilly, Carl

2013-12-01

97

CAST  

NSDL National Science Digital Library

The Council for Agricultural Science and Technology (CAST) was formed in 1972 as a result of a meeting sponsored by the National Academy of Sciences' National Research Council. CAST's mission is to "assemble, interpret, and communicate credible science-based information regionally, nationally, and internationally to legislators, regulators, policymakers, the media, the private sector and the public." Visitors will find the Education tab near the top of the page to be particularly helpful for those who want to pursue agricultural careers or learn about agricultural education, such as 4-H or Future Farmers of America. The CAST Videos section has a number of PowerPoint presentations on current topics of importance in agriculture, such as "The Science and Regulation of Food from Genetically Engineered Animals," "Food Safety and Fresh Produce," and "Probiotics in Human Health." A number of the papers that accompany the PowerPoint presentations are available for free.

98

CAST  

NSDL National Science Digital Library

The Council for Agricultural Science and Technology (CAST) was formed in 1972 as a result of a meeting sponsored by the National Academy of Sciences' National Research Council. CAST's mission is to "assemble, interpret, and communicate credible science-based information regionally, nationally, and internationally to legislators, regulators, policymakers, the media, the private sector and the public." Visitors will find the Education tab near the top of the page to be particularly helpful for those who want to pursue agricultural careers or learn about agricultural education, such as 4-H or Future Farmers of America. The CAST Videos section has a number of PowerPoint presentations on current topics of importance in agriculture, such as "The Science and Regulation of Food from Genetically Engineered Animals," "Food Safety and Fresh Produce," and "Probiotics in Human Health." A number of the papers that accompany the PowerPoint presentations are available for free.

2012-02-03

99

The Role of Microstructure on Ductility of Die-Cast AM50 and AM60 Magnesium Alloys  

NASA Astrophysics Data System (ADS)

Die-cast AM50 and AM60 magnesium alloys have been examined to determine the fracture processes in bending and tension and to elucidate the influences of microstructure and porosity distribution on mechanical properties. The effect of section thickness has been explored using 2-, 6-, and 10-mm-thick die-cast plates. The processes of damage accumulation in terms of crack initiation, growth, and linkage leading to eventual failure have been studied qualitatively using progressive tensile straining experiments and three-point bend studies. The presence of a heterogeneous distribution of porosity played a critical role in the observed differences between strains to fracture in tension and in bending. More rapid damage accumulation at lower strains was observed in the high porosity regions with the rate of damage accumulation strongly dependent on the loading mode. Fracture processes at the microstructural level were characterized by scanning electron microscopy using an in-situ bending fixture. Crack initiation and growth occurred predominantly in the interdendritic eutectic regions, both in the presence of porosity and, to a lesser extent, in pore-free regions. The role of porosity volume fraction and distribution on ductility in these alloys has been examined using a modified Brown-Embury model. This model allows the prediction of fracture location in either loading mode by predicting the critical strains for the onset of cracking in differently strained regions of the test samples.

Chadha, Gurjeev; Allison, John E.; Jones, J. Wayne

2007-02-01

100

Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels  

NASA Astrophysics Data System (ADS)

Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels are in a select group of cast components that have strict specifications for both mechanical and aesthetic characteristics due to their important structural requirements and their visibility on a vehicle. The modern aluminum alloy automotive wheel continues to experience tightened tolerances relating to defects to improve mechanical performance and/or the physical appearance. Automotive aluminum alloy wheels are assessed against three main criteria: wheel cosmetics, mechanical performance, and air tightness. Failure to achieve the required standards in any one of these categories will lead to the wheel either requiring costly repair or being rejected and remelted. Manufacturers are becoming more reliant on computational process modeling as a design tool for the wheel casting process. This article discusses and details examples of the use of computational process modeling as a predictive tool to optimize the casting process from the standpoint of defect minimization with the emphasis on those defects that lead to failure of aluminum automotive wheels, namely, macroporosity, microporosity, and oxide films. The current state of applied computational process modeling and its limitations with regard to wheel casting are discussed.

Reilly, C.; Duan, J.; Yao, L.; Maijer, D. M.; Cockcroft, S. L.

2013-09-01

101

The use of friction-stir technology to modify the surfaces of AM60B magnesium die castings  

NASA Astrophysics Data System (ADS)

These experiments were done to evaluate the feasibility of locally modifying the surface properties of magnesium alloys with friction-stir processing. The magnesium alloy used for the study was high-pressure die-cast AM60B, nominally Mg-6Al-0.13 Mn (wt.%). Friction-stir passes were made with a translation speed of 1.7 mm/s using tool-rotation speeds of 1,250 rpm or 2,500 rpm. Stir passes with good appearance were obtained under both conditions. In some cases up to five passes were overlapped on a single bar to produce stir zones with cross-sectional dimensions of about 1.5 mm×10 mm. Metallographic examinations indicated that the stir zones were largely comprised of a magnesium solid solution with equiaxed grains on the order of 5-10 ?m in size. Hardness mapping showed that the stir zones experienced increases of 16-25% compared to the as-cast metal. Room-temperature testing showed that, compared to the cast metal, the stir zones had flow stresses nearly 20% higher with about twice the tensile elongation.

Santella, Michael; Frederick, Alan; Degen, Cassandra; Pan, Tsung-Yu

2006-05-01

102

Thermal fatigue behavior of H-13 die steel for aluminum die casting with various ion sputtered coatings  

NASA Technical Reports Server (NTRS)

Sputtered coatings of Mo, W, Pt, Ag, Au, Co, Cr, Ni, Ag + Cu, Mo + Pt, Si3N4, A1N, Cr3C2, Ta5Si3, and ZrO2 were applied to a 2-inch-square, 7-inch-long thermal fatigue test specimen which was then internally water cooled and alternately immersed in molten aluminum and cooled in air. After 15,000 cycles the thermal fatigue cracks at the specimen corners were measured. Results indicate that a significant improvement in thermal fatigue resistance was obtained with platinum, molybdenum, and tungsten coatings. Metallographic examination indicates that the improvement in thermal fatigue resistance resulted from protection of the surface of the die steel from oxidation. The high yield strength and ductility of molybdenum and tungsten contributed to the better thermal fatigue resistance.

Nieh, C. Y.; Wallace, J. F.

1981-01-01

103

25 CFR 301.4 - Application of dies.  

Code of Federal Regulations, 2013 CFR

...Section 301.4 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER AND TURQUOISE PRODUCTS; STANDARDS § 301.4 Application of dies. Dies are to be applied to the object with the aid of nothing...

2013-04-01

104

25 CFR 301.4 - Application of dies.  

...Section 301.4 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER AND TURQUOISE PRODUCTS; STANDARDS § 301.4 Application of dies. Dies are to be applied to the object with the aid of nothing...

2014-04-01

105

25 CFR 301.4 - Application of dies.  

Code of Federal Regulations, 2010 CFR

...Section 301.4 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER AND TURQUOISE PRODUCTS; STANDARDS § 301.4 Application of dies. Dies are to be applied to the object with the aid of nothing...

2010-04-01

106

25 CFR 301.4 - Application of dies.  

Code of Federal Regulations, 2011 CFR

...Section 301.4 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER AND TURQUOISE PRODUCTS; STANDARDS § 301.4 Application of dies. Dies are to be applied to the object with the aid of nothing...

2011-04-01

107

25 CFR 301.4 - Application of dies.  

Code of Federal Regulations, 2012 CFR

...Section 301.4 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER AND TURQUOISE PRODUCTS; STANDARDS § 301.4 Application of dies. Dies are to be applied to the object with the aid of nothing...

2012-04-01

108

Low Cost Al-Si Casting Alloy As In-Situ Composite for High Temperature Applications  

NASA Technical Reports Server (NTRS)

A new aluminum-silicon (Al-Si) alloy has been successfully developed at NASA- Marshall Space Flight Center (MSFC) that has significant improvement in tensile and fatigue strength at elevated temperatures (500 F-700 F). The alloy offers a number of benefits such as light weight, high hardness, low thermal expansion and high surface wear resistance. In hypereutectic form, this alloy is considered as an in-situ Al-Si composite with tensile strength of about 90% higher than the auto industry 390 alloy at 600 F. This composite is very economically produced by using either conventional permanent steel molds or die casting. The projected material cost is less than $0.90 per pound, and automotive components such as pistons can be cast for high production rate using conventional casting techniques with a low and fully accounted cost. Key Words: Metal matrix composites, In-situ composite, aluminum-silicon alloy, hypereutectic alloy, permanent mold casting, die casting.

Lee, Jonathan A.

2000-01-01

109

SiC Die Attach for High-Temperature Applications  

NASA Astrophysics Data System (ADS)

Eutectic solders AuIn19 and AuGe12 and nanosilver paste were investigated for SiC die attach in high-temperature (300°C) applications. The soldering or sintering conditions were optimized through die shear tests performed at room temperature. In particular, application of static pressure (3.5 MPa) during sintering resulted in greatly improved mechanical behavior of the nanosilver-based joint. Microstructural study of the eutectic solders showed formation of Au-rich grains in AuGe die attach and significant diffusion of Au and In through the Ni layer in AuIn19 die attach, which could lead to formation of intermetallic compounds. Die shear tests versus temperature showed that the behaviors of the studied die attaches are different; nevertheless they present suitable shear strengths required for high-temperature applications. The mechanical behavior of joints under various levels of thermal and mechanical stress was also studied. Creep experiments were carried out on the eutectic solders to describe the thermomechanical behavior of the complete module; only one creep mechanism was observed in the working range.

Drevin-Bazin, A.; Lacroix, F.; Barbot, J.-F.

2013-11-01

110

Tape cast bioactive metal-ceramic laminates for structural application  

NASA Astrophysics Data System (ADS)

Bioglass 45S5, is a silica based glass which is able to rapidly form strong bonds with bone and soft tissue in vivo. It is used clinically to replace damaged ear ossicles and in dental surgery to help maintain the structural integrity of the jaw bone. The goal of the research was to demonstrate that Bioglass can be toughened by lamination with metallic layers while maintaining bioactivity. Improvement of the mechanical properties of Bioglass 45SS would allow for additional clinical applications, such as fracture fixation plates, or vertebral spacers. Bioglass 45S5 was tape cast and laminated with clinically relevant metals (316L, stainless steel and titanium) as well as copper in an effort to demonstrate that the effective toughness, or area under the load-deflection diagram can be increased significantly through ductile layer lamination. The average strength of monolithic tape cast sintered Bioglass was as high as 150 MPa and the toughness measured approximately 1.0 MPa m1/2. Copper-Bioglass laminates clearly demonstrated the toughening effect of metal layers on tape cast sintered Bioglass 45S5. Steel-Bioglass laminates, although less tough than the copper-Bioglass laminates, showed higher strengths. In vitro bioactivity tests of both titanium and steel Bioglass laminates showed the formation of mature and thick hydroxyapatite layers after 24 hours in Tris buffer solution. Under the standard test conditions, the bioactivity of monolithic tape cast sintered Bioglass increased with increasing sintering temperature. For samples sintered at 1000°C, thick crystalline layers of hydroxyapatite formed within 24 hours in Tris buffer solution. The bioactivity of these samples approached that of amorphous bulk Bioglass. Samples processed at 800°C were able to form thick crystalline hydroxyapatite layer after 24 hours when the test solution volume was increased by eight times.

Clupper, Daniel Christopher

111

Cathodic chromium carbide coatings for molding die applications  

Microsoft Academic Search

Chromium carbide coating on steel is a good candidate for applications on forming and molding dies. The high mechanical strength, chemical resistance and high temperature stability of Cr3C2 phase can be compatible with the severe abrasive wear and corrosion found in these manufacture operations. Chromium carbide coatings have been deposited on hardened steel probes by cathodic arc evaporation (CAE) from

J. Esteve; J. Romero; M. Gómez; A. Lousa

2004-01-01

112

Neurobehavioral testing of subjects exposed residentially to groundwater contaminated from an aluminum die-casting plant and local referents  

SciTech Connect

Residents adjoining a die-casting plant had excessive headaches, numbness of hands and feet, dizziness, blurred vision, staggering, sweating, abnormal heart rhythm, and depression, which led to measurements of neurobehavioral performance, affective status, and the frequency of symptoms. They had all been exposed via well water and proximity to the plant to volatile organic chemicals (VOC) and to polychlorinated biphenyls (PCBs). The 117 exposed women and men and 46 unexposed referents were studied together for simple and choice visual reaction time, body sway speed, blink reflex latency, color discrimination, Culture Fair (a nonverbal nonarithmetic intelligence test), recall of stories, figures, and numbers, cognitive and psychomotor control (slotted pegboard and trail making A and B), long-term memory, profile of mood states (POMS), and scores and frequencies of 34 symptoms. Choice reaction time, sway speed, and blink latency were impaired in both sexes of the exposed group and trail making B was impaired in exposed women. The POMS scores and frequencies of 30 of 34 symptoms were elevated in both sexes, compared to referents. Recall, long-term memory, psychomotor speed, and other cognitive function tests were reduced in exposed subjects and in the referents as compared to national referents. Neurophysiological impairment, and cognitive and psychomotor dysfunction and affective disorders, especially depression and excessive frequency of symptoms, were associated with the use of wells contaminated with VOCs, TCE and PCBs.

Kilburn, K.H.; Warshaw, R.H. (Univ. of California School of Medicine, Los Angeles (United States))

1993-08-01

113

Fatigue characterization of high pressure die-cast magnesium AM60B alloy using experimental and computational investigations  

NASA Astrophysics Data System (ADS)

The object of the current dissertation is to foster fundamental advances in microstructure-fatigue characteristics of a high pressure die cast magnesium AM60B alloy. First, high cycle fatigue staircase experiments were conducted on specimens extracted from automobile instrument panels. The resulting fracture surfaces were then examined with scanning electron microscopic imaging to elucidate the fatigue crack initiation sites and propagation paths at different stages of the fatigue life. Due to the fact that the qualification of the crack initiation and propagation mechanisms through experiment alone is difficult, complementary micromechanical finite element simulations were conducted. Particularly, the effects of different applied loading conditions and the porosity morphology (e.g. pore shape, pore size, pore spacing, proximity to the free surface) on the maximum plastic shear strain range, as a driving force for crack initiation, were analyzed. Moreover, at the microstructually small crack (MSC) propagation stage, the shielding effects of beta-phase Mg17Al12 particles were systematically studied. Based on the distribution of the maximum principal stress within the particles and the maximum hydrostatic stress along the particle/matrix interfaces, the relative influence of the pre-damaged (fractured or debonded) particles and various particle cluster morphologies were carefully investigated. In the finite element simulations, the constitutive behaviours of AM60B alloy and the alpha-matrix were simulated by the advanced kinematic hardening law tuned with experimentally determined material parameters under cyclic loading.

Lu, You

114

Influence of Electrolytic Plasma Oxidation Coating on Tensile Behavior of Die-Cast AM50 Alloy Subjected to Salt Corrosion  

NASA Astrophysics Data System (ADS)

Three different thickness ceramic coatings were deposited on die-cast AM50 magnesium alloy in KOH and NaAlO2 solution using electrolytic plasma oxidation (EPO) technology for corrosion prevention. Immersion corrosion tests were carried out in 3.5% NaCl solution for 336 hours to investigate the effect of coating thicknesses on tensile and fracture behaviors of the coated AM50 alloys. The results show that the yield strength (YS) and ultimate tensile strength (UTS) of the coated AM50 alloy subjected to immersion corrosion increase with an increase in coating thicknesses. Further analyses on stress and strain curves indicate that the coating enhances the strain-hardening rates of the corroded alloy during its plastic deformation. SEM examination on the fractured surface manifests that the substrate AM50 alloys exhibit characteristics of ductile deformation with deep dimples. However, brittle features prevail on the fractured surface of the mixed layer of coating plus oxidation corrosion product. Micro cracks were observed between the mixed layer and the AM50 alloy substrate induced by corrosion and within the mixed layer induced by EPO process, which could be responsible for the brittle fracture.

Han, Lihong; Nie, Xueyuan; Zhang, Peng; Zhang, Qiang; Hu, Henry

115

Clean Metal Casting  

SciTech Connect

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.

Makhlouf M. Makhlouf; Diran Apelian

2002-02-05

116

Dynamic Water Modeling and Application of Billet Continuous Casting  

Microsoft Academic Search

The continuous casting process is used for solidifying molten steel into semi-finished steel. The technology of secondary cooling is extremely important for output of the casting machine and billet quality. A dynamic water model was introduced, including solidification model in the secondary cooling, feedforward control strategy based on continuous temperature measurement in tundish, and feedback control strategy based on surface

Wen-hong LIU; Zhi XIE; Zhen-ping JI; Biao WANG; Zhao-yi LAI; Guang-lin JIA

2008-01-01

117

Energy and Technolgy Assessment of Zinc and Magnesium Casting Plants, Technical Report Close-out, August 25,2006  

SciTech Connect

Twin City Die Castings Company of Minneapolis, Minnesota, Twin City Die Castings Company was awarded project No. DE-FG36-05GO15097 to perform plant wide assessments of ten (10) die casting facilities that produce zinc and magnesium alloy castings in order to determine improvements and potential cost savings in energy use. Mr. Heider filled the role of team leader for the project and utilized the North American Die Casting Association (NADCA) to conduct audits at team participant plants so as to hold findings specific to each plant proprietary. The intended benefits of the project were to improve energy use through higher operational and process efficiency for the plants assessed. An improvement in energy efficiency of 5 – 15% was targeted. The primary objectives of the project was to: 1) Expand an energy and technology tool developed by the NADCA under a previous DOE project titled, “Energy and Technology Assessment for Die Casting Plants” for assessing aluminum die casting plants to be more specifically applicable to zinc and magnesium die casting facilities. 2) Conduct ten (10) assessments of zinc and magnesium die casting plants, within eight (8) companies, utilizing the assessment tool to identify, evaluate and recommend opportunities to enhance energy efficiency, minimize waste, and improve productivity. 3) Transfer the assessment tool to the die casting industry at large.

Twin City Die Castings Company; Tom Heider; North American Die Castings Association

2006-08-25

118

The application of quality criteria for the prediction of porosity in the design of casting processes  

SciTech Connect

Solidification parameters calculated from temperature measurements and experimentally determined distributions of porosity in gain- refined Al-4.5% Cu alloy castings are linked to provide quality criteria for the prediction of porosity in the computer-aided design and analysis of casting processes. The quality criteria applicable to a particular casting process are dependent on the thermal conditions and the solidification mode of the alloy. Accordingly, casting processes and alloy types are divided into four groups according to whether porosity distribution is dominated by liquid transport, dendrite structure, or bubble pressure, and a different set of quality criteria is obtained for each group. Results from test castings of Al-4.5% Cu alloy cast in a variety of configurations and mold media are used to develop models and extract quality criteria. The results obtained on Al-4.5% Cu alloy are tested on data on Al-7% Si-0.3% Mg alloy castings reported in the literature. The results show that the quality criteria developed for USSR Cu alloy are also applicable to other alloy systems. The procedure for applying quality criteria for the prediction of microporosity distributions in commercial casting processes is outlined.

Viswanathan, S.; Sikka, V.K. (Oak Ridge National Lab., TN (United States)); Brody, H.D. (Connecticut Univ., Storrs, CT (United States). School of Engineering)

1993-01-01

119

Improved life of die casting dies of H13 steel by attaining improved mechanical properties and distortion control during heat treatment. Year 1 report, October 1994--September 1995  

SciTech Connect

Optimum heat treatment of dies (quenching) is critical in ensuring satisfactory service performance: rapid cooling rates increase the thermal fatigue/heat checking resistance of the steel, although very fast cooling rates can also lead to distortion and lower fracture toughness, increasing the danger of catastrophic fracture. Goal of this project is to increase die life by using fast enough quenching rates (> 30 F/min ave cooling rate from 1750 to 550 F, 1/2 in. below working surfaces) to obtain good toughness and fatigue resistance in Premium grade H-13 steel dies. An iterative approach of computer modeling validated by experiment was taken. Cooling curves during gas quenching of H-13 blocks and die shapes were measured under 2, 5, and 7.5 bar N2 and 4 bar Ar. Resulting dimensional changes and residual stresses were determined. To facilitate the computer modeling work, a database of H-13 mechanical and physical properties was compiled. Finite element analysis of the heat treated shapes was conducted. Good fit of modeled vs measured quenched rates was demonstrated for simple die shapes. The models predict well the phase transformation products from the quench. There is good fit between predicted and measured distortion contours; however magnitude of predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required.

Wallace, J.F.; Schwam, D. [Case Western Reserve Univ., Cleveland, OH (United States)

1995-03-01

120

Predicting Pattern Tooling and Casting Dimensions for Investment Casting - Phase II  

SciTech Connect

The investment casting process allows the production of complex-shape parts and close dimensional tolerances. One of the most important phases in the investment casting process is the design of the pattern die. Pattern dies are used to create wax patterns by injecting wax into dies. The wax patterns are used to create a ceramic shell by the application of a series of ceramic coatings, and the alloy is cast into the dewaxed shell mold (Fig. 1.1). However, the complexity of shape and the close dimensional tolerances required in the final casting make it difficult to determine tooling dimensions. The final linear dimension of the casting depends on the cumulative effects of the linear expansions or contractions in each step of the investment casting process (Fig. 1.2). In most cases, the mold geometry or cores restrict the shrinkage of the pattern or the cast part, and the final casting dimensions may be affected by time-dependent processes such as viscoelastic deformation of the wax, and viscoplastic creep and plastic deformations of the shell and alloy. The pattern die is often reworked several times to produce castings whose dimensions are within acceptable tolerances. To date, investment casting technology has been based on hands-on training and experience. Technical literature is limited to experimental, phenomenological studies aimed at obtaining empirical correlations for quick and easy application in industry. The goal of this project was to predict casting dimensions for investment castings in order to meet blueprint nominal during the first casting run. Several interactions have to be considered in a coupled manner to determine the shrinkage factors: these are the die-wax, wax-shell, and shell-alloy interactions (as illustrated in Fig. 1.3). In this work, the deformations of the die-wax and shell-alloy systems were considered in a coupled manner, while the coupled deformation of the wax-shell system was not considered. Future work is needed in order to deliver to industry a computer program in which all three systems are coupled for determining the dimensions of the wax pattern, the shell mold, and casting in a sequential but coupled manner.

Sabau, Adrian S [ORNL

2005-09-01

121

Assessment of skin dose modification caused by application of immobilizing cast in head and neck radiotherapy.  

PubMed

Skin dose assessment for radiotherapy patients is important to ensure that the dose received by skin is not excessive and does not cause skin reactions. Immobilizing casts may have a buildup effect, and can enhance the skin dose. This study has quantified changes to the surface dose as a result of head and neck immobilizing casts. Medtech and Renfu casts were stretched on the head of an Alderson Rando-Phantom. Irradiation was performed using 6 and 15 MV X-rays, and surface dose was measured by thermoluminescence dosimeters. In the case of 15MV photons, immobilizing casts had no effect on the surface dose. However, the mean surface dose increase reached up to 20 % when 6MV X-rays were applied. Radiation incidence angle, thickness, and meshed pattern of the casts affected the quantity of dose enhancement. For vertical beams, the surface dose increase was more than tangential beams, and when doses of the points under different areas of the casts were analysed separately, results showed that only doses of the points under the thick area had been changed. Doses of the points under the thin area and those within the holes were identical to the same points without immobilizing casts. Higher dose which was incurred due to application of immobilizing casts (20 %) would not affect the quality of life and treatment of patients whose head and neck are treated. Therefore, the benefits of head and neck thermoplastic casts are more than their detriments. However, producing thinner casts with larger holes may reduce the dose enhancement effect. PMID:24964872

Soleymanifard, Shokouhozaman; Toossi, Mohammad Taghi Bahreyni; Khosroabadi, Mohsen; Noghreiyan, Atefeh Vejdani; Shahidsales, Soodabeh; Tabrizi, Fatemeh Varshoee

2014-09-01

122

Modeling of an industrial microwave furnace for metal casting applications  

Microsoft Academic Search

Microwaves can be used efficiently for casting metals using specially designed industrial microwave ovens. Their designs, however, is a challenging multi-physics problem that would require addressing concurrently electromagnetic, thermal, material and chemical issues. In this paper, a simplified model has been developed to model the operation of an industrial microwave oven. Our EM and thermal results were obtained using FEM

Mohamed H. Awida; Nikit Shah; Brian Warren; Ed Ripley; Aly E. Fathy

2008-01-01

123

The development of comprehensive material models of the structure-property relationships for die-cast magnesium alloy AM60B  

NASA Astrophysics Data System (ADS)

The purpose of this study was to conduct experiments to determine the relevant microstructural features that influence mechanical properties of the high-pressure die-cast magnesium alloy AM60B. From these resulting experimental data, predictive capabilities of these relationships were developed. This work continues from a previous M.E.Sc. thesis [1]. Metallographic and indentation techniques were used to determine the skin thickness in regions of different solidification conditions throughout the die-casting. It was determined that the yield strength of AM6OB samples tested in uniaxial tension is described by a modified Hall-Petch relationship. These results were then used in FE (finite element) simulations to establish the predicted yield strength for uniaxial tensile samples given the average grain size. Medium- (˜8mum) and high-resolution (˜1mum) X-ray tomography testing were completed on several samples of AM60B, and one sample at several levels of loading during uniaxial tension, prior to fracture. The fracture location, strain and stress of the sample during uniaxial tensile testing were predicted using a critical strain model, previously presented in [1], and a new, modified failure model. FE simulations were used to simulate the fracture of uniaxial tensile samples with porosity. It was determined that the critical features leading to fracture of AM6OB samples are the area fraction of porosity, and the proximity of the centre of mass of the porosity to a free surface. With these two features, a mathematical model was formulated capable of predicting the fracture strain of six AM6OB samples tested in uniaxial tension within an error percentage of 6.8%. Multi-axial testing was completed on several samples of AM60B. Uniaxial compression, plane-strain compression, and shear testing were completed to fracture. FE simulations were found to accurately predict the deformation and true stress-true strain curves each of these loading states. An accurate yield surface was then established for the deformation of AM6OB in plane-stress up to 10% true effective strain. FE simulations were completed under plane-strain tension, balanced bi-axial tension, shear testing, and uniaxial tensile testing to determine a fracture surface for different area fractions of porosity for plane-stress loading. These fracture surfaces were validated using results from uniaxial tensile testing. Keywords: Finite element analysis simulations, high-resolution X-ray tomography, X-ray diffraction techniques, magnesium die-castings, failure modelling, multi-axial material testing, structure-property relationships.

Weiler, Jonathan P.

124

3D characterization of intermetallics in a high pressure die cast Mg alloy using focused ion beam tomography  

SciTech Connect

The degree of spatial interconnection of the Mg{sub 17}Al{sub 12} ({beta}-phase) intermetallic in a Mg-9Al-1Zn alloy was assessed through serial sectioning at the centre and near a corner in a casting cross-section. The three dimensional reconstructions showed that the intermetallics were profusely interconnected forming a scaffold-like network over the entire cross-section, but especially near the casting surface. The scale and degree of the interconnection appeared determined by the local concentration of large dendritic grains injected from the shot sleeve. The volume fractions of intermetallics obtained through the 3D reconstruction indicated a higher content of {beta}-phase at the corner regions in comparison with the core. The volume fractions obtained by FIB were consistent with theoretical and experimental values obtained using other techniques.

Nagasekhar, A.V. [ARC Centre of Excellence for Design in Light Metals, Materials Engineering, University of Queensland, Brisbane, QLD 4072 (Australia); Caceres, C.H., E-mail: c.caceres@uq.edu.au [ARC Centre of Excellence for Design in Light Metals, Materials Engineering, University of Queensland, Brisbane, QLD 4072 (Australia); Kong, C. [Electron Microscope Unit, UNSW Analytical Centre, University of New South Wales, Sydney, NSW 2052 (Australia)

2010-11-15

125

Virtual aluminum castings: An industrial application of ICME  

NASA Astrophysics Data System (ADS)

The automotive product design and manufacturing community is continually besieged by Hercule an engineering, timing, and cost challenges. Nowhere is this more evident than in the development of designs and manufacturing processes for cast aluminum engine blocks and cylinder heads. Increasing engine performance requirements coupled with stringent weight and packaging constraints are pushing aluminum alloys to the limits of their capabilities. To provide high-quality blocks and heads at the lowest possible cost, manufacturing process engineers are required to find increasingly innovative ways to cast and heat treat components. Additionally, to remain competitive, products and manufacturing methods must be developed and implemented in record time. To bridge the gaps between program needs and engineering reality, the use of robust computational models in up-front analysis will take on an increasingly important role. This article describes just such a computational approach, the Virtual Aluminum Castings methodology, which was developed and implemented at Ford Motor Company and demonstrates the feasibility and benefits of integrated computational materials engineering.

Allison, John; Li, Mei; Wolverton, C.; Su, Xuming

2006-11-01

126

New industrial technology for producing mill balls in a continuous-casting deformation complex  

Microsoft Academic Search

The fields of application of grinding steel balls are in ore processing and the cement industry (material grinding in ball mills); large-size rolling bearings, etc. In mass machine production, for the manufacturing of axisymmetric forgings, cylindrical billets can be effectively replaced by balls. Balls are now produced by casting, die forging, and rolling. Cast grinding balls find a limited application.

S. P. Bourkine; E. A. Korshunov; Yu. N. Loginov; N. A. Babailov; V. A. Tchestnov

1999-01-01

127

Improved ceramic slip casting technique. [application to aircraft model fabrication  

NASA Technical Reports Server (NTRS)

A primary concern in modern fluid dynamics research is the experimental verification of computational aerothermodynamic codes. This research requires high precision and detail in the test model employed. Ceramic materials are used for these models because of their low heat conductivity and their survivability at high temperatures. To fabricate such models, slip casting techniques were developed to provide net-form, precision casting capability for high-purity ceramic materials in aqueous solutions. In previous slip casting techniques, block, or flask molds made of plaster-of-paris were used to draw liquid from the slip material. Upon setting, parts were removed from the flask mold and cured in a kiln at high temperatures. Casting detail was usually limited with this technique -- detailed parts were frequently damaged upon separation from the flask mold, as the molded parts are extremely delicate in the uncured state, and the flask mold is inflexible. Ceramic surfaces were also marred by 'parting lines' caused by mold separation. This adversely affected the aerodynamic surface quality of the model as well. (Parting lines are invariably necessary on or near the leading edges of wings, nosetips, and fins for mold separation. These areas are also critical for flow boundary layer control.) Parting agents used in the casting process also affected surface quality. These agents eventually soaked into the mold, the model, or flaked off when releasing the case model. Different materials were tried, such as oils, paraffin, and even an algae. The algae released best, but some of it remained on the model and imparted an uneven texture and discoloration on the model surface when cured. According to the present invention, a wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell mold of the calcium sulfate-bonded investment material. The shell mold is cooled to room temperature, and a ceramic slip is poured therein. After a ceramic shell of desired thickness has set up in the shell mold, excess ceramic slip is poured out. While still wet, the shell mold is peeled from the ceramic shell to expose any delicate or detailed parts, after which the ceramic shell is cured to provide a complete, detailed, precision ceramic article without parting lines.

Buck, Gregory M. (inventor); Vasquez, Peter (inventor)

1993-01-01

128

Commercialization of NASA's High Strength Cast Aluminum Alloy for High Temperature Applications  

NASA Technical Reports Server (NTRS)

In this paper, the commercialization of a new high strength cast aluminum alloy, invented by NASA-Marshall Space Flight Center, for high temperature applications will be presented. Originally developed to meet U.S. automotive legislation requiring low- exhaust emission, the novel NASA aluminum alloy offers dramatic improvement in tensile and fatigue strengths at elevated temperatures (450 F-750 F), which can lead to reducing part weight and cost as well as improving performance for automotive engine applications. It is an ideal low cost material for cast components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. NASA alloy also offers greater wear resistance, dimensional stability, and lower thermal expansion compared to conventional aluminum alloys, and the new alloy can be produced economically from sand, permanent mold and investment casting. Since 2001, this technology was licensed to several companies for automotive and marine internal combustion engines applications.

Lee, Jonathan A.

2003-01-01

129

The Application and Research of 3-D Standard P-Lib of the Die CAD  

Microsoft Academic Search

In this paper, through further study on the data structure of CATIA system , the product design philosophy and the relevant application module, based on further study on the die design process and concrete working content, utilize the developing tool CAA in CATIA and VC software and establishes the comprehensive 3D standard P-Lib for die CAD. The function and operating

Jianfeng Liu; Yong Jiang; Gengyue Song

2007-01-01

130

Cast CF8C-Plus Stainless Steel for Turbocharger Applications  

SciTech Connect

The purpose of this Cooperative Research and Development Agreement (CRADA) project is to provide the critical test data needed to qualify CF8C-Plus cast stainless steel for commercial production and use for turbocharger housings with upgraded performance and durability relative to standard commercial cast irons or stainless steels. The turbocharger technologies include, but are not limited to, heavy-duty highway diesel engines, and passenger vehicle diesel and gasoline engines. This CRADA provides additional critical high-temperature mechanical properties testing and data analysis needed to quality the new CF8C-Plus steels for turbocharger housing applications.

Maziasz, P.J.; Shyam, A.; Evans, N.D.; Pattabiraman, K. (Honeywell Turbo Technologies

2010-06-30

131

Feasibility Assessment for Pressure Casting of Ceramic-Aluminum Composites for NASA's Propulsion Applications  

NASA Technical Reports Server (NTRS)

Feasibility assessment of pressure casting of ceramic-aluminum composites for NASA% propulsion applications is summarized. A combination of several demonstration projects to produce three unique components for liquid hydrogen-oxygen rocket engine% flanges, valves and turbo-pump housing are conducted. These components are made from boron carbide, silicon carbide and alumina powders fabricated into complex net shaped parts using dry green powder compaction, slip casting or a novel 3D ink-jet printing process, followed by sintering to produce performs that can be pressure cast by infiltration with molten aluminum. I n addition, joining techniques are also explored to insure that these components can be assembled into a structure without degrading their highly tailored properties. The feasibility assessment was made to determine if these new materials could provide a significant weight savings, thereby reducing vehicle launch costs, while being durable materials to increase safety and performance for propulsion system.

Lee, Jonathan A.

2005-01-01

132

21 CFR 888.5980 - Manual cast application and removal instrument.  

...nonpowered hand-held device intended to be used in applying or removing a cast. This generic type of device includes the cast knife, cast spreader, plaster saw, plaster dispenser, and casting stand. (b) Classification. Class I (general...

2014-04-01

133

21 CFR 888.5980 - Manual cast application and removal instrument.  

Code of Federal Regulations, 2010 CFR

...nonpowered hand-held device intended to be used in applying or removing a cast. This generic type of device includes the cast knife, cast spreader, plaster saw, plaster dispenser, and casting stand. (b) Classification. Class I (general...

2010-04-01

134

21 CFR 888.5980 - Manual cast application and removal instrument.  

Code of Federal Regulations, 2012 CFR

...nonpowered hand-held device intended to be used in applying or removing a cast. This generic type of device includes the cast knife, cast spreader, plaster saw, plaster dispenser, and casting stand. (b) Classification. Class I (general...

2012-04-01

135

38 CFR 11.128 - Veteran dies without having filed application for final settlement.  

Code of Federal Regulations, 2012 CFR

...BY BANKS ON AND PAYMENT OF ADJUSTED SERVICE CERTIFICATES Application for Payment of Adjusted Service Certificate Under the World War Adjusted Compensation Act, As Amended (pub. L. 120, 68th Cong.) § 11.128 Veteran dies without having...

2012-07-01

136

38 CFR 11.128 - Veteran dies without having filed application for final settlement.  

Code of Federal Regulations, 2010 CFR

...BY BANKS ON AND PAYMENT OF ADJUSTED SERVICE CERTIFICATES Application for Payment of Adjusted Service Certificate Under the World War Adjusted Compensation Act, As Amended (pub. L. 120, 68th Cong.) § 11.128 Veteran dies without having...

2010-07-01

137

Synthesis of Ag nanorods and application to soft die attaching  

Microsoft Academic Search

In this paper, we report the synthesis of Ag nanoparticles paste, a new bonding agent using between chips and substrates in semiconductor devices. Ag nanorods with varied yield have been successfully synthesized by simply adjusting the concentration of additive salt, the moral ratio of capping agent to AgNO3. The Ag nanoparticles can be sintered to form porous die attach layer

Jinting Jiu; Keiichi Murai; Keunsoo Kim; Katsuaki Suganuma

2008-01-01

138

Evaluation and comparison of casting materials in forensic sciences Applications to tool marks and foot\\/shoe impressions  

Microsoft Academic Search

Elastomeric products used for casting toolmarks and footprints have been tested as to their dimensional stability, elastical memory, viscosity and application time. A survey of products used by different police forces in Europe has also shown the perceived advantages or drawbacks of 13 different products. New products have been tested and adapted for footmark casting. Side by side comparison of

E. Du Pasquier; J. Hebrard; P. Margot; M. Ineichen

1996-01-01

139

Urinary casts  

MedlinePLUS

... casts; Casts in the urine; Fatty casts; Red blood cell casts; White blood cell casts ... dehydration, exercise, or (water pills) diuretic medicines. Red blood cell casts are a sign of bleeding into ...

140

A partitioned resolution for concurrent fluid flow and stress analysis during solidification: application to ingot casting  

E-print Network

casting, or in the mould during continuous casting. The proposed approach consists of a partitioned two in continuous casting) and solid mechanics (stress-strain in solidified regions). This is of crucial importance of ingot casting, or during continuous casting. The current state-of-the-art consists in separating

Paris-Sud XI, Université de

141

Fabrication of fiber reinforced metal matrix composites by squeeze casting technology  

Microsoft Academic Search

Squeeze forming process is a special casting technique that combines the advantages of traditional high pressure die casting, gravity permanent mold die casting and common forging technology. It is a relatively new casting process. It is otherwise called squeeze forming, liquid forging, liquid pressing, extrusion casting, liquid metal stamping, pressure crystallization and corthias casting. The above said process was first

T. R. Vijayaram; S. Sulaiman; A. M. S. Hamouda; M. H. M. Ahmad

2006-01-01

142

Ni3Al-based alloys for die and tool application  

DOEpatents

A novel Ni.sub.3 Al-based alloy exhibits strengths and hardness in excess of the standard base alloy IC-221M at temperatures of up to about 1000.degree. C. The alloy is useful in tool and die applications requiring such temperatures, and for structural elements in engineering systems exposed to such temperatures.

Liu, Chain T. (Oak Ridge, TN); Bloom, Everett E. (Kingston, TN)

2001-01-01

143

Cryogenic Fracture Toughness Evaluation of an Investment Cast Al-Be Alloy for Structural Applications  

NASA Technical Reports Server (NTRS)

Aluminum-Beryllium metal matrix composite materials are useful due to their desirable performance characteristics for aerospace applications. Desirable characteristics of this material includes light-weight, dimensional stability, stiffness, good vibration damping characteristics, low coefficient of thermal expansion, and workability, This material is 3.5 times stiffer and 22% lighter than conventional aluminum alloys. electro-optical systems, advanced sensor and guidance components for flight and satellite systems, components for light-weight high-performance aircraft engines, and structural components for helicopters. Aluminum-beryllium materials are now available in the form of near net shape investment castings. In this materials properties characterization study, the cryogenic tensile and fracture properties of an investment casting alloy, Beralcast 363, were determined. Tensile testing was performed at 21 C (70 F), -73.3 C (-100 F), -195.5 C (-320 F) and -252.8 C (-423 F), and fracture (K(sub lc) and da/dN) testing was performed at -73.3 C (-100 F), -195.5 C (-320 F) and -252.8 C (-423 F). Their use is attractive for weight critical structural applications such as advanced

Gamwell, W. R.; McGill, P. B.

2006-01-01

144

Matched metal die compression molded structural random fiber sheet molding compound flywheel. [Patent application  

DOEpatents

A flywheel is described that is useful for energy storage in a hybrid vehicle automotive power system or in some stationary applications. The flywheel has a body of essentially planar isotropic high strength structural random fiber sheet molding compound (SMC-R). The flywheel may be economically produced by a matched metal die compression molding process. The flywheel makes energy intensive efficient use of a fiber/resin composite while having a shape designed by theory assuming planar isotropy.

Kulkarni, S.V.; Christensen, R.M.; Toland, R.H.

1980-09-24

145

Compaction die for forming a solid annulus on a right circular cylinder. [Patent application  

DOEpatents

A compacting die is disclosed wherein the improvement comprises providing a screen in the die cavity, the screen being positioned parallel to the side walls of said die and dividing the die cavity into center and annular compartments. In addition, the use of this die in a method for producing an annular clad ceramic fuel material is disclosed.

Harlow, J.L.

1981-09-14

146

Research and Application of Dynamic Control System for Secondary Cooling of Billet Continuous Casting  

Microsoft Academic Search

The continuous casting process is used for the solidification of molten steel into semi-finished shapes. The technology of secondary cooling is extremely important for output of the casting machine and quality of the strand. This paper presents a dynamic control system, including solidification model in the secondary cooling, feedforward control based on continuous temperature measurement in tundish and feedback control

Wenhong Liu; Zhi Xie; Zhenping Ji; Biao Wang

2007-01-01

147

Design and application of dynamic control system for secondary cooling of billet continuous casting  

Microsoft Academic Search

The continuous casting process is used for the solidification of molten steel into semi-finished shapes. The technology of secondary cooling is extremely important for output of the casting machine and quality of the strand. In the paper, a dynamic control system is presented, including solidification model in the secondary cooling, feedforward control based on continuous temperature measurement in tundish and

Wenhong Liu; Zhi Xie

2010-01-01

148

Large shaped parts of melt cast BSCCO for applications in electrical engineering  

Microsoft Academic Search

A melt casting process (MCP) that is tailor made for BSCCO, especially for the 2212 phase, is described. It is reported that melt casting offers an easy access to a variety of different shapes and sizes. The properties of the material obtained by MCP have been significantly improved by admixing strontium sulphate. Jc values superior to those of sintered ceramics

J. Bock; H. Bestgen; S. Elschner; E. Preisler

1993-01-01

149

A partitioned resolution for concurrent fluid flow and stress analysis during solidification: application to ingot casting  

NASA Astrophysics Data System (ADS)

In simulation of solidification processes, an open issue is the concurrent modelling of fluid flow and solid mechanics. This is critical for the prediction of cracks formed in solidified regions during the filling stage of ingot casting, or in the mould during continuous casting. The proposed approach consists of a partitioned two-step resolution strategy.

Bellet, Michel; Boughanmi, Okba; Fidel, Grégory

2012-07-01

150

75 FR 20387 - Contech Castings, LLC, Including Workers Whose Unemployment Insurance (UI) Wages Are Reported...  

Federal Register 2010, 2011, 2012, 2013

...workers are engaged in activities related to the production of aluminum and magnesium die casted component parts for automobiles. New information shows that...magnesium die casted component parts for automobiles. The amended notice...

2010-04-19

151

The improvement of aluminium casting process control by application of the new CRIMSON process  

NASA Astrophysics Data System (ADS)

All The traditional foundry usually not only uses batch melting where the aluminium alloys are melted and held in a furnace for long time, but also uses the gravity filling method in both Sand Casting Process (SCP) and Investment Casting Process (ICP). In the gravity filling operation, the turbulent behaviour of the liquid metal causes substantial entrainment of the surface oxide films which are subsequently trapped into the liquid and generate micro cracks and casting defects. In this paper a new CRIMSON process is introduced which features instead of gravity filling method, using the single shot up-casting method to realize the rapid melting and rapid filling mould operations which reduce the contact time between the melt and environment thus reducing the possibility of defect generation. Another advantage of the new process is the drastic reduction of energy consumption due to shortened melting and filling time. Two types of casting samples from SCP and ICP were compared with the new process. The commercial software was used to simulate the filling and solidification processes of the casting samples. The results show that the new process has a more improved behaviour during filling a mould and solidification than the two conventional casting processes.

Dai, X.; Jolly, M.; Zeng, B.

2012-07-01

152

Effect of composition and processing on the thermal fatigue and toughness of high performance die steels. Year 1 report  

SciTech Connect

The goal of this project is to extend the lifetime of dies for die casting by 20%. Since the die contributes about 10% to the cost of die cast parts, such an improvement in lifetime would result in annual savings of over $200 Million dollars. This is based on the estimated annual die production of one Billion dollars in the US. The major tasks of this two year project are: (1) Evaluate NEW DIE STEEL COMPOSITIONS that have been developed for demanding applications and compare them to Premium Grade H-13 die steel. (2) Optimize the AUSTENITIZING TREATMENT of the new composition. Assess the effects of fast, medium and slow COOLING RATES DURING HEAT TREATMENT, on the thermal fatigue resistance and toughness of the die steel. (3) Determine the effect of ELECTRO-DISCHARGE MACHINING (EDM) on the thermal fatigue resistance and impact properties of the steel. (4) Select demanding components and conduct IN-PLANT TESTING by using the new steel. Compare the performance of the new steel with identical components made of Premium Grade H-13. The immersion thermal fatigue specimen developed at CWRU is being used to determine resistance to heat checking, and the Charpy V-notch test for evaluating the toughness. The overall result of this project will be identification of the best steel available on the market and the best processing methods for aluminum die casting dies. This is an interim report for year 1 of the project.

Wallace, J.F.; Wang, Yumin; Schwam, D.

1996-06-01

153

Promising composite die-bonding materials for high-power GaN-based LED applications  

NASA Astrophysics Data System (ADS)

In this paper we propose a promising die-bonding material consisted of diamond-added AgSnCu solders for chip package, and combine it with our well-established cup-shaped copper technique for chip heat dissipation. The composite solder was prepared by mixing the commercial Sn-3wt.%Ag- 0.5wt.%Cu (SAC305) solder paste with the diamond paste [0.25(W)475-MA, Engis, USA] in a weight ratio of 10:1. Thermal resistance analysis shows that total thermal resistance of the LED packaged using the composite solder is only 6.4 K/W, which is much lower than both the LED using AgSnCu solder (9.2 K/W) and the LED using silver paste (10.4 K/W). As a result, the LED with the composite solder exhibits larger light output power and smaller junction temperature than the other two samples. The improved device performance is mainly due to enhanced heat dissipation of the die-bonding materials used. These results suggest that the composite diamond-added AgSnCu solder is promising in high-power LED application.

Horng, Ray-Hua; Hong, Jhih-Sin; Tsai, Yu-Li; Chen, Chia-Ju; Chen, Chih-Ming; Wuu, Dong-Sing

2010-03-01

154

Rapid casting solutions: a review  

Microsoft Academic Search

Purpose – This paper seeks to review the industrial applications of state-of-the-art additive manufacturing (AM) techniques in metal casting technology. An extensive survey of concepts, techniques, approaches and suitability of various commercialised rapid casting (RC) solutions with traditional casting methods is presented. Design\\/methodology\\/approach – The tooling required for producing metal casting such as fabrication of patterns, cores and moulds with

Munish Chhabra; Rupinder Singh

2011-01-01

155

Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Mechanical Performance of Dies  

SciTech Connect

As a net shape process, die casting is intrinsically efficient and improvements in energy efficiency are strongly dependent on design and process improvements that reduce scrap rates so that more of the total consumed energy goes into acceptable, usable castings. A casting that is distorted and fails to meet specified dimensional requirements is typically remelted but this still results in a decrease in process yield, lost productivity, and increased energy consumption. This work focuses on developing, and expanding the use of, computer modeling methods that can be used to improve the dimensional accuracy of die castings and produce die designs and machine/die setups that reduce rejection rates due to dimensional issues. A major factor contributing to the dimensional inaccuracy of the casting is the elastic deformations of the die cavity caused by the thermo mechanical loads the dies are subjected to during normal operation. Although thermal and die cavity filling simulation are widely used in the industry, structural modeling of the die, particularly for managing part distortion, is not yet widely practiced. This may be due in part to the need to have a thorough understanding of the physical phenomenon involved in die distortion and the mathematical theory employed in the numerical models to efficiently model the die distortion phenomenon. Therefore, two of the goals of this work are to assist in efforts to expand the use of structural modeling and related technologies in the die casting industry by 1) providing a detailed modeling guideline and tutorial for those interested in developing the necessary skills and capability and 2) by developing simple meta�¢���models that capture the results and experience gained from several years of die distortion research and can be used to predict key distortion phenomena of relevance to a die caster with a minimum of background and without the need for simulations. These objectives were met. A detailed modeling tutorial was provided to NADCA for distribution to the industry. Power law based meta�¢���models for predicting machine tie bar loading and for predicting maximum parting surface separation were successfully developed and tested against simulation results for a wide range of machines and experimental data. The models proved to be remarkably accurate, certainly well within the requirements for practical application. In addition to making die structural modeling more accessible, the work advanced the state-of-the-art by developing improved modeling of cavity pressure effects, which is typically modeled as a hydrostatic boundary condition, and performing a systematic analysis of the influence of ejector die design variables on die deflection and parting plane separation. This cavity pressure modeling objective met with less than complete success due to the limits of current finite element based fluid�¢���structure�¢���interaction analysis methods, but an improved representation of the casting/die interface was accomplished using a combination of solid and shell elements in the finite element model. This approximation enabled good prediction of final part distortion verified with a comprehensive evaluation of the dimensions of test castings produced with a design experiment. An extra deliverable of the experimental work was development of high temperature mechanical properties for the A380 die casting alloy. The ejector side design objective was met and the results were incorporated into the metamodels described above. This new technology was predicted to result in an average energy savings of 2.03 trillion BTU�¢����s/year over a 10 year period. Current (2011) annual energy saving estimates over a ten year period, based on commercial introduction in 2009, a market penetration of 70% by 2014 is 4.26 trillion BTU�¢����s/year by 2019. Along with these en

R. Allen Miller, Principal Investigator; Contributors: Khalil Kabiri-Bamoradian; Abelardo Delgado-Garza; Karthik Murugesan; Adham Ragab

2011-09-13

156

Oxide films, pores and the fatigue lives of cast aluminum alloys  

NASA Astrophysics Data System (ADS)

In the absence of gross defects such as cold shuts, the fatigue properties of castings are largely determined by the sizes of microstructural defects, particularly pores and oxide films. In contrast, the effects of grain size, second-phase particles, and nonmetallic inclusions are insignificant. The authors review the fatigue properties of castings made by gravity die casting, sand casting, lost-foam casting, squeeze casting, and semisolid casting, and compare A356/357 alloys with 319-type alloys. The application of fracture mechanics enables the properties to be rationalized in terms of the defects that are characteristic of each casting process, noting both the sizes and types of defect. The differences in the properties of castings are entirely attributed to their different defect populations. No single process is inherently superior. For defects of the same size (in terms of projected area normal to the loading direction), oxide films are less detrimental to fatigue life than pores. Areas of current controversy are highlighted and suggestions for further work are made.

Wang, Q. G.; Crepeau, P. N.; Davidson, C. J.; Griffiths, J. R.

2006-12-01

157

Application of Bezier surfaces to the 3-D inverse geometry problem in continuous casting  

Microsoft Academic Search

In this article, a three-dimensional (3-D) numerical solution of the inverse geometry problem for a continuous casting process of an aluminium alloy is presented. In particular, an accurate determination of the interface location between the liquid and solid phases based on temperature measurements at several internal points of the body is discussed. This problem is crucial for the design and

Iwona Nowak; Jacek Smolka; Andrzej J. Nowak

2011-01-01

158

Application of fuzzy logic control for continuous casting mold level control  

Microsoft Academic Search

This paper deals with the problem of molten metal level control in continuous casting. Under normal circumstances, proportional integral derivative (PID) control performs quite well, but abnormal conditions (in particular nozzle clogging\\/unclogging) require manual intervention. Indeed, when the flow of matter into the mold increases suddenly, the PID controller is not always able to prevent large level variations that can

Michel Dussud; Sylvie Galichet; Laurent P. Foulloy

1998-01-01

159

The Second Phase of ToxCast and Initial Applications to Chemical Prioritization  

EPA Science Inventory

Tens of thousands of chemicals and other contaminants exist in our environment, but only a fraction of these have been characterized for their potential hazard to humans. ToxCast is focused on closing this data gap and improving the management of chemical risk through a high thro...

160

Overview of the ToxCast Research Program: Applications to Predictive Toxicology and Chemical Prioritization  

EPA Science Inventory

EPA?s ToxCast program, the NTP?s HTS initiative, and the NCGC?s Molecular Libraries Initiative into a collaborative research program focused on identifying toxicity pathways and developing in vitro assays to characterize the ability of chemicals to perturb those pathways. The go...

161

An innovative approach to sampling complex industrial emissions for use in animal toxicity tests: application to iron casting operations.  

PubMed

Sampling of complex mixtures of airborne contaminants for chronic animal toxicity tests often involves numerous sampling devices, requires extensive sampling time, and yields forms of collected materials unsuitable for administration to animals. A method is described which used a high volume, wet venturi scrubber for collection of respirable fractions of emissions from iron foundry casting operations. The construction and operation of the sampler are presented along with collection efficiency data and its application to the preparation of large quantities of samples to be administered to animals by intratracheal instillation. PMID:6846144

Palmer, W G; Scholz, R C; Moorman, W J

1983-03-01

162

Application of EDS microanalysis in the identification of inhomogeneities in surface protective layers on ductile cast iron parts  

NASA Astrophysics Data System (ADS)

In this study, the results of the application of both scanning electron microscopy and EDS microanalysis in investigations of the process of the protective layer formation on the surface of ductile cast iron (the substrate material) turbine blades are presented. The turbine blades, designated for operation in an aggressive environment, were coated with protective chromium carbide layers using plasma spraying methods. The first turbine blade was coated using a standard plasma spraying technique, followed by superficial remelting treatment, while the second one was coated using a modified plasma technology, i.e., HVOF (High Velocity Oxy Fuel) spraying technique.

Boro?, ?.; Tchórz, A.

2010-02-01

163

Precision cast vs. wrought superalloys  

NASA Technical Reports Server (NTRS)

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.

Tien, J. K.; Borofka, J. C.; Casey, M. E.

1986-01-01

164

43 CFR 3502.40 - What happens if an applicant or successful bidder for a permit or lease dies before the permit or...  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false What happens if an applicant or successful bidder for a permit or lease dies before the permit or lease is issued...Concerns § 3502.40 What happens if an applicant or successful bidder for a permit or lease dies before the permit or lease is...

2011-10-01

165

43 CFR 3502.40 - What happens if an applicant or successful bidder for a permit or lease dies before the permit or...  

...2014-10-01 false What happens if an applicant or successful bidder for a permit or lease dies before the permit or lease is issued...Concerns § 3502.40 What happens if an applicant or successful bidder for a permit or lease dies before the permit or lease is...

2014-10-01

166

PREFACE: International Conference on Advancement in Science and Technology 2012 (iCAST): Contemporary Mathematics, Mathematical Physics and their Applications  

NASA Astrophysics Data System (ADS)

The 4th International Conference on the Advancement of Science and Technology 2012 (iCAST 2012), with theme 'Contemporary Mathematics, Mathematical Physics and their Applications', took place in Kuantan, Malaysia, from Wednesday 7 to Friday 9 November 2012. The conference was attended by more than 100 participants, and hosted about 160 oral and poster papers by more than 140 pre-registered authors. The key topics of the 4th iCAST 2012 include Pure Mathematics, Applied Mathematics, Theoretical/Mathematical Physics, Dynamical Systems, Statistics and Financial Mathematics. The scientific program was rather full since after the Keynote and Invited Talks in the morning, four parallel sessions ran every day. However, according to all attendees, the program was excellent with a high level of talks and the scientific environment was fruitful; thus all attendees had a creative time. The conference aimed to promote the knowledge and development of high-quality research in mathematical fields concerned with the application of other scientific fields as well as modern technological trends in physics, chemistry, biology, medicine, economics, sociology and environmental sciences. We would like to thank the Keynote and the Invited Speakers for their significant contributions to 4th iCAST 2012. We would also like to thank the members of the International Scientific Committee and the members of the Organizing Committee. We cannot end without expressing our many thanks to International Islamic University Malaysia and our sponsors for their financial support . This volume presents selected papers which have been peer-reviewed. The editors hope that it may be useful and fruitful for scholars, researchers, and advanced technical members of the industrial laboratory facilities for developing new tools and products. Guest Editors Nasir Ganikhodjaev, Farrukh Mukhamedov and Pah Chin Hee The PDF contains the committee lists, board list and biographies of the plenary speakers.

Ganikhodjaev, Nasir; Mukhamedov, Farrukh; Hee, Pah Chin

2013-04-01

167

Processing of Advanced Cast Alloys for A-USC Steam Turbine Applications  

NASA Astrophysics Data System (ADS)

The high-temperature components within conventional supercritical coal-fired power plants are manufactured from ferritic/martensitic steels. To reduce greenhouse-gas emissions, the efficiency of pulverized coal steam power plants must be increased to as high a temperature and pressure as feasible. The proposed steam temperature in the DOE/NETL Advanced Ultra Supercritical power plant is high enough (760°C) that ferritic/martensitic steels will not work for the majority of high-temperature components in the turbine or for pipes and tubes in the boiler due to temperature limitations of this class of materials. Thus, Ni-based superalloys are being considered for many of these components. Off-the-shelf forged nickel alloys have shown good promise at these temperatures, but further improvements can be made through experimentation within the nominal chemistry range as well as through thermomechanical processing and subsequent heat treatment. However, cast nickel-based superalloys, which possess high strength, creep resistance, and weldability, are typically not available, particularly those with good ductility and toughness that are weldable in thick sections. To address those issues related to thick casting for turbine casings, for example, cast analogs of selected wrought nickel-based superalloys such as alloy 263, Haynes 282, and Nimonic 105 have been produced. Alloy design criteria, melt processing experiences, and heat treatment are discussed with respect to the as-processed and heat-treated microstructures and selected mechanical properties. The discussion concludes with the prospects for full-scale development of a thick section casting for a steam turbine valve chest or rotor casing.

Jablonski, Paul D.; Hawk, Jeffery A.; Cowen, Christopher J.; Maziasz, Philip J.

2012-02-01

168

A robust frequency domain identification method revisited: Application in steel casting  

Microsoft Academic Search

The mould level process in continuous steel casting is a very tough system because of nonlinearities, dead-time, integrating\\u000a effects, time-varying characteristics and a very high level of stochastic disturbances. Consequently the model identification\\u000a is the most difficult part in the design of a model based predictive controller for this process. A method based on frequency\\u000a domain identification concepts has been

R. DeKeyser; S. Zhang

169

Scuffing of cast iron and Al390-T6 materials used in compressor applications  

Microsoft Academic Search

Scuffing can lead to catastrophic failure in engineering components, but the surface mechanism that leads to scuffing is not well understood. In this experimental study, the surface and subsurface changes on gray cast iron and Al390-T6 were investigated under starved lubrication (a mixture of R410A refrigerant combined with a polyolester lubricant) and pure sliding. Controlled tribological experiments were conducted using

Allison Y. Suh; Jayesh J. Patel; Andreas A. Polycarpou; Thomas F. Conry

2006-01-01

170

An application of fractal geometry to complex microstructures: Numerical characterization of graphite in cast irons  

SciTech Connect

It is demonstrated how the complexities of graphite shapes and distributions in cast irons can be described by fractal geometry. A selection of typical graphite morphologies, flake-like and spherulitic, is described unambiguously by two numbers, a shape factor, a, and fractal exponent, D. The meaning of these numbers is discussed and their possible correlations with growth kinetics and mechanical properties are briefly explored.

Lu, S.Z.; Hellawell, A. (Michigan Technological Univ., Houghton, MI (United States). Dept. of Metallurgical and Materials Engineering)

1994-12-01

171

A study of the interface reaction mechanism between molten aluminum and ferrous die materials  

Microsoft Academic Search

One of the main concerns in the aluminum die casting industry is the problem of die soldering. Die soldering is when aluminum sticks to the surface of the die material, mostly H-13 tool steel, and remains there after ejection of the cast part. In recent times, this defect has posed a major concern because of the notable decrease in productivity

Sumanth Shankar

2000-01-01

172

Application of heat pipe technology in permanent mold casting of nonferrous alloys  

NASA Astrophysics Data System (ADS)

The issue of mold cooling is one, which presents a foundry with a dilemma. On the one hand; the use of air for cooling is safe and practical, however, it is not very effective and high cost. On the other hand, water-cooling can be very effective but it raises serious concerns about safety, especially with a metal such as magnesium. An alternative option that is being developed at McGill University uses heat pipe technology to carry out the cooling. The experimental program consisted of designing a permanent mold to produce AZ91E magnesium alloy and A356 aluminum alloy castings with shrinkage defects. Heat pipes were then used to reduce these defects. The heat pipes used in this work are novel and are patent pending. They are referred to as McGill Heat Pipes. Computer modeling was used extensively in designing the mold and the heat pipes. Final designs for the mold and the heat pipes were chosen based on the modeling results. Laboratory tests of the heat pipe were performed before conducting the actual experimental plan. The laboratory testing results verified the excellent performance of the heat pipes as anticipated by the model. An industrial mold made of H13 tool steel was constructed to cast nonferrous alloys. The heat pipes were installed and initial testing and actual industrial trials were conducted. This is the first time where a McGill heat pipe was used in an industrial permanent mold casting process for nonferrous alloys. The effects of cooling using heat pipes on AZ91E and A356 were evaluated using computer modeling and experimental trials. Microstructural analyses were conducted to measure the secondary dendrite arm spacing, SDAS, and the grain size to evaluate the cooling effects on the castings. The modeling and the experimental results agreed quite well. The metallurgical differences between AZ91E and A356 were investigated using modeling and experimental results. Selected results from modeling, laboratory and industrial trials are presented. The results show a promising future for heat pipe technology in cooling permanent molds for the casting of nonferrous alloys.

Elalem, Kaled

173

Microstructure and Corrosion Characterization of Squeeze Cast AM50 Magnesium Alloys  

NASA Astrophysics Data System (ADS)

Squeeze casting of magnesium alloys potentially can be used in lightweight chassis components such as control arms and knuckles. This study documents the microstructural analysis and corrosion behavior of AM50 alloys squeeze cast at different pressures between 40 and 120 MPa and compares them with high-pressure die cast (HPDC) AM50 alloy castings and an AM50 squeeze cast prototype control arm. Although the corrosion rates of the squeeze cast samples are slightly higher than those observed for the HPDC AM50 alloy, the former does produce virtually porosity-free castings that are required for structural applications like control arms and wheels. This outcome is extremely encouraging as it provides an opportunity for additional alloy and process development by squeeze casting that has remained relatively unexplored for magnesium alloys compared with aluminum. Among the microstructural parameters analyzed, it seems that the ?-phase interfacial area, indicating a greater degree of ? network, leads to a lower corrosion rate. Weight loss was the better method for determining corrosion behavior in these alloys that contain a large fraction of second phase, which can cause perturbations to an overall uniform surface corrosion behavior.

Sachdeva, Deepika; Tiwari, Shashank; Sundarraj, Suresh; Luo, Alan A.

2010-12-01

174

Squeeze casting of magnesium alloys and their composites  

Microsoft Academic Search

Squeeze casting, also known as liquid metal forging, extrusion casting and pressure crystallization, is a process in which molten metal soldifies in a die under an applied high pressure. The concept of squeeze casting was invented in Russia over 100 years ago. Later the process was exploited in North America, Japan and Europe to produce various automotive components. With the

H. Hu

1998-01-01

175

A Partitioned Fluid-Structure Interaction Approach during Steel Solidification: Application to the simulation of Ingot Casting  

E-print Network

(ingot mould filling, nozzle jet in continuous casting) and solid mechanics (stress-strain in solidified region during continuous casting. The current state-of-the-art [15-17-21] consists in separating for continuous casting when it comes to predict cracks in the thin solidified shell formed in the mould region

Paris-Sud XI, Université de

176

Melting and casting of FeAl-based cast alloy  

SciTech Connect

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.

Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

1998-11-01

177

Low Temperature Consolidation of Micro/Nanosilver Die-Attach Preforms  

NASA Astrophysics Data System (ADS)

Organically passivated silver nanopowder paste-based sintering is considered a promising solution for die-attach in high temperature power and sensing electronic devices. However, oxygen requirements during burnout and inherently high shrinkage rates limit their use to small die sizes. This work reports an alternative fabrication method that resolves decomposition and shrinkage issues of the die-attach by utilizing a prestressed optimized tape cast mixture of micro- and nanosilver particles with a polypropylene carbonate binder. The effects of prestressing, micro/nanosilver bimodal distribution, and polymer content on resulting microstructure and shear strength were investigated. Prior to application as a die-attach, uniaxial compression of the tape was found to significantly decrease shrinkage and improve green strength. This pre-stressing strategy allows for a decoupling of the resulting die-attach materials properties from the pressure applied during assembly. Bimodal mixtures consisting of 1-3 ?m spherical powders with nanosilver resulted in shear strengths comparable to those of pure nanosilver. Shear strength decreased as bimodal particle size increased above 5 ?m. A polymer content of ˜10 wt.% polypropylene carbonate combined with prestressing was identified as optimal for maximizing die-attach shear strength while still maintaining pliability and formability. Tape casts that were prestressed to 212 MPa by uniaxially compression and formulated with 10 wt.% of polypropylene carbonate resulted in a die-attach material with a shear strength of 54 MPa when sintered. These materials were used to demonstrate void-free 25-mm2 die-attach assemblies, suggesting that tape cast micro/nanosilver materials may be a promising die-attach method for high temperature and large-area electronics devices.

McCoppin, Jared; Reitz, Thomas L.; Miller, Ryan; Vijwani, Hema; Mukhopadhyay, Sharmila; Young, Daniel

2014-09-01

178

Worldline Casting of the Stochastic Vacuum Model and Non-Perturbative Properties of QCD: General Formalism and Applications  

E-print Network

The Stochastic Vacuum Model for QCD, proposed by Dosch and Simonov, is fused with a Worldline casting of the underlying theory, i.e. QCD. Important, non-perturbative features of the model are studied. In particular, contributions associated with the spin-field interaction are calculated and both the validity of the loop equations and of the Bianchi identity are explicitly demonstrated. As an application, a simulated meson-meson scattering problem is studied in the Regge kinematical regime. The process is modeled in terms of the "helicoidal" Wilson contour along the lines introduced by Janik and Peschanski in a related study based on a AdS/CFT-type approach. Working strictly in the framework of the Stochastic Vacuum Model and in a semiclassical approximation scheme the Regge behavior for the Scattering amplitude is demonstrated. Going beyond this approximation, the contribution resulting from boundary fluctuation of the Wilson loop contour is also estimated.

A. I. Karanikas; C. N. Ktorides

2009-02-16

179

Predicting Pattern Tooling and Casting Dimensions for Investment Casting, Phase II  

SciTech Connect

The investment casting process allows the production of complex-shape parts and close dimensional tolerances. One of the most important phases in the investment casting process is the design of the pattern die. Pattern dies are used to create wax patterns by injecting wax into dies. The first part of the project involved preparation of reports on the state of the art at that time for all the areas under consideration (die-wax, wax-shell, and shell-alloy). The primary R&D focus during Phase I was on the wax material since the least was known about it. The main R&D accomplishments during this phase were determination of procedures for obtaining the thermal conductivity and viscoelastic properties of an unfilled wax and validating those procedures. Phase II focused on die-wax and shell-alloy systems. A wax material model was developed based on results obtained during the previous R&D phase, and a die-wax model was successfully incorporated into and used in commercial computer programs. Current computer simulation programs have complementary features. A viscoelastic module was available in ABAQUS but unavailable in ProCAST, while the mold-filling module was available in ProCAST but unavailable in ABAQUS. Thus, the numerical simulation results were only in good qualitative agreement with experimental results, the predicted shrinkage factors being approximately 2.5 times larger than those measured. Significant progress was made, and results showed that the testing and modeling of wax material had great potential for industrial applications. Additional R&D focus was placed on one shell-alloy system. The fused-silica shell mold and A356 aluminum alloy were considered. The experimental part of the program was conducted at ORNL and commercial foundries, where wax patterns were injected, molds were invested, and alloys were poured. It was very important to obtain accurate temperature data from actual castings, and significant effort was made to obtain temperature profiles in the shell mold. A model for thermal radiation within the shell mold was developed, and the thermal model was successfully validated using ProCAST. Since the fused silica shells had the lowest thermal expansion properties in the industry, the dewaxing phase, including the coupling between wax-shell systems, was neglected. The prefiring of the empty shell mold was considered in the model, and the shell mold was limited to a pure elastic material. The alloy dimensions were obtained from numerical simulations only with coupled shell-alloy systems. The alloy dimensions were in excellent quantitative agreement with experimental data, validating the deformation module. For actual parts, however, the creep properties of the shell molds must also be obtained, modeled, and validated.

Nick Cannell (EMTEC); Adrian S. Sabau (ORNL)

2005-09-30

180

Optimization of Composition and Heat Treating of Die Steels for Extended Lifetime  

SciTech Connect

An ''average'' die casting die costs fifty thousand dollars. A die used in making die cast aluminum engine blocks can cost well over one million dollars. These costs provide a strong incentive for extension of die life. While vacuum quenched Premium Grade H13 dies have become the most widely used in the United States, tool makers and die casters are constantly searching for new steels and heat treating procedures to extend die life. This project was undertaken to investigate the effects of composition and heat treating on die life and optimize these parameters.

David Schwam; John F. Wallace; Quanyou Zhou

2002-01-30

181

Fit of Porcelain Fused-to-metal Crown and Bridge Castings  

Microsoft Academic Search

The dimensional accuracy of porcelain fused to metal crown and bridge castings was determined on truncated cone-shaped steel dies. Ni-Cr castings produced in manufacturers' laboratories were consistently undersize, while precious metal castings were consistently oversize. Ni-Cr castings, produced in NBS laboratories using a modified investing technique, were routinely oversize.

G. T. Eden; O. M. Franklin; J. M. Powell; Y. Ohta; George Dickson

1979-01-01

182

Newly developed magnesium alloys for powertrain applications  

NASA Astrophysics Data System (ADS)

Several new magnesium alloys have been developed recently for high-temperature applications to obtain an optimal combination of die cast-ability, creep resistance, mechanical properties, corrosion performance, and affordability. Unfortunately, it is difficult to achieve an adequate combination of properties and, in fact, most of the new alloys can only partially meet the required performance and cost. The ZE41 alloy, which is used for most gravity-casting applications, has moderate strength and creep resistance combined with good cast-ability. Although this alloy exhibits poor corrosion resistance, it is still preferred for certain applications.

Aghion, E.; Bronfín, B.; von Buch, F.; Schumann, S.; Friedrich, H.

2003-11-01

183

Marginal discrepancy as affected by selective placement of die-spacer: an in vitro study.  

PubMed

An increase in the marginal discrepancy is seen after cementation with a luting agent and provision of cement space with a die-spacer is the most preferred method to avoid it. Recommended thickness of die-spacer is 25-40 ?m. Smaller die-spacer thickness was consistently found at the axio-occlusal line angles as compared to the other surfaces which has been postulated to that the spacer paint tends to flow away from the sharp line angles and cusp tips as a result of increased surface tension. The absence of adequate relief spaces in these areas impedes the flow of cement beyond the occlusal portion of the casting, which would result in incomplete seating because of hydraulic pressure. Fifty stone dies were duplicated from a steel die and were divided into five groups of sample size 10, where the die-spacer was selectively placed. Measurements were taken at four points, 90° apart from each other with the help of optical microscope. Later all the castings were cemented using Glass Inomer cement as a luting agent, under a 10 kg static load and measurements were recorded. Statistical analysis showed samples with no spacer had the maximum pre and post cementation gap while the least discrepancy was seen in group with additional layer of die-spacer painted over the axio-occlusal line angle. The results were highly significant which clearly indicated the superiority of this group over others. Within limitations of the study, it can be said that application of additional layer of die-spacer at the axio-occlusal line angle will help in decreasing the post cementation marginal discrepancy in full cast metal crowns. PMID:23997463

Aditya, Priyam; Madhav, V N V; Bhide, S V; Aditya, Amita

2012-09-01

184

Numerical simulation of macrostructure formation in centrifugal casting of particle reinforced metal matrix composites. Part 2: simulations and practical applications  

NASA Astrophysics Data System (ADS)

Centrifugal casting is a widely applied method for production of graded metal matrix composites (MMCs). This paper discusses some aspects of the macrostructure management of centrifugally cast particle reinforced MMCs. A specially developed software product is applied for the analysis of many technological regimes for casting cylindrical sleeves of composite alloy A356 and SiC particles as reinforcing phase. A number of technological recommendations are made. Castings of aluminium alloy A356 and copper alloy C90300 with Ni coated graphite particles of diameter 100 mum introduced as reinforcing phase are discussed. Some typical and unusual casting structures are analysed using the specially developed software product. This software is based on the mathematical model described in detail in part 1.

Drenchev, Ludmil; Sobczak, Jerzy; Malinov, Savko; Sha, Wei

2003-07-01

185

Die Führungskräftebeurteilung  

Microsoft Academic Search

\\u000a Es ist Intention dieses Buches, die natürliche Verknüpfung von Unternehmensplanung und Führungskräftebeurteilung herauszuarbeiten.\\u000a Wir interpretieren die Unternehmensplanung als einen zukunftsorientierten, auf das Unternehmen in seiner Gesamtheit ausgerichteten\\u000a Prozess, in dessen Verlauf das Management Ziele und Strategien entwickelt, die sich auf simulierte Umweltsituationen beziehen,\\u000a und zwar unabhängig davon, ob neue Umweltlagen mit oder ohne Einwirken des Unternehmens entstehen. Weil die Planung

Peter Maier

186

Cast Away  

Microsoft Academic Search

To strand actor Tom hanks on a deserted island, Cast Away begins with a visceral plane crash sequence incorporating CG water & waves, live action & miniature photography and numerous subtle digital effects. Once on the island, Hanks surveys the landscape revealing his isolation. Combining live action photography filmed in a parking lot in Malibu with a completely CG created

2001-01-01

187

Casting methods  

DOEpatents

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.

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

2012-12-18

188

Waardebetrokkenheid, die sosiologie en die sosioloog  

Microsoft Academic Search

Die gedagte dat daar niks nuuts onder die son is nie, is 'n populere een wat so oud as die mensdom selfis. A1hoewel die modeme kennissosioloog hierdie idee in meer gesofistikeerde terme sal stel, val dit nietemin op hoedanig bepaalde temas en polemieke herhaaldelik in die kontlik van idees op die voorgrond is. Ten spyte van die feit dat die

C. Dawfre Roode

1972-01-01

189

Correlating Hardness Retention and Phase Transformations of Al and Mg Cast Alloys for Aerospace Applications  

NASA Astrophysics Data System (ADS)

The methodology based on correlating hardness and phase transformations was developed and applied to determine the maximum temperature of hardness retention of selected Al-based and Mg-based alloys for aerospace applications. The Al alloys: A356, F357, and C355 experienced 34-66% reduction of the initial hardness, in comparison to 4-22% hardness reduction observed in Mg alloys: QE22A, EV31A, ZE41A, and WE43B after the same annealing to 450 °C. For Al alloys the hardness reduction showed a steep transition between 220 and 238 °C. In contrast, Mg alloys showed a gradual hardness decrease occurring at somewhat higher temperatures between 238 and 250 °C. The hardness data were correlated with corresponding phase transformation kinetics examined by dilatometer and electrical resistivity measurements. Although Mg alloys preserved hardness to higher temperatures, their room temperature tensile strength and hardness were lower than Al alloys. The experimental methodology used in the present studies appears to be very useful in evaluating the softening temperature of commercial Al- and Mg-based alloys, permitting to assess their suitability for high-temperature applications.

Kasprzak, W.; Czerwinski, F.; Niewczas, M.; Chen, D. L.

2015-01-01

190

ASM Handbook, Volume 15, Casting, Division 4: Modeling and Analysis of Casting Processes, American Society of Metals (2008) 449-461  

E-print Network

used to solve them, and a few examples of recent applications in shape castings and continuous castingASM Handbook, Volume 15, Casting, Division 4: Modeling and Analysis of Casting Processes, American the quality of the final product that is desired by the casting industry. Accurate calculation

Paris-Sud XI, Université de

191

Micromechanical die attachment surcharge  

DOEpatents

An attachment structure is disclosed for attaching a die to a supporting substrate without the use of adhesives or solder. The attachment structure, which can be formed by micromachining, functions purely mechanically in utilizing a plurality of shaped pillars (e.g. round, square or polygonal and solid, hollow or slotted) that are formed on one of the die or supporting substrate and which can be urged into contact with various types of mating structures including other pillars, a deformable layer or a plurality of receptacles that are formed on the other of the die or supporting substrate, thereby forming a friction bond that holds the die to the supporting substrate. The attachment structure can further include an alignment structure for precise positioning of the die and supporting substrate to facilitate mounting the die to the supporting substrate. The attachment structure has applications for mounting semiconductor die containing a microelectromechanical (MEM) device, a microsensor or an integrated circuit (IC), and can be used to form a multichip module. The attachment structure is particularly useful for mounting die containing released MEM devices since these devices are fragile and can otherwise be damaged or degraded by adhesive or solder mounting.

Filter, William F. (Albuquerque, NM); Hohimer, John P. (Albuquerque, NM)

2002-01-01

192

Precision design of roll-forging die and its application in the forming of automobile front axles  

Microsoft Academic Search

Roll-forging is an efficient way to produce long or thin metal parts, and the design of rolling die is a sophisticated problem duo to the complex relative motions of dies and forging piece. In the first part of this paper, the kinematic relation between the surface of rolling die and that of forging piece during the roll-forging process are analysed,

Zhong-Yi Cai

2005-01-01

193

Clamshell Casting! Stefanie Wuhrer  

E-print Network

Clamshell Casting! By Stefanie Wuhrer A thesis submitted to the Faculty of Graduate Studies and Research acceptance of the thesis, Clamshell Casting! submitted by Stefanie Wuhrer Douglas Howe (Director is casting, where liquid is poured into a cast and the cast is removed once the liquid has hardened. We

Wuhrer, Stefanie

194

The application and field experience of high strength 12% Cr centrifugally cast pipe for gas gathering system  

SciTech Connect

Centrifugal cast method is one of the processes to provide high quality seamless pipe. The advantages of the process are (1) heavy wall pipe can be manufactured (2) relatively flexible in material selection for manufacturing pipe. For sweet corrosion environment caused by CO{sub 2} where carbon steels can not be used, centrifugally cast 12% Cr martensitic stainless steel pipes and fittings have been developed. One of the key factors of this material applied to pipeline is the weldability, especially high hardness of the welds or its heat affected zone which causes for brittle rupture as well as stress corrosion cracking of the pipeline. Cast 12% Cr pipe which has high strength with low hardness even at the weld joint has been developed. Besides of the development of straight pipe, several types of fittings have been developed. These pipes and fittings have been used for natural gas gathering lines and booster compression lines in sweet corrosion service.

Yoshitake, A.; Teraoka, M.; Torigoe, T. [Kubota Corp., Hirakata, Osaka (Japan). Hirakata Plant; Amako, S. [Kubota America Corp., Houston, TX (United States)

1995-10-01

195

Casting materials  

SciTech Connect

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.

Chaudhry, Anil R. (Xenia, OH); Dzugan, Robert (Cincinnati, OH); Harrington, Richard M. (Cincinnati, OH); Neece, Faurice D. (Lyndurst, OH); Singh, Nipendra P. (Pepper Pike, OH)

2011-06-14

196

Development of an inverse heat conduction model and its application to determination of heat transfer coefficient during casting solidification  

NASA Astrophysics Data System (ADS)

The interfacial heat transfer coefficient (IHTC) is required for the accurate simulation of heat transfer in castings especially for near net-shape processes. The large number of factors influencing heat transfer renders quantification by theoretical means a challenge. Likewise experimental methods applied directly to temperature data collected from castings are also a challenge to interpret because of the transient nature of many casting processes. Inverse methods offer a solution and have been applied successfully to predict the IHTC in many cases. However, most inverse approaches thus far focus on use of in-mold temperature data, which may be a challenge to obtain in cases where the molds are water-cooled. Methods based on temperature data from the casting have the potential to be used however; the latent heat released during the solidification of the molten metal complicates the associated IHTC calculations. Furthermore, there are limits on the maximum distance the thermocouples can be placed from the interface under analysis. An inverse conduction based method have been developed, verified and applied successfully to temperature data collected from within an aluminum casting in proximity to the mold. A modified specific heat method was used to account for latent heat evolution in which the rate of change of fraction solid with temperature was held constant. An analysis conducted with the inverse model suggests that the thermocouples must be placed no more than 2 mm from the interface. The IHTC values calculated for an aluminum alloy casting were shown to vary from 1,200 to 6,200 Wm-2 K-1. Additionally, the characteristics of the time-varying IHTC have also been discussed.

Zhang, Liqiang; Reilly, Carl; Li, Luoxing; Cockcroft, Steve; Yao, Lu

2014-07-01

197

Die Systemsteuerung  

Microsoft Academic Search

\\u000a In der Windows-Systemsteuerung, die aus dem Startmenü aufgerufen werden kann, befinden sich viele Programme, mit denen die\\u000a Einstellungen und die Arbeitsweise von Windows 7 angepasst werden können (siehe Abb. 4.1). Diese Abbildung ist jedoch nur\\u000a als Beispiel zu verstehen, denn in Abhängigkeit von der in einem System installierten Hard-\\/Software (z. B. Bluetooth-Adapter,\\u000a Apple Quicktime etc.) und Windows-7-Funktionen (bsp. für TabletPCs)

Martin Grotegut

198

Casting the Spirit: A Handmade Legacy  

ERIC Educational Resources Information Center

This article discusses how an art therapist working in a hospital palliative care unit has incorporated a ritual of hand casting to help bring closure to dying patients and family members who are grieving as death approaches. The finished hand sculptures depict the hands of the patients and, sometimes, of their loved ones. They are faithful and…

Rutenberg, Mona

2008-01-01

199

76 FR 5840 - The Basic Aluminum Castings Co., Cleveland, OH; Notice of Revised Determination on Reconsideration  

Federal Register 2010, 2011, 2012, 2013

...Administration [TA-W-73,091] The Basic Aluminum Castings Co., Cleveland, OH; Notice...workers and former workers of The Basic Aluminum Castings Co., Cleveland, Ohio (subject...employment related to the production of aluminum die castings. New information...

2011-02-02

200

Application of variable-metric chaos optimization neural network in predicting slab surface temperature of the continuous casting  

Microsoft Academic Search

A slab surface temperature prediction model of the continuous casting based on the variable-metric chaos optimization neural network is presented to solve the problem which the slab surface temperatures can not be measured continuously directly for plentiful inhalator, water film and ferric oxide on the slab surface in the secondary cooling zone. The model is shown to fit the actual

Fengxiang Gao; Changsong Wang; Yubao Zhang; Xiao Chen

2009-01-01

201

Die Primzahlen  

Microsoft Academic Search

Ihren mystischen Nimbus haben die natürlichen Zahlen nach und nach verloren; aber niemals ist das Interesse von Mathematikern\\u000a und Laien an den Gesetzen der Zahlenwelt schwächer geworden. Es mag sein, daß Euklids Ruhm auf der geometrischen Deduktion seiner „Elemente“ beruht; bis heute haben die „Elemente“ jedenfalls den Unterricht\\u000a in der Geometrie entscheidend beeinflußt. Und doch war Euklids Geometrie im wesentlichen

Richard Courant; Herbert Robbins

202

Casting of electron field defining apertures: casting with the metal mold kits.  

PubMed

Cerrobend alloy casts are made to define the desired electron field shapes. These custom casts are fabricated for the selected electron applicator size that has been chosen for the patient. When the cast is placed into that selected electron applicator, it will block out areas that are not to be treated. When an all metal mold assembly was used for the fabrication of these casts, the lip region of the cast which is used to accurately align the cast in the actual treatment applicator, had an irregular edge that prevented an accurate alignment of the cast. To eliminate the irregular edges on the lip region of the cast, the metal mold assembly was heated to approximately 80-85 degrees C before the molten cerrobend alloy was poured into it. The heating of the metal mold assembly helps eliminate the irregular edges on the lip region of the cast. Unfortunately it also created new flaws such as holes, dents, cracks and/or crystallization of the cast as it solidified. These flaws were controlled by cooling the metal mold assembly and the cast immediately after the pouring of the molten cerrobend alloy, evenly with water. PMID:3151256

Dea, D; San Luis, E

1988-09-01

203

Simulating the deformation of dies in the foundry  

NASA Astrophysics Data System (ADS)

Digital simulation (QuikCAST, ProCAST) is already used extensively when designing metallic dies for founding, in particular to design filling and gating systems. Simulation of the steady-state temperature cycles of dies has also been mastered. With large castings, the temperature gradient induced between the moulding surface and the rear surfaces of the die leads to deformations that may be large enough to measure, and incompatible with the required dimensional accuracy. The temperature gradient also creates thermal fatigue stresses that cause crazing of the die surface. In the study conducted by CTIF, aimed at measuring tooling deformations, various ways of measuring displacements at high temperatures (with and without contact) were investigated in order to evaluate their capabilities and limitations. An experimental device was designed - a test bench combining a metallic die having a simple geometry, in which an aluminium part could be cast, and instrumentation (temperature and displacement sensors). The deformations of the die were measured during first cycles of temperature homogenization. Concurrently, thermomechanical calculations were carried out on the same geometry using PROCAST. The calculation results are well correlated with the experimental measurements and validate the tools and the calculation methods. This thermomechanical approach makes it possible to optimize die design in the foundry and to predict high-temperature deformations as early as the design stage. Knowledge of these deformations makes it possible in turn to anticipate the geometrical and dimensional variations undergone by the castings themselves and so to improve their accuracy. The designer can act on the temperature of the die or the design of the casting, or create a die in which the expected thermal deformation is reversed so as to produce a casting having the correct dimensions. In short, thermomechanical simulation can be applied to this problem to achieve a better understanding of the phenomena and to test solutions in advance.

Chabod, A.; Longa, Y.; Dracon, J. M.; Chailler, K.; Hairy, P.; Da Silva, A.

2012-07-01

204

Pb-Free Glass Paste: A Metallization-Free Die-Attachment Solution for High-Temperature Application on Ceramic Substrates  

NASA Astrophysics Data System (ADS)

A lead-free glass frit paste as a die-attach material for high-temperature microelectronic application is proposed in this study. The glass paste containing Bi-based powder with a moderate amount of solvent was used for joining Si dice on ceramic substrates without any metallization preparation for either of the bonding surfaces. The die was bonded to a ceramic substrate at 430°C for 10 min. The study focuses on the mechanical and microstructural characterization of the joints with Si dice on two different types of ceramic substrate. Shear strength measurements were carried out at both ambient and 250°C to evaluate room- and high-temperature performance. Furthermore, the effect of aging at 300°C for 500 h on the mechanical properties is presented. The results of the mechanical and microstructural characterization demonstrate that low-temperature glass frit bonding is an effective die-attach method for harsh-environment electronic packaging.

Sharif, Ahmed; Lim, Jun zhang; Made, Riko I.; Lau, Fu Long; Phua, Eric Jian Rong; Lim, Ju Dy; Wong, Chee Cheong; Gan, Chee Lip; Chen, Zhong

2013-08-01

205

Mechanical behavior of cast and forged magnesium alloys and their microstructures  

Microsoft Academic Search

Effects of manufacturing processes on microstructure and mechanical properties of magnesium alloys AM60 and AZ31B were investigated. The magnesium alloy AM60 was produced by high-pressure die cast (HPDC) with two different casting processors but AZ31B was produced by forging. Casting defects were investigated with SEM observations for the specimens obtained from the two casting processors. The fatigue tests were conducted

Hong Tae Kang; Terry Ostrom

2008-01-01

206

The application of higher than atmospheric pressure to the risers of steel castings has been reported in the foundry literature going back at least to the 1940's. In these reports, the  

E-print Network

1 1 2 1 1 2 ABSTRACT The application of higher than atmospheric pressure to the risers of steel to feed a greater distance than a riser operating under normal atmospheric pressure. The primary goals, the application of pressure to risers resulted in increased feeding distances, increased casting yield

Beckermann, Christoph

207

Optimization of Squeeze Casting for Aluminum Alloy Parts  

SciTech Connect

This study was initiated with the installation of a new production size UBE 350 Ton VSC Squeeze Casting system in the Metal Casting Laboratory at Case Western University. A Lindberg 75k W electrical melting furnace was installed alongside. The challenge of installation and operation of such industrial-size equipment in an academic environment was met successfully. Subsequently, a Sterling oil die heater and a Visi-Track shot monitoring system were added. A significant number of inserts were designed and fabricated over the span of the project, primarily for squeeze casting different configurations of test bars and plates. A spiral ''ribbon insert'' for evaluation of molten metal fluidity was also fabricated. These inserts were used to generate a broad range of processing conditions and determine their effect on the quality of the squeeze cast parts. This investigation has studied the influence of the various casting variables on the quality of indirect squeeze castings primarily of aluminum alloys. The variables studied include gating design, fill time and fill patter, metal pressure and die temperature variations. The quality of the die casting was assessed by an analysis of both their surface condition and internal soundness. The primary metal tested was an aluminum 356 alloy. In addition to determining the effect of these casting variables on casting quality as measured by a flat plate die of various thickness, a number of test bar inserts with different gating designs have been inserted in the squeeze casting machine. The mechanical properties of these test bars produced under different squeeze casting conditions were measured and reported. The investigation of the resulting properties also included an analysis of the microstructure of the squeeze castings and the effect of the various structural constituents on the resulting properties. The main conclusions from this investigation are as follows: The ingate size and shape are very important since it must remain open until the casting is solidified and pressure is maintained on the solidifying casting. Fanned gates, particularly on the smaller section castings avoid jetting effects at the ingate end. The fan type ingate helps accomplish a rapid fill without high velocities. The molten metal has to fill the cavity before localized solidification occurs. This is best accomplished with a larger ingate to attain rapid filling without excessive velocity or jetting that occurs at high metal velocities. Straight gates are prone to case jetting of the metal stream even a low velocities. Fanned gates allow use of higher fill velocity without excessive jetting. A higher metal pressure provides a more complete fill of the die including improved compensation for solidification shrinkage. With the proper filling pattern, ingates, overflows and die temperature for a given die, very good tensile properties can be attained in squeeze casting. In general, the smaller squeeze castings require higher die temperatures. Computer models using the UES Procast and MagmaSoft finite element software can, after suitable adjustments, predict the flow pattern in the die cavity.

David Schwam; John F. Wallace; Qingming Chang; Yulong Zhu

2002-07-30

208

Properties of tape-cast Y-substituted strontium titanate for planar anode substrates in SOFC applications  

Microsoft Academic Search

This work evaluates the use of fine-grained yttrium-substituted strontium titanate powders for the preparation of planar anode\\u000a supported solid oxide fuel cells. Starting from a submicron-sized powder of Y-substituted strontium titanate Sr0.895Y0.07TiO3 (SYT), which was synthesised via spray pyrolysis followed by a grinding process, suspensions of high solid concentration\\u000a were prepared by steric stabilisation. From these suspensions, tape casting slurries

Pavel Vozdecky; Andreas Roosen; Qianli Ma; Frank Tietz; Hans Peter Buchkremer

2011-01-01

209

Spray casting project final report  

Microsoft Academic Search

Lockheed Martin Energy Systems, Inc. (Energy Systems), along with other participating organizations, has been exploring the feasibility of spray casting depleted uranium (DU) to near-net shape as a waste minimization effort. Although this technology would be useful in a variety of applications where DU was the material of choice, this effort was aimed primarily at gamma-shielding components for use in

S. R. Churnetski; J. E. Thompson

1996-01-01

210

Sensor-based assessment of cast placement and removal.  

PubMed

Appropriate pressure during the application of a cast is critical to provide adequate stabilization of fractures. Force-sensing resistors (FSR) were used to measure pressure during cast placement and removal. The data demonstrated a signature pattern of skin pressure during the different steps of cast placement and removal. This reproducible signal provides validity evidence for our model. PMID:24732518

Maag, Anne-Lise D; Laufer, Shlomi; Kwan, Calvin; Cohen, Elaine R; Lenhart, Rachel L; Stork, Natalie C; Halanski, Matthew A; Pugh, Carla M

2014-01-01

211

A Fourier Theory for Cast Shadows Ravi Ramamoorthi1  

E-print Network

A Fourier Theory for Cast Shadows Ravi Ramamoorthi1 , Melissa Koudelka2 , and Peter Belhumeur1 1.koudelka@yale.edu Abstract. Cast shadows can be significant in many computer vision applications such as lighting non-local interactions in non-convex regions, making formal analysis difficult. While general cast

O'Brien, James F.

212

Microstructure and tensile properties of squeeze cast magnesium alloy AM50  

NASA Astrophysics Data System (ADS)

High-pressure die cast magnesium alloy AM50 is currently used extensively in large and complex shaped thin-wall automotive components. For further expansion of the alloy usage in automobiles, novelmanufacturing processes need to be developed. In this study, squeeze casting of AM50 alloy with a relatively thick cross section was carried out using a hydraulic press with an applied pressure of 70 MPa. Microstructure and mechanical properties of the squeeze cast AM50 with a cross-section thickness of 10 mm were characterized in comparison with the die cast counterpart. The squeeze cast AM50 alloy exhibits virtually no porosity in the microstructure as evaluated by both optical microscopy and the density measurement technique. The results of tensile testing indicate the improved tensile properties, specifically ultimate tensile strength and elongation, for the squeeze cast samples over the conventional high-pressure die cast parts. The analysis of tensile behavior show that the strain-hardening rate during the plastic deformation of the squeeze cast specimens is constantly higher than that of the die cast specimens. The scanning electron microscopy fractography evidently reveals the ductile fracture features of the squeeze cast alloy AM50.

Zhou, Ming; Hu, Henry; Li, Naiyi; Lo, Jason

2005-08-01

213

[Application of gypsum-bonded investment containing niobium carbide on casting of alloy for metal-ceramic restoration].  

PubMed

Experimental gypsum-bonded investments containing 0.5-5.0 wt% NbC were prepared by mechanical mixing of each powder. Setting and thermal expansion measurement, compressive strength and casting accuracy for Ni-Cr alloy for metal-ceramic restoration were investigated. Analysis of NbC during heating was carried out by X-ray diffraction, TG-DTA and SEM. NbC was oxidized to Nb2O5 with a volume change between 300-600 degrees C, as in the following equation: 2NbC + 4 1/2O2----Nb2O5 + 2CO2 The theoretical volume of 1/2Nb2O5 calculated from the lattice constants according to JCPDS file was approximately 4 times larger than that of NbC. The experimental investments of 70 wt% cristobalite and 30 wt% gypsum containing 2.0, 3.0 and 5.0 wt% NbC showed large thermal expansion of 7.0, 10.0 and 13.0% respectively. The investment containing 2.0 wt% NbC showed nearly the same casting accuracy for Ni-Cr alloys for metal-ceramic restoration as the commercial phosphate-bonded investment. PMID:2134827

Tsuruta, S; Ban, S; Hasegawa, J; Hayashi, S; Iiyama, K; Yamamura, Y

1990-07-01

214

A Benchmark Study on Casting Residual Stress  

SciTech Connect

Stringent regulatory requirements, such as Tier IV norms, have pushed the cast iron for automotive applications to its limit. The castings need to be designed with closer tolerances by incorporating hitherto unknowns, such as residual stresses arising due to thermal gradients, phase and microstructural changes during solidification phenomenon. Residual stresses were earlier neglected in the casting designs by incorporating large factors of safety. Experimental measurement of residual stress in a casting through neutron or X-ray diffraction, sectioning or hole drilling, magnetic, electric or photoelastic measurements is very difficult and time consuming exercise. A detailed multi-physics model, incorporating thermo-mechanical and phase transformation phenomenon, provides an attractive alternative to assess the residual stresses generated during casting. However, before relying on the simulation methodology, it is important to rigorously validate the prediction capability by comparing it to experimental measurements. In the present work, a benchmark study was undertaken for casting residual stress measurements through neutron diffraction, which was subsequently used to validate the accuracy of simulation prediction. The stress lattice specimen geometry was designed such that subsequent castings would generate adequate residual stresses during solidification and cooling, without any cracks. The residual stresses in the cast specimen were measured using neutron diffraction. Considering the difficulty in accessing the neutron diffraction facility, these measurements can be considered as benchmark for casting simulation validations. Simulations were performed using the identical specimen geometry and casting conditions for predictions of residual stresses. The simulation predictions were found to agree well with the experimentally measured residual stresses. The experimentally validated model can be subsequently used to predict residual stresses in different cast components. This enables incorporation of the residual stresses at the design phase along with external loads for accurate predictions of fatigue and fracture performance of the cast components.

Johnson, Eric M. [John Deere -- Moline Tech Center; Watkins, Thomas R [ORNL; Schmidlin, Joshua E [ORNL; Dutler, S. A. [MAGMA Foundry Technologies, Inc.

2012-01-01

215

The effect of four sprue shapes on the quality of cobalt-chromium cast removable partial denture frame-works  

PubMed Central

Statement of Problem: Sprue design is a factor that controls the velocity and adequate supply of metal to the mould. Currently various manufacturers recommend different shapes of sprue, which have not been advocated in textbooks and literature is lacking for their routine applications. Purpose: This in vitro study was carried out to determine the efficacy of four sprue shapes in producing complete, void free cobalt-chrome removable partial denture frameworks. Materials and Methods: A brass metal die with a Kennedy class III, modification 1, partially edentulous arch was used and four sprue shapes (Group A-Ribbon, Group B-Square, Group C-Round and Group D- Round with reservoir) were evaluated. 40 refractory casts were made, 10 wax patterns for each sprue design were waxed up, invested with phosphate bonded investment material and castings done with induction casting machine by the same operator under standardized protocols. The cast frameworks were evaluated for 1. The defects observed visually before finishing and polishing procedures, 2. Fit on the master die as seen with naked eye and 3. Defects on radiographic evaluation. Data were tabulated and statistically analyzed with 1-way ANOVA followed by Student ‘t’ test. Results: The results differed significantly (P < 0.0001) between the Groups with maximum defects in the castings of Group A followed in decreasing order by Group B, Group C and Group D. When comparing between the Groups (P < 0.05), the defects in Groups C and D was significantly lower than Group A and Group B. Conclusions: Round sprues with reservoir produced most satisfactory fit of castings with minimum number of internal and external defects. PMID:24014998

Viswambaran, M.; Agarwal, S. K.

2013-01-01

216

Vacuum casting of thick polymeric films  

NASA Technical Reports Server (NTRS)

Bubble formation and layering, which often plague vacuum-evaporated films, are prevented by properly regulating process parameters. Vacuum casting may be applicable to forming thick films of other polymer/solvent solutions.

Cuddihy, E. F.; Moacanin, J.

1979-01-01

217

Cool Cast Facts  

MedlinePLUS

... Get Placed? First, the doctor or cast technician — tech for short (or another person who is trained ... some water on it. The doctor or cast tech wraps the plaster or fiberglass around the soft ...

218

40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?  

Code of Federal Regulations, 2011 CFR

...meeting the standards for continuous lamination/casting operations? 63.5820...lamination line and each continuous casting line complies with the applicable...continuous lamination and continuous casting lines combined, comply...

2011-07-01

219

40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?  

...meeting the standards for continuous lamination/casting operations? 63.5820...lamination line and each continuous casting line complies with the applicable...continuous lamination and continuous casting lines combined, comply...

2014-07-01

220

40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?  

Code of Federal Regulations, 2012 CFR

...meeting the standards for continuous lamination/casting operations? 63.5820...lamination line and each continuous casting line complies with the applicable...continuous lamination and continuous casting lines combined, comply...

2012-07-01

221

40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?  

Code of Federal Regulations, 2010 CFR

...meeting the standards for continuous lamination/casting operations? 63.5820...lamination line and each continuous casting line complies with the applicable...continuous lamination and continuous casting lines combined, comply...

2010-07-01

222

40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?  

Code of Federal Regulations, 2013 CFR

...meeting the standards for continuous lamination/casting operations? 63.5820...lamination line and each continuous casting line complies with the applicable...continuous lamination and continuous casting lines combined, comply...

2013-07-01

223

LLNL casting technology  

NASA Astrophysics Data System (ADS)

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.

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

1994-01-01

224

LLNL casting technology  

SciTech Connect

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.

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

1994-01-01

225

Casting and Molding  

NSDL National Science Digital Library

This activity was designed for blind learners, but all types of learners can explore the process used to cast and mold molten metal, glass, and plastics. Using gelatin, the learner will work with a variety of molds to create castings. When the shapes are unmolded, the learner can tactually explore the casts.

Perkins School for the Blind

2012-06-26

226

Materials processing threshold report: 2. Use of low gravity for cast iron process development  

NASA Technical Reports Server (NTRS)

Potential applications of a low gravity environment of interest to the commercial producers of cast iron were assessed to determine whether low gravity conditions offer potential opportunities to producers for improving cast iron properties and expanding the use of cast irons. The assessment is limited to the gray and nodular types of iron, however, the findings are applicable to all cast irons. The potential advantages accrued through low gravity experiments with cast irons are described.

Frankhouser, W. L.

1980-01-01

227

Methods and apparatus for manufacturing monocrystalline cast silicon and monocrystalline cast silicon bodies for photovoltaics  

DOEpatents

Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of monocrystalline silicon may be formed that is free of, or substantially free of, radially-distributed impurities and defects and having at least two dimensions that are each at least about 35 cm is provided.

Stoddard, Nathan G

2014-01-14

228

Evaluation of Heat Checking and Washout of Heat Resistant Superalloys and Coatings for Die inserts  

SciTech Connect

This project had two main objectives: (1) To design, fabricate and run a full size test for evaluating soldering and washout in die insert materials. This test utilizes the unique capabilities of the 350 Ton Squeeze Casting machine available in the Case Meal Casting Laboratory. Apply the test to evaluate resistance of die materials and coating, including heat resistant alloys to soldering and washout damage. (2) To evaluate materials and coatings, including heat resistant superalloys, for use as inserts in die casting of aluminum alloys.

David Schwam; John F. Wallace; Yulong Zhu; Edward Courtright; Harold Adkins

2005-01-30

229

Influence of Applied Pressure on Tensile Behaviour and Microstructure of Squeeze Cast Mg Alloy AM50 with Ca Addition  

NASA Astrophysics Data System (ADS)

The development of alternative manufacturing processes is essential for the success in applying Ca-containing magnesium alloys for automotive applications due to their relatively poor die castability. Squeeze casting with its inherent advantages has been demonstrated capable of minimizing the formation of casting defects in Mg-Al-Ca alloys. In this study, the effect of applied pressures on tensile behavior and microstructure of squeeze cast Mg-5wt.%Al-1%wt.%Ca alloy (AMX501) was investigated with the applied pressure varying from 3 to 90 MPa. The results of tensile testing indicate that the tensile properties of AMX501 alloy including ultimate tensile strength, yield strength, and elongation ( E f) increase from 153.7, 80 MPa and 3.26% to 183.7, 90.5, and 5.42% with increasing applied pressure levels from 3 to 90 MPa, respectively. The analysis of true stress versus strain curves shows that an increase in applied pressure levels result in high straining hardening rates during the plastic deformation of the alloy. Microstructural analysis and density measurements indicate that, as the applied pressure increases, the porosity levels of the alloy decrease considerably, despite of almost no significant reduction in grain sizes of the squeeze cast alloys due to their high aspect ratio of cylindrical castings. Hence, the improvement in tensile properties should be primarily attributed to casting densification resulting from applied pressures. The scanning electron microscopy observation on fractured surfaces reveals that the fracture modes of the squeeze cast alloys transit to ductile from brittle with increasing applied pressures.

Zhang, Qiang; Masoumi, Mohsen; Hu, Henry

2012-01-01

230

Shrinkage Prediction for the Investment Casting of Stainless Steels  

SciTech Connect

In this study, the alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. Dimensions of the die tooling, wax pattern, and casting were measured using a Coordinate Measurement Machine in order to obtain the actual tooling allowances. The alloy dimensions were obtained from numerical simulation results of solidification, heat transfer, and deformation phenomena. The numerical simulation results for the shrinkage factors were compared with experimental results.

Sabau, Adrian S [ORNL

2007-01-01

231

Prediction of ALLOY SHRINKAGE FACTORS FOR THE INVESTMENT CASTING PROCESS  

SciTech Connect

This study deals with the experimental measurements and numerical predictions of alloy shrinkage factors (SFs) related to the investment casting process. The dimensions of the A356 aluminum alloy casting were determined from the numerical simulation results of solidification, heat transfer, fluid dynamics, and deformation phenomena. The investment casting process was carried out using wax patterns of unfilled wax and shell molds that were made of fused silica with a zircon prime coat. The dimensions of the die tooling, wax pattern, and casting were measured, in order to determine the actual tooling allowances. Several numerical simulations were carried out, to assess the level of accuracy for the casting shrinkage. The solid fraction threshold, at which the transition from the fluid dynamics to the solid dynamics occurs, was found to be important in predicting shrinkage factors (SFs). It was found that accurate predictions were obtained for all measued dimensions when the shell mold was considered a deformable material.

Sabau, Adrian S [ORNL

2006-01-01

232

DIE Deflection Modeling: Empirical Validation and Tech Transfer  

SciTech Connect

This report summarizes computer modeling work that was designed to help understand how the die casting die and machine contribute to parting plane separation during operation. Techniques developed in earlier research (8) were applied to complete a large computational experiment that systematically explored the relationship between the stiffness of the machine platens and key dimensional and structural variables (platen area covered, die thickness, platen thickness, thickness of insert and the location of the die with respect to the platen) describing the die/machine system. The results consistently show that there are many significant interactions among the variables and it is the interactions, more than the individual variables themselves, which determine the performance of the machine/die system. That said, the results consistently show that it is the stiffness of the machine platens that has the largest single impact on die separation.

R. Allen Miller

2003-05-28

233

Application of the ToxMiner Database: Network Analysis Linking the ToxCast Chemicals to Known Disease-Gene Associations  

EPA Science Inventory

The US EPA ToxCast program is using in vitro HTS (High-Throughput Screening) methods to profile and model bioactivity of environmental chemicals. The main goals of the ToxCast program are to generate predictive signatures of toxicity, and ultimately provide rapid and cost-effecti...

234

Cast aluminized explosives (review)  

Microsoft Academic Search

This paper reviews the current status and future trends of aluminized explosives. The major focus is on cast compositions,\\u000a which encompass both the melt-cast trinitrotoluene (TNT) based and the slurry cast polymer-based compositions. Widely reported\\u000a RDX and HMX based aluminized compositions with TNT used as a binder are discussed in detail. Various researchers have suggested\\u000a a 15–20% Al content as

P. P. Vadhe; R. B. Pawar; R. K. Sinha; S. N. Asthana; A. Subhananda Rao

2008-01-01

235

Anxiety reaction in children during removal of their plaster cast with a saw  

Microsoft Academic Search

e have had experience of an 18-month-old boy with a cardiomyopathy who died a few minutes after removal of his cast with a saw, apparently from a malignant cardiac arrhythmia triggered by anxiety. We therefore examined the anxiety reaction to this method of removal of a plaster cast in 20 healthy children; ten were provided with hearing protectors and ten

K. Katz; R. Fogelman; J. Attias; E. Baron; M. Soudry

2001-01-01

236

Internal adaptation of cast titanium crowns.  

PubMed

As the adaptation of titanium crowns obtained by Rematitan Plus investment, specific for titanium, is not recognized to be suitable, this study evaluated the effect of the concentration of the specific liquid and the temperature of the mold of investments on the internal misfit of crowns cast on commercially pure titanium. Individual dies of epoxy resin were obtained, representing teeth prepared for full-crown restoration with a 6-degree axial surface convergence angle and shoulder (1.0 mm). For the waxing of each crown, a ring-shaped stainless steel matrix (8.0mm internal diameter; 7.5 mm height) was adapted above the individual dies of epoxy resin. The Rematian Plus investment was mixed according to the manufacturer's instructions using two different concentrations of the specific liquid: 100%, 75%. Casting was performed in a Discovery Plasma Ar-arc vacuum-pressure casting machine with molds at temperatures of 430 degrees C, 515 degrees C and 600 degrees C. The crowns were cleaned individually in a solution (1% HF + 13% HNO3) for 10 min using a ultrasonic cleaner, with no internal adaptations, and luted with zinc phosphate cement under a 5 kg static load. The crown and die assemblies were embedded in resin and sectioned longitudinally. The area occupied by cement was observed using stereoscopic lens (10X) and measured by the Leica Qwin image analysis system (mm(2)). The data for each experimental condition (n=8) were analyzed by Kruskal-Wallis non-parametric test (á=0.05). The results showed that liquid dilution and the increase in mold temperature did not significantly influence the levels of internal fit of the cast titanium crowns. The lowest means (+/-SD) of internal misfit were obtained for the 430 degrees C/100%: (7.25 mm(2) +/-1.59) and 600 degrees C/100% (8.8 mm(2) +/-2.25) groups, which presented statistically similar levels of internal misfit. PMID:19089139

da Rocha, Sicknan Soares; Adabo, Gelson Luis; Ribeiro, Ricardo Faria; Fonseca, Renata Garcia

2007-08-01

237

Villafranca Die Kabinete und die Revolutionen.  

E-print Network

dabei. Unter der Fahne der Nationalitäten flog der Kampf gegen die alten Throne durch die Länder von den Kampf vom 24. Juni, der Sturm der Rothen gegen die gemä�igten Republikaner, der socialen Clubs gegen die Verpfändung von Arenenberg und meines Grundbesitzes in der Schweiz. Au�erdem werden Sie drei Millionen Francs

Wagner, Stephan

238

Metallic Fuel Casting Development and Parameter Optimization Simulations  

SciTech Connect

One of the advantages of metallic fuel is the abilility to cast the fuel slugs to near net shape with little additional processing. However, the high aspect ratio of the fuel is not ideal for casting. EBR-II fuel was cast using counter gravity injection casting (CGIC) but, concerns have been raised concerning the feasibility of this process for americium bearing alloys. The Fuel Cycle Research and Development program has begun developing gravity casting techniques suitable for fuel production. Compared to CGIC gravity casting does not require a large heel that then is recycled, does not require application of a vacuum during melting, and is conducive to re-usable molds. Development has included fabrication of two separate benchscale, approximately 300 grams, systems. To shorten development time computer simulations have been used to ensure mold and crucible designs are feasible and to identify which fluid properties most affect casting behavior and therefore require more characterization.

R.S. Fielding; J. Crapps; C. Unal; J.R. Kennedy

2013-03-01

239

NWIS MEASUREMENTS FOR URANIUM METAL ANNULAR CASTINGS  

SciTech Connect

This report describes measurements performed with annular uranium metal castings of different enrichments to investigate the use of {sup 252}Cf-source-driven noise analysis measurements as a means to quantify the amount of special nuclear material (SNM) in the casting. This work in FY 97 was sponsored by the Oak Ridge Y-12 Plant and the DOE Office of Technology Development Programs. Previous measurements and calculational studies have shown that many of the signatures obtained from the source-driven measurement are very sensitive to fissile mass. Measurements were performed to assess the applicability of this method to standard annular uranium metal castings at the Oak Ridge Y-12 plant under verification by the International Atomic Energy Agency (IAEA) using the Nuclear Weapons Identification System (NWIS) processor. Before the measurements with different enrichments, a limited study of source-detector-casting moderator configurations was performed to enhance the correlated information. These configurations consisted of a casting with no reflector and with various thicknesses of polyethylene reflectors up to 10.16 cm in 2.54 cm steps. The polyethylene moderator thickness of 7.62 cm was used for measurements with castings of different enrichments reported here. The sensitivity of the measured parameters to fissile mass was investigated using four castings each with a different enrichment. The high sensitivity of this measurement method to fissile mass and to other material and configurations provides some advantages over existing safeguards methods.

MATTINGLY, J.K.; VALENTINE, T.E.; MIHALCZO, J.T.

1998-03-13

240

Evaluation of Die-Attach Bonding Using High-Frequency Ultrasonic Energy for High-Temperature Application  

NASA Astrophysics Data System (ADS)

Room-temperature die-attach bonding using ultrasonic energy was evaluated on Cu/In and Cu/Sn-3Ag metal stacks. The In and Sn-3Ag layers have much lower melting temperatures than the base material (Cu) and can be melted through the heat generated during ultrasonic bonding, forming intermetallic compounds (IMCs). Samples were bonded using different ultrasonic powers, bonding times, and forces and subsequently aged at 300°C for 500 h. After aging, die shear testing was performed and the fracture surfaces were inspected by scanning electron microscopy. Results showed that the shear strength of Cu/In joints reached an upper plateau after 100 h of thermal aging and remained stable with aging time, whereas that of the Cu/Sn-3Ag joints decreased with increasing aging time. ?-Cu7In4 and (Cu,Au)11In9 IMCs were observed at the Cu/In joint, while Cu3Sn and (Ag,Cu)3Sn IMCs were found at the Cu/Sn-3Ag joint after reliability testing. As Cu-based IMCs have high melting temperatures, they are highly suitable for use in high-temperature electronics, but can be formed at room temperature using an ultrasonic approach.

Lee, Jong-Bum; Aw, Jie-Li; Rhee, Min-Woo

2014-09-01

241

Hickey, W8206, all casts Hickey, W8206, all casts, page 1  

E-print Network

Hickey, W8206, all casts Hickey, W8206, all casts, page 1 #12;Hickey, W8206, all casts Hickey, W8206, all casts, page 2 #12;Hickey, W8206, all casts Hickey, W8206, all casts, page 3 #12;Hickey, W8206, all casts Hickey, W8206, all casts, page 4 #12;Hickey, W8206, all casts Hickey, W8206, all casts, page

Hickey, Barbara

242

Cast Metals Coalition Technology Transfer and Program Management Final Report  

SciTech Connect

The Cast Metals Coalition (CMC) partnership program was funded to ensure that the results of the Department of Energy's (DOE) metalcasting research and development (R&D) projects are successfully deployed into industry. Specifically, the CMC program coordinated the transfer and deployment of energy saving technologies and process improvements developed under separately funded DOE programs and projects into industry. The transition of these technologies and process improvements is a critical step in the path to realizing actual energy savings. At full deployment, DOE funded metalcasting R&D results are projected to save 55% of the energy used by the industry in 1998. This closely aligns with DOE's current goal of driving a 25% reduction in industrial energy intensity by 2017. In addition to benefiting DOE, these energy savings provide metalcasters with a significant economic advantage. Deployment of already completed R&D project results and those still underway is estimated to return over 500% of the original DOE and industry investment. Energy savings estimates through December 2008 from the Energy-Saving Melting and Revert Reduction Technology (E-SMARRT) portfolio of projects alone are 12 x 1012 BTUs, with a projection of over 50 x 1012 BTUs ten years after program completion. These energy savings and process improvements have been made possible through the unique collaborative structure of the CMC partnership. The CMC team consists of DOE's Office of Industrial Technology, the three leading metalcasting technical societies in the U.S: the American Foundry Society; the North American Die Casting Association; and the Steel Founders Society of America; and the Advanced Technology Institute (ATI), a recognized leader in distributed technology management. CMC provides collaborative leadership to a complex industry composed of approximately 2,100 companies, 80% of which employ less than 100 people, and only 4% of which employ more than 250 people. Without collaboration, new technologies enabling energy efficiencies and environment-friendly improvements are slow to develop, and have trouble obtaining a broad application. The CMC team was able to effectively and efficiently transfer the results of DOE's metalcasting R&D projects to industry by utilizing and delivering the numerous communication vehicles identified in the proposal. The three metalcasting technical associations achieved significant technology transition results under this program. In addition to reaching over 23,000 people per year through Modern Casting and 28,000 through Engineered Casting Solutions, AFS had 84 national publications and reached over 1,200 people annually through Cast Metals Institute (CMI) education courses. NADCA's education department reached over 1,000 people each year through their courses, in addition to reaching over 6,000 people annually through Die Casting Engineer, and publishing 58 papers. The SFSA also published 99 research papers and reached over 1,000 people annually through their member newsletters. In addition to these communication vehicles, the CMC team conducted numerous technical committee meetings, project reviews, and onsite visits. All of these efforts to distribute the latest metalcasting technologies contributed to the successful deployment of DOE's R&D projects into industry. The DOE/CMC partnership demonstrated significant success in the identification and review of relevant and easy-to-implement metalcasting energy-saving processes and technologies so that the results are quickly implemented and become general practice. The results achieved in this program demonstrate that sustained technology transfer efforts are a critical step in the deployment of R&D projects to industry.

Gwyn, Mike

2009-03-31

243

Application of Rapid Prototyping to the Investment Casting of Test Hardware (MSFC Center Director's Discretionary Fund Final Report, Project No. 98-08)  

NASA Technical Reports Server (NTRS)

Investment casting masters of a selected propulsion hardware component, a fuel pump housing, were rapid prototyped on the several processes in-house, along with the new Z-Corp process acquired through this project. Also, tensile samples were prototyped and cast using the same significant parameters. The models were then shelled in-house using a commercial grade zircon-based slurry and stucco technique. Next, the shelled models were fired and cast by our in-house foundry contractor (IITRI), with NASA-23, a commonly used test hardware metal. The cast models are compared by their surface finish and overall appearance (i.e., the occurrence of pitting, warping, etc.), as well as dimensional accuracy.

Cooper, K. G.; Wells, D.

2000-01-01

244

75 FR 71456 - Algonac Cast Products, Inc., Algonac, MI; Notice of Affirmative Determination Regarding...  

Federal Register 2010, 2011, 2012, 2013

...Employment and Training Administration [TA-W-74,549] Algonac Cast Products, Inc., Algonac, MI; Notice of Affirmative Determination...Assistance (TAA) applicable to workers and former workers of Algonac Cast Products, Inc., Algonac, Michigan (subject firm)....

2010-11-23

245

Mechanisms of stabilization of earthworm casts and artificial casts  

Microsoft Academic Search

Fresh casts were collected from the earthworm species Aporrectodea caliginosa, and artificial casts were also made. The casts were subjected to ageing, drying-rewetting, and sterilization by hexanol vapour. Clay dispersion was determined, as a measure of the lack of stability of the casts. Two soils were used, the topsoil of a recently reclaimed polder soil in the Netherlands and the

J. C. Y. Marinissen; A. R. Dexter

1990-01-01

246

Die Medien in Mittelosteuropa  

Microsoft Academic Search

\\u000a In den mittelosteuropäischen Staaten beklagen sich die einheimischen Journalisten weniger über ihren mangelnden Einfluss auf\\u000a Politik und Gesellschaft als über die auch inhaltliche Dominanz westeuropäischer Medienkonzerne. Was in Rumänien die WAZ,\\u000a ist in Tschechien die Verlagsgruppe Passau. 85 Prozent des Medienmarktes in Osteuropa wird von ausländischem Kapital kontrolliert,\\u000a darunter drei Viertel von deutschem Kapital. Dabei wird gerne gefragt, wie die

Marc Stegherr; Kerstin Liesem

247

Thermal fatigue of materials for die-casting tooling  

Microsoft Academic Search

This research is conducted to study the thermal fatigue resistance of different hot-work tool steels; AISI H11 and H13, special tool steel and 18% Ni maraging steel. The maraging steel is surface cladded by GTA welding to study the thermal fatigue resistance of surface layer. An influence of mechanical and microstructural properties on thermal fatigue resistance is evaluated. An innovative

D. Klob?ar; J. Tušek; B. Taljat

2008-01-01

248

Vitamin E in cardiovascular disease: has the die been cast?  

PubMed

Cardiovascular disease, in particular coronary artery disease (CAD), remains the most important cause of morbidity and mortality in developed countries and, in the near future, more so in the developing world. Atherosclerotic plaque formation is the underlying basis for CAD. Growth of the plaque leads to coronary stenosis, causing a progressive decrease in blood flow that results in angina pectoris. Acute myocardial infarction and unstable angina were recently recognised as related to plaque rupture, not progressive coronary stenosis. Acute thrombus formation causes an abrupt coronary occlusion. The characteristics of the fibrin cap, contents of the plaque, rheological factors and active inflammation within the plaque contribute to plaque rupture. Oxidative processes are important in plaque formation. Oxidized low density lipoproteins (LDL) but not unoxidized LDL is engulfed by resident intimal macrophages, transforming them into foam cells which develop into fatty streaks, the precursors of the atherosclerotic plaque. Inflammation is important both in plaque formation and rupture. Animal studies have shown that antioxidants reduce plaque formation and lead to plaque stabilisation. In humans, high intakes of antioxidants are associated with lower incidence of CAD, despite high serum cholesterol levels. This observation suggests a role for inflammation in CAD and that reducing inflammation using antioxidants may ameliorate these processes. Men and women with high intakes of vitamin E were found to have less CAD. Vitamin E supplementation was associated with a significant reduction in myocardial infarction and cardiovascular events in the incidence of recurrent myocardial infarction. In the hierarchy of evidence in evidence-based medicine, data from large placebo-controlled clinical trials is considered necessary. Results from various mega-trials have not shown benefits (nor adverse effects) conferred by vitamin E supplementation, suggesting that vitamin E has no role in the treatment of CAD. These results do not seem to confirm, at the clinical level, the effect of antioxidants against active inflammation during plaque rupture. However, a closer examination of these studies showed a number of limitations, rendering them inconclusive in addressing the role of vitamin E in CAD prevention and treatment. Further studies that specifically address the issue of vitamin E in the pathogenesis of atherosclerosis and in the treatment of CAD need be performed. These studies should use the more potent antioxidant property of alpha-tocotrienol vitamin E. PMID:12492632

Yusoff, Khalid

2002-01-01

249

Application of in situ thermography for evaluating the high-cycle and very high-cycle fatigue behaviour of cast aluminium alloy AlSi7Mg (T6).  

PubMed

The present paper illustrates the application of infrared thermal measurements for the investigation of crack initiation point and crack propagation in the high-cycle and the very high-cycle fatigue range of cast AlSi7Mg alloy (A356). The influence of casting defects, their location, size and amount was studied both by fractography and thermography. Besides internal and surface fatigue crack initiation as a further crack initiation type multiple fatigue crack initiation was observed via in situ thermography which can be well correlated with the results from fractography obtained by SEM investigations. In addition, crack propagation was studied by the development of the temperature measured via thermography. Moreover, the frequency influence on high-cycle fatigue behaviour was investigated. The presented results demonstrate well that the combination of fractography and thermography can give a significant contribution to the knowledge of crack initiation and propagation in the VHCF regime. PMID:23541962

Krewerth, D; Weidner, A; Biermann, H

2013-12-01

250

Newly developed magnesium alloys for powertrain applications  

Microsoft Academic Search

Several new magnesium alloys have been developed recently for high-temperature applications to obtain an optimal combination\\u000a of die cast-ability, creep resistance, mechanical properties, corrosion performance, and affordability. Unfortunately, it\\u000a is difficult to achieve an adequate combination of properties and, in fact, most of the new alloys can only partially meet\\u000a the required performance and cost. The ZE41 alloy, which is

E. Aghion; B. Bronfín; F. Von Buch; S. Schumann; H. Friedrich

2003-01-01

251

Method of casting aerogels  

DOEpatents

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.

Poco, J.F.

1993-09-07

252

Method of casting aerogels  

DOEpatents

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.

Poco, John F. (Livermore, CA)

1993-01-01

253

A Winning Cast  

NASA Technical Reports Server (NTRS)

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.

2001-01-01

254

Casting the Die before the Die Is Cast: The Importance of the Home Numeracy Environment for Preschool Children  

ERIC Educational Resources Information Center

Mathematical competencies are important not only for academic achievement at school but also for professional success later in life. Although we know a lot about the impact of "Home Literacy Environment" on the development of early linguistic competencies, research on "Home Numeracy Environment" (HNE) and the assessment of its…

Niklas, Frank; Schneider, Wolfgang

2014-01-01

255

Neutron radiography inspection of investment castings.  

PubMed

Investment casting, also known as the lost wax process, is a manufacturing method employed to produce near net shape metal articles. Traditionally, investment casting has been used to produce structural titanium castings for aero-engine applications with wall thickness less than 1 in (2.54 cm). Recently, airframe manufacturers have been exploring the use of titanium investment casting to replace components traditionally produced from forgings. Use of titanium investment castings for these applications reduces weight, cost, lead time, and part count. Recently, the investment casting process has been selected to produce fracture critical structural titanium airframe components. These airframe components have pushed the traditional inspection techniques to their physical limits due to cross sections on the order of 3 in (7.6 cm). To overcome these inspection limitations, a process incorporating neutron radiography (n-ray) has been developed. In this process, the facecoat of the investment casting mold material contains a cocalcined mixture of yttrium oxide and gadolinium oxide. The presence of the gadolinium oxide, allows for neutron radiographic imaging (and eventual removal and repair) of mold facecoat inclusions that remain within these thick cross sectional castings. Probability of detection (POD) studies have shown a 3 x improvement of detecting a 0.050 x 0.007 in2 (1.270 x 0.178 mm2) inclusion of this cocalcined material using n-ray techniques when compared to the POD using traditional X-ray techniques. Further, it has been shown that this n-ray compatible mold facecoat material produces titanium castings of equal metallurgical quality when compared to the traditional materials. Since investment castings can be very large and heavy, the neutron radiography facilities at the University of California, Davis McClellan Nuclear Radiation Center (UCD/MNRC) were used to develop the inspection techniques. The UCD/MNRC has very unique facilities that can handle large parts up to 39 ft (12 m) in length and 13 ft (4 m) high weighing up to 5000 lbs (2300 kg). These handling systems are robotically driven. The neutron radiographic system consists of a highly thermalized neutron beam. The neutron beam has an intensity of 5.6 x 10(6) n/cm2 s, with a L/D = 200 at a power of 2 MW. A divergent beam collimator is used which provides a beam of approximately 22 in (56 cm) in diameter at the film plane. A vacuum cassette with a gadolinium vapor deposited screen is used to collect the image. Exposure times can be as short as 3 min, or up to 30 min. PMID:15246417

Richards, W J; Barrett, J R; Springgate, M E; Shields, K C

2004-10-01

256

Control design and implementation in continuous steel casting  

Microsoft Academic Search

Accurate control of the mold level in continuous casting is believed to be a key factor in improving the quality of the cast product. This paper describes an application of advanced control to this problem leading to a complete recommissioning of the mold level control system. Careful physical modeling identified smooth as well as nonsmooth nonlinearities in the process. Three

S. F. Graebe; G. C. Goodwin; G. Elsley

1995-01-01

257

Reaction synthesis of carbide-reinforced cast iron  

Microsoft Academic Search

Cast irons have found widespread uses as a result of their comparative low cost and their diversity of engineering properties. The low coefficient of friction of grey cast iron has led to its use in applications involving sliding surfaces such as piston rings, cylinder bores and brake discs in the automotive industry. Good sliding wear resistance is therefore one of

A. Chrysanthou; N. W. Davies; J. Li; P. Tsakiropoulos; O. S. Chinyamakobvu

1996-01-01

258

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

DOEpatents

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.

Johnson, Robert Alan (Simpsonville, SC); Schaeffer, Jon Conrad (Greenville, SC); Lee, Ching-Pang (Cincinnati, OH); Abuaf, Nesim (Lincoln City, OR); Hasz, Wayne Charles (Pownal, VT)

2002-01-01

259

Displaced capillary dies  

DOEpatents

An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.

Kalejs, Juris P. (Wellesley, MA); Chalmers, Bruce (Falmouth, MA); Surek, Thomas (Englewood, CO)

1982-01-01

260

Displaced capillary dies  

DOEpatents

An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.

Kalejs, Juris P. (Wellesley, MA); Chalmers, Bruce (Falmouth, MA); Surek, Thomas (Englewood, CO)

1984-01-01

261

Extending the Derek-Meteor Workflow to Predict Chemical-Toxicity Space Impacted by Metabolism: Application to ToxCast and Tox21 Chemical Inventories  

EPA Science Inventory

A central aim of EPA?s ToxCast project is to use in vitro high-throughput screening (HTS) profiles to build predictive models of in vivo toxicity. Where assays lack metabolic capability, such efforts may need to anticipate the role of metabolic activation (or deactivation). A wo...

262

Application of Targeted Functional Assays to Assess a Putative Vascular Disruption Developmental Toxicity Pathway Informed By ToxCast High-Throughput Screening Data  

EPA Science Inventory

Chemical perturbation of vascular development is a putative toxicity pathway which may result in developmental toxicity. EPA?s high-throughput screening (HTS) ToxCast program contains assays which measure cellular signals and biological processes critical for blood vessel develop...

263

Cheminformatics Analysis of EPA ToxCast Chemical Libraries to Identify Domains of Applicability for Predictive Toxicity Models and Prioritize Compounds for Toxicity Testing  

EPA Science Inventory

An important goal of toxicology research is the development of robust methods that use in vitro and chemical structure information to predict in vivo toxicity endpoints. The US EPA ToxCast program is addressing this goal using ~600 in vitro assays to create bioactivity profiles o...

264

Die soldering: Mechanism of the interface reaction between molten aluminum alloy and tool steel  

Microsoft Academic Search

Die soldering is the result when molten aluminum sticks to the surface of the die material and remains there after the ejection\\u000a of the part; it results in considerable economic and production losses in the casting industry, and is a major quality detractor.\\u000a In order to alleviate or mitigate die soldering, one must have a thorough understanding of the mechanism

Sumanth Shankar; Diran Apelian

2002-01-01

265

Die Coin Experiment  

NSDL National Science Digital Library

This resource consists of a Java applet and expository text. The applet simulates the experiment of rolling a die and then tossing a coin the number of times shown on the die. The die distribution and the probability of heads can be specified. The applet illustrates a two-stage experiment.

Siegrist, Kyle

266

Es lebe die Unverfrorenheit !\\  

Microsoft Academic Search

uber seine physikalische Interpr etation einer harmlos aus- sehenden, von ihn selbst zuvor aufgestellten Formel, die das spektrale Verhalten der sogenannten Warmestrahlung beschreibt. Maßgeblich durch das Eingreifen Albert Einsteins entwickelte sich daraus im folgenden Vierteljahrhundert eine fundamentale Krise der Physik, die dann in einer wissenschaftlichen Revolution großten Ausmaßes mundete: der Quantentheorie. Die Quantentheorie entwickelte sich von Anfang an diametral gegen

Domenico Giulini

267

Die Beratung der Gesellschaft  

Microsoft Academic Search

I. Es gibt viele strukturelle Eigenschaften, die die heraufziehende und von Manuel Castells und Niklas Luhmann diagnostizierte Computergesellschaft mit früheren Gesellschaften teilt. Das kann auch nicht weiter verwundern, denn die Gesellschaft ist, mit einem Begriff der Biologie, eine Einmalerfindung, deren basaler Formalismus derselbe bleibt, auch wenn er sich in den ver- schiedenen Epochen der oralen Stammesgesellschaft, der literalen Hochkultur, der

Dirk Baecker

268

Cast shadow segmentation using invariant color features  

Microsoft Academic Search

Shadows are integral parts of natural scenes and one of the elements contributing to nat- uralness of synthetic scenes. In many image analysis and interpretation applications, shadows interfere with fundamental tasks such as object extraction and description. For this reason, shadow segmentation is an important step in image analysis. In this paper, we propose a new cast shadow segmentation algorithm

Elena Salvador; Andrea Cavallaro; Touradj Ebrahimi

2004-01-01

269

Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings  

Microsoft Academic Search

Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D

L. Bichler; C. Ravindran

2010-01-01

270

Strain Rate Dependency of Bronze Metal Matrix Composite Mechanical Properties as a Function of Casting Technique  

Microsoft Academic Search

Strain rate dependency of mechanical properties of tungsten carbide (WC)-filled bronze castings fabricated by centrifugal and sedimentation-casting techniques are examined, in this study. Both casting techniques are an attempt to produce a functionally graded material with high wear resistance at a chosen surface. Potential applications of such materials include shaft bushings, electrical contact surfaces, and brake rotors. Knowledge of strain

Lloyd Brown; Peter Joyce; Joshua Radice; Dro Gregorian; Michael Gobble

2011-01-01

271

The effect of Sr and Fe additions on the microstructure and mechanical properties of a direct squeeze cast Al-7Si-0.3Mg alloy  

SciTech Connect

This article describes the results of an investigation into the microstructure and mechanical properties of a gravity die cast and direct squeeze cast LM25 alloy (Al-7Si-0.3Mg-0.3Fe). The direct squeeze cast LM25 alloy has superior mechanical properties compared to the gravity die cast LM25 alloy, especially with regard to ductility, which is increased from {approximately}1.7 pct for the gravity die cast LM25 alloy to {approximately}8.0 pct for the direct squeeze cast LM25 alloy in the T6 heat-treated conditions. This increase in ductility is due to (1) the removal of porosity, (2) a decrease in Si particle size, and (3) a refinement of the Fe-Si-aluminide particles. High cooling rates in direct squeeze casting result in quench modification of the Si particles, such that chemical modification with Sr or Na may not be required. In addition, direct squeeze casting is more tolerant of Fe impurities in the alloy, due to the formation of smaller Fe-Si-aluminide particles than those in gravity die cast material. The direct squeeze cast LM25 + Fe alloy (Al-7Si-0.3Mg-1.0Fe) has a ductility of {approximately}6.5 pct, compared to that of {approximately}0.5 pct for the gravity die cast LM25 + Fe alloy in the T6 heat-treated condition. This increase in tolerance to Fe impurities can lead to a substantial reduction in manufacturing costs due to (1) reduced raw-material costs, (2) reduced die sticking, and (3) improved die life.

Dong, J.X.; Karnezis, P.A.; Durrant, G.; Cantor, B. [Univ. of Oxford (United Kingdom). Dept. of Materials

1999-05-01

272

(silicon die) Die block A B  

E-print Network

, Coupled Logic) NMOS CMOS µ µ 4 ULSI VLSI µ () MOS (Metal, Oxide Semiconductor) ) (Complimentary MOS block A B Die #12; µ µ 3 #12;VLSI LSI MSI SSI TTL (Transistor, Transistor Logic) ECL (Emitter

Kavousianos, Xrysovalantis

273

Composites for Advanced Space Transportation Systems (CASTS)  

NASA Technical Reports Server (NTRS)

A summary is given of the in-house and contract work accomplished under the CASTS Project. In July 1975 the CASTS Project was initiated to develop graphite fiber/polyimide matrix (GR/PI) composite structures with 589K (600 F) operational capability for application to aerospace vehicles. Major tasks include: (1) screening composites and adhesives, (2) developing fabrication procedures and specifications, (3) developing design allowables test methods and data, and (4) design and test of structural elements and construction of an aft body flap for the Space Shuttle Orbiter Vehicle which will be ground tested. Portions of the information are from ongoing research and must be considered preliminary. The CASTS Project is scheduled to be completed in September 1983.

Davis, J. G., Jr. (compiler)

1979-01-01

274

TiC reinforced cast chromium steels  

SciTech Connect

A series of new titanium carbide reinforced cast chromium steels were developed for wear applications. Objective of the program was to enhance wear resistant alloys and, if possible, improve mechanical properties. The new steels which were melted in a vacuum induction furnace contained 12 Cr, 3-5 Ti, 1-2 C in weight percent. Alloying with Ti changed the precipitate microstructure from Cr carbide to TiC dispersed in a martensitic matrix. Yield strength and impact resistance improved with Ti alloying. Wear rates of the cast Cr/TiC steels, (determined from high- and low-stress abrasion tests, erosion test, and scratch tests) were generally lower than both the as-cast and heat-treated AISI type 440°C steel and were often further reduced by increasing the Ti alloy concentration. The exceptions were the erosion test for which all materials had similar wear rate.

Dogan, Omer N.; Rawers, James C.; Hawk, Jeffrey A.; Schrems, Karol K.

2003-11-01

275

Villafranca Die Kabinete und die Revolutionen.  

E-print Network

Carl heirathen könnte, obschon sie doch wei�, da� er es war, der ihr den Leutnant in der um Rahel oder der Ritter von der feurigen Rose um die schöne Kunijundes von der Blutburg?« »Ich kenn's nich leidet. Aber ich wei� mehr als sie Alle!« »Woher?« Die Frau war etwas verlegen und wandte den Kopf

Prodinger, Helmut

276

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

277

Hickey, C8206_all casts Hickey, C8206_all casts, page 1  

E-print Network

Hickey, C8206_all casts Hickey, C8206_all casts, page 1 #12;Hickey, C8206_all casts Hickey, C8206_all casts, page 2 #12;Hickey, C8206_all casts Hickey, C8206_all casts, page 3 #12;Hickey, C8206_all casts Hickey, C8206_all casts, page 4 #12;Hickey, C8206_all casts Hickey, C8206_all casts, page 5 #12

Hickey, Barbara

278

Application of X-ray microtomography to study the influence of the casting microstructure upon the tensile behaviour of an Al-Si alloy  

NASA Astrophysics Data System (ADS)

In cast aluminium alloys used in the automotive industry the microstructure inherited from the foundry process has a strong influence on the mechanical properties. In the cylinder heads produced by the Lost Foam Casting process, the microstructure consists of hard intermetallic phases and large gas and microshrinkage pores. To study its influence, full field measurements at the microstructure scale were performed during a tensile test performed in situ under X-ray microtomography. Intermetallics were used as a natural speckle pattern. Feasibility of Digital Volume Correlation on this alloy was proved and the accuracy of the measurement was assessed and discussed in light of the small volume fraction of intermetallics and in comparison with the accuracy of Digital Image Correlation performed on optical images at a finer spatial resolution.

Limodin, Nathalie; El Bartali, Ahmed; Wang, Long; Lachambre, Joël; Buffiere, Jean-Yves; Charkaluk, Eric

2014-04-01

279

Composite Materials Processing of Cast Iron and Ceramics Using Compo-Casting Technology  

NASA Astrophysics Data System (ADS)

The compo-casting technology of ceramics and cast iron is expected to be one of the major casting technologies that can expand the application fields of cast iron. This technique allows the heat energy of the molten metal to be utilized to produce cast iron products which are added with functions of ceramic materials. The largest problem in compo-casting technology is generation of cracks caused by thermal shock. Although this crack generation can be prevented by reducing the thermal stress by means of preheating ceramics, the necessary preheating temperature is considerably high and its precise controlling is difficult at the practical foundry working sites. In this study, we tried to numerically predict the critical preheating temperature of ceramics using the thermal stress analysis in unsteady heat transfer and the Newman's diagram, and found that the preheating of ceramics to reduce thermal stress could be substituted with placing an appropriate cast iron cover around the ceramics. Excellent results were obtained by using a method whereby a ceramic bar was covered with a flake graphite cast iron cover and fixed in a sand mold and then molten metal was poured. Then, two or three ceramics were examined at the same time under the compocasting condition. As a result, three specimens could be done at the same time by adjusting the cover space to 15mm. Moreover, irregular shape ceramics were examined under the compocasting condition. As a result, the compocasting could be done by devising the cover shape. In each condition, it was confirmed that the cover shape made from the analytical result was effective to the compocasting by doing the thermometry of the specimens.

Tomita, Yoshihiro; Sumimoto, Haruyoshi

280

Ohno continuous casting  

Microsoft Academic Search

Production of net-shape products directly from the liquid is an attractive manufacturing route for alloys that are difficult to process or that cannot be rolled, drawn, or extruded. Developed at the Chiba Institute of Technology in Japan, the Ohno Continuous Casting (OCC) approach not only provides significant cost savings, but also has the potential to create new products. OCC process

H. Soda; A. McLean; G. Motoyasu; A. Ohno

1995-01-01

281

Extrusion cast explosive  

DOEpatents

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.

Scribner, Kenneth J. (Livermore, CA)

1985-01-01

282

Casting and Angling.  

ERIC Educational Resources Information Center

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…

Smith, Julian W.

283

Mix/Cast Contamination Control  

NASA Technical Reports Server (NTRS)

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.

Wallentine, M.

2005-01-01

284

Usefulness of gel-casting method in the fabrication of nonstoichiometric CaZrO{sub 3}-based electrolytes for high temperature application  

SciTech Connect

Hydrogels obtained from lower toxicity monomers of N-(hydroxymethyl)acrylamide and N,N'-methylenebisacrylamide were applied to form nonstoichiometric CaZrO{sub 3}-based electrolytes. A coprecipitation-calcination method with ((NH{sub 4}){sub 2}C{sub 2}O{sub 4}) in concentrated NH{sub 3} aqueous solution was used to synthesise CaZrO{sub 3} involving 51 mol.% CaO (CZ-51) powder. The gas-tight CaZrO{sub 3}-based rods were prepared by the gel-casting method with 45 vol.% suspension and then sintered at 1500 deg. C-2 h. It was found that in low oxygen partial pressure, the nonstoichiometric CaZrO{sub 3} obtained by gel-casting method were pure oxide ion conductors. These samples exhibited comparable electrical conductivity values to isostatically compressed pellets starting from the same powder. The results of experiments on thermochemical stability of CZ-51 gel-cast shapes at high temperatures in air or gas mixtures involving 2-50 vol.% H{sub 2}, as well as the corrosion resistance in exhaust gases from a self-ignition engine were also presented and discussed. The thermal resistance of CaZrO{sub 3} obtained rods against molten nickel or iron was also examined. Based upon these investigations, it is evident that only in hydrogen-rich gas atmospheres can the stability of CaZrO{sub 3} shapes be limited due to the presence of CaO precipitation as a second phase. The nonstoichiometric CaZrO{sub 3} (CZ-51) gel-cast materials were also tested in solid galvanic cells, designed to study thermodynamic properties of oxide materials, important for SOFC and energy technology devices. In this way, the Gibbs energy of NiM{sub 2}O{sub 4}, M = Cr, Fe, at 650-1000 deg. C was determined. The CaZrO{sub 3} involving 51 mol.% CaO gel-cast sintered shapes seems to be promising solid electrolytes for electrochemical oxygen probes in control of metal processing and thermodynamic studies of materials important for the development of the energy industry.

Dudek, Magdalena [AGH - University of Science and Technology, Faculty of Energy and Fuels, 30-059 Cracow (Poland)

2009-09-15

285

DIE BEDEUTUNG DER REBEN (VITIS spp.) ALS POLLENSPENDER FR DIE HONIGBIENE  

E-print Network

DIE BEDEUTUNG DER REBEN (VITIS spp.) ALS POLLENSPENDER FÃ?R DIE HONIGBIENE (APIS MELLIFICA) L.) It was possible to document in various manners that vine flowers are visited by honey- bees : 1. by proving Vitis-pollen in the body hair and the alimentary canal of bees which had been killed by application of pesticides

Paris-Sud XI, Université de

286

Die singulation method  

DOEpatents

A method is disclosed for singulating die from a semiconductor substrate (e.g. a semiconductor-on-insulator substrate or a bulk silicon substrate) containing an oxide layer (e.g. silicon dioxide or a silicate glass) and one or more semiconductor layers (e.g. monocrystalline or polycrystalline silicon) located above the oxide layer. The method etches trenches through the substrate and through each semiconductor layer about the die being singulated, with the trenches being offset from each other around at least a part of the die so that the oxide layer between the trenches holds the substrate and die together. The trenches can be anisotropically etched using a Deep Reactive Ion Etching (DRIE) process. After the trenches are etched, the oxide layer between the trenches can be etched away with a HF etchant to singulate the die. A release fixture can be located near one side of the substrate to receive the singulated die.

Swiler, Thomas P [Albuquerque, NM; Garcia, Ernest J [Albuquerque, NM; Francis, Kathryn M [Rio Rancho, NM

2014-01-07

287

Reinraumtechnik für die Medizintechnik  

NASA Astrophysics Data System (ADS)

Die Reinraumtechnik ist heute ein unverzichtbarer Bestandteil bei der Fertigung von Produkten der Life Sciences, den Bereichen Pharma, Lebensmittel, Kosmetik und Medizintechnik. In Anbetracht der langen Historie der Medizintechnik ist sie jedoch eine sehr junge Disziplin. Die Bedeutung von Keimen und die richtige Einschätzung ihrer Größe wurden zwar sehr früh bereits durch Paracelsus erkannt, jedoch wurden daraus noch keine speziellen oder kontinuierlich umgesetzten Hygienevorschriften abgeleitet. Die erste bekannte technische Umsetzung von Hygieneempfehlungen geht auf den Franzosen François Nicolas Appert zurück, der eine aseptische Abfüllmethode für Lebensmittel entwickelte und diese 1810 veröffentlichte [1]. Die erste dokumentierte medizinische Umsetzung stellten Hygienevorschriften für Ärzte dar, die Ignaz Philipp Semmelweis nach 1847 in der Wiener Klinik für Geburtshilfe einführte [2].

Petek, Max; Jungbluth, Martin; Krampe, Erhard

288

Die singulation method  

DOEpatents

A method is disclosed for singulating die from a semiconductor substrate (e.g. a semiconductor-on-insulator substrate or a bulk silicon substrate) containing an oxide layer (e.g. silicon dioxide or a silicate glass) and one or more semiconductor layers (e.g. monocrystalline or polycrystalline silicon) located above the oxide layer. The method etches trenches through the substrate and through each semiconductor layer about the die being singulated, with the trenches being offset from each other around at least a part of the die so that the oxide layer between the trenches holds the substrate and die together. The trenches can be anisotropically etched using a Deep Reactive Ion Etching (DRIE) process. After the trenches are etched, the oxide layer between the trenches can be etched away with an HF etchant to singulate the die. A release fixture can be located near one side of the substrate to receive the singulated die.

Swiler, Thomas P.; Garcia, Ernest J.; Francis, Kathryn M.

2013-06-11

289

Extrusion die and method  

DOEpatents

A method and die apparatus for manufacturing a honeycomb body of rhombic cell cross-section by extrusion through an extrusion die of triangular cell discharge slot configuration, the die incorporating feedholes at selected slot intersections only, such that slot segments communicating directly with the feedholes discharge web material and slot segments not so connected do not discharge web material, whereby a rhombic cell cross-section in the extruded body is provided.

Lipp, G. Daniel (Painted Post, NY)

1994-04-26

290

Energy Saving Melting andRevert Reduction Technology (E0SMARRT): Predicting Pattern Tooling and Casting Dimension for Investment Casting  

SciTech Connect

The investment casting process is an expendable mold process where wax patterns of the part and rigging are molded, assembled, shelled and melted to produce a ceramic mold matching the shape of the component to be cast. Investment casting is an important manufacturing method for critical parts because of the ability to maintain dimensional shape and tolerances. However, these tolerances can be easily exceeded if the molding components do not maintain their individual shapes well. In the investment casting process there are several opportunities for the final casting shape to not maintain the intended size and shape, such as shrinkage of the wax in the injection tool, the modification of the shape during shell heating, and with the thermal shrink and distortion in the casting process. Studies have been completed to look at the casting and shell distortions through the process in earlier phases of this project. Dr. Adrian Sabau at Oak Ridge National Labs performed characterizations and validations of 17-4 PH stainless steel in primarily fused silica shell systems with good agreement between analysis results and experimental data. Further tasks provided material property measurements of wax and methodology for employing a viscoelastic definition of wax materials into software. The final set of tasks involved the implementation of the findings into the commercial casting analysis software ProCAST, owned and maintained by ESI Group. This included: o the transfer of the wax material property data from its raw form into separate temperature-dependent thermophysical and mechanical property datasets o adding this wax material property data into an easily viewable and modifiable user interface within the pre-processing application of the ProCAST suite, namely PreCAST o and validating the data and viscoelastic wax model with respect to experimental results

Nick Cannell; Dr. Mark Samonds; Adi Sholapurwalla; Sam Scott

2008-11-21

291

Hickey, TT162, Casts 2-5 Hickey, TT162, Casts 2-5, page 1  

E-print Network

Hickey, TT162, Casts 2-5 Hickey, TT162, Casts 2-5, page 1 CTD002 #12;Hickey, TT162, Casts 2-5 Hickey, TT162, Casts 2-5, page 2 CTD002 #12;Hickey, TT162, Casts 2-5 Hickey, TT162, Casts 2-5, page 3 CTD002 #12;Hickey, TT162, Casts 2-5 Hickey, TT162, Casts 2-5, page 4 CTD002 #12;Hickey, TT162, Casts 2

Hickey, Barbara

292

Hickey, TT162, casts 6-7 Hickey, TT162, casts 6-7, page 1  

E-print Network

CTD006 Hickey, TT162, casts 6-7 Hickey, TT162, casts 6-7, page 1 #12;CTD006 Hickey, TT162, casts 6-7 Hickey, TT162, casts 6-7, page 2 #12;CTD006 Hickey, TT162, casts 6-7 Hickey, TT162, casts 6-7, page 3 #12;CTD006 Hickey, TT162, casts 6-7 Hickey, TT162, casts 6-7, page 4 #12;CTD006 Hickey, TT162, casts 6

Hickey, Barbara

293

Hickey, TT136, casts 3-5 Hickey, TT136, casts 3-5, page 1  

E-print Network

Hickey, TT136, casts 3-5 Hickey, TT136, casts 3-5, page 1 CTD003 #12;Hickey, TT136, casts 3-5 Hickey, TT136, casts 3-5, page 2 CTD003 #12;Hickey, TT136, casts 3-5 Hickey, TT136, casts 3-5, page 3 CTD003 #12;Hickey, TT136, casts 3-5 Hickey, TT136, casts 3-5, page 4 CTD003 #12;Hickey, TT136, casts 3

Hickey, Barbara

294

Hickey, TT136, casts 6-10 Hickey, TT136, casts 6-10, page 1  

E-print Network

Hickey, TT136, casts 6-10 Hickey, TT136, casts 6-10, page 1 CTD006 #12;Hickey, TT136, casts 6-10 Hickey, TT136, casts 6-10, page 2 CTD006 #12;Hickey, TT136, casts 6-10 Hickey, TT136, casts 6-10, page 3 CTD006 #12;Hickey, TT136, casts 6-10 Hickey, TT136, casts 6-10, page 4 CTD006 #12;Hickey, TT136, casts

Hickey, Barbara

295

USGS CoreCast  

NSDL National Science Digital Library

Just about everyone seems to be creating a podcast these days, and a number of government agencies have entered the fray as of late. The United States Geological Survey recently decided to hang out their own podcast shingle, and the results of their labors can be explored here. The site states that their "CoreCast" is "natural science from the inside out", which seems like an appropriate label. The podcasts range in length from two to fifteen minutes, and they cover topics such as polar bear research, sex-changing fish, and climate change. One podcast that shouldn't be overlooked is "This Episode of CoreCast is Highly Questionable". In a mere three minutes, host Scott Horvath responds to a number of questions in an engaging fashion. After listening to an episode or two, visitors will probably want to sign up to receive email updates about new episodes.

296

Volume MLS ray casting.  

PubMed

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

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

2008-01-01

297

Extrusion cast explosive  

DOEpatents

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.

Scribner, K.J.

1985-01-29

298

Extrusion cast explosive  

DOEpatents

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.

Scribner, K.J.

1985-11-26

299

Die Darwinsche Theorie und die Eukaryoten  

E-print Network

Geologe Charles Darwin 1859 in der Darwin Theorie. 6.1 Die Darwin-Theorie der Evolution Lebewesen kämpfen Darwin-Theorie zugrunde liegt, bereits in der präbiotischen Welt. Dort trägt es zur chemischen Evolution eine gewaltige Evolution statt. Diese Entwicklung des Lebens beschrieb der englische Biologe und

Ulmschneider, Peter

300

Extrusion die and method  

DOEpatents

A method and die apparatus for manufacturing a honeycomb body of triangular cell cross-section and high cell density, the die having a combination of (i) feedholes feeding slot intersections and (ii) feedholes feeding slot segments not supplied from slot intersections, whereby a reduction in feedhole count is achieved while still retaining good extrusion efficiency and extrudate uniformity.

Lipp, G. Daniel (Painted Post, NY)

1994-05-03

301

Improvement in Mechanical Properties of A356 Tensile Test Bars Cast in a Permanent Mold by Application of a Knife Ingate  

NASA Astrophysics Data System (ADS)

As a standard test-bar permanent mold, the "Stahl" Mold has been widely used in foundries to assess the properties of cast alloys. However, inferior mechanical properties are often obtained with this mold due to shrinkage-induced microporosity in the gage section. In order to improve the mechanical properties, a design modification comprising a thin knife ingate between the feeder and test-bar cavity was evaluated in this work. The new design was studied by computer-aided simulation. Simulations predicted that the knife ingate improved the metal feeding capability and reduced the shrinkage microporosity at the gage section from 3 to 1 pct. Experimental verification work has been undertaken with aluminum alloy A356, and the results were analyzed by a statistics theory-based factorial analysis method. The new design resulted in main effects with ultimate tensile strength (UTS) improvement of 20 MPa (relative 12 pct) and elongation increment of 2 pct (relative 45 pct) for the as-cast test bars.

Wang, Yaou; Schwam, David; Neff, David V.; Chen, Chai-Jung; Zhu, Xuejun

2012-03-01

302

Modal Vibration Analysis of Large Castings  

NASA Technical Reports Server (NTRS)

The art of experimental modal vibration analysis (MVA) has been extended to apply to large castings. This extension was made to enable the use of experimental MVA as a relatively inexpensive, simple means of assessing the internal structural integrity of tread shoes of crawler transporters used to move spacecraft to the launch pad at Kennedy Space Center. Each tread shoe is made from cast iron and weighs about a ton (has a mass .907 kg). The present extended version of experimental MVA could also be applied to other large castings. It could be especially useful to manufacturers as a means of rapidly discriminating against large castings that contain unacceptably large concentrations of internal defects. The use of experimental MVA to assess structural integrity is not new. What are new here are those aspects of the extension of experimental MVA that pertain to the application of MVA to objects so massive that it may not be practical or cost effective to mount them in special test fixtures that impose special test boundary conditions to test them in place under normal conditions of use.

Werlink, Rudolph J.; Margasahayam, Ravi N.

2009-01-01

303

Characterization of Ni-Cr alloys using different casting techniques and molds.  

PubMed

This study differentiated the mechanical properties of nickel-chromium (Ni-Cr) alloys under various casting techniques (different casting molds and casting atmospheres). These techniques were sampled by a sand mold using a centrifugal machine in ambient air (group I) and electromagnetic induction in an automatic argon castimatic casting machine (group II). The specimen casting used a graphite mold by a castimatic casting machine (group III). The characteristics of the Ni-Cr alloys, yield and ultimate tensile strength, bending modulus, microhardness, diffraction phase, grindability, ability to spring back, as well as ground microstructure and pattern under different casting conditions were evaluated. The group III specimens exhibited the highest values in terms of strength, modulus, hardness, and grindability at a grind rate of 500 rpm. Moreover, group III alloys exhibited smaller grain sizes, higher ability to spring back, and greater ductility than those casted by sand investment (groups I and II). The main factor, "casting mold," significantly influenced all mechanical properties. The graphite mold casting of the Ni-Cr dental alloys in a controlled atmosphere argon casting system provided an excellent combination of high mechanical properties and good ability to spring back, and preserved the ductile properties for application in Ni-Cr porcelain-fused system. The results can offer recommendations to assist a prosthetic technician in selecting the appropriate casting techniques to obtain the desired alloy properties. PMID:24411373

Chen, Wen-Cheng; Teng, Fu-Yuan; Hung, Chun-Cheng

2014-02-01

304

Die Anwendung des Logit Modells auf die Daten der  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1 Space Shuttle: Orbiter, externer Brennstofftank, Raketentriebwerke, Field JointsDie Anwendung des Logit Modells auf die Daten der Challenger-Katastrophe Bachelorarbeit Stefanie 15 4.1 Technische Aspekte der Challenger . . . . . . . . . . . . . . . . . . . . . . . 15 4.2 Die

305

Hickey, TT162, Casts 73-82 Hickey, TT162, Casts 73-82, page 1  

E-print Network

Hickey, TT162, Casts 73-82 Hickey, TT162, Casts 73-82, page 1 CTD073 #12;Hickey, TT162, Casts 73-82 Hickey, TT162, Casts 73-82, page 2 CTD073 #12;Hickey, TT162, Casts 73-82 Hickey, TT162, Casts 73-82, page 3 CTD073 #12;Hickey, TT162, Casts 73-82 Hickey, TT162, Casts 73-82, page 4 CTD074 #12;Hickey, TT162

Hickey, Barbara

306

Hickey, TT162, Casts 48-49 Hickey, TT162, Casts 48-49, page 1  

E-print Network

Hickey, TT162, Casts 48-49 Hickey, TT162, Casts 48-49, page 1 CTD048 #12;Hickey, TT162, Casts 48-49 Hickey, TT162, Casts 48-49, page 2 CTD048 #12;Hickey, TT162, Casts 48-49 Hickey, TT162, Casts 48-49, page 3 CTD048 #12;Hickey, TT162, Casts 48-49 Hickey, TT162, Casts 48-49, page 4 CTD048 #12;Hickey, TT162

Hickey, Barbara

307

Hickey, TT162, Casts 38-47 Hickey, TT162, Casts 38-47, page 1  

E-print Network

Hickey, TT162, Casts 38-47 Hickey, TT162, Casts 38-47, page 1 CTD038 #12;Hickey, TT162, Casts 38-47 Hickey, TT162, Casts 38-47, page 2 CTD039 #12;Hickey, TT162, Casts 38-47 Hickey, TT162, Casts 38-47, page 3 CTD039 #12;Hickey, TT162, Casts 38-47 Hickey, TT162, Casts 38-47, page 4 CTD040 #12;Hickey, TT162

Hickey, Barbara

308

Hickey, TT162, Casts 63-72 Hickey, TT162, Casts 63-72, page 1  

E-print Network

Hickey, TT162, Casts 63-72 Hickey, TT162, Casts 63-72, page 1 CTD063 #12;Hickey, TT162, Casts 63-72 Hickey, TT162, Casts 63-72, page 2 CTD063 #12;Hickey, TT162, Casts 63-72 Hickey, TT162, Casts 63-72, page 3 CTD063 #12;Hickey, TT162, Casts 63-72 Hickey, TT162, Casts 63-72, page 4 CTD064 #12;Hickey, TT162

Hickey, Barbara

309

Hickey, TT136, casts 46-47 Hickey, TT136, casts 46-47, page 1  

E-print Network

Hickey, TT136, casts 46-47 Hickey, TT136, casts 46-47, page 1 CTD046 #12;Hickey, TT136, casts 46-47 Hickey, TT136, casts 46-47, page 2 CTD046 #12;Hickey, TT136, casts 46-47 Hickey, TT136, casts 46-47, page 3 CTD046 #12;Hickey, TT136, casts 46-47 Hickey, TT136, casts 46-47, page 4 CTD046 #12;Hickey, TT136

Hickey, Barbara

310

Hickey, W8201, casts 26-32 Hickey, W8201, casts 26-32, page 1  

E-print Network

Hickey, W8201, casts 26-32 Hickey, W8201, casts 26-32, page 1 CTD026 #12;Hickey, W8201, casts 26-32 Hickey, W8201, casts 26-32, page 2 CTD026 #12;Hickey, W8201, casts 26-32 Hickey, W8201, casts 26-32, page 3 CTD027 #12;Hickey, W8201, casts 26-32 Hickey, W8201, casts 26-32, page 4 CTD027 #12;Hickey, W8201

Hickey, Barbara

311

Hickey, TT136, casts 52-55 Hickey, TT136, casts 52-55, pager 1  

E-print Network

Hickey, TT136, casts 52-55 Hickey, TT136, casts 52-55, pager 1 CTD052 #12;Hickey, TT136, casts 52-55 Hickey, TT136, casts 52-55, pager 2 CTD052 #12;Hickey, TT136, casts 52-55 Hickey, TT136, casts 52-55, pager 3 CTD052 #12;Hickey, TT136, casts 52-55 Hickey, TT136, casts 52-55, pager 4 CTD052 #12;Hickey, TT

Hickey, Barbara

312

Hickey, TT136, casts 91-95 Hickey, TT136, casts 91-95, page 1  

E-print Network

Hickey, TT136, casts 91-95 Hickey, TT136, casts 91-95, page 1 CTD091 #12;Hickey, TT136, casts 91-95 Hickey, TT136, casts 91-95, page 2 CTD091 #12;Hickey, TT136, casts 91-95 Hickey, TT136, casts 91-95, page 3 CTD091 #12;Hickey, TT136, casts 91-95 Hickey, TT136, casts 91-95, page 4 CTD091 #12;Hickey, TT136

Hickey, Barbara

313

Hickey, W8201, casts 11-18 Hickey, W8201, casts 11-18, page 1  

E-print Network

Hickey, W8201, casts 11-18 Hickey, W8201, casts 11-18, page 1 CTD011 #12;Hickey, W8201, casts 11-18 Hickey, W8201, casts 11-18, page 2 CTD011 #12;Hickey, W8201, casts 11-18 Hickey, W8201, casts 11-18, page 3 CTD011 #12;Hickey, W8201, casts 11-18 Hickey, W8201, casts 11-18, page 4 CTD011 #12;Hickey, W8201

Hickey, Barbara

314

Hickey, TT162, Casts 83-87 Hickey, TT162, Casts 83-87, page 1  

E-print Network

Hickey, TT162, Casts 83-87 Hickey, TT162, Casts 83-87, page 1 CTD083 #12;Hickey, TT162, Casts 83-87 Hickey, TT162, Casts 83-87, page 2 CTD083 #12;Hickey, TT162, Casts 83-87 Hickey, TT162, Casts 83-87, page 3 CTD083 #12;Hickey, TT162, Casts 83-87 Hickey, TT162, Casts 83-87, page 4 CTD083 #12;Hickey, TT162

Hickey, Barbara

315

Hickey, TT136, casts 96-97 Hickey, TT136, casts 96-97, page 1  

E-print Network

Hickey, TT136, casts 96-97 Hickey, TT136, casts 96-97, page 1 CTD096 #12;Hickey, TT136, casts 96-97 Hickey, TT136, casts 96-97, page 2 CTD096 #12;Hickey, TT136, casts 96-97 Hickey, TT136, casts 96-97, page 3 CTD096 #12;Hickey, TT136, casts 96-97 Hickey, TT136, casts 96-97, page 4 CTD096 #12;Hickey, TT136

Hickey, Barbara

316

Hickey, TT136, casts 56-76 Hickey, TT136, casts 56-76, page 1  

E-print Network

Hickey, TT136, casts 56-76 Hickey, TT136, casts 56-76, page 1 CTD056 #12;Hickey, TT136, casts 56-76 Hickey, TT136, casts 56-76, page 2 CTD056 #12;Hickey, TT136, casts 56-76 Hickey, TT136, casts 56-76, page 3 CTD056 #12;Hickey, TT136, casts 56-76 Hickey, TT136, casts 56-76, page 4 CTD056 #12;Hickey, TT136

Hickey, Barbara

317

Hickey, TT136, casts 48, 49, 51 Hickey, TT136, casts 48, 49, 51, page 1  

E-print Network

Hickey, TT136, casts 48, 49, 51 Hickey, TT136, casts 48, 49, 51, page 1 CTD048 #12;Hickey, TT136, casts 48, 49, 51 Hickey, TT136, casts 48, 49, 51, page 2 CTD048 #12;Hickey, TT136, casts 48, 49, 51 Hickey, TT136, casts 48, 49, 51, page 3 CTD048 #12;Hickey, TT136, casts 48, 49, 51 Hickey, TT136, casts

Hickey, Barbara

318

Hickey, TT136, casts 11-20 Hickey, TT136, casts 11-20, page 1  

E-print Network

Hickey, TT136, casts 11-20 Hickey, TT136, casts 11-20, page 1 CTD011 #12;Hickey, TT136, casts 11-20 Hickey, TT136, casts 11-20, page 2 CTD011 #12;Hickey, TT136, casts 11-20 Hickey, TT136, casts 11-20, page 3 CTD012 #12;Hickey, TT136, casts 11-20 Hickey, TT136, casts 11-20, page 4 CTD013 #12;Hickey, TT136

Hickey, Barbara

319

Hickey, TT136, casts 27-36 Hickey, TT136, casts 27-36, page 1  

E-print Network

Hickey, TT136, casts 27-36 Hickey, TT136, casts 27-36, page 1 CTD027 #12;Hickey, TT136, casts 27-36 Hickey, TT136, casts 27-36, page 2 CTD027 #12;Hickey, TT136, casts 27-36 Hickey, TT136, casts 27-36, page 3 CTD027 #12;Hickey, TT136, casts 27-36 Hickey, TT136, casts 27-36, page 4 CTD027 #12;Hickey, TT136

Hickey, Barbara

320

Hickey, TT136, casts 21-26 Hickey, TT136, casts 21-26, page 1  

E-print Network

Hickey, TT136, casts 21-26 Hickey, TT136, casts 21-26, page 1 CTD021 #12;Hickey, TT136, casts 21-26 Hickey, TT136, casts 21-26, page 2 CTD021 #12;Hickey, TT136, casts 21-26 Hickey, TT136, casts 21-26, page 3 CTD021 #12;Hickey, TT136, casts 21-26 Hickey, TT136, casts 21-26, page 4 CTD021 #12;Hickey, TT136

Hickey, Barbara

321

Hickey, W8201, Casts 1-10 Hickey, W8201, Casts 1-10, page 1  

E-print Network

CTD001 Hickey, W8201, Casts 1-10 Hickey, W8201, Casts 1-10, page 1 #12;CTD001 Hickey, W8201, Casts 1-10 Hickey, W8201, Casts 1-10, page 2 #12;CTD002 Hickey, W8201, Casts 1-10 Hickey, W8201, Casts 1-10, page 3 #12;CTD002 Hickey, W8201, Casts 1-10 Hickey, W8201, Casts 1-10, page 4 #12;CTD003 Hickey, W8201

Hickey, Barbara

322

Hickey, TT136, casts 98-99 Hickey, TT136, casts 98-99, page 1  

E-print Network

Hickey, TT136, casts 98-99 Hickey, TT136, casts 98-99, page 1 CTD098 #12;Hickey, TT136, casts 98-99 Hickey, TT136, casts 98-99, page 2 CTD098 #12;Hickey, TT136, casts 98-99 Hickey, TT136, casts 98-99, page 3 CTD098 #12;Hickey, TT136, casts 98-99 Hickey, TT136, casts 98-99, page 4 CTD098 #12;Hickey, TT136

Hickey, Barbara

323

Hickey, TT162, Casts 56-62 Hickey, TT162, Casts 56-62, page 1  

E-print Network

Hickey, TT162, Casts 56-62 Hickey, TT162, Casts 56-62, page 1 CTD056 #12;Hickey, TT162, Casts 56-62 Hickey, TT162, Casts 56-62, page 2 CTD056 #12;Hickey, TT162, Casts 56-62 Hickey, TT162, Casts 56-62, page 3 CTD056 #12;Hickey, TT162, Casts 56-62 Hickey, TT162, Casts 56-62, page 4 CTD056 #12;Hickey, TT162

Hickey, Barbara

324

Hickey, TT136, casts 41-43 Hickey, TT136, casts 41-43, page 1  

E-print Network

CTD041 Hickey, TT136, casts 41-43 Hickey, TT136, casts 41-43, page 1 #12;CTD041 Hickey, TT136, casts 41-43 Hickey, TT136, casts 41-43, page 2 #12;CTD041 Hickey, TT136, casts 41-43 Hickey, TT136, casts 41-43, page 3 #12;CTD041 Hickey, TT136, casts 41-43 Hickey, TT136, casts 41-43, page 4 #12;CTD041

Hickey, Barbara

325

Hickey, TT136, casts 37-40 Hickey, TT136, casts 37-40, page 1  

E-print Network

CTD037 Hickey, TT136, casts 37-40 Hickey, TT136, casts 37-40, page 1 #12;CTD037 Hickey, TT136, casts 37-40 Hickey, TT136, casts 37-40, page 2 #12;CTD037 Hickey, TT136, casts 37-40 Hickey, TT136, casts 37-40, page 3 #12;CTD037 Hickey, TT136, casts 37-40 Hickey, TT136, casts 37-40, page 4 #12;CTD037

Hickey, Barbara

326

Hickey, TT162, Casts 17-24 Hickey, TT162, Casts 17-24, page 1  

E-print Network

Hickey, TT162, Casts 17-24 Hickey, TT162, Casts 17-24, page 1 CTD017 #12;Hickey, TT162, Casts 17-24 Hickey, TT162, Casts 17-24, page 2 CTD017 #12;Hickey, TT162, Casts 17-24 Hickey, TT162, Casts 17-24, page 3 CTD018 #12;Hickey, TT162, Casts 17-24 Hickey, TT162, Casts 17-24, page 4 CTD018 #12;Hickey, TT162

Hickey, Barbara

327

Hickey, TT162, Casts 88-92 Hickey, TT162, Casts 88-92, page 1  

E-print Network

Hickey, TT162, Casts 88-92 Hickey, TT162, Casts 88-92, page 1 CTD088 #12;Hickey, TT162, Casts 88-92 Hickey, TT162, Casts 88-92, page 2 CTD088 #12;Hickey, TT162, Casts 88-92 Hickey, TT162, Casts 88-92, page 3 CTD088 #12;Hickey, TT162, Casts 88-92 Hickey, TT162, Casts 88-92, page 4 CTD088 #12;Hickey, TT162

Hickey, Barbara

328

Hickey, TT136, casts 77-90 Hickey, TT136, casts 77-90, page 1  

E-print Network

Hickey, TT136, casts 77-90 Hickey, TT136, casts 77-90, page 1 CTD077 #12;Hickey, TT136, casts 77-90 Hickey, TT136, casts 77-90, page 2 CTD077 #12;Hickey, TT136, casts 77-90 Hickey, TT136, casts 77-90, page 3 CTD077 #12;Hickey, TT136, casts 77-90 Hickey, TT136, casts 77-90, page 4 CTD077 #12;Hickey, TT136

Hickey, Barbara

329

Hickey, TT136, casts 44-46 Hickey, TT136, casts 44-46, page 1  

E-print Network

Hickey, TT136, casts 44-46 Hickey, TT136, casts 44-46, page 1 CTD044 #12;Hickey, TT136, casts 44-46 Hickey, TT136, casts 44-46, page 2 CTD044 #12;Hickey, TT136, casts 44-46 Hickey, TT136, casts 44-46, page 3 CTD044 #12;Hickey, TT136, casts 44-46 Hickey, TT136, casts 44-46, page 4 CTD044 #12;Hickey, TT136

Hickey, Barbara

330

Die gegenwärtigen Schwerpunkte der Gesundheitserziehung  

Microsoft Academic Search

Zusammenfassung Auf Wunsch von Westdeutschen Institutionen öffentlicher Gesundheitspflege wurden die gesundheitlichen Verhältnisse im Kanton Zürich und die schweizerischen Bestrebungen zur Einführung der Gesundheitserziehung geschildert.

Hans Wespi

1962-01-01

331

Die Informationspflichten der Verbraucherrechterichtlinie.  

E-print Network

??Inhalt der vorliegenden Arbeit ist die umfassende Untersuchung der Informationspflichten der Verbraucherrechterichtlinie (Richtlinie 2011/83/EG), welche im November 2011 in Kraft trat und deren Bestimmungen grundsätzlich… (more)

Neuner, Sophie

2012-01-01

332

Meisternovellen 1. DIE ROSE  

E-print Network

Emil Ertl Meisternovellen 1. DIE ROSE »Du solltest aber doch auch an die Luft gehn, Papa!« sagte«, obgleich er nicht ihr, sondern der Papa ihrer Kinder war; aber sie sah ja alles mit den Augen der Kinder Papiere, zu Quartblättern zugeschnit- ten. Gretlis, seines Lieblings, Geschäft war es, diese Vorräte #12

Prodinger, Helmut

333

Coin Die Experiment  

NSDL National Science Digital Library

This resource consists of a Java applet and expository text. The applet is a simulation of the experiment that consists of tossing a coin and then rolling either a red die or a green die, depending on the outcome of the coin toss. The probability of heads and the distributions of the two dice can be specified. The applet illustrates a two-stage experiment.

Siegrist, Kyle

334

21 CFR 888.5940 - Cast component.  

Code of Federal Regulations, 2012 CFR

...8 2012-04-01 2012-04-01 false Cast component. 888.5940 Section 888.5940...ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a device intended for medical...

2012-04-01

335

21 CFR 888.5940 - Cast component.  

Code of Federal Regulations, 2011 CFR

...8 2011-04-01 2011-04-01 false Cast component. 888.5940 Section 888.5940...ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a device intended for medical...

2011-04-01

336

21 CFR 888.5940 - Cast component.  

Code of Federal Regulations, 2013 CFR

...8 2013-04-01 2013-04-01 false Cast component. 888.5940 Section 888.5940...ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a device intended for medical...

2013-04-01

337

21 CFR 888.5940 - Cast component.  

...8 2014-04-01 2014-04-01 false Cast component. 888.5940 Section 888.5940...ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a device intended for medical...

2014-04-01

338

21 CFR 888.5940 - Cast component.  

Code of Federal Regulations, 2010 CFR

...8 2010-04-01 2010-04-01 false Cast component. 888.5940 Section 888.5940...ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a device intended for medical...

2010-04-01

339

Stress Corrosion Cracking Behavior of Cast Stainless Steels  

SciTech Connect

Casting of austenitic stainless steels offers the possibility of directly producing large and/or relatively complex structures, such as the first wall shield modules or the diverter cassette for the ITER fusion reactor. Casting offers major cost savings when compared to fabrication via welding of quarter modules machined from large forgings. However, the strength properties of such cast components are typically considered inferior to those of conventionally forged and annealed components. To improve and validate cast stainless steel as a substitute for wrought stainless steel, a development and testing program was initiated, utilizing nitrogen and manganese additions to promote improved performance. This paper focuses on the response of the first set of developmental alloys to neutron-irradiation and susceptibility to stress corrosion cracking. These cast materials may also have applications for different components in light water reactors. Results showed that all steels exhibited irradiation-induced hardening and a corresponding drop in ductility, as expected, although there is still considerable ductility in the irradiated samples. The cast steels all exhibited reduced hardening in comparison to a wrought reference steels, which may be related to a larger grain size. Higher nitrogen contents did not negatively influence irradiation performance. Regarding stress corrosion cracking susceptibility, the large difference in grain size limits the comparison between wrought and cast materials, and inclusions in a reference and archive cast alloy tests complicate analysis of these samples. Results suggest that the irradiated archive heat was more susceptible to cracking than the modified alloys, which may be related to the more complex microstructure. Further, the results suggest that the modified cast steel is at least as SCC resistant as wrought 316LN. The beneficial effect of nitrogen on the mechanical properties of the alloys remains after irradiation and is not detrimental to SCC resistance.

Teysseyre, Sebastien [University of Michigan; Busby, Jeremy T [ORNL; Was, Gary [University of Michigan

2009-01-01

340

Lost-Soap Aluminum Casting.  

ERIC Educational Resources Information Center

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)

Mihalow, Paula

1980-01-01

341

Education and Caste in India  

ERIC Educational Resources Information Center

This paper analyses the policy of reservation for lower castes in India. This policy is similar to that of affirmative action in the United States. The paper provides a brief overview of the caste system and discusses the types of groups that are eligible for reservation, based on data from government reports. The stance of this paper is that…

Chauhan, Chandra Pal Singh

2008-01-01

342

Clogging in Continuous Casting Nozzles  

Microsoft Academic Search

Nozzle clogging is a serious productivity and qua lity problem in continuous casting. This work reviews the causes, effects, and solutions to cloggi ng in continuous casting nozzles. The results of a one-dimensional, steady state analysis of the heat loss from the molten steel stream through the nozzle wall are discussed. The analyses show that steel may freeze within the

K. G. Rackers; B. G. Thomas

343

Management of Intolerance to Casting the Upper Extremities in Claustrophobic Patients  

PubMed Central

Introduction. Some patients showed unusual responses to the immobilization without any objective findings with casts in upper extremities. We hypothesized their that intolerance with excessive anxiety to casts is due to claustrophobia triggered by cast immobilization. The aim of this study is to analyze the relevance of cast immobilization to the feeling of claustrophobia and discover how to handle them. Methods. There were nine patients who showed the caustrophobic symptoms with their casts. They were assesed whether they were aware of their claustrophobis themselves. Further we investigated the alternative immobilization to casts. Results. Seven out of nine cases that were aware of their claustrophobic tendencies either were given removable splints initially or had the casts converted to removable splints when they exhibited symptoms. The two patients who were unaware of their latent claustrophobic tendencies were identified when they showed similar claustrophobic symptoms to the previous patients soon after short arm cast application. We replaced the casts with removable splints. This resolved the issue in all cases. Conclusions. We should be aware of the claustrophobia if patients showed unusual responses to the immobilization without any objective findings with casts in upper extremities, where removal splint is practical alternative to cast to continue the treatment successfully. PMID:25379544

Nagura, Issei; Kanatani, Takako; Sumi, Masatoshi; Inui, Atsuyuki; Mifune, Yutaka; Kokubu, Takeshi; Kurosaka, Masahiro

2014-01-01

344

Volatile Species Retention During Metallic Fuel Casting  

SciTech Connect

Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, although the loss values varied from the model results the same trend was seen. Bases on these results it is very probably that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

Randall S. Fielding; Douglas L. Proter

2013-10-01

345

Volatile species retention during metallic fuel casting  

NASA Astrophysics Data System (ADS)

Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

Fielding, Randall S.; Porter, Douglas L.

2013-10-01

346

The USAMP magnesium powertrain cast components project  

NASA Astrophysics Data System (ADS)

The U.S. Automotive Materials Partnership (USAMP) and the U.S. Department of Energy launched the Magnesium Powertrain Cast Components Project in 2001 to determine the feasibility of producing a magnesiumintensive engine—a six-cylinder engine with a magnesium block, bedplate, oil pan, and front cover. As the project approaches its midpoint, two goals are near completion: evaluation of the best available low-cost, creep-resistant magnesium alloys and design of engine components using the properties of the best alloys. Phase II of the project sets three additional goals: casting and testing the magnesium components in assembled powertrains, developing a powertrain magnesium alloy design database and common specification for magnesium powertrain alloys, and funding and promoting research to enable even more advanced powertrain applications in North America.

Powell, Bob R.

2003-11-01

347

A New Method For Advanced Virtual Design Of Stamping Tools For Automotive Industry: Application To Nodular Cast Iron EN-GJS-600-3  

NASA Astrophysics Data System (ADS)

This contribution presents an approach combining the stamping numerical processing simulations and structure analysis in order to improve the design for optimizing the tool fatigue life. The method consists in simulating the stamping process via AutoForm® (or any FEM Code) by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis. The result of this analysis is used for life prediction of the tool using S-N fatigue curve. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This optimization method is applied for a cast iron EN-GJS-600-3 as candidate stamping tool materiel. The room temperature fatigue S-N curves of this alloy are established in laboratory under uniaxial push/pull cyclic experiments on cylindrical specimens under a load ratio of R (?min/?max) = -2.

Ben-Slima, Khalil; Penazzi, Luc; Mabru, Catherine; Ronde-Oustau, François; Rezaï-Aria, Farhad

2011-05-01

348

Effect of microstructure on the mechanical properties of as-cast Ti-Nb-Al-Cu-Ni alloys for biomedical application.  

PubMed

The correlation between the microstructure and mechanical behavior during tensile loading of Ti68.8Nb13.6Al6.5Cu6Ni5.1 and Ti71.8Nb14.1Al6.7Cu4Ni3.4 alloys was investigated. The present alloys were prepared by the non-equilibrium processing applying relatively high cooling rates. The microstructure consists of a dendritic bcc ?-Ti solid solution and fine intermetallic precipitates in the interdendritic region. The volume fraction of the intermetallic phases decreases significantly with slightly decreasing the Cu and Ni content. Consequently, the fracture mechanism in tension changes from cleavage to shear. This in turn strongly enhances the ductility of the alloy and as a result Ti71.8Nb14.1Al6.7Cu4Ni3.4 demonstrates a significant tensile ductility of about 14% combined with the high yield strength of above 820 MPa already in the as-cast state. The results demonstrate that the control of precipitates can significantly enhance the ductility and yet maintaining the high strength and the low Young's modulus of these alloys. The achieved high bio performance (ratio of strength to Young's modulus) is comparable (or even superior) with that of the recently developed Ti-based biomedical alloys. PMID:24094189

Okulov, I V; Pauly, S; Kühn, U; Gargarella, P; Marr, T; Freudenberger, J; Schultz, L; Scharnweber, J; Oertel, C-G; Skrotzki, W; Eckert, J

2013-12-01

349

SKANOORD-KAAP Een van die mees innoverende strukture wat tans vir die die MeerKAT-teleskoop gebou word, is die ondergrondse gebou vir die  

E-print Network

. Ondergrondse bouwerk vir MeerKAT Stuur gerus enige vrae of voorstelle vir "SKA Nuus vir die Noord-Kaap" aan. MeerKAT gaan regs van KAT-7 gebou word, terwyl die kern van die SKA-terrein links van die bestaande beskerming teen weerlig. MeerKAT skep werk en opleidings- geleenthede Dit is vir die SKA SA-Projek baie

Jarrett, Thomas H.

350

A mixed-integer linear programming model for the continuous casting planning  

Microsoft Academic Search

The development of optimization models for planning and scheduling is one of the most useful tools for improving productivity of a large number of manufacturing companies. This paper presents a mixed-integer programming model for scheduling steelmaking-continuous casting production. We first review the recent works in continuous casting planning. We focus on a model inspired from an application of steelmaking-continuous casting

A. Bellabdaoui; J. Teghem

2006-01-01

351

Microstructural modification of as-cast NiAl bronze by friction stir processing  

Microsoft Academic Search

The application of friction stir processing (FSP) to a cast NiAl bronze (NAB) material is presented as a means for selective\\u000a modification of the near-surface layers by converting as-cast microstructures to a wrought condition in the absence of macroscopic\\u000a shape change. This may enable selective surface hardening of cast components. The complex physical metallurgy of the NAB is\\u000a reviewed, and

Keiichiro Oh-Ishi; Terry R. McNelley

2004-01-01

352

Laser-Ultrasonic Inspection of MG/AL Castings  

SciTech Connect

Laser-ultrasonics is used to assess the metallurgical bond between Mg/Al materials in die-cast Magnesium/Aluminum composite. The acoustic impedances of Mg, Al and air are such that the amplitude of ultrasonic echoes reflected back from a void is many times larger than the amplitude of those reflected back from a well-bonded interface. In addition, the polarity of echoes from a void is inverted compared to that from a well-bonded interface. Laser-ultrasonic F-SAFT is also used for imaging tilted Mg/Al interfaces. Experimental setup, signal processing and results for detecting voids in the Mg/Al interface of cast parts are presented.

Blouin, Alain; Levesque, Daniel; Monchalin, Jean-Pierre [Industrial Materials Institute, National Research Council Canada, 75 de Mortagne blvd, Boucherville, Quebec, J4B 6Y4 (Canada); Baril, Eric [Noranda Inc., 2250 Alfred Nobel blvd, St-Laurent, Quebec, H4S 2C9 (Canada); Fischersworring-Bunk, Andreas [BMW Group, Hufelandstr.8a, 80788 Munich (Germany)

2005-04-09

353

Experiments in hot-rolling and forging of ductile cast iron  

SciTech Connect

The Bureau of Mines investigated hot-rolling and forging characteristics of experimental ductile iron castings both sand and permanent-mold, made with charges containing up to 70% foundry pig iron and 95% steelmaking pit iron. Between 1550 and 1950/sup 0/F, most castings could be rolled to 90% reduction or forged to 70% reduction without serious cracking. Charge and composition have less bearing on workability than on subsequent properties. Permanent mold castings could be worked as readily as sand castings at 1750 and 1950/sup 0/F. Plasticity improved with temperature. Small billets were also forged cold to 50% reduction without cracking. The feasibility of die-forging and bar-rolling of ductile iron was evaluated in trial tests conducted under a Bureau contract. Although workability and ductility of ductile iron are inferior to those of steel, more advantage could be taken of ductile iron's plasticity to work rough shapes to final dimensions.

Neumeier, L.A.; Betts, B.A.; Crosby, R.L.

1980-01-01

354

Hickey -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM) Total Scan  

E-print Network

Hickey -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM;Hickey -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM) Total -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM) Total Scan

Hickey, Barbara

355

Strip casting apparatus and method  

DOEpatents

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.

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

1988-09-20

356

SKANOORD-KAAP Op die oomblik is die SKA-terrein in die Karoo  

E-print Network

KAT-antennas teen die einde van 2016 te oorhandig, sê MeerKAT se projekbestuurder,Willem Esterhuyse. "Die eerste antenna behoort teen Desember 2013 geïnstalleer te wees.Teen die einde van 2015 moet 32 antennas in plek wees, en al 64 teen die einde van 2016. Die MeerKAT-projekspan is gemotiveerd om 'n teleskoop te bou

Jarrett, Thomas H.

357

Pre-Cast Gel Electrophoresis Guide  

E-print Network

Novex® Pre-Cast Gel Electrophoresis Guide Version B January 27, 2003 IM-1002 Novex® Pre-Cast Gel Electrophoresis Guide General information and protocols for using Novex® pre-cast gels www.invitrogen.com tech.....................................................................................................................1 Novex® Pre-Cast Gels

Kirschner, Marc W.

358

Hickey -TT136 casts 1-2 Hickey -TT136,Casts 1-2, page 1  

E-print Network

Hickey -TT136 casts 1-2 Hickey -TT136,Casts 1-2, page 1 CTD001 #12;Hickey -TT136 casts 1-2 Hickey -TT136,Casts 1-2, page 2 CTD001 #12;Hickey -TT136 casts 1-2 Hickey -TT136,Casts 1-2, page 3 CTD001 #12;Hickey -TT136 casts 1-2 Hickey -TT136,Casts 1-2, page 4 CTD001 #12;Hickey -TT136 casts 1-2 Hickey -TT136

Hickey, Barbara

359

Poetry and the Dying.  

ERIC Educational Resources Information Center

Demonstrates roles poetry can play as people confront the death of loved ones and their own dying. Gives examples of Heinrich Heine transforming his agony into art and, from the poetry of two college students, both in advanced stages of neurological disease, which was read aloud in class, teaching all present something about how to approach their…

Kramer, Aaron

1992-01-01

360

"Einfhrung in die Bioinformatik"  

E-print Network

the session · Jonas Neuner will be the first moderator. Moderator 5Proseminar "Einführung in die Bioinformatik-seq Philipp Weber 29.01.2013 Wie sehen Proteine aus: Vorhersage der Sekundärstruktur Jonas Neuner 05

Nieselt, Kay

361

Dying to Play.  

ERIC Educational Resources Information Center

In August 1995, a young football player died as a result of heat exhaustion suffered on the first day of football practice in Arkansas. Spurred by this tragedy, the district made some changes that every school district with an athletic program should consider. These include using a heat-stress monitor; abandoning the practice of group physical…

Miller, John K.

1998-01-01

362

Dying Piñon Pine  

USGS Multimedia Gallery

A massive forest die-off is projected to occur more frequently in the Southwest. Piñon pines, normally evergreen, have reddish-brown foliage in October 2002 (left). By May 2004 (right), the dead piñon pines have lost all their needles, exposing gray trunks and branches. The photos were...

363

Archimedes, und die gestorten  

E-print Network

Archimedes, und die gest¨orten Kreise Vortrag im Naturhistorischen Museum Mainz Prof. Dr. Duco van;Archimedes Gem¨alde von Jusepe de Ribera (1630) (Madrid) #12;Archimedes Gem¨alde von Domenico Fetti (1620-241 #12;· 263: Friedensvertrag mit Rom · Fast f¨unfzig Jahre Frie- den! · Archimedes wird Berater am Hof

van Straten, Duco

364

Casting evaluation of U-Zr alloy system fuel slug for SFR prepared by injection casting method  

SciTech Connect

Metal fuel slugs of U-Pu-Zr alloys for Sodium-cooled Fast Reactor (SFR) have conventionally been fabricated by a vacuum injection casting method. Recently, management of minor actinides (MA) became an important issue because direct disposal of the long-lived MA can be a long-term burden for a tentative repository up to several hundreds of thousand years. In order to recycle transuranic elements (TRU) retained in spent nuclear fuel, remote fabrication capability in a shielded hot cell should be prepared. Moreover, generation of long-lived radioactive wastes and loss of volatile species should be minimized during the recycled fuel fabrication step. In order to prevent the evaporation of volatile elements such as Am, alternative fabrication methods of metal fuel slugs have been studied applying gravity casting, and improved injection casting in KAERI, including melting under inert atmosphere. And then, metal fuel slugs were examined with casting soundness, density, chemical analysis, particle size distribution and microstructural characteristics. Based on these results there is a high level of confidence that Am losses will also be effectively controlled by application of a modest amount of overpressure. A surrogate fuel slug was generally soundly cast by improved injection casting method, melted fuel material under inert atmosphere.

Song, Hoon; Kim, Jong-Hwan; Kim, Ki-Hwan; Lee, Chan-Bock [Korea Atomic Energy Research Institute, Daedeok-daro 989-111, Yuseong-gu, Daejeon (Korea, Republic of)

2013-07-01

365

Informatics approach using metabolic reactivity classifiers to link in vitro to in vivo data in application to the ToxCast Phase I dataset  

EPA Science Inventory

Strategic combinations and tiered application of alternative testing methods to replace or minimize the use of animal models is attracting much attention. With the advancement of high throughput screening (HTS) assays and legacy databases providing in vivo testing results, suffic...

366

Innovations in cast magnesium alloys  

Microsoft Academic Search

This article examines questions related to aspects of the production of castings of magnesium alloys in molds made by volumetric\\u000a stamping without the use of the corresponding tooling. Information is presented on features of the gating-feeding systems\\u000a used to obtain magnesium-alloy castings in molds made by volumetric stamping. Also examined are features of the effect of\\u000a small additions of calcium

V. D. Belov; A. V. Koltygin; N. A. Belov; I. V. Plisetskaya

2010-01-01

367

Finite element analysis of prestressed die set in cold forging  

Microsoft Academic Search

An application-oriented finite-element approach to forging die structural analysis is presented in this paper. The die set structural analysis problem is formulated as a contact problem with both shrink fit and preloaded clamping considered, solved iteratively by a varying penalty method. The loading condition is extracted automatically from forging simulation. A predicted solution is compared with analytical one and two

M. S. Joun; M. C. Lee; J. M. Park

2002-01-01

368

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Light Metals Permanent Mold Casting  

SciTech Connect

Current vehicles use mostly ferrous components for structural applications. It is possible to reduce the weight of the vehicle by substituting these parts with those made from light metals such as aluminum and magnesium. Many alloys and manufacturing processes can be used to produce these light metal components and casting is known to be most economical. One of the high integrity casting processes is permanent mold casting which is the focus of this research report. Many aluminum alloy castings used in automotive applications are produced by the sand casting process. Also, aluminum-silicon (Al-Si) alloys are the most widely used alloy systems for automotive applications. It is possible that by using high strength aluminum alloys based on an aluminum-copper (Al-Cu) system and permanent mold casting, the performance of these components can be enhanced significantly. This will also help to further reduce the weight. However, many technological obstacles need to be overcome before using these alloys in automotive applications in an economical way. There is very limited information in the open literature on gravity and low-pressure permanent mold casting of high strength aluminum alloys. This report summarizes the results and issues encountered during the casting trials of high strength aluminum alloy 206.0 (Al-Cu alloy) and moderate strength alloy 535.0 (Al-Mg alloy). Five engineering components were cast by gravity tilt-pour or low pressure permanent mold casting processes at CanmetMATERIALS (CMAT) and two production foundries. The results of the casting trials show that high integrity engineering components can be produced successfully from both alloys if specific processing parameters are used. It was shown that a combination of melt processing and mold temperature is necessary for the elimination of hot tears in both alloys.

Fasoyinu, Yemi [CanmetMATERIALS] [CanmetMATERIALS

2014-03-31

369

CAST STONE TECHNOLOGY FOR THE TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE  

SciTech Connect

Cast stone technology is being evaluated for potential application in the treatment and immobilization of Hanford low-activity waste. The purpose of this document is to provide background information on cast stone technology. The information provided in the report is mainly based on a pre-conceptual design completed in 2003.

MINWALL HJ

2011-04-08

370

Clean ferrous casting technology research. Annual report, September 29, 1994--September 28, 1995  

SciTech Connect

This annual report covers work performed in the second year of research on Clean Ferrous Casting Technology Research. Significant progress was made in establishing pouring practices which avoid re-oxidation of steel during pouring; application of revised pouring practices have led to reduced inclusion levels in commercially poured steel castings.

Griffin, J.; Bates, C.E.; Piwonka, T.S.

1995-10-31

371

Robustness of Ability Estimation to Multidimensionality in CAST with Implications to Test Assembly  

ERIC Educational Resources Information Center

Computer Adaptive Sequential Testing (CAST) is a test delivery model that combines features of the traditional conventional paper-and-pencil testing and item-based computerized adaptive testing (CAT). The basic structure of CAST is a panel composed of multiple testlets adaptively administered to examinees at different stages. Current applications…

Zhang, Yanwei; Nandakumar, Ratna

2006-01-01

372

Integration of reverse engineering and rapid technologies for rapid investment casting of gas turbine blades  

Microsoft Academic Search

The aim of this research work is to offer a unique procedure of integrated Reverse Engineering (RE) and Additive Manufacturing (AM) technologies through implementation of a comprehensive experimental study to present an extensive comparison between applicable rapid technologies for blade rapid investment casting. Different direct and indirect AM techniques were used to produce sacrificial investment casting patterns. In addition, an

Mohammad Vaezi; Davood Safaeian; Mohsen Shakeri

2011-01-01

373

Über die Umwandlungsreihen des Urans, die durch Neutronenbestrahlung erzeugt werden  

Microsoft Academic Search

Zusammenfassung In einer Reihe vorangehender Arbeiten ist gezeigt worden, daß die Bestrahlung von Uran mit Neutronen zu drei neuen Umwandlungsreihen führt, deren einzelne Glieder zum größten Teile Elemente jenseits Uran sind. Wir haben im Laufe der weiteren Untersuchung neue Ergebnisse erhalten, über die hier berichtet werden soll, so weit sie mehr physikalische Fragen berühren. Die Darstellung der chemischen Eigenschaften der

L. Meitner; O. Hahn; F. Strassmann

1937-01-01

374

Hauptseminar Die Einfhrung in die Java Card Technologie  

E-print Network

Hauptseminar Die Einführung in die Java Card Technologie Nachweis von Sicherheitseigenschaften für Java Card durch Approximative Programmauswertung Veranstalter Pr. T. Nipkow Dr. M. Strecker Autor Tao Zhuang 07,01,2002 #12;�berblick ·Einleitung ·Smart Card Basis ·�berblick der Java Card Technologie ·Die

Cengarle, María Victoria

375

Heated die facilitates tungsten forming  

NASA Technical Reports Server (NTRS)

Tungsten forming in a press brake employs a bottom die assembly with a heating manifold between two water-cooled die sections. The manifold has hydrogen-oxygen burners spaced along its length for even heat during forming.

Chattin, J. H.; Haystrick, J. E.; Laughlin, J. C.; Leidy, R. A.

1966-01-01

376

Die Chemische Bindung  

Microsoft Academic Search

\\u000a In der Regel findet man in der Natur keine einzelnen Atome, sondem Atomgruppierungen, d.h. miteinander verbundene Atome. Aus\\u000a energetischen Gründen ist es nämlich günstiger, wenn sich die Atome Bindungspartner suchen und mit diesen zu größeren Gebilden\\u000a zusammentreten. Aufwelche Weise dieses Zusammengehen erfolgt, hängt von der Elektronenkonfiguration der Atome abo Daher unterscheidet\\u000a man verschiedene Bindungsarten.

Dirk Flottmann; Detlev Forst; Helmut Roßwag

377

Die pharmakologische Wirkung des Ephedrins  

Microsoft Academic Search

Zusammenfassung 1.Die pharmakologische Wirkung des Ephedrins wurde zu analysieren versucht durch Studium der Beeinflussung des Blutdrucks, der Herzaktion und der Gefäße, des Effekts am Atemzentrum und an den Bronchien, der Wirkung auf die Pupillenweite, auf den Darm und den Uterus, auf die Sekretion verschiedener Drüsen und den Blutzuckerspiegel.2.Es wurden folgende Wirkungen gefunden: Der Blutdruck wird erhöht durch kleine Dosen, erniedrigt

H. Kreitmair

1927-01-01

378

Manufacturing of Dies and Molds  

Microsoft Academic Search

The design and manufacturing of dies and molds represent a significant link in the entire production chain because nearly all mass produced discrete parts are formed using production processes that employ dies and molds. Thus, the quality, cost and lead times of dies and molds affect the economics of producing a very large number of components, subassemblies and assemblies, especially

Taylan Altan; Blaine Lilly; Y. C. Yen

2001-01-01

379

Die Systemarchitektur von Windows 7  

Microsoft Academic Search

\\u000a Windows 7 ist die siebte und damit gegenwärtig neueste Version der Windows- Betriebssystem-Familie. Über die „7” im Namen\\u000a gab es viele Spekulationen: Ist die „7” eine Anlehnung an den Nachnamen von Bill Gates als einem der drei Microsoft-Gründern?\\u000a Schließlich ist das „G” der siebte Buchstabe im Alphabet.

Martin Grotegut

380

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

SciTech Connect

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.

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

2002-10-15

381

Fillability of Thin-Wall Steel Castings  

SciTech Connect

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.

Robert C. Voigt; Joseph Bertoletti; Andrew Kaley; Sandi Ricotta; Travis Sunday

2002-07-30

382

CTD019Hickey, W8201_casts 19-22 Hickey, W8201_casts 19-22, page 1  

E-print Network

CTD019Hickey, W8201_casts 19-22 Hickey, W8201_casts 19-22, page 1 #12;CTD019Hickey, W8201_casts 19-22 Hickey, W8201_casts 19-22, page 2 #12;CTD019Hickey, W8201_casts 19-22 Hickey, W8201_casts 19-22, page 3 #12;CTD019Hickey, W8201_casts 19-22 Hickey, W8201_casts 19-22, page 4 #12;CTD019Hickey, W8201_casts 19

Hickey, Barbara

383

CTD023Hickey, W8201_casts 23-25 Hickey, W8201_casts 23-25, page 1  

E-print Network

CTD023Hickey, W8201_casts 23-25 Hickey, W8201_casts 23-25, page 1 #12;CTD023Hickey, W8201_casts 23-25 Hickey, W8201_casts 23-25, page 2 #12;CTD023Hickey, W8201_casts 23-25 Hickey, W8201_casts 23-25, page 3 #12;CTD023Hickey, W8201_casts 23-25 Hickey, W8201_casts 23-25, page 4 #12;CTD023Hickey, W8201_casts 23

Hickey, Barbara

384

CTD021Hickey, W8101_casts 21-23 Hickey, W8101_casts 21-23, page 1  

E-print Network

CTD021Hickey, W8101_casts 21-23 Hickey, W8101_casts 21-23, page 1 #12;CTD021Hickey, W8101_casts 21-23 Hickey, W8101_casts 21-23, page 2 #12;CTD021Hickey, W8101_casts 21-23 Hickey, W8101_casts 21-23, page 3 #12;CTD021Hickey, W8101_casts 21-23 Hickey, W8101_casts 21-23, page 4 #12;CTD021Hickey, W8101_casts 21

Hickey, Barbara

385

Control of inclusion characteristics in direct cast steel billets  

Microsoft Academic Search

Two main criteria are used to characterize steel cleanliness. First the number and size of inclusions must be at the minimum level achievable with state-of-the-art steelmaking and casting equipment and procedures. Second the remaining small inclusions must have a chemical composition suitable for the steel application. In high carbon steel destined for wire drawing, inclusions need to be as deformable

Martin Gagné; Eric Thibault

1999-01-01

386

A Medial Point Cloud based Algorithm for Dental Cast Segmentation  

E-print Network

as dental cast scans) for the application in consumer oral healthcare devices. Although these can shape analysis requirements. I. INTRODUCTION Oral Healthcare devices targeted at the consumer market re the shape properties of a personal oral healthcare device, one has to use simpler, however less detailed

Telea, Alexandru C.

387

Casting Castings: A Classroom Hands-on Activity  

NSDL National Science Digital Library

This learning activity will provide a useful technique for students to learn casting concepts. The class will be allowed a hands-on experience with casting. Students will make their own fishing sinkers. The lesson plan document includes step by step instructions for the lesson along with photographs.This activity would be appropriate for high school and college level students. The lesson should take about one hour of class time. This document will serve as a framework for instructors and may be downloaded in PDF format.

Johnson, Craig

2012-11-08

388

Die Logik der Grenzerhaltung und die Logik der Grenzüberschreitungen: Niklas Luhmann und die Kulturtheorien  

Microsoft Academic Search

Die intellektuelle Entwicklung der westlichen Sozial-, Kultur- und Gesellschaftstheorien befindet sich gegenwärtig auf einem Zwischenplateau: Eine Phase der Theorieentwicklung, die in den 1960er Jahren begann, kommt seit den 1990er Jahren allmählich an ihr Ende. Anfangs umstrittene Theoretiker sind mittlerweile klassisch geworden und zum Gegenstand umfänglicher Interpretationsaktivitäten avanciert; eine ganze Generation von Sozial- und Gesellschaftstheoretikern verläßt derweil die Bühne, was im

Andreas Reckwitz

389

Yield improvement and defect reduction in steel casting  

SciTech Connect

This research project investigated yield improvement and defect reduction techniques in steel casting. Research and technology development was performed in the following three specific areas: (1) Feeding rules for high alloy steel castings; (2) Unconventional yield improvement and defect reduction techniques--(a) Riser pressurization; and (b) Filling with a tilting mold; and (3) Modeling of reoxidation inclusions during filling of steel castings. During the preparation of the proposal for this project, these areas were identified by the High Alloy Committee and Carbon and Low Alloy Committee of the Steel Founders' Society of America (SFSA) as having the highest research priority to the steel foundry industry. The research in each of the areas involved a combination of foundry experiments, modeling and simulation. Numerous SFSA member steel foundries participated in the project through casting trials and meetings. The technology resulting from this project will result in decreased scrap and rework, casting yield improvement, and higher quality steel castings produced with less iteration. This will result in considerable business benefits to steel foundries, primarily due to reduced energy and labor costs, increased capacity and productivity, reduced lead-time, and wider use and application of steel castings. As estimated using energy data provided by the DOE, the technology produced as a result of this project will result in an energy savings of 2.6 x 10{sup 12} BTU/year. This excludes the savings that were anticipated from the mold tilting research. In addition to the energy savings, and corresponding financial savings this implies, there are substantial environmental benefits as well. The results from each of the research areas listed above are summarized.

Kent Carlson

2004-03-16

390

Tape-cast sensors and method of making  

DOEpatents

A method of making electrochemical sensors in which an electrolyte material is cast into a tape. Prefabricated electrodes are then partially embedded between two wet layers of the electrolyte tape to form a green sensor, and the green sensor is then heated to sinter the electrolyte tape around the electrodes. The resulting sensors can be used in applications such as, but not limited to, combustion control, environmental monitoring, and explosive detection. A electrochemical sensor formed by the tape-casting method is also disclosed.

Mukundan, Rangachary (Santa Fe, NM); Brosha, Eric L. (Los Alamos, NM); Garzon, Fernando H. (Santa Fe, NM)

2009-08-18

391

Strain Rate Dependency of Bronze Metal Matrix Composite Mechanical Properties as a Function of Casting Technique  

NASA Astrophysics Data System (ADS)

Strain rate dependency of mechanical properties of tungsten carbide (WC)-filled bronze castings fabricated by centrifugal and sedimentation-casting techniques are examined, in this study. Both casting techniques are an attempt to produce a functionally graded material with high wear resistance at a chosen surface. Potential applications of such materials include shaft bushings, electrical contact surfaces, and brake rotors. Knowledge of strain rate-dependent mechanical properties is recommended for predicting component response due to dynamic loading or impact events. A brief overview of the casting techniques for the materials considered in this study is followed by an explanation of the test matrix and testing techniques. Hardness testing, density measurement, and determination of the volume fraction of WC particles are performed throughout the castings using both image analysis and optical microscopy. The effects of particle filling on mechanical properties are first evaluated through a microhardness survey of the castings. The volume fraction of WC particles is validated using a thorough density survey and a rule-of-mixtures model. Split Hopkinson Pressure Bar (SHPB) testing of various volume fraction specimens is conducted to determine strain dependence of mechanical properties and to compare the process-property relationships between the two casting techniques. The baseline performances of C95400 bronze are provided for comparison. The results show that the addition of WC particles improves microhardness significantly for the centrifugally cast specimens, and, to a lesser extent, in the sedimentation-cast specimens, largely because the WC particles are more concentrated as a result of the centrifugal-casting process. Both metal matrix composites (MMCs) demonstrate strain rate dependency, with sedimentation casting having a greater, but variable, effects on material response. This difference is attributed to legacy effects from the casting process, namely, porosity and localized WC particle grouping.

Brown, Lloyd; Joyce, Peter; Radice, Joshua; Gregorian, Dro; Gobble, Michael

2012-07-01

392

Blasting casting to raise productivity  

SciTech Connect

Normally, surface mines employ draglines or truck and shovel systems to remove overburden. Blasting merely fragments and displaces the overburden enough to allow for easy digging. But during the past two decades, the effect of inflation and increased labor costs have encouraged unconventional methods of overburden removal. All of us are aware of the tremendous inflationary effects on costs of equipment, fuel, labor, interest, insurance, environmental compliance, etc. This has allowed the authors to take a new look at the use of explosives as an effective alternate method of overburden removal. This technique is known by several names, but basically blast casting or just casting best describes it. Other terms in vogue are explosive casting, controlled trajectory blasting, trajectory control blasting, and whatever terminology comes to mind.

Pilshaw, S.R.

1987-07-01

393

CAST results and Axion review  

E-print Network

We present results from the CERN Axion Solar Telescope (CAST) and the Axion Dark Matter eXperiment (ADMX), together with a brief review on prospects on Axion searches with a variety of experimental techniques. CAST has explored masses up to 0.64 eV setting the most stringent limit on the axion-photon coupling, apart for the micro-eV region where ADMX is the most competitive experiment. CAST is aiming at surpassing the 1eV WMAP upper limit and possibly revisiting the operation in vacuum with extra sensitive X-ray detectors, while ADMX, using improved extra sensitive SQUID amplifiers will explore the micro-eV mass range.

T. Geralis; for the CAST collaboration

2009-05-26

394

Heat treatment in high Cr white cast iron Nb alloy  

NASA Astrophysics Data System (ADS)

Wear resistance of high Cr white cast irons can be improved by means of heat treatment. This type of cast iron alloy may present a microstructure with retained austenite. The amount of retained austenite changes with the applied heat treatment, which will have an influence on wear properties. The purpose of this work was to study the influence of several parameters such as quenching and tempering temperatures and subzero treatment in the wear performance of the high Cr white cast iron Nb alloy. In this way, the performance was evaluated using pin-on-disc abrasion test. The worn surface was examined by scanning electron microscopy, and the main wear mechanisms were identified. The microstructural characterization was also performed with carbide identification. This Fe alloy has proven to be good for applications in mining and alcohol-sugar industries.

Farah, A. F.; Crnkovic, O. R.; Canale, L. C. F.

2001-02-01

395

Tool and Die Apprenticeship  

NSDL National Science Digital Library

The Manufacturing & Technology Center at Jefferson State Community College is constantly at work with local industry and students. An example of one local industry's Department of Labor approved apprenticeship program is the Tool and Die option with Ogihara America Corp. This type of program is a win/win situation with the student and the sponsor company. After completing specified classes at Jefferson State Community College, the student may continue on to an Associates of Applied Science in a manufacturing program or continue working in the sponsor industry.

Hatley, Andy

396

Casting propellant in rocket engine  

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

397

Cast-a-Box: Casting Conditions and Macroporosity  

NSDL National Science Digital Library

An illustration of three-dimensional finite difference simulation of heat conduction with phase change and complex boundary conditions, this requires students to adjust boundary conditions to make the top surface of a regular hexahedral "casting" to freeze last, eliminating macroporosity.

Powell, Adam C., IV

2004-08-24

398

Lower Restrictions for Sheet Metal Trimming Processes can Reduce Die Costs in The Automotive Industry  

Microsoft Academic Search

To reduce costs of trimming dies influencing parameters of the shearing process were identified, new technical approaches for a more cost efficient die design were developed, and comprehensive investigations on a sample tool were done. These approaches will be verified on a trimming die in series production. If this pilot application is successful, many sheet metal forming parts can be

Markus Hogg; Martin Rohleder; Karl Roll

2011-01-01

399

ATTEN ATTEN Hickey, W8101, casts 1-10  

E-print Network

ATTEN ATTEN Hickey, W8101, casts 1-10 Hickey, W8101, casts 1-10, page 1 #12;Hickey, W8101, casts 1-10 Hickey, W8101, casts 1-10, page 2 #12;Hickey, W8101, casts 1-10 Hickey, W8101, casts 1-10, page 3 #12;ATTEN ATTEN Hickey, W8101, casts 1-10 Hickey, W8101, casts 1-10, page 4 #12;ATTEN ATTEN Hickey, W8101

Hickey, Barbara

400

Biocompatibility of Dental Casting Alloys  

Microsoft Academic Search

Most cast dental restorations are made from alloys or commercially pure titanium (cpTi). Many orthodontic appliances are also fabricated from metallic materials. It has been documented in vitro and in vivo that metallic dental devices release metal ions, mainly due to corrosion. Those metallic components may be locally and systemically distributed and could play a role in the etiology of

Werner Geurtsen

2002-01-01

401

Scheduled Castes and Land Deprivation  

Microsoft Academic Search

The paper is more in the form of setting broad contours for a comprehensive buildup. It is divided into four sections. The first section discusses the landlessness or nearlandlessness of majority of Scheduled Caste households and the benefits of land assigned to them as a part of redistributive land reform strategy. The second section analyses the impact of redistributive land

D. Narasimha Reddy

402

Math: Objectives Guide. Project CAST.  

ERIC Educational Resources Information Center

The guide lists math objectives needed for independent living by secondary special education students. One of a series of Project CAST (Community and School Together) life skills manuals, the guide outlines basic competencies in terms of goal statements, behavioral objectives, and specialized vocabulary for the following areas: money, making…

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

403

Homogenization heat treating cast microstructure  

NSDL National Science Digital Library

Cast microstructures have variations in composition on the length scale of dendrites and homogenization heat treatments are performed to smooth out these variations. This problem is an integral analysis of the 1D diffusion mass transfer in this problem. The results using two different assumed profiles are compared.

Krane, Matthew J. M.

2008-10-25

404

Overview of ToxCast?  

EPA Science Inventory

In 2007, EPA launched ToxCast? in order to develop a cost-effective approach for prioritizing the toxicity testing of large numbers of chemicals in a short period of time. Using data from state-of-the-art high throughput screening (HTS) bioassays developed in the pharmaceutical i...

405

ENVIRONMENTAL ASSESSMENT OF IRON CASTING  

EPA Science Inventory

Sampling of ductile iron casting in green sand molds with phenolic isocyanate cores and in phenol-formaldehyde bound shell molds did not provide definitive proof that environmentally hazardous organic emission occur. Both molding systems produced the same type of major emissions,...

406

Electroslag casting of compressor crankshafts  

Microsoft Academic Search

Of all of the methods of production of crankshaft castings a method making it possible to melt sections of it with three molds was used. The essence of production of castinss of sections using the method selected is as follows. In one mold a crank is produced by remelting of a consumable electrode with obtaining of a crank (with axes)

A. P. Alikin; A. A. Dan'kin

1993-01-01

407

Molding A Cast Metals Program  

ERIC Educational Resources Information Center

The cast metals program, a two-year associate degree program, at Muskegon Community College, Musegon, Michigan operates in close cooperation with the local foundry industry to provide a background for entry-level technical jobs and for continued studies toward a four-year degree. (EA)

Trumble, Dale E.

1975-01-01

408

21 CFR 880.6185 - Cast cover.  

... 8 2014-04-01 2014-04-01 false Cast cover. 880.6185 Section 880.6185 Food...Personal Use Miscellaneous Devices § 880.6185 Cast cover. (a) Identification. A cast cover is a device intended for medical...

2014-04-01

409

21 CFR 880.6185 - Cast cover.  

Code of Federal Regulations, 2013 CFR

... 8 2013-04-01 2013-04-01 false Cast cover. 880.6185 Section 880.6185 Food...Personal Use Miscellaneous Devices § 880.6185 Cast cover. (a) Identification. A cast cover is a device intended for medical...

2013-04-01

410

21 CFR 880.6185 - Cast cover.  

Code of Federal Regulations, 2011 CFR

... 8 2011-04-01 2011-04-01 false Cast cover. 880.6185 Section 880.6185 Food...Personal Use Miscellaneous Devices § 880.6185 Cast cover. (a) Identification. A cast cover is a device intended for medical...

2011-04-01

411

A Microbiological Study of Earthworm Casts  

Microsoft Academic Search

SUMMARY Microbiological, physical and chemical changes were followed in worm casts ageing in the field. Filamentous fungi and yeasts increased in number rapidly after the cast was produced, but not bacteria or actinomycetes which were initially numerous. Measurements of hyphal length confirmed the increased growth of fungi. Ageing casts showed a declining respiratory activity, possibly because the bacteria formed resting

J. N. Parle

1963-01-01

412

Coping with type casts in C  

Microsoft Academic Search

The use of type casts is pervasive in C. Although casts provide great flexibility in writing programs, their use obscures the meaning of programs, and can present obstacles during maintenance. Casts involving pointers to structures (C structs) are particularly problematic, because by using them, a programmer can interpret any memory region to be of any desired type, thereby compromising C's

Michael Siffr; Satish Chandra; Thomas Ball; Krishna Kunchithapadam; Thomas W. Reps

1999-01-01

413

21 CFR 880.6185 - Cast cover.  

Code of Federal Regulations, 2012 CFR

... 8 2012-04-01 2012-04-01 false Cast cover. 880.6185 Section 880.6185 Food...Personal Use Miscellaneous Devices § 880.6185 Cast cover. (a) Identification. A cast cover is a device intended for medical...

2012-04-01

414

July/August 20056 Casting aluminum  

E-print Network

includes `continuous' casting of Al, whereby the solid is formed in the water- cooled casterJuly/August 20056 Bob Rapp Casting aluminum Lay people unfamiliar with metallurgical processing to cast Al commercially. Perhaps I can interest the reader with a summary of this important process. I

Colton, Jonathan S.

415

Development of a New Membrane Casting Apparatus for Studying Macrovoid Defects in Low-G  

NASA Technical Reports Server (NTRS)

A new membrane-casting apparatus is developed for studying macrovoid defects in polymeric membranes made by the wet- and dry-casting process in low-gravity. Macrovoids are large (10-50 micron), open cavities interspersed among the smaller pores in the substructure under the gelled skin surface layer of the cast membrane. Although their occurrence is considered endemic to the wet- and dry-casting process since they can lead to compaction or skin rupture in the membrane process, recent studies suggest several useful applications such as transdermal and osmotic drug delivery systems, miniature bioreactors, etc. However, lack of knowledge about the macrovoid formation mechanism is an obstacle to further development of applications using them. An on-going debate is the role of the surface-tension-driven solutocapillary convection during macrovoid formation. The rapid growth of macrovoids within 1-5 seconds and the high polymer concentration in and near macrovoids make it difficult to explain the mechanism of macrovoid growth by diffusion alone, which is the widely accepted hypothesis proposed by Reuvers et al. The hypothesis advanced by our research group can explain this rapid growth via a mechanism that involves diffusion from the casting solution in the meta-stable region to the macrovoid enhanced by solutocapillary convection induced by the steep nonsolvent concentration gradient in the vicinity of the macrovoid. Since macrovoid growth is hypothesized to be the interplay of a solutocapillary-induced driving force counteracted by viscous drag and buoyancy, eliminate the latter provides a means for testing this hypothesis. Moreover, free convection mass transfer in the nonsolvent immersion bath used to cause phase-separation in membrane casting complicates developing a model for both the wet-casting process and macrovoid growth. The low-g environment minimizes gravitationally induced free convection thereby permitting a tractable solution to the ternary diffusion equations that characterize membrane formation. NASA's Parabolic Flight Research Aircraft provides a small window of low-g (approximately 25 s) that can be used to study macrovoid development in both wet- and dry-cast membranes if an appropriate casting apparatus is used. This casting apparatus should be able to cast the membrane in both low- and high-g in a manner so that essential one-dimensional mass transfer conditions are achieved to insure lateral uniformity in the membrane. The apparatus used in previous research on membrane casting in low-gravity was operated with the plunger driven mechanism. The spring-loaded plunger pushes the bottom block containing the polymer casting solution well directly under the absorbent chamber located in the upper stationary block. However, membranes made via this casting apparatus often displayed lateral nonuniformities that precluded obtaining quantitative information on the macrovoid growth process. Thus, it was necessary to determine the reason for these structural irregularities observed in the low-g casting apparatus. Both experimental as well as computer simulation studies of the low-g casting apparatus established that the impulsive action of the plunger caused the undesired structural nonuniformities. The simulation results showed that the width-to-depth aspect ratio of the shallow well that contains the casting solution in this apparatus was not an important factor in minimizing this problem. Even for a 40:1 (width : depth) aspect ratio, any convection induced by the horizontal motion of the interface of the casting solution will be damped out within 6.25x10(exp 4) seconds. However, the experimental studies revealed that the impulsive motion of the plunger caused a 'sloshing' of the casting solution that had to be eliminated. Therefore, the plungerdriven mechanism was changed to a cam-driven mechanism that did not cause any impulsive motion of the casting solution. Other refinements to this new membrane-casting apparatus include provision for removing the membranes from the casting wells in a less destructive manner.

Lee, Hanyong; Hwang, Sun-Tak; Krantz, William B.; Greenberg, Alan R.; Khare, Vivek; Zartman, Jeremiah; Todd, Paul W.

2002-01-01

416

Integrally cored ceramic investment casting mold fabricated by ceramic stereolithography  

NASA Astrophysics Data System (ADS)

Superalloy airfoils are produced by investment casting (IC), which uses ceramic cores and wax patterns with ceramic shell molds. Hollow cored superalloy airfoils in a gas turbine engine are an example of complex IC parts. The complex internal hollow cavities of the airfoil are designed to conduct cooling air through one or more passageways. These complex internal passageways have been fabricated by a lost wax process requiring several processing steps; core preparation, injection molding for wax pattern, and dipping process for ceramic shell molds. Several steps generate problems such as high cost and decreased accuracy of the ceramic mold. For example, costly tooling and production delay are required to produce mold dies for complex cores and wax patterns used in injection molding, resulting in a big obstacle for prototypes and smaller production runs. Rather than using separate cores, patterns, and shell molds, it would be advantageous to directly produce a mold that has the casting cavity and the ceramic core by one process. Ceramic stereolithography (CerSLA) can be used to directly fabricate the integrally cored ceramic casting mold (ICCM). CerSLA builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This dissertation addresses the integrally cored casting ceramic mold (ICCM), the ceramic core with a ceramic mold shell in a single patternless construction, fabricated by ceramic stereolithography (CerSLA). CerSLA is considered as an alternative method to replace lost wax processes, for small production runs or designs too complex for conventional cores and patterns. The main topic is the development of methods to successfully fabricate an ICCM by CerSLA from refractory silica, as well as related issues. The related issues are the segregation of coarse fused silica powders in a layer, the degree of segregation parameter to prevent segregation, and sintering and cristobalite transformation in fused silica compacts.

Bae, Chang-Jun

417

Über die ?-Strahlung des Protactiniums  

Microsoft Academic Search

Zusammenfassung 1. Das a-strahlende Element Protactinium emittiert, ähnlich wie Radium, Radioactinium, Actinium X, auch sekundäre ß-Strahlen. 2. Es werden Absorptionskurven dieser ß-Strahlen aufgenommen und mit analogen Absorptionskurven der ß-Strahlen des Radioaetiniums verglichen. Die zeitlichen Änderungen der Kurven geben einen weiteren Beweis dafür, daß die ß-Strahlung beim Protactinium nicht etwa von irgendwelchen Verunreinigungen herrührt. 3. Es wird die Intensität der ß-Strahlen

Otto Hahn; Aristid v. Grosse

1928-01-01

418

Graphite/Thermoplastic-Pultrusion Die  

NASA Technical Reports Server (NTRS)

Attachment to extruder produces thermoplastic-impregnated graphite tape. Consists of profile die, fiber/resin collimator, and crosshead die body. Die designed to be attached to commercially available extrusion machine capable of extruding high-performance thermoplastics. Simple attachment to commercial extruder enables developers of composites to begin experimenting with large numbers of proprietary resins, fibers, and hybrid composite structures. With device, almost any possible fiber/resin combination fabricated.

Wilson, Maywood L.; Frye, Mark W.; Johnson, Gary S.; Stanfield, Clarence E.

1990-01-01

419

Effect of process parameters on density of magnesium alloy parts by low-pressure expendable pattern casting  

Microsoft Academic Search

The combination of magnesium alloys with the low-pressure expendable pattern casting (LP-EPC) process would bright future for application of magnesium alloys. The researches are focused on the effect of process parameters on the internal casting quality of magnesium alloy parts. AZ91D magnesium alloy castings were produced for different combinations of the LP-EPC process parameters. Specifically, pouring temperature, vacuum, filling velocity

LI Ji-qiang; DONG Xuan-pu

420

Hickey, W8009C, casts 992-995 Hickey, W8009C, casts 992-995, page 1  

E-print Network

Hickey, W8009C, casts 992-995 Hickey, W8009C, casts 992-995, page 1 #12;Hickey, W8009C, casts 992-995 Hickey, W8009C, casts 992-995, page 2 #12;Hickey, W8009C, casts 992-995 Hickey, W8009C, casts 992-995, page 3 #12;Hickey, W8009C, casts 992-995 Hickey, W8009C, casts 992-995, page 4 #12;Hickey, W8009C

Hickey, Barbara

421

Cyberbullying: die Perspektive der Eltern.  

E-print Network

??Nach eingehendem Studium der Literaturbefunde wurde ersichtlich, dass das Thema Cyberbullying in Österreich noch wenig erforscht ist. Ziel dieser explorativen Studie ist die Einschätzung des… (more)

Schopper, Nathalie

2010-01-01

422

Die Ibaditen und der Oman.  

E-print Network

??Die Ibadiya als islamische Denkrichtung ist eine der ältesten innerhalb der islamischen Kulturgeschichte; neben der jahrhunderte alten Geschichte - welche in der vorliegenden Arbeit vorgestellt… (more)

Sarmini, Jasmin

2008-01-01

423

Directional migration in the Hindu castes: inferences from mitochondrial, autosomal and Y-chromosomal data.  

PubMed

Genetic, ethnographic, and historical evidence suggests that the Hindu castes have been highly endogamous for several thousand years and that, when movement between castes does occur, it typically consists of females joining castes of higher social status. However, little is known about migration rates in these populations or the extent to which migration occurs between caste groups of low, middle, and high social status. To investigate these aspects of migration, we analyzed the largest collection of genetic markers collected to date in Hindu caste populations. These data included 45 newly typed autosomal short tandem repeat polymorphisms (STRPs), 411 bp of mitochondrial DNA sequence, and 43 Y-chromosomal single-nucleotide polymorphisms that were assayed in more than 200 individuals of known caste status sampled in Andrah Pradesh, in South India. Application of recently developed likelihood-based analyses to this dataset enabled us to obtain genetically derived estimates of intercaste migration rates. STRPs indicated migration rates of 1-2% per generation between high-, middle-, and low-status caste groups. We also found support for the hypothesis that rates of gene flow differ between maternally and paternally inherited genes. Migration rates were substantially higher in maternally than in paternally inherited markers. In addition, while prevailing patterns of migration involved movement between castes of similar rank, paternally inherited markers in the low-status castes were most likely to move into high-status castes. Our findings support earlier evidence that the caste system has been a significant, long-term source of population structuring in South Indian Hindu populations, and that patterns of migration differ between males and females. PMID:15232732

Wooding, Stephen; Ostler, Christopher; Prasad, B V Ravi; Watkins, W Scott; Sung, Sandy; Bamshad, Mike; Jorde, Lynn B

2004-08-01

424

Properties and applications of molybdenum  

SciTech Connect

Metallic Moly is consolidated into commercial products by the powder-metallurgy process (P/M) and by the consumable electrode vacuum-arc casting process (VAC). Moly's high melting point and low vapor pressure at extreme temperatures justify its applications to cold wall vacuum or inert atmosphere furnace equipment. These properties, as well as Moly's high thermal conductivity and good electrical and chemical properties, lead to applications in glass-making manufacture of fibers and containers. Moly is also widely used in electronics, solid-state devices, X-ray tubes, crystal growing, heat pipes, photoetched masks, etc. TZM Moly Alloy is the best commercial high strength, high temperature material for hot-work tool applications such as die casting (even ferrous metals), hot extrusion (nonferrous and ferrous metals), hot piercing stainless steel tubes, isothermal forging tools, isothermal shape rolling, hot gas valves and seals, and hot turbine components. The Moly-30% tungsten alloy (Mo-30W) is commercially employed for its high melting temperature of 2829/sup 0/C (5125/sup 0/F) and its chemical inertness in corrosive molten zinc, especially the high purity grades. Moly and Moly-base alloys are commercially used for principally high temperature applications in hot equipment, hot working tools, and hot operating machines.

Burman, R.

1982-09-01

425

Die letzte heie Revolution und die erste coole Revolte  

E-print Network

Akteure des Spektakels mit böser Genauigkeit »Die Kinder von Karl Marx und Coca-Cola«. Der damals schon etwas ältere Karl Markus Michel, der bei Suhrkamp die erste legendäre, von Jürgen Habermas, Dieter

426

Untersuchungen über die periumbilikale Demarkationsentzündung im Hinblick auf die Lebendgeburt  

Microsoft Academic Search

Im Interesse der Klarstellung der widersprechenden Angaben in der Literatur betreffs der periumbilikalen Demarkationsentzündung haben die Verfasser 115 Nabelschnurreste histologisch untersucht` 83 der Feten waren lebend geboren und hatten 1 min bis 10 Tage nach der Geburt gelebt, die übrigen 32 waren Totgeburten. Bei der Bewertung der Demarkationsentzündung fand der Entwicklungsgrad der Feten Berücksichtigung. Das Untersuchungsmaterial wurde in drei Gruppen

I. Gy. Fazekas; F. Kósa; E. Fábrik

1969-01-01

427

Study of Thermal Fatigue of H13 Die Steel with Various Surface Treatments  

NASA Astrophysics Data System (ADS)

Surfaces of die-casting dies are subjected to very severe conditions of cyclical thermal and mechanical load, and chemical and mechanical wear. Dies mostly fail due to a combination of heat checking, erosion, corrosion and soldering. It is conceivable that appropriate surface treatments and coatings have a favourable influence on the temperature dependant performance of the surface of the die. The objective of this study was to examine various surface treatments and coatings. including shot peening, nitriding, nitro-carburizing, laser hardening and remelting, electro-spark alloying (deposition) and plasma spraying, under thermal fatigue conditions. Thermal cycling tests were conducted by alternate dipping of treated samples in an LM24 melt and in water. Results and interpretation are presented in this paper. The best thermal fatigue resistance was shown for a double surface treatment of laser hardening plus electro-spark deposition.

Ivanov, V. V.; Ferguson, W. G.; Paine, I. R.

428

Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments  

SciTech Connect

Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the pitting and intergranular corrosion resistance for both the wrought and cast duplex alloys; (3) Castings generally have better toughness than their wrought counterparts in the temperature range of �������¢����������������80���������������°C to +20���������������°C; (4) All shield metal arc (SMA) test welds in DSS castings, with recommended or over matching filler metal, indicate that welding is not a significant factor when considering DSS applications.

Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

2005-09-30

429

Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments  

SciTech Connect

Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the pitting and intergranular corrosion resistance for both the wrought and cast duplex alloys; (3) Castings generally have better toughness than their wrought counterparts in the temperature range of -80 C to +20 C; (4) All shield metal arc (SMA) test welds in DSS castings, with recommended or over matching filler metal, indicate that welding is not a significant factor when considering DSS applications.

Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

2005-09-30

430

Viscosity of casting fluxes used during continuous casting of steel  

Microsoft Academic Search

Molten flux viscosity of eighteen commercially available casting fluxes has been measured as a function of temperature in\\u000a the range of 1223 to 1723 K. Results show that, at a constant temperature, the flux viscosity is primarily dependent on the\\u000a mole fractions of SiO2 and A12O3. The calculated activation energy for viscous flow at 1573 K varies from 59 to

Michael D. Lanyi; Casimir J. Rosa

1981-01-01

431

Process development of thin strip steel casting  

SciTech Connect

An important new frontier is being opened in steel processing with the emergence of thin strip casting. Casting steel directly to thin strip has enormous benefits in energy savings by potentially eliminating the need for hot reduction in a hot strip mill. This has been the driving force for numerous current research efforts into the direct strip casting of steel. The US Department of Energy initiated a program to evaluate the development of thin strip casting in the steel industry. In earlier phases of this program, planar flow casting on an experimental caster was studied by a team of engineers from Westinghouse Electric corporation and Armco Inc. A subsequent research program was designed as a fundamental and developmental study of both planar and melt overflow casting processes. This study was arranged as several separate and distinct tasks which were often completed by different teams of researchers. An early task was to design and build a water model to study fluid flow through different designs of planar flow casting nozzles. Another important task was mathematically modeling of melt overflow casting process. A mathematical solidification model for the formation of the strip in the melt overflow process was written. A study of the material and conditioning of casting substrates was made on the small wheel caster using the melt overflow casting process. This report discusses work on the development of thin steel casting.

Sussman, R.C.; Williams, R.S.

1990-12-01

432

Permanent mold casting of titanium alloy Ti-6Al-4V  

SciTech Connect

A literature review indicated that data on the effect of various casting defects, such as inclusions and porosity, on the properties of titanium alloy castings were not readily available. This information is required to reduce the cost of fabricating titanium castings for potential automotive applications. To this end, a research project was initiated to develop data on the as-cast properties of titanium alloy Ti-6Al-4V (Ti64). Step plate castings with 3.2, 6.3, 13, and 25 mm thick steps were produced in a high-density graphite mold following melting in an induction furnace with water-cooled copper hearth. The mechanical properties were determined in the as-cast condition and were found to be close to the values reported in standards. Few casting defects such as inclusions and porosity were observed, and the loss of strength due to these defects is not significant. It is shown that titanium castings with good mechanical properties can be produced in high-density graphite molds.

Sadayappan, M. (CANMET-MTL, Ottawa, Canada); Sahoo, M. (CANMET-MTL, Ottawa, Canada); Lavender, C. (PNNL); paul.jablonski, P.D.

2008-01-01

433

Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings  

SciTech Connect

Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D and AE42 magnesium alloys cast via the permanent mold casting process was investigated. Computer simulations of the casting process predicted the development of a turbulent metal flow in a critical casting region with abrupt geometrical transitions. SEM and light optical microscopy examinations revealed the presence of folds in this region for both alloys. However, each alloy exhibited a unique mechanism responsible for fold formation. In the AZ91D alloy, melt oxidation and velocity gradients in the critical casting region prevented fusion of merging metal front streams. In the AE42 alloy, limited solubility of rare-earth intermetallic compounds in the {alpha}-Mg phase resulted in segregation of Al{sub 2}RE particles at the leading edge of a metal front and created microstructural inhomogeneity across the fold.

Bichler, L. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada); Ravindran, C., E-mail: rravindr@ryerson.ca [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada)

2010-03-15

434

Manufacture of large castings in permanent molds  

SciTech Connect

A new technological process has been introduced for manufacturing large cast-iron pulley blanks in permanent molds. The pulley casting weighs 137 kg and has a rim diameter of 650 mm. The permanent mold is split horizontally. Before pouring metal the mold is heated with a gas torch to a temperature of 200-250/sup 0/C and coated with a layer of thermal insulation material. The molten metal is poured at a temperature of 1280-1300/sup 0/C within a period of 40-50 seconds. The casting is held in the mold for 4-5 minutes. A simple pneumatic machine has been designed for ejecting the castings. The permanent mold, being made of cast iron, can be used for more than 500 castings. Introduction of the new technological process for casting pulleys in permanent molds has reduced the labor requirement by four times, eliminated rejections caused by using sand molds, and improved the working conditions.

Panin, V.I.; Baryshnikov, V.G.; Papandopoulo, A.N.

1983-01-01

435

Die Funkenspannung der elektrolytischen Ventilwirkung  

Microsoft Academic Search

Zusammenfassung Als Elektrolyte dienten Schwefelsäure, reine bei 0° C gesättigte Boraxlösung und eine bei Zimmertemperatur gesättigte Boraxlösung mit etwas Zusatz von Borsäure. -Von der Stromdichte ist die Funkenspannung völlig unabhängig. Mit der Temperatur des Elektrolyten steigt sie ein wenig an. -Wird vor den Versuchen das Al längere Zeit bei geringer Spannung vorformiert, so liegt die Funkenspannung etwas höher als ohne

Werner Bär

1935-01-01

436

Two Piece Compaction Die Design  

SciTech Connect

Compaction dies used to create europium oxide and tantalum control plates were modeled using ANSYS 11.0. Two-piece designs were considered in order to make the dies easier to assemble than the five-piece dies that were previously used. The two areas of concern were the stresses at the interior corner of the die cavity and the distortion of the cavity wall due to the interference fit between the two pieces and the pressure exerted on the die during the compaction process. A successful die design would have stresses less than the yield stress of the material and a maximum wall distortion on the order of 0.0001 in. Design factors that were investigated include the inner corner radius, the value of the interference fit, the compaction force, the size of the cavity, and the outer radius and geometry of the outer ring. The results show that for the europium oxide die, a 0.01 in. diameter wire can be used to create the cavity, leading to a 0.0055 in. radius corner, if the radial interference fit is 0.003 in. For the tantalum die, the same wire can be used with a radial interference fit of 0.001 in. Also, for the europium oxide die with a 0.003 in. interference fit, it is possible to use a wire with a diameter of 0.006 in. for the wire burning process. Adding a 10% safety factor to the compaction force tends to lead to conservative estimates of the stresses but not for the wall distortion. However, when the 10% safety factor is removed, the wall distortion is not affected enough to discard the design. Finally, regarding the europium oxide die, when the cavity walls are increased by 0.002 in. per side or the outer ring is made to the same geometry as the tantalum die, all the stresses and wall distortions are within the desired range. Thus, the recommendation is to use a 0.006 in. diameter wire and a 0.003 in. interference fit for the europium oxide die and a 0.01 in. diameter wire and a 0.001 in. interference fit for the tantalum die. The dies can also be made to have the same outer geometry if desired.

Coffey, Ethan N [ORNL

2010-03-01

437

Influence of Casting Parameters on the Critical Casting Size of Bulk Metallic Glass  

NASA Astrophysics Data System (ADS)

The effect of various casting parameters and thermophysical properties of bulk metallic glasses (BMGs) on critical section size, defined as the maximum casting size that generates a through-section amorphous alloy, has been analyzed using a simple heat-transfer model. It was found that the interfacial heat transfer between the mold and the casting has a strong influence on the critical section thickness of a BMG. It is argued herein that the critical cooling rate rather than the critical casting size is a more robust indicator of glass-forming ability (GFA). Further, with respect to the critical cooling rate and heat-transfer effects during casting, a distinct difference was found between the critical casting thickness in rectangular-shaped castings and the critical casting diameter in rod-shaped castings, and a relationship was derived for relating these parameters.

Laws, Kevin J.; Gun, Bulent; Ferry, Michael

2009-10-01

438

Casting inorganic structures with DNA molds.  

PubMed

We report a general strategy for designing and synthesizing inorganic nanostructures with arbitrarily prescribed three-dimensional shapes. Computationally designed DNA strands self-assemble into a stiff "nanomold" that contains a user-specified three-dimensional cavity and encloses a nucleating gold "seed." Under mild conditions, this seed grows into a larger cast structure that fills and thus replicates the cavity. We synthesized a variety of nanoparticles with 3-nanometer resolution: three distinct silver cuboids with three independently tunable dimensions, silver and gold nanoparticles with diverse cross sections, and composite structures with homo- and heterogeneous components. The designer equilateral silver triangular and spherical nanoparticles exhibited plasmonic properties consistent with electromagnetism-based simulations. Our framework is generalizable to more complex geometries and diverse inorganic materials, offering a range of applications in biosensing, photonics, and nanoelectronics. PMID:25301973

Sun, Wei; Boulais, Etienne; Hakobyan, Yera; Wang, Wei Li; Guan, Amy; Bathe, Mark; Yin, Peng

2014-11-01

439

TiC reinforced cast Cr steels  

SciTech Connect

A new class of materials, namely TiC-reinforced cast chromium (Cr) steels, was developed for applications requiring high abrasion resistance and good fracture toughness. The research approach was to modify the carbide structure of commercial AISI 440C steel for better fracture resistance while maintaining the already high abrasion resistance. The new alloys contained 12Cr, 2.5–4.5Ti, and 1–1.5C (wt.%) and were melted in a vacuum induction furnace. Their microstructure was composed primarily of a martensitic matrix with a dispersion of TiC precipitates. Modification of TiC morphology was accomplished through changing the cooling rate during solidification. Wear rates of the TiC-reinforced Cr steels were comparable to that of AISI 440C steel, but the impact resistance was much improved.

Dogan, O.N.; Hawk, J.A.; Schrems, K.K.

2006-06-01

440

General requirement for effective overburden casting  

SciTech Connect

Effective overburden casting requires the efficient use of todays explosives and initiations systems if a mine is to survive. This paper uses a major coal stripping operation as an example of the proper application of explosives and initiation system to their conditions. High speed photography, rock analysis and computer modeling were used to assist in determining the effective use of the explosives and the initiation systems. The high speed photography confirmed the computer modeling done by SABREX, the Scientific Approach to Blasting Rock with Explosives developed by ICI Explosives world group of companies. The major coal company used in this paper mines the 36 inch Sewanee coal seam in Tennessee for TVA steam generation. The overburden is usually in excess of 100 ft. of sandstone.

Cook, J.D. [Tennessee Nitrate Technology, Inc., Dunlap, TN (United States); McCutchen, D. [ICI Explosives USA Inc., Roswell, GA (United States)

1994-12-31

441

Casting Alloys: Side-Effects  

Microsoft Academic Search

Side-effects from dental materials are a minor problem, but should be recognized. In recent questionnaire surveys about side-effects, the incidence was estimated to be 1:300 in periodontics and 1:2600 in pedodontics. None of these reactions was related to dental casting alloys. In prosthodontics, the incidence was calculated to be about 1:400, and about 27% were related to base-metal alloys forremovable

Arne Hensten-Pettersen

1992-01-01

442

Silicon cast wafer recrystallization for photovoltaic applications  

E-print Network

Current industry-standard methods of manufacturing silicon wafers for photovoltaic (PV) cells define the electrical properties of the wafer in a first step, and then the geometry of the wafer in a subsequent step. The ...

Hantsoo, Eerik T. (Eerik Torm)

2008-01-01

443

Hickey, W8009C, casts 1-9 Hickey, W8009C, casts 1-9, page 1  

E-print Network

Hickey, W8009C, casts 1-9 Hickey, W8009C, casts 1-9, page 1 #12;Hickey, W8009C, casts 1-9 Hickey, W8009C, casts 1-9, page 2 #12;Hickey, W8009C, casts 1-9 Hickey, W8009C, casts 1-9, page 3 #12;Hickey, W8009C, casts 1-9 Hickey, W8009C, casts 1-9, page 4 #12;Hickey, W8009C, casts 1-9 Hickey, W8009C, casts

Hickey, Barbara

444

Wie LCC-Management die Produktionstechnik und die Instandhaltung verändert  

NASA Astrophysics Data System (ADS)

Die zunehmende Komplexität von Produktionsanlagen und deren steigende Investitionssummen erfordern eine intensive Nutzung und überschaubare Folgekosten, zum Beispiel in der Instandhaltung. Um diese Ziele beim Investitionsvorgang von Anlagen effizienter als in der Vergangenheit zu gestalten sind Organisationsverfahren wie Life Cycle Cost Management (LCC-Management) bzw. Total Cost of Ownership (TCO) sinnvoll. Dieser Beitrag zeigt, wie Hersteller und Betreiber bis heute mit diesen Verfahren die Auslegung und das Betriebsverhalten von Anlagen entwickeln, deren reduzierten Instandhaltungsaufwand prognostizieren und die Leistungen zum Vorteil beider Vertragspartner steigern.

Zick, Manfred

445

Clean Ferrous Casting Technology Research. Annual report, September 29, 1993--September 28, 1994  

SciTech Connect

This annual report covers work performed in the first year of research on Clean Ferrous Casting Technology Research. During this year the causes of penetration of cast iron in sand molds were defined and a program which predicts the occurrence of penetration was written and verified in commercial foundries. Calculations were made to size a reaction chamber to remove inclusions from liquid steel using electromagnetic force and the chamber was built. Finally, significant progress was made in establishing pouring practices which avoid re-oxidation of steel during pouring application of revised pouring practices have led to reduced inclusion levels in commercially poured steel castings.

Stefanescu, D.M.; Lane, A.M.; Giese, S.R.; Pattabhi, R.; El-Kaddah, N.H.; Griffin, J.; Bates, C.E.; Piwonka, T.S.

1994-10-01

446

Development of Lead-Free Copper Alloy-Graphite Castings  

SciTech Connect

In this project, graphite is used as a substitute for lead in order to maintain the machinability of plumbing components at the level of leaded brass. Graphite dispersed in Cu alloy was observed to impart good machinability and reduce the sizes of chips during machining of plumbing components in a manner similar to lead. Copper alloys containing dispersed graphite particles could be successfully cast in several plumbing fixtures which exhibited acceptable corrosion rate, solderability, platability, and pressure tightness. The power consumption for machining of composites was also lower than that of the matrix alloy. In addition, centrifugally cast copper alloy cylinders containing graphite particles were successfully made. These cylinders can therefore be used for bearing applications, as substitutes for lead-containing copper alloys. The results indicate that copper graphite alloys developed under this DOE project have a great potential to substitute for lead copper alloys in both plumbing and bearing applications.

Rohatgi, P.K. [Univ. of Wisconsin-Milwaukee (US)

1999-10-01

447

Development and Demonstration of Adanced Tooling Alloys for Molds and Dies  

SciTech Connect

This report summarizes research results in the project Development and Demonstration of Advanced Tooling Alloys for Molds and Dies. Molds, dies and related tooling are used to manufacture most of the plastic and metal products we use every day. Conventional fabrication of molds and dies involves a multiplicity of machining, benching and heat treatment unit operations. This approach is very expensive and time consuming. Rapid Solidifcation Process (RSP) Tooling is a spray-forming technology tailored for producing molds and dies. The appraoch combines rapid solidifcation processing and net-shape materials processing in a single step. An atomized spray of a tool-forming alloy, typically a tool steel, is deposited onto an easy-to-form tool pattern to replicate the pattern's shape and surface features. By so doing, the approach eliminates many machining operations in conventional mold making, significantly reducing cost, lead time and energy. Moreover, rapid solidification creates unique microstructural features by suppressing carbide precipitation and growth, and creating metastable phases. This can result in unique material properties following heat treatment. Spray-formed and aged tool steel dies have exhibited extended life compared to conventional dies in many forming operations such as forging, extrusion and die casting. RSP Tooling technolocy was commercialized with the formation of RSP Tooling, LLC in Solon, Oh.

Kevin M. McHugh; Enrique J. Lavernia

2006-01-01

448

Gating of Permanent Molds for ALuminum Casting  

SciTech Connect

This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

David Schwam; John F. Wallace; Tom Engle; Qingming Chang

2004-03-30

449

Segregation at halfway cracks in continuously cast steel  

Microsoft Academic Search

The mechanism of hot-short embrittlement in a continuously cast steel was explored through application of Auger electron spectroscopy\\u000a (AES) and Secondary Ion Mass Spectrometry. The AES results demonstrated that the interdendritic fracture surface of previously\\u000a cracked specimens were highly oxidized with a relatively high sulfur concentration. These results were confirmed with the\\u000a ion microprobe. AES results showing sulfur segregation to

F. Weinberg; H. Odelius; W. C. Johnson

1979-01-01

450

PromoCast™: A New Forecasting Method for Promotion Planning  

Microsoft Academic Search

This article describes the implementation of a promotion-event forecasting system, PromoCast™, and its performance in several pilot applications and validity studies. Pilot studies involved retail grocery chains with 95 to 185 stores per trading area. The goal was to provide short-term, tactical forecasts useful for planning promotions from a retailer's perspective. Thus, the forecast system must be able to handle

Lee G. Cooper; Penny Baron; Wayne Levy; Michael Swisher; Paris Gogos

1999-01-01

451

A numerical simulation of the D.C. continuous casting process including nucleate boiling heat transfer  

Microsoft Academic Search

The steady-state thermal problem associated with the direct-chill continuous casting of A6063 aluminum cylindrical ingots\\u000a is solved using the numerical finite element technique. Excellent correlation is demonstrated between the numerical model\\u000a and experimental data from ingots cast at two different speeds. By application of the model, effective heat transfer coefficients\\u000a are calculated as a function of vertical position on the

D. C. Weckman; P. Niessen

1982-01-01

452

A numerical simulation of the D.C. continuous casting process including nucleate boiling heat transfer  

Microsoft Academic Search

The steady-state thermal problem associated with the direct-chill continuous casting of A6063 aluminum cylindrical ingots\\u000a is solved using the numerical finite element technique. Excellent correlation is demonstrated between the numerical model\\u000a and experimental data from ingots cast at two different speeds. By application of the model, effective heat transfer coefficients\\u000a are calculated as a function of vertical position on the

D. C. Weckman; P. Niessen

1992-01-01

453

Morphological characterization of ? phase in poly-(vinylidenefluoride) film prepared by spin cast method  

SciTech Connect

Poly-(Vinylidene fluoride) PVDF film was prepared by spin casting method to control the pore size of the matrix. The morphological spherulitic structure was confirmed Scanning Electron Microscopy (SEM) after gold sputtering and the presence of ? phase was ensured in spin cast PVDF film by the FTIR spectroscopy. The ? phase is very important in the application because it improve the properties like piezoelectricity by modifying PVDF crystallinity.

Mehtani, Hitesh Kumar, E-mail: kkraina@gmail.com; Kumar, Rishi, E-mail: kkraina@gmail.com; Raina, K. K., E-mail: kkraina@gmail.com [School of Physics and Materials Science, Thapar University, Patiala-147004 (India)

2014-04-24

454

Casting an Object with a Core Hee-Kap Ahn  

E-print Network

Casting an Object with a Core Hee-Kap Ahn Sang Won Bae Siu-Wing Cheng Kyung-Yong Chwa Abstract This paper addresses geometric problems that concern manufacturing an object using a cast with a core. In casting, molten material is poured into the cavity of the cast and allowed to solidify. The cast has two

Cheng, Siu-Wing

455

Die Gleichnisse von dem Wahlverwandschaften  

E-print Network

KU ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Die Gleichnisse von dem Wahlverwandschaften 1911 by Mattie Kent This work was digitized by the KU Libraries’ Office of Scholarly Communication and Copyright...

Kent, Mattie

1911-01-01

456

Die fermentative Spaltung des Acetylcholins  

Microsoft Academic Search

Zusammenfassung Es wird eine neue Methode zum Nachweis des Fermentes, das Acetylcholin in Cholin und Essigsäure hydrolysiert, die Cholinesterase, beschrieben. Das Verfahren ist nach derWarburgschen Methode aufgebaut.

R. Ammon

1934-01-01

457

Improving care of dying children.  

PubMed Central

Every year about 5,000 children aged 0 to 14 years need hospice care in the United States. Children seem to know that they are dying, although this is difficult for parents to accept. Clear, empathic understanding is needed. Communication with clarity and understanding is imperative with the changes in goals from cure to palliation to comfort. The ideal place for most dying children is at home, where symptoms can be managed as effectively as in a hospital. PMID:7571589

Martinson, I M

1995-01-01

458

Release of ToxCastDB and ExpoCastDB databases  

EPA Science Inventory

EPA has released two databases - the Toxicity Forecaster database (ToxCastDB) and a database of chemical exposure studies (ExpoCastDB) - that scientists and the public can use to access chemical toxicity and exposure data. ToxCastDB users can search and download data from over 50...

459

Hickey, W8010A casts 1-6 Hickey, W8010A casts 1-6, page 1  

E-print Network

Hickey, W8010A casts 1-6 Hickey, W8010A casts 1-6, page 1 CTD001 #12;Hickey, W8010A casts 1-6 Hickey, W8010A casts 1-6, page 2 CTD001 #12;Hickey, W8010A casts 1-6 Hickey, W8010A casts 1-6, page 3 CTD001 #12;Hickey, W8010A casts 1-6 Hickey, W8010A casts 1-6, page 4 CTD001 #12;Hickey, W8010A casts 1

Hickey, Barbara

460

Transformation of nitrogen compounds and dynamics of microbial biomass in fresh casts of Aporrectodea caliginosa  

NASA Astrophysics Data System (ADS)

A comparative assessment of the contents of total nitrogen, ammonium, nitrates, and fungal and bacterial biomasses and of the activity of nitrogen transformation in fresh casts of Aporrectodea caliginosa and in a soddy-podzolic soil was performed. The total content of nitrogen in the casts was similar to or slightly higher than that in the soil; the content of inorganic forms of nitrogen in the casts was significantly higher than in the soil. The intensities of ammonification, nitrification, and denitrification and the pool of microbial biomass with a predominance of fungi during the 1.5-week-long incubation were also significantly higher in the casts. The activity of nitrogen fixation in the casts was lower than that in the soil. In the course of the incubation, the values of these parameters in the casts became closer to those in the soil. The inhibition of fungi in the casts with cycloheximide resulted in an increasing content of inorganic nitrogen and a higher activity of denitrification. In our opinion, this phenomenon is related to the fact that limitation of the fungal growth decreases the intensity of immobilization of nitrates and the fungal competition with denitrifying bacteria for available carbon. It was supposed that the activation of the fungal growth via application of plant substrates into the soil with a high population density of earthworms could suppress the emission of gaseous nitrogen compounds. The soil processing by earthworms had a positive effect on the soil properties.

Kharin, S. A.; Kurakov, A. V.

2009-01-01

461

Gating of Permanent Molds for Aluminum Casting  

SciTech Connect

This report summarizes a two-year project, DE-FC07-011D13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. Other studies have been conducted using water flow and behavior of liquid aluminum in sand mold using real time photography. This investigation utilizes graphite molds transparent to X-Rays making it possible to observe the flow pattern through a number of vertically oriented grating systems. These have included systems that are choked at the base of a rounded vertical sprue and vertical gating systems with a variety of different ingates into the bottom of a mold cavity. These systems have also been changed to include gating systems with vertical and horizontal gate configurations. Several conclusions can be derived from this study. A sprue-well, as designed in these experiments, does not eliminate the vena contracta. Because of the swirling at the sprue-base, the circulating metal begins to push the entering metal stream toward the open runner mitigating the intended effect of the sprue-well. Improved designs of sprue-wells should be evaluated. In order for a runner extension to operate efficiently, it must have a small squared cross-section. If it is tapered, the first metal to enter the first metal to enter the system is not effectively trapped. If the cross section is large, there is less turbulence when the aluminum enters the mold cavity in comparison to the smaller cross sectioned, squared runner. However, a large runner reduces yield. In bottom-feeding gating systems, a filter can significantly improve the filling of the casting. The filter helps to slow the metal flow rate enough to reduce jetting into the mold cavity. In top feeding gating systems, a filter can initially slow the metal flow rate, but because the metal drops after passing the filter, high velocities are achieved during free fall when a filter is in place. Side feeding gating systems provide less turbulent flow into the mold cavity. The flow is comparable to a bottom-feeding gating system with a filter. Using properly designed side-gating system instead of a bottom-feeding system with a filter can potentially save the cost of the filter. Rough coatings promote better fill than smooth coatings. This conclusion seems at first counter intuitive. One tends to assume a rough coating creates more friction resistance to the flow of molten metal. In actuality the molten aluminum stream flows inside an oxide film envelope. When this film rests on top of the ridges of a rough coating the microscopic air pockets between the coating and the oxide film provide more thermal insulation than in a smooth coating. This insulation promotes longer feeding distances in the mold as demonstrated in the experiments. Much of this work is applicable to vertically parted sand molds as well, although the heat transfer conditions do vary from a metal mold generally used in permanent molding of aluminum. The flow measurements were conducted using graphite molds and real time X-Ray radiography recorded at a rate of 30 images per second through those molds. The facilities at Arrow Aluminum Foundry were used in the study. The resu

David Schwam; John F. Wallace; Tom Engle; Qingming Chang

2004-01-01

462

AN INTRODUCTION TO R-CAST Developing Simple Agents Using Decision-making Modeling and the R-CAST Architecture  

E-print Network

AN INTRODUCTION TO R-CAST Developing Simple Agents Using Decision-making Modeling and the R-CAST and Technology The Pennsylvania State University #12;ALL RIGHTS RESERVED © 2006. This R-CAST tutorial, the R-CAST. Prindible For more information. Visit: http://agentlab.psu.edu/ 2 #12;R-CAST 2.5 SYSTEM REQUIREMENTS Minimum

463

Yield Improvement in Steel Casting (Yield II)  

SciTech Connect

This report presents work conducted on the following main projects tasks undertaken in the Yield Improvement in Steel Casting research program: Improvement of Conventional Feeding and Risering Methods, Use of Unconventional Yield Improvement Techniques, and Case Studies in Yield Improvement. Casting trials were conducted and then simulated using the precise casting conditions as recorded by the participating SFSA foundries. These results present a statistically meaningful set of experimental data on soundness versus feeding length. Comparisons between these casting trials and casting trials performed more than forty years ago by Pellini and the SFSA are quite good and appear reasonable. Comparisons between the current SFSA feeding rules and feeding rules based on the minimum Niyama criterion reveal that the Niyama-based rules are generally less conservative. The niyama-based rules also agree better with both the trials presented here, and the casting trails performed by Pellini an d the SFSA years ago. Furthermore, the use of the Niyama criterion to predict centerline shrinkage for horizontally fed plate sections has a theoretical basis according to the casting literature reviewed here. These results strongly support the use of improved feeding rules for horizontal plate sections based on the Niyama criterion, which can be tailored to the casting conditions for a given alloy and to a desired level of soundness. The reliability and repeatability of ASTM shrinkage x-ray ratings was investigated in a statistical study performed on 128 x-rays, each of which were rated seven different times. A manual ''Feeding and Risering Guidelines for Steel Castings' is given in this final report. Results of casting trials performed to test unconventional techniques for improving casting yield are presented. These use a stacked arrangement of castings and riser pressurization to increase the casting yield. Riser pressurization was demonstrated to feed a casting up to four time s the distance of a non-pressurized riser, and can increase casting yield by decreasing the required number of risers. All case studies for this projects were completed and compiled into an SFSA Technical Report that is submitted part of this Final Report

Richard A. Hardin; Christoph Beckermann; Tim Hays

2002-02-18

464

Clean cast steel technology. Final report  

SciTech Connect

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.

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

1998-06-01

465

Effects of alloy composition and casting speed on structure formation and hot tearing during direct-chill casting of Al-Cu alloys  

NASA Astrophysics Data System (ADS)

Effects of casting speed and alloy composition on structure formation and hot tearing during direct-chill (DC) casting of 200-mm round billets from binary Al-Cu alloys are studied. It is experimentally shown that the grain structure, including the occurrence of coarse grains in the central part of the billet, is strongly affected by the casting speed and alloy composition, while the dendritic arm spacing is mostly dependent on the casting speed. The hot cracking pattern reveals the maximum hot-tearing susceptibility in the range of low-copper alloys (1 to 1.5 pct) and at high casting speeds (180 to 200 mm/min). The clear correlation between the amount of nonequilibrium eutectics (representing the reserve of liquid phase in the last stage of solidification) and hot tearing is demonstrated. A casting speed-copper concentration-hot-tearing susceptibility chart is constructed experimentally for real-scale DC casting. Computed dimensions of the solidification region in the billet are used to explain the experimentally observed structure patterns and hot cracking. Thermomechanical finite-element simulation of the solidifying billet was used as a tool for testing the applicability to DC casting of several hot-tearing criteria based on different principles. The results are compared to the experimentally observed hot tearing. It is noted that hot-tearing criteria that account for the dynamics of the process, e.g., strain rate, actual stress-strain situation, feeding rate, and melt flow, can be successfully used for the qualitative prediction of hot tearing.

Suyitno; Savran, V. I.; Katgerman, L.; Eskin, D. G.

2004-11-01

466

76 FR 13665 - Cambridge Tool & Die, Including On-Site Leased Workers From Action Total Staffing, Cambridge, OH...  

Federal Register 2010, 2011, 2012, 2013

...Administration [TA-W-74,605] Cambridge Tool & Die, Including On-Site Leased Workers From...applicable to workers of Cambridge Tool & Die, Cambridge, Ohio. The workers are engaged...Cambridge, Ohio location of Cambridge Tool & Die Corporation. The Department has...

2011-03-14

467

21 CFR 888.5960 - Cast removal instrument.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 2012-04-01 false Cast removal instrument. 888.5960 Section...DEVICES Surgical Devices § 888.5960 Cast removal instrument. (a) Identification. A cast removal instrument is an AC-powered,...

2012-04-01

468

21 CFR 888.5960 - Cast removal instrument.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Cast removal instrument. 888.5960 Section...DEVICES Surgical Devices § 888.5960 Cast removal instrument. (a) Identification. A cast removal instrument is an AC-powered,...

2013-04-01

469

21 CFR 888.5960 - Cast removal instrument.  

... 2014-04-01 2014-04-01 false Cast removal instrument. 888.5960 Section...DEVICES Surgical Devices § 888.5960 Cast removal instrument. (a) Identification. A cast removal instrument is an AC-powered,...

2014-04-01

470

21 CFR 888.5960 - Cast removal instrument.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Cast removal instrument. 888.5960 Section...DEVICES Surgical Devices § 888.5960 Cast removal instrument. (a) Identification. A cast removal instrument is an AC-powered,...

2010-04-01

471

21 CFR 888.5960 - Cast removal instrument.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 2011-04-01 false Cast removal instrument. 888.5960 Section...DEVICES Surgical Devices § 888.5960 Cast removal instrument. (a) Identification. A cast removal instrument is an AC-powered,...

2011-04-01

472

Blast casting requires fresh assessment of methods  

SciTech Connect

The article says that because blast casting differs from conventional blasting, our ideas about explosive products, drilling, and initiating methods must change. The author discusses how to select a casting explosive and what factors are important in its selection. He also looks at how to determine the best blasthole diameter and burden blasting pattern.

Pilshaw, S.R.

1987-08-01

473

Level Responsive Control with Continuous Casting  

Microsoft Academic Search

REFERENCES TO THE concept of continuous casting of metals are found in literature dating as far back as 1840. Machines were actually constructed in the mid 1800s for the continuous casting of long sections, such as pipes, of nonferrous materials. Since that time, there have been many modifications of the basic ideas, and a large percentage of nonferrous materials are

Torrence E. DeViney; L. J. Penkowski

1965-01-01

474

Control of semicontinuous aluminum casting process  

Microsoft Academic Search

In a semicontinuous casting process, the metal level is controlled by the inflow of liquid metal. The quality of the cast product depends on the accuracy of the mold level control. There is a need for a control strategy giving better results than the fixed parameter controller and simple enough to be implemented on the existing control structure, in order

A. Besancon-Voda; C. Delclos

1998-01-01

475

The CAST (Childhood Asperger Syndrome Test)  

ERIC Educational Resources Information Center

The Childhood Asperger Syndrome Test (CAST) is a parental questionnaire to screen for autism spectrum conditions. In this validation study, the CAST was distributed to 1925 children aged 5-11 in mainstream Cambridgeshire schools. A sample of participants received a full diagnostic assessment, conducted blind to screen status. The sensitivity of…

Williams, Jo; Scott, Fiona; Stott, Carol; Allison, Carrie; Bolton, Patrick; Baron-Cohen, Simon; Brayne, Carol

2005-01-01

476

Bone response to machined cast titanium implants  

Microsoft Academic Search

The aim was to evaluate the bone response to machined cast titanium (Ti) implants. Commercially pure (c.p.) machined Ti implants served as controls. Analyses of the surface composition and topography by Auger electron spectroscopy (AES) and scanning electron microscopy (SEM) revealed no differences comparing the two materials. Cast screw-shaped and identical machined Ti implants were inserted in the tibial metaphysis

S. Mohammadi; M. Esposito; L. Wictorin; B.-O. Aronsson; P. Thomsen

2001-01-01

477

Iron/Phosphorus Alloys for Continuous Casting  

NASA Technical Reports Server (NTRS)

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.

Dufresne, E. R.

1986-01-01

478

Thermomechanical model of a continuous casting process  

Microsoft Academic Search

A model for the analysis of thermal stresses arising at the early stage of a continuous casting process is proposed. The model is used to simulate the casting of round billets assuming axial symmetry. Thermal analysis takes into account phase-change in the material and heat transfer through the mould. The heat balance equation is solved using an Eulerian formulation for

A. E. Huespe; A. Cardona; V. Fachinotti

2000-01-01

479

Slip casting and nitridation of silicon powder  

NASA Technical Reports Server (NTRS)

Powdered Silicon was slip-cast with a CaSO4 x 0.5H2O mold and nitrided in a N atm. containing 0 or 5 vol. % H at 1000 to 1420 deg. To remove the castings, the modeling faces were coated successively with an aq. salt soap and powdered cellulose containing Na alginate, and thus prevented the sticking problem.

Seiko, Y.

1985-01-01

480

Dimensional variability of production steel castings  

SciTech Connect

Work is ongoing to characterize the dimensional variability of steel casting features. Data are being collected from castings produced at representative Steel Founders` Society of America foundries. Initial results based on more than 12,500 production casting feature measurements are presented for carbon and low alloy steel castings produced in green sand, no-bake, and shell molds. A comprehensive database of casting, pattern, and feature variables has been developed so that the influence of the variables on dimensional variability can be determined. Measurement system analysis is conducted to insure that large measurement error is not reported as dimensional variability. Results indicate that the dimensional variability of production casting features is less than indicated in current US (SFSA) and international (ISO) standards. Feature length, casting weight, parting line and molding process all strongly influence dimensional variability. Corresponding pattern measurements indicate that the actual shrinkage amount for casting features varies considerably. This variation in shrinkage will strongly influence the ability of the foundry to satisfy customer dimensional requirements.

Peters, F.E.; Risteu, J.W.; Vaupel, W.G.; DeMeter, E.C.; Voigt, R.C.

1994-12-31

481

Aqueous tape casting of silicon nitride  

Microsoft Academic Search

Slurries consisting of a low cost silicon nitride powder, sintering aids yttria and alumina, dispersants, binders, defoamers and water as a solvent were optimised for tape casting by electroacoustic and viscosity measurements and by casting experiments. The slurries exhibit shear-thinning behaviour due to the highly shear-thinning binder emulsion. Crack free tapes with a maximum thickness of approx. 250 ?m and

Bernd Bitterlich; Jürgen G Heinrich

2002-01-01

482

Knee motion in a long leg cast  

Microsoft Academic Search

Five principles to reestablish static ligamentous sta bility are introduced, including secure, temporary, ti biofemoral fixation to protect against early postoper ative stretch or disruption. The necessity for empha sizing this point is demonstrated by a cadaver study. Knee motion in and out of long leg plaster casts was carefully studied in necropsy specimens. Casts ap plied over minimal or

Kenneth A. Krackow; William Laughlin Vetter

1981-01-01

483

Live and let die  

PubMed Central

Gene transfer into hematopoietic stem cells (HSC) provides a potential means of correcting monogenic defects and altering drug sensitivity of normal bone marrow to cytotoxic agents. These applications have significant therapeutic potential but the translation of successful murine studies into human therapies has been hindered by low gene transfer in large animals (including humans), and recent serious side effects in a human immunodeficiency trial related to insertional mutagenesis. The latter trial, along with other subsequent trials, while bringing into focus the potential risks of integrating vector systems, also clearly demonstrate the potential usefulness of in vivo selection as it relates to inefficient stem cell transduction. Developing from initial studies by our group and other investigators in which drug resistance was utilized to demonstrate the feasibility of using gene transfer to effect protection from myelotoxicity of chemotherapeutic agents, expression of mutant forms of O6-methyguanine-DNA-methytransferase (MGMT) coupled with the simultaneous use of pharmacologic inhibitors and chemotherapeutic agents has been shown to provide a powerful method to select HSC in vivo. While stem and progenitor cell protection and resulting selection in vivo has potential applications for the treatment of selected cancers (allowing dose escalation) andor correction of monogenic disease (allowing an iatrogenic survival advantage of transduced cells in vivo), such an in vivo selection may have untoward effects on stem cell behavior. These deleterious effects may include stem cell exhaustion; lineage skewing; accumulation of genotoxic lesions; and clonal dominance driven towards a pro-leukemic phenotype. Knowledge of the likelihood of such deleterious events occurring as well as their potential implications will be critical to future clinical applications and may also enhance our understanding of both normal stem cell behavior and the evolution of hematopoietic malignancies. PMID:17482893

Milsom, Michael D.; Williams, David A.

2007-01-01

484

Prediction of Cooling Curves for Squeeze Cast Al/SiCp Composites Using Finite Element Analysis  

NASA Astrophysics Data System (ADS)

This paper reports the experimental and finite element analyses of the solidification behavior of Al/SiCp composites, fabricated by the squeeze casting technique. Experiments were carried out by varying the melt temperatures for cylindrical-shaped composite castings. The composite samples were produced at the following constant temperatures: melt—1023 K, 1073 K, 1123 K, and 1173 K (750 °C, 800 °C, 850 °C, and 900 °C); and die—673 K (400 °C). The pressure applied throughout the experiment is 100 MPa. The melt temperature shows significant influence on the solidification behavior of the metal matrix composite. It was observed that the solidification time was 40 seconds when the melt temperature was 1023 K (750 °C) but it increased to 51 seconds when the melt temperature was at 1173 K (900 °C). The results also showed that the cooling rate decreased on increasing the melt temperature. Cooling curves for our system, squeeze cast composites, were predicted using the finite element software ANSYS. K-type thermocouples were interfaced to the die and the microcomputer from which the experimental cooling curves were constructed. The experimental and predicted cooling curves were then compared. While both show similar trends, the finite element analysis consistently under-predicts the temperature. In addition, finite element stress analysis reveals that both radial and tangential thermal stresses increase with the melt temperature.

Gurusamy, P.; Balasivanandha Prabu, S.; Paskaramoorthy, R.

2015-01-01

485

Dying Calls for Mother: Factual or Fanciful?  

Microsoft Academic Search

There are anecdotal family reports of dying members vocalizing “mother” and cognate words. Do these dying words reflect fanciful accounts at the highly charged time of death, or are there such dying words from reliable witnesses? A search of the professional care literature found minimal relevant information, but nonfiction and fiction sources of combat deaths provided examples of dying warriors

Roy B. Lacoursiere

2010-01-01

486

Innovations in cold forging die design  

Microsoft Academic Search

The demand of the market to the major industrial cold forgers for the development and production of complicated net shape parts at fairly low unit costs requires innovative new die designs for the optimisation of die deflections. The high-stiffness STRECON® E+ containers influence the stresses, strains, and deflections in critical dies so that die lives can be improved by factors

Jens Groenbaek; Torben Birker

2000-01-01

487

Die kombinierte Kompressionsmarknagelarthrodese von OSG und USG  

Microsoft Academic Search

Zusammenfassung Die operative Versteifung von oberem (OSG) und unterem Sprunggelenk (USG) ist bei fortgeschrittenen degenerativen Veränderungen beider Gelenke unterschiedlicher Genese auch bei zunehmender Verbreitung des Oberflächenersatzes am OSG die Therapie der Wahl. Bisher sind verschiedene Techniken zur tibiotalokalkanealen Arthrodese beschrieben worden, wobei sich die Kompressionsarthrodese mit internen Implantaten durchgesetzt hat. 20 Patienten, bei denen die kombinierte Arthrodese von OSG und

M. Goebel; T. Mückley; L. Gerdesmeyer; M. Militz; V. Bühren

2003-01-01

488

USAMP Magnesium Powertrain Cast Components: Fundamental research summary  

NASA Astrophysics Data System (ADS)

The Magnesium Powertrain Cast Components (MPCC) Project is an effort, jointly sponsored by the U.S. Department of Energy and the U.S. Automotive Materials Partnership (USAMP), to demonstrate the readiness of magnesium for use in powertrain applications by testing a set the magnesium-intensive engines which were designed, cast, and assembled. A second MPCC goal is to promote new and strengthen existing magnesium scientific research in North America. The project investigated several of the newly developed high-temperature (creep-resistant) magnesium alloys, which will potentially experience service conditions in the temperature range of 150-200°C and about 50-110 MPa in stresses (typical powertrain). However, the mechanical and physical behaviors of these new alloys are not fully understood. This article outlines MPCC-supported fundamental scientific r