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1

Casting Technology.  

ERIC Educational Resources Information Center

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

Wright, Michael D.; And Others

1992-01-01

2

Electroslag Casting.  

National Technical Information Service (NTIS)

The report contains an examination of the most important characteristics of the physico-mechanical properties of electroslag cast metal in comparison with the properties of open hearth steel, subjected to deformation by forging or used in the cast form.

B. E. Paton B. I. Medovar G. A. Boiko

1975-01-01

3

Die Casting.  

National Technical Information Service (NTIS)

Contents: Mechanical properties of creep resistant zinc die casting alloys; Studies on a gravity die cast zinc base alloy; Parashot system for turbulence-free injection of metal; Zinc--the versatile metal; Prevention of metal dribble on hot chamber die ca...

1977-01-01

4

Investment casting  

SciTech Connect

Materials and manufacturing technologies for investment casting have made impressive gains over the past several years, resulting in higher productivity, shorter lead times, and superior castings. To improve efficiency, investment casters have applied total quality control methods, new management concepts, and computer controls. Management and production efficiency improvements have been critical factors in maintaining and expanding market share.

Bidwell, H.T. [Investment Casting Inst., Dallas, TX (United States)

1996-04-01

5

Special Casting Techniques (Chapter 9).  

National Technical Information Service (NTIS)

Special casting techniques are progressive production methods. These casting techniques include the following: metal mold casting (chill mold casting), shell-mold casting, investment casting, centrifugal casting, and others. Each of these methods of casti...

N. P. Dubinin

1965-01-01

6

CASTING FURNACES  

DOEpatents

A device is described for casting uranium which comprises a crucible, a rotatable table holding a plurality of molds, and a shell around both the crucible and the table. The bottom of the crucible has an eccentrically arranged pouring hole aligned with one of the molds at a time. The shell can be connected with a vacuum.

Ruppel, R.H.; Winters, C.E.

1961-01-01

7

Project CAST.  

ERIC Educational Resources Information Center

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

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

8

Cast Aluminum Structures Technology, Phase III (Cast).  

National Technical Information Service (NTIS)

The objective of CAST is to establish the necessary structural and manufacturing technologies and to demonstrate the validate the integrity, producibility, and viability of cast aluminum primary airframe structures. The baseline design is the AMST prototy...

D. Goehler

1978-01-01

9

INTERIOR VIEW WITH CASTING MACHINE AND CASTING FOREMAN OBSERVING OPERATION ...  

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

INTERIOR VIEW WITH CASTING MACHINE AND CASTING FOREMAN OBSERVING OPERATION TO ENSURE MAXIMUM PRODUCTION AND QUALITY. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

10

Titanium Castings Today.  

National Technical Information Service (NTIS)

Titanium castings weighing from a few grams to over half a ton are being produced. Three foundries produce castings in rammed graphite molds chiefly for applications where high resistance to corrosion is important. Three other foundries use investment mol...

J. G. Kura

1973-01-01

11

Casting Characteristics of Aluminum Die Casting Alloys  

Microsoft Academic Search

The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a

Makhlouf M. Makhlouf; Diran Apelian

2002-01-01

12

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

13

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

14

Egyptian Caste System  

NSDL National Science Digital Library

Understand the culture, character, and societal characteristics of different classes in the ancient Egyptian caste system Understand the culture, character, and societal characteristics of different classes in the ancient Egyptian caste system Go to these sites to learn about the Egyptian Caste System ...

Issen, Ms.

2009-09-17

15

Advances in aluminum casting technology  

SciTech Connect

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

Tiryakioglu, M.; Campbell, J. (eds.)

1998-01-01

16

Tape Casting Method and Tape Cast Materials.  

National Technical Information Service (NTIS)

A precursor tape casting method is one in which chemical precursors are converted into a final chemical phase from green tapes to products. Because chemical precursors are employed rather than the final powder materials, sintering is not required to form ...

D. Xiao M. Wu S. Hui Y. Zhang

2005-01-01

17

Casting Design Knowledge Management  

Microsoft Academic Search

India has a global competitive advantage in medium-volume engineering-intensive metal products, such as automobile castings. To maintain and enhance this advantage, foundries need to adopt a systematic approach to preserve and reuse their in-house knowledge accumulated through years of experience. In this paper, we present a casting knowledge management system that facilitates: (1) capturing and updating casting knowledge in the

B. Ravi

18

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

19

Some Economic Implications of Caste  

Microsoft Academic Search

This paper compares outcomes across two types of villages in a poor region of rural India. The two types of villages systematically vary by which caste is dominant, i.e., the caste group which owns the majority of land. The dominant caste is either from an upper caste or a lower backward caste. The key finding is that income is substantially

Siwan Anderson

20

Evolution of halictine castes  

NASA Astrophysics Data System (ADS)

Social halictine bees have female castes that range from species with no size differences to those with a discrete bimodality. Female caste differences are inversely correlated with the number of males produced in the first brood. It is proposed that the sexual dimorphism of solitary forms is being usurped by the female caste system of species in the process of turning social. Thus, caste differences and summer male suppression are greatest in the social species originating from solitary precursors with distinct sexual dimorphism, and are least in species evolving from solitary ancestors with a continuous sexual polymorphism.

Knerer, Gerd

1980-03-01

21

Cast Aluminum Structures Technology (CAST) Manufacturing Methods--Phase II.  

National Technical Information Service (NTIS)

The objective of CAST is to establish the necessary structural and manufacturing technologies and to demonstrate and validate the integrity, producibility, and viability of cast aluminum primary airframe structures. The necessary casting foundry practices...

D. D. Goehler R. G. Christner

1978-01-01

22

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

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

INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' PIPE. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

23

INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE ...  

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

INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE AND OPERATOR JOHNNY NIXON. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

24

LLNL casting technology.  

National Technical Information Service (NTIS)

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 ...

A. B. Shapiro W. J. Comfort

1994-01-01

25

Expendable Pattern Casting Technology  

NASA Astrophysics Data System (ADS)

The expendable pattern casting (EPC) process is a potential casting process breakthrough which could dramatically improve the competitiveness of the U.S. foundry industry. Cooperatively supported by U.S. Industry and the Department of Energy and managed by the American Foundrymen's Society, a project was started in May 1989 to develop and optimize expendable pattern casting technology. Four major tasks were conducted in the first phase of the project. Those tasks involved: (1) reviewing published literature to determine the major problems in the EPC process; (2) evaluating factors influencing sand flow and compaction; (3) evaluating and comparing casting precision obtained in the EPC process with that obtained in other processes; and (4) identifying critical parameters that control dimensional precision and defect formation in EP castings.

1990-07-01

26

Casting in Sport  

PubMed Central

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

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

1994-01-01

27

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

28

CENTRIFUGAL CASTING MACHINE  

DOEpatents

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

Shuck, A.B.

1958-04-01

29

New approaches in microcasting: permanent mold casting and composite casting  

Microsoft Academic Search

For several years, microcasting was based on investment casting. New approaches are now the permanent mold casting and composite\\u000a casting of micro parts. Casting was performed with aluminum bronze of the type CuAl10Ni5Fe4. Permanent mold casting was commenced with steel mold inserts in a lost mold. The development of a band heater enabled the\\u000a heating of permanent molds inside the

G. Baumeister; D. Buqezi-Ahmeti; J. Glaser; H.-J. Ritzhaupt-Kleissl

2011-01-01

30

MOLDS FOR CASTING PLUTONIUM  

DOEpatents

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

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

1962-02-27

31

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

32

Aluminum Fluidity in Casting  

NASA Astrophysics Data System (ADS)

The understanding and control of fluidity is, and has been, a major aspect of foundry technology development. This paper reviews the progress made in this area over the years as it applies to aluminum castings. As a result of this development, thin-wall, high-integrity aluminum castings which were previously not thought possible have been produced. Further work in this area is expected to allow metal-matrix composites to fulfill their technical and economic promise.

Mollard, Francois R.; Flemings, Merton C.; Niyama, Eisuke F.

1987-11-01

33

Casting critical components  

NASA Astrophysics Data System (ADS)

Investment casting is an essential processing route for critical rotating and static aero gas turbine components and for a wide spectrum of high integrity parts. These must perform reliably under arduous operating conditions involving high stresses and, frequently, extremely hostile environments. The advanced technology, in-process controls, rigorous specifications, and stringent testing and inspection procedures required for high integrity investment castings are considered along with some examples of the technological 'spin-off' into diverse industry sectors.

McCallum, R.

1982-06-01

34

Casting Characteristics of Aluminum Die Casting Alloys  

SciTech Connect

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

Makhlouf M. Makhlouf; Diran Apelian

2002-02-05

35

Slip casting under pressure  

NASA Astrophysics Data System (ADS)

The addition of a pressure during slip casting increases the rate of material deposition and enables larger pieces to be fabricated. In this study, this process has been further developed using monolithic Al2O3 and Al2O3-SiC composites. Slip casting formulations based on both dispersed and coagulated slurries have been analyzed. Excellent results are achieved using coagulated slurries, with no cracking present after drying. The effect of pressure is to increase the green density with a consequent increase in the fired density. In addition, homogeneous microstructures are achieved in the composite system, despite the large difference in particle size used.

Grazzini, H. H.; Wilkinson, D. S.

1992-08-01

36

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

37

Aluminum Castings for Anodic Oxidation.  

National Technical Information Service (NTIS)

The significance of the manufacture of decorative anodically oxidized aluminum castings is demonstrated by means of examples, and alloys suitable for this are enumerated. Then dealt with are errors of casting and melting technique which become apparent wi...

A. A. Bloch

1966-01-01

38

Investment Casting of Columbium Alloys.  

National Technical Information Service (NTIS)

The state of the art of columbium alloy investment castings has been advanced. In addition to demonstration of castability of four different alloys, the cast material itself has been characterized with respect to microstructure, alloy segregation, weldabi...

J. R. Humphrey A. I. Niravath

1975-01-01

39

Investment casting of gold jewellery  

Microsoft Academic Search

Changes in temperature which take place during pouring of a melt and flow into the mould vary greatly, and also depend on\\u000a the casting technique used. Understanding these changes is important for optimum casting practice.

Dieter Ott; Christoph J. Raub

1986-01-01

40

The fractography of casting alloys  

Microsoft Academic Search

Several types of casting alloys were fractured using various loading modes (uniaxial tension, bending, impact, and torsion, and cyclic stressing), and the corresponding mechanical properties were determined. The unetched and etched fracture surfaces and the microstructures were examined using conventional techniques. The types of casting alloys that were the subjects f these investigations include gray iron, ductile iron, cast steel,

G POWELL

1994-01-01

41

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.

42

Nickel based casting alloy  

Microsoft Academic Search

A nickel base casting alloy containing 10 to 25 percent chromium, 3 to 8 percent manganese, 3 to 10 percent niobium, 0 to 3.5 percent aluminum, 0.5 to 2.0 percent beryllium which exhibits lower melting characteristics allowing enhanced compatibility to gypsum bonded investments.

A. P. Burnett; W. C. Bollinger

1985-01-01

43

Casting the Untrained Actor.  

ERIC Educational Resources Information Center

Discusses the arduous task of casting and directing untrained middle and secondary school actors in terms of auditioning, getting started, planning for the first meeting, focusing on the obvious, rehearsing, learning the lines, becoming the character, running work-through rehearsals, and doing run-throughs and performances. Notes not to forget to…

Bogar, Thomas A.

2000-01-01

44

ShakeCast Manual  

USGS Publications Warehouse

ShakeCast is a freely available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users? facilities, and generates potential damage assessment notifications, facility damage maps, and other Web-based products for emergency managers and responders.

Lin, Kuo-Wan; Wald, David J.

2008-01-01

45

Clad Cast Steel Strip.  

National Technical Information Service (NTIS)

A process for producing continuous cast hot band crystalline metal strips comprising feeding thin gauge metal strips and molten metal into a gap formed between opposed quenching surfaces. The film of molten metal is cooled while in contact with the quench...

R. L. Sheneman

1983-01-01

46

Computer cast blast modelling  

SciTech Connect

Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than normal is required plus an initiation technique designed to produce a much greater degree of horizontal muck movement. This paper compares two blast models known as DMC (Distinct Motion Code) and SABREX (Scientific Approach to Breaking Rock with Explosives). DMC, applies discrete spherical elements interacted with the flow of explosive gases and the explicit time integration to track particle motion resulting from a blast. The input to this model includes multi-layer rock properties, and both loading geometry and explosives equation-of-state parameters. It enables the user to have a wide range of control over drill pattern and explosive loading design parameters. SABREX assumes that heave process is controlled by the explosive gases which determines the velocity and time of initial movement of blocks within the burden, and then tracks the motion of the blocks until they come to a rest. In order to reduce computing time, the in-flight collisions of blocks are not considered and the motion of the first row is made to limit the motion of subsequent rows. Although modelling a blast is a complex task, the DMC can perform a blast simulation in 0.5 hours on the SUN SPARCstation 10--41 while the new SABREX 3.5 produces results of a cast blast in ten seconds on a 486-PC computer. Predicted percentage of cast and face velocities from both computer codes compare well with the measured results from a full scale cast blast.

Chung, S. [ICI Explosives Canada, North York, ON (Canada); McGill, M. [ICI Explosives USA, Dallas, TX (United States); Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States)

1994-07-01

47

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

48

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

49

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.

50

USGS ShakeCast  

USGS Publications Warehouse

Automating, Simplifying, and Improving the Use of ShakeMap for Post-Earthquake Decisionmaking and Response. ShakeCast is a freely available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users facilities, and generates potential damage assessment notifications, facility damage maps, and other Web-based products for emergency managers and responders.

Wald, David; Lin, Kuo-Wan

2007-01-01

51

Cast Tenzaloy aluminum optics  

NASA Astrophysics Data System (ADS)

Since the early sixties, cast aluminum optics has held out a promise of low cost, durability, lightweight, ease of manufacture, the possibility of welding together sections to form large optics and a good match of some astronomical programs such as photometry. Needless to say, this rosy future has been fraught with difficulties. Poor short-term stability, sensitivity to temperature, porosity, bimetallic warping, soft optical surface, poor specularity, nickel adhesion problems, poor image quality, and the inability to generate aspherics, have all contributed to the bad name cast aluminum optics has acquired over the years. With the advent of improved aluminum alloys, long-term dimensional stability data, advances in adaptive optics and the need for very large monolithic mirrors with a relatively low handling risk, aluminum optics deserve another look. This paper is a collection of some of the early attempts to build cast aluminum mirrors using the stable alloy, Tenzaloy. The results of those efforts are discussed together with recommendations for future aluminum metal mirror work.

Forbes, Fred F.

1993-10-01

52

Melting and casting of FeAl-based cast alloy  

Microsoft Academic Search

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

V. K. Sikka; D. Wilkening; J. Liebetrau; B. Mackey

1998-01-01

53

Modeling of alloy casting solidification  

NASA Astrophysics Data System (ADS)

Alloy casting solidification processes involve many physical phenomena such as chemistry variation, phase transformation, heat transfer, fluid flow, microstructure evolution, and mechanical stress.1 Simulation technologies are applied extensively in casting industries to understand the effects of these phenomena on the formation of defects and on the final mechanical properties of the castings. As of today, defect prediction is still one of the main purposes for casting solidification simulation. In this paper, we will first present the commonly used microstructure simulation methods, then discuss the predictions of the major defects of a casting, such as porosity, hot tearing, and macrosegregation. The modeling of casting solidification can be chained with later stages of heat treatment such that the resultant microstructure, defects, and mechanical state will be used as the initial conditions of the subsequent processes, ensuring the tracking of the component history and maintaining a high level of accuracy across metallurgical stages.

Guo, Jianzheng; Samonds, Mark

2011-07-01

54

LOST FOAM CASTING OF MAGNESIUM ALLOYS  

SciTech Connect

The lost foam casting process has been successfully used for making aluminum and cast iron thin walled castings of complex geometries. Little work has been carried out on cast magnesium alloys using the lost foam process. The article describes the research activities at Oak Ridge National Laboratory and Tennessee Technological University on lost foam casting of magnesium alloys. The work was focused on castings of simple geometries such as plate castings and window castings. The plate castings were designed to investigate the mold filling characteristics of magnesium and aluminum alloys using an infrared camera. The pate castings were then characterized for porosity distribution. The window castings were made to test the castability of the alloys under lost foam conditions. Significant differences between lost foam aluminum casting and lost foam magnesium casting have been observed.

Han, Qingyou [ORNL; Dinwiddie, Ralph Barton [ORNL; Sklad, Philip S [ORNL; Currie, Kenneth [Tennessee Technological University; Abdelrahman, Mohamed [Tennessee Technological University; Vondra, Fred [Tennessee Technological University; Walford, Graham [Walford Technologies; Nolan, Dennis J [Foseco-Morval

2007-01-01

55

Steel casting by diffusion solidification  

Microsoft Academic Search

A new process for casting and welding carbon steels is described in which carbon diffuses isothermally or adiabatically within\\u000a an intimate mixture of solid low carbon steel and high carbon liquid iron to effect solidification and subsequent homogenization\\u000a with respect to carbon. Advantages over conventional casting processes and products result from 1) 150 to 200‡C lower casting\\u000a temperature; 2) reduced

George Langford; Robert E. Cunningham

1978-01-01

56

Steel casting by diffusion solidification  

Microsoft Academic Search

A new process for casting and welding carbon steels is described in which carbon diffuses isothermally or adiabatically within\\u000a an intimate mixture of solid low carbon steel and high carbon liquid iron to effect solidification and subsequent homogenization\\u000a with respect to carbon. Advantages over conventional casting processes and products result from 1) 150 to 200°C lower casting\\u000a temperature; 2) reduced

George Langford; Robert E. Cunningham

1978-01-01

57

The Caste-Class Association in India  

Microsoft Academic Search

This paper empirically analyzes the association between caste and class in India. I find a tentative congruence between castes and classes at the extremes of the caste system and a slight weakening in this association over time. Although Scheduled Castes have low upward mobility, higher castes are not entirely protected from downward mobility.

Divya Vaid

2012-01-01

58

STME T\\/C casting technology  

Microsoft Academic Search

The T\\/C casting technology developed by the National Launch System for the Space Transportation Main Engine is described. Special attention is given to the selection of JBK-75 as the combustion chamber casting alloy, some unique casting issues, and the development castings which were produced. Current plans call for producing a 650K full cast jacket mockup in the 4500 pound furnace.

J. R. Lobitz; P. C. Ackerman; S. L. Weber

1992-01-01

59

COMPARISON OF FATIGUE BEHAVIOR FOR CENTRIFUGALLY CAST AND KEEL BLOCK CAST STEEL  

Microsoft Academic Search

The objective of this research was to determine if location through the wall thickness of centrifugal castings affects fatigue properties and to compare fatigue and monotonic tensile properties of centrifugal castings to statically cast keel block castings. Specimens were machined from centrifugal and keel block AISI 8630 steel castings. Centrifugal casting specimens were taken from three different locations (outer, middle

J. J. Gradman; R. I. Stephens; R. A. Hardin; C. Beckermann

60

High Strength Aluminum Casting Technology: Squeeze Casting of 7075 Alloy.  

National Technical Information Service (NTIS)

The objective of this investigation was to develop wrought 7075-T6 mechanical properties in a cast aluminum alloy component of net or near-net shape. A squeeze casting process was selected as the manufacturing process. Following a limited heat treatment o...

J. R. Thompson

1977-01-01

61

Investment Casting of Magnesium-Lithium Alloys.  

National Technical Information Service (NTIS)

A method was developed for investment casting magnesium-lithium alloys into inhibited gypsum-bonded molds. Both prototype castings and separately cast test bars (0.252 inch) were produced. Visual and metallographic examination showed no evidence of metal-...

A. Saia R. E. Edelman

1966-01-01

62

14 CFR 29.621 - Casting factors.  

Code of Federal Regulations, 2013 CFR

...of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in...

2013-01-01

63

14 CFR 27.621 - Casting factors.  

Code of Federal Regulations, 2013 CFR

...of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in...

2013-01-01

64

Improved Foundry Castings Utilizing CAD/CAM.  

National Technical Information Service (NTIS)

The CAD/Cam Casting process is being developed as an aid to casting engineers in designing better steel castings in a fraction of the time presently required. The computer routines incorporate drafting routines and computer assisted computations relative ...

T. Wassel J. Chevalier R. Nariman W. S. Hwang S. Miller

1981-01-01

65

Electroslag-Casting Process and Properties.  

National Technical Information Service (NTIS)

The electroslag-casting process is an extension of the electroslag-remelting process. The castings produced by this technique have the advantages of smooth defect-free finish, freedom from conventional casting defects, more reproducible mechanical propert...

V. K. Sikka

1986-01-01

66

Prototype casting fabrication by stereolithography  

SciTech Connect

The evolution of the new technology of producing CAD models by ultraviolet solidification of resin materials ( STEREOLITHOGRAPHY'') continues to progress. The potential application area of rigid fabrication of prototype investment castings is becoming more feasible as we continue to successfully yield experimental castings by the SHELL'' processing method. This supplemental (to 11/90 publication) report briefly reviews the original project objectives, activities related to these objectives since November 1990, and progress made through December 1991. We discuss several new case studies involving new resin materials (and other materials) tested along with investment casting processing results. The most recent success, the processing of the highly complex C'' HOUSING design by the shell'' mold process in both aluminum and steel, will be discussed. This is considered a major breakthrough toward establishing this new technology as a viable approach to the rapid development of prototype investment castings, employing the most common aerospace (precision) cast process. Our future planning calls for expanding the study to help the investment casting industry in refining related processing techniques and to continue our evaluation of new resins suitable for the casting process. Present project planning calls for the completion of this study by the third quarter FY93 or sooner. We believe that with the continued excellent cooperation of our casting supplier study team and an accelerated effort by resin materials producers to further refine related materials, we can achieve all objectives during the planned time frame.

Cromwell, W.E.

1992-03-01

67

Prototype casting fabrication by stereolithography  

SciTech Connect

The evolution of the new technology of producing CAD models by ultraviolet solidification of resin materials (``STEREOLITHOGRAPHY``) continues to progress. The potential application area of rigid fabrication of prototype investment castings is becoming more feasible as we continue to successfully yield experimental castings by the ``SHELL`` processing method. This supplemental (to 11/90 publication) report briefly reviews the original project objectives, activities related to these objectives since November 1990, and progress made through December 1991. We discuss several new case studies involving new resin materials (and other materials) tested along with investment casting processing results. The most recent success, the processing of the highly complex ``C`` HOUSING design by the ``shell`` mold process in both aluminum and steel, will be discussed. This is considered a major breakthrough toward establishing this new technology as a viable approach to the rapid development of prototype investment castings, employing the most common aerospace (precision) cast process. Our future planning calls for expanding the study to help the investment casting industry in refining related processing techniques and to continue our evaluation of new resins suitable for the casting process. Present project planning calls for the completion of this study by the third quarter FY93 or sooner. We believe that with the continued excellent cooperation of our casting supplier study team and an accelerated effort by resin materials producers to further refine related materials, we can achieve all objectives during the planned time frame.

Cromwell, W.E.

1992-03-01

68

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

69

Education and caste in India  

Microsoft Academic Search

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 affirmative

Chandra Pal Singh Chauhan

2008-01-01

70

Machine Casting of Ferrous Alloys.  

National Technical Information Service (NTIS)

Emphasis of the work is on development of a process or processes involving casting of semi-solid alloys. During the six month period of research covered by the report, emphasis was on developing casting systems which combine (1) a method of producing a se...

J. R. Melcher M. C. Flemings N. Matsumoto R. Mehrabian R. G. Riek

1974-01-01

71

Surface carburization of steel castings  

Microsoft Academic Search

Shaping methods based on sand-resin mixtures have undoubted benefits and accordingly are increas? ingly used in the manufacture of highperformance iron, steel, and nonferrousalloy castings. However, they cannot be unconditionally recommended for lowcarbon steel castings. This is because heat from the molten metal destroys the organic components present in such molds. At low temperatures (150 °C), these mixtures mainly emit

E. B. Ten; O. A. Kol’; I. B. Badmazhapova; M. P. Klyuev

2011-01-01

72

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

73

Electroslag component casting. [Nickel aluminide  

Microsoft Academic Search

This project is directed toward the development of electroslag-casting (ESC) technology for use in coal conversion components such as valve bodies, pump housings, and pipe fittings. The aim is also to develop a sufficient data base to permit electroslag casting to become an ASME Code-accepted process. It is also intended to transfer the ESC process technology to private industry. A

Sikka

1986-01-01

74

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

75

Casting Freedom, 1860-1862  

ERIC Educational Resources Information Center

|Thomas Crawford, an American Sculptor, created the full-size figure of Freedom in clay. Molds were made, from which a full-size positive plaster model was cast in five main sections. This model is on view today in the basement rotunda of the Russell Senate Office Building. Clark Mills was a self-taught American sculptor with experience in casting

Social Education, 2005

2005-01-01

76

Electroslag component casting. [Nickel aluminide  

SciTech Connect

This project is directed toward the development of electroslag-casting (ESC) technology for use in coal conversion components such as valve bodies, pump housings, and pipe fittings. The aim is also to develop a sufficient data base to permit electroslag casting to become an ASME Code-accepted process. It is also intended to transfer the ESC process technology to private industry. A total of 32 electroslag castings of 2.25Cr-1Mo, 9Cr-1Mo, type 316, and nickel aluminide were procured from four facilities for evaluation (Table 1). The most complex castings procured during this program were the valve bodies shown in Figure 2. The castings were subjected to various heat treatments (Table 2), checked for chemical composition uniformity from top to bottom, and subjected to macrostructural evaluation and mechanical properties testing. Results are discussed. 10 refs., 7 figs., 3 tabs.

Sikka, V.K.

1986-01-01

77

An evaluation of fiberglass cast application techniques.  

PubMed

Cylindrical casts constructed from 2, 3, 4, and 5 inch widths of fiberglass casting material were evaluated for strength in bending using an unstable fracture model. Five-inch casting material produced the strongest casts. The effect of longitudinal splinting with 2-inch fiberglass tape was evaluated in cylindrical casts constructed from 4-inch tape. Casts with splints on the compression side or with splints on both the tension and compression sides were stronger in bending than casts with a single splint on the tension side or casts without splints. PMID:7778250

Wilson, D G; Vanderby, R

78

Instant Casting Movie Theater: The Future Cast System  

NASA Astrophysics Data System (ADS)

We have developed a visual entertainment system called “Future Cast” which enables anyone to easily participate in a pre-recorded or pre-created film as an instant CG movie star. This system provides audiences with the amazing opportunity to join the cast of a movie in real-time. The Future Cast System can automatically perform all the processes required to make this possible, from capturing participants' facial characteristics to rendering them into the movie. Our system can also be applied to any movie created using the same production process. We conducted our first experimental trial demonstration of the Future Cast System at the Mitsui-Toshiba pavilion at the 2005 World Exposition in Aichi Japan.

Maejima, Akinobu; Wemler, Shuhei; Machida, Tamotsu; Takebayashi, Masao; Morishima, Shigeo

79

Strip casting with fluxing agent applied to casting roll  

DOEpatents

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

Williams, Robert S. (Fairfield, OH); O' Malley, Ronald J. (Miamisburg, OH); Sussman, Richard C. (West Chester, OH)

1997-01-01

80

Strip casting with fluxing agent applied to casting roll  

DOEpatents

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

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

1997-07-29

81

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

82

The niche for steel castings  

SciTech Connect

In the early days of the steel casting industry, little was known about shrinkage cavities, inclusions, sulfur content, cooling rates, quenching, and all the other factors that influence casting quality. Since then, steel founders have learned how to control and reduce porosity and shrinkage, and have discovered how inclusions form and how they can be eliminated. Other advances in foundry technology include new refining techniques and molding processes, computer-aided design, new quenchants, and improved machining methods. Today's foundries can produce high-quality, sound casting in shapes and sizes that the forging process cannot emulate and that would be too costly to fabricate by welding.

Blair, M. (Steel Founders' Society of America, Des Plaines, IL (United States))

1994-08-01

83

Biomimetic Materials by Freeze Casting  

NASA Astrophysics Data System (ADS)

Natural materials, such as bone and abalone nacre, exhibit exceptional mechanical properties, a product of their intricate microstructural organization. Freeze casting is a relatively simple, inexpensive, and adaptable materials processing method to form porous ceramic scaffolds with controllable microstructural features. After infiltration of a second polymeric phase, hybrid ceramic-polymer composites can be fabricated that closely resemble the architecture and mechanical performance of natural bone and nacre. Inspired by the narwhal tusk, magnetic fields applied during freeze casting can be used to further control architectural alignment, resulting in freeze-cast materials with enhanced mechanical properties.

Porter, Michael M.; Mckittrick, Joanna; Meyers, Marc A.

2013-06-01

84

RETHINKING POWER AND CASTE IN RURAL INDIA  

Microsoft Academic Search

Caste as a system of social stratification remains an important aspect in the lives of many peoples throughout the world. Dimensions of caste are found in Africa, Asia, the Pacific and even North America. Yet, it is India that stands out among nations as the most notable in terms of caste stratification today. Although elements of the caste system, such

KIRK JOHNSON; MICHAEL KARLBERG

85

Modeling of casting microstructures and defects.  

National Technical Information Service (NTIS)

Casting is an ancient art that has been a trial-and-error process for more than 4000 years. To predict the size, shape, and quality of a cast product, casting manufacturers typically cast full-size prototypes. If one part of the process is done incorrectl...

A. B. Shapiro L. T. Summers D. J. Eckels V. Sahai

1997-01-01

86

Clinical experience with a new casting tape.  

PubMed

Between October 1977 and 1978, 93 CutterCast casts were applied at the Veterans Administration Hospital in Atlanta, Georgia. The composition and application of this new casting system are described, and the performance of the 93 casts is evaluated in relation to ease of application, roentgenographic clarity, skin condition, patient comfort, and ease of removal. The advantages and disadvantages are discussed. PMID:7375970

Fleming, L L; Miller, K; Sinback, M

1980-05-01

87

Use of high-strength alloyed cast iron for heat-resistant castings  

Microsoft Academic Search

The Institute of Casting Problems has developed technology for cupola melting of aluminum-containing heat-resistant cast irons. The favorable effect of aluminum in increasing the scale resistance of materials is increased further in spheroidal graphite cast irons. Two variants of master alloys were made to obtain these conditions. Tests and experimental casting of inoculated cast iron was carried out. Scale resistance

G. N. Shtyka; A. V. Borodin; V. N. Oleinik; S. N. Primerov

1983-01-01

88

Investment casting design of experiment. Final report  

SciTech Connect

Specific steps in the investment casting process were analyzed in a designed experiment. The casting`s sensitivity to changes in these process steps was experimentally determined Dimensional and radiographic inspection were used to judge the sensitivity of the casting. Thirty-six castings of different pedigrees were poured and measured. Some of the dimensional inspection was conducted during the processing. It was confirmed that wax fixturing, number of gates, gate location, pour and mold temperature, pour speed, and cooling profile all affected the radiographic quality of the casting. Gate and runner assembly techniques, number of gates, and mold temperature affect the dimensional quality of the casting.

Owens, R.

1997-10-01

89

Prototype casting fabrication by stereolithography.  

National Technical Information Service (NTIS)

A new product development technology is emerging which could have a major impact on the investment casting industry. It's identified by several names, the most common of which is ''STEREOLITHOGRAPHY.'' This technology involves a three-dimensional printing...

W. E. Cromwell

1990-01-01

90

Prototype casting fabrication by stereolithography.  

National Technical Information Service (NTIS)

The evolution of the new technology of producing CAD models by ultraviolet solidification of resin materials (''STEREOLITHOGRAPHY'') continues to progress. The potential application area of rigid fabrication of prototype investment castings is becoming mo...

W. E. Cromwell

1992-01-01

91

Ingot Casting by Electroslag Remelting.  

National Technical Information Service (NTIS)

Conditions influencing the development of the cast structure of ingots produced by electroslag remelting are discussed. Reference is made to a two-dimensional analogue model and to experimental melts within transparent moulds which allow the behavior of m...

J. D. W. Rawson D. I. Dawson

1972-01-01

92

AGARD handbook on advanced casting  

NASA Astrophysics Data System (ADS)

The need to improve aircraft performance and, simultaneously, to reduce costs has led to a re-examination of the use of casting processes in aircraft manufacture. The Structures and Materials Panel of AGARD has provided practical information about design, mechanical values, applications, quality assurance and damage tolerance. By providing the data in this form it is hoped that the designer will be encouraged to exploit the many recent advances in casting to optimum effect.

Mietrach, Dietmar

1991-03-01

93

Investment casting of gold jewellery  

Microsoft Academic Search

Porosity is one of the important causes for the rejection of jewellery items cast by the lost wax process. If it is of the\\u000a shrinkage type, then there is a considerable reservoir of knowledge, arising from experience in the casting of dental gold\\u000a and other gold alloys, which can be drawn upon to overcome the problem. If it is gas

Dieter Ott; Christoph J. Raub; William S. Rapson

1985-01-01

94

Modelling of flow phenomena during DC casting  

Microsoft Academic Search

Modelling of Flow Phenomena during DC Casting Jan Zuidema\\u000aThe production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an instantaneous transformation, but occurs in temperature interval. In the casting process the latent heat is moved

J. Zuidema

2005-01-01

95

Moldless casting by laser  

NASA Astrophysics Data System (ADS)

The principle of laser cladding involves the use of high power carbon-dioxide lasers and powder deposition technology to provide wear and corrosion resistant surface coatings to engineering components. By injecting metal powder into a laser generated melt pool on a moving substrate a solidified metal track can be produced. Deposition of successive tracks produces a multi-layer build. Laser direct casting (LDC) utilizes a coaxial nozzle enabling consistent omnidirectional deposition to produce 3D components from a selection of metal powders. The influence of the principal process parameters over the process features namely, powder catchment efficiency, beam shape and build rates are presented with several successfully generated 3D components. Nickel, stainless steel and satellite powders were deposited at laser powders of 0.4 to 1.4 kW and speeds of 500 to 1000 mm/min achieving build rates of 3 to 9 mm3/s. Fully dense metallurgical structures have been produced with no cracking or porosity and powder catchment efficiencies up to 85% have been achieved.

McLean, Marc A.; Shannon, G. J.; Steen, William M.

1997-09-01

96

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

97

Flow impact on cast ingots  

NASA Astrophysics Data System (ADS)

Aluminium alloys are a standard cast metal used in a number of automotive and transportation applications, allowing manufacturers to reduce vehicle weight, increase the strength of components and improve emission controls. One of the most challenging problems associated with aluminium casting is the influence of convection during all stages of solidification. The strength of fluid flow changes the as-cast internal structure (microstructure) such that the yield, fracture and fatigue strengths of the cast ingot can vary considerably. Although the importance of fluid flow has been recognised for decades, not even a simple model has been developed to predict the effect on microstructure. The MICAST project aims to identify and control experimentally the fluid-flow patterns that affect microstructure evolution during casting processes, and to develop analytical and advanced numerical models. The microgravity environment of the International Space Station and sounding rockets is of special importance to this project because only there are all gravity-induced convections eliminated and well-defined conditions for solidification prevail that can be disturbed by fluid flow controlled by experimenters.

Ratke, Lorenz; Fautrelle, Yves; Lacaze, Jacques; Müller, Georg; Roosz, Andras; Zimmermann, Gerhard; Jarry, Phillippe; Kieft, Rene; Csepeli, Zsolt; Sándor, Józef; Grün, Gerd-Ulrich; Sillinger, Nándor; Gerke-Cantow, Ralf

2005-10-01

98

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

99

STME T/C casting technology  

NASA Astrophysics Data System (ADS)

The T/C casting technology developed by the National Launch System for the Space Transportation Main Engine is described. Special attention is given to the selection of JBK-75 as the combustion chamber casting alloy, some unique casting issues, and the development castings which were produced. Current plans call for producing a 650K full cast jacket mockup in the 4500 pound furnace. Once a 650K mockup casting has been successfully produced, a design of experiments (DOE) will be conducted to establish the best gating system. This will be followed by the design of permanent wax pattern tooling, gating tooling, and process fixtures, and, finally, by a process DOE.

Lobitz, J. R.; Ackerman, P. C.; Weber, S. L.

1992-07-01

100

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

101

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

102

INTERIOR VIEW WITH CASTING MACHINE AND A 4" DUCTILE IRON ...  

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

INTERIOR VIEW WITH CASTING MACHINE AND A 4" DUCTILE IRON PIPE BEING EXTRACTED FROM CASTING MACHINE - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

103

INTERIOR VIEW OF CASTING MACHINE WITH 4' DUCTILE IRON PIPE ...  

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

INTERIOR VIEW OF CASTING MACHINE WITH 4' DUCTILE IRON PIPE BEING WEIGHED ON SCALES AT CASTING MACHINE. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

104

INTERIOR VIEW WITH CASTING MACHINE COOLING A 20' IRON PIPE ...  

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

INTERIOR VIEW WITH CASTING MACHINE COOLING A 20' IRON PIPE PRIOR TO EXTRACTION FROM CASTING MACHINE. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

105

INTERIOR VIEW, LOOKING NORTH, WITH CASTING SUPERINTENDENT OVERSEEING TRANSFER OF ...  

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

INTERIOR VIEW, LOOKING NORTH, WITH CASTING SUPERINTENDENT OVERSEEING TRANSFER OF MOLTEN METAL TO A CASTING MACHINE. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

106

Dimensional variability of production steel castings.  

National Technical Information Service (NTIS)

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 cas...

F. E. Peters J. W. Risteu W. G. Vaupel E. C. DeMeter R. C. Voigt

1994-01-01

107

Processing of IN-718 Lattice Block Castings.  

National Technical Information Service (NTIS)

Recently a low cost casting method known as lattice block casting has been developed by JAM Corporation, Wilmington, Massachusetts for engineering materials such as aluminum and stainless steels that has shown to provide very high stiffness and strength w...

M. G. Hebsur

2002-01-01

108

Thermal transport properties of grey cast irons.  

National Technical Information Service (NTIS)

Thermal diffusivity and thermal conductivity of grey cast iron have been measured as a function of graphite flake morphology, chemical composition, and position in a finished brake rotor. Cast iron samples used for this investigation were cut from ''step ...

R. L. Hecht R. B. Dinwiddie W. D. Porter H. Wang

1996-01-01

109

Investment casting design of experiment. Final report.  

National Technical Information Service (NTIS)

Specific steps in the investment casting process were analyzed in a designed experiment. The casting's sensitivity to changes in these process steps was experimentally determined Dimensional and radiographic inspection were used to judge the sensitivity o...

R. Owens

1997-01-01

110

Investment Castings: A National Security Assessment.  

National Technical Information Service (NTIS)

A national security/industrial capabilities assessment of the domestic investment casting industry. The report includes a detailed review of the investment casting industry and its performance, production capabilities, surge and mobilization capabilities,...

1987-01-01

111

Mundrabilla: A Microgravity Casting  

NASA Astrophysics Data System (ADS)

The name "Mundrabilla" is applied to two nickel-iron meteorite masses (combined mass over 22,700 kg), which apparently were a single mass before atmospheric entry [1]. A medium octahedrite, Mundrabilla exhibits the microstructural features common to other nickel-iron meteorites such as Widmanstatten structure and troilite; however, its macrostructure is anything but common. Described by Buchwald as "anomalous" [1], Mundrabilla's macrostructural morphology is characterized by strikingly prominent, rounded Widmanstatten areas separated by regions of sulfur segregation (Fig. 1). While microstructural development of a metal can reflect both solidification and solid state reactions, macrostructural features are determined during solidification. Thus, a typical metallurgist, unfamiliar with microgravity solidification, might describe Mundrabilla's macrostructure as an "anomalous" casting. Those familiar with microgravity solidification might characterize Mundrabilla's macrostructural features as due to solidification of two immiscible liquids [2]--one rich in nickel-iron, the other rich in sulfur. Combining these observations, Mundrabilla's macrostructural features are consistent with that of a liquid mass solidified under microgravity conditions [3,4]. Since nickel-iron meteorite cooling rates often serve as the foundation for assumptions about the formation of solar system bodies, information on the solidification time for the Mundrabilla mass may give additional insights. How long did it take for Mundrabilla, with a minimum "as received" mass of approximately 22,700 kg to solidify? Because Mundrabilla's mass before atmospheric entry is unknown, we take as an upper boundary a mass of 4.1 x 10^15kg. These masses, assumed spherical, range in diameter between 1.8 meters and 10 kilometers, respectively. Mundrabilla can be idealized as a pure iron liquid mass cooling from the melting point of pure iron (1535C) by radiation into space at absolute zero. The latent heat of transformation for iron is used to calculate "excess temperature," i.e., the amount the mass temperature can be raised due to recalescence. Solidification is considered complete when the center of the mass is solid. Fig. 2, is a plot of the solidification times for an iron mass in the range 1.8 meters to 10 kilometers in diameter. At the lower bound, solidification time is about 1.6 hours; at the upper bound, solidification time is on the order of 3,400 years. References: [1] Buchwald V. F. (1975) Handbook of Iron Meteorites, University of California, Berkeley. [2] Carlberg T. and Fredriksson H. (1980) Metallurgical Transactions A, 11A, 1665-1676. [3] Budka P. Z. (1988) Metallurgical Transactions A, 19A, 1919-1923. [4] Budka P. Z. (1988) J. Metals, 40, 9, 6-9. Fig. 1, which appears here in the hard copy, shows Mundrabilla--a scale in inches. Figure 2, which appears here in the hard copy, shows solidification time vs. diameter.

Budka, P. Z.; Viertl, J. R. M.

1993-07-01

112

Effect of ferrite on cast stainless steels  

SciTech Connect

Premature failure of stainless steel castings in bleach washing service is attributed to poor casting quality high porosity and to a high ferrite content, which makes the castings susceptible to corrosion by hot acid chloride solutions. A survey of the chemical compositions and ferrite contents of corrosion-resistant castings in bleach plants at three pulp mills found high [delta]-ferrite levels in the austenitic matrix due to the improper balance between austenite and ferrite stabilizers.

Nadezhdin, A.; Cooper, K. (Noranda Technology Centre, Pointe Claire, Quebec (Canada)); Timbers, G. (James Maclaren Inc., Quebec (Canada). Kraft Pulp Division)

1994-09-01

113

Titanium investiment casting defects: A metallographic overview  

NASA Astrophysics Data System (ADS)

Although titanium castings have been used in aerospace structures for decades, those uses have largely been in secondary applications. Expanding the use of titanium castings in critical applications would be encouraged by a better understanding of investment casting defects in titanium alloy systems. This paper describes several types of casting-related defects that are identified as potentially affecting the design life of a structure: inclusions, voids, and weld repair defects.

Cotton, J. D.; Clark, L. P.; Phelps, H. R.

2006-06-01

114

New fibreglass casting system in orthopaedic practice.  

PubMed

The composition, manufacture and application of a new fibreglass casting system for use in orthopaedic practice are described. The performance of the first 51 fibreglass casts used in routine fracture work is reviewed. The advantages (the cast is waterprof, extremely light and strong) and the disadvantages (an ultraviolet light source is required to cure the cast and the fiberglass tape is rather expensive) are evaluated. PMID:979766

Davis, B; Dooley, B

1976-06-26

115

Cast data matrix symbols performance characterization  

Microsoft Academic Search

Data matrix symbols are used as a robust means of unique part identification in many industries. Research of cast data matrix symbols has been limited and expected symbol performance unknown. To develop knowledge of cast data matrix symbol performance, the investigation initially focused on feasibility of casting data matrix symbol. Results of a feasibility experiment led to further investigation of

Greg Carl Saveraid

2010-01-01

116

CONTROLLED DIFFUSION SOLIDIFICATION: APPLICATION TO METAL CASTING  

Microsoft Academic Search

Wrought aluminum-based alloys exhibit superior physical and mechanical properties compared to conventional cast alloys. However, wrought alloys cannot be cast because they develop hot tears and hot cracks during solidification. For this reason, these alloys are typically cast into ingots and are subsequently brought to final shape by mechanical processes such as rolling, extrusion, drawing and forging. Controlled Diffusion Solidification

K. Symeonidis; D. Apelian; M. M. Makhlouf

117

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

118

The Ins and Outs of Relief Casting.  

ERIC Educational Resources Information Center

Describes a unit on clay casting that introduces students to relief sculpture. The unit takes three 45 to 50 minute class periods three weeks apart. Discusses each class session in detail: (1) creating the casting; (2) turning out and rinsing the casting; and (3) enriching the surface with color. (CMK)

Greene, Yvonne

2000-01-01

119

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

120

Prediction of Microporosity in Shrouded Impeller Castings  

SciTech Connect

The purpose of this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Morris Bean and Company was to link computer models of heat and fluid flow with previously developed quality criteria for the prediction of microporosity in a Al-4.5% Cu alloy shrouded impeller casting. The results may be used to analyze the casting process design for the commercial production of 206 o alloy shrouded impeller castings. Test impeller castings were poured in the laboratory for the purpose of obtaining thermal data and porosity distributions. Also, a simulation of the test impeller casting was conducted and the results validated with porosity measurements on the test castings. A comparison of the predicted and measured microporosity distributions indicated an excellent correlation between experiments and prediction. The results of the experimental and modeling studies undertaken in this project indicate that the quality criteria developed for the prediction of microporosity in Al-4.5% Cu alloy castings can accurately predict regions of elevated microporosity even in complex castings such as the shrouded impeller casting. Accordingly, it should be possible to use quality criteria for porosity prediction in conjunction with computer models of heat and fluid flow to optimize the casting process for the production of shrouded impeller castings. Since high levels of microporosity may be expected to result in poor fatigue properties, casting designs that are optimized for low levels of microporosity should exhibit superior fatigue life.

Viswanathan, S. Nelson, C.D.

1998-09-01

121

Conversion of RP models to investment castings  

Microsoft Academic Search

The Tooling and Casting subgroup of the European Action on Rapid Prototyping (EARP) has undertaken a project to investigate the problems associated with using rapid prototype models as sacrificial patterns for investment casting. The accuracy and surface finish of the models and the castings were also assessed so that a comparison could be made. Models from each process were manufactured

P. M. Dickens; R. Stangroom; M. Greul; B. Holmer; K. K. B. Hon; R. Hovtun; R. Neumann; S. Noeken; D. Wimpenny

1995-01-01

122

Tape casting of nanocrystalline ceria gadolinia powder  

Microsoft Academic Search

A ceramic ceria gadolinia solid solution membrane for solid oxide fuel cells was fabricated by tape casting using a nanopowder of 37nm average particle size. A novel combination of solvent and dispersant was used to disperse the nanoparticles. The polymer was added in a dilute stage to guarantee a homogeneous distribution. After casting a remarkable densification of the cast tape

Lorenz P. Meier; Lukas Urech; Ludwig J. Gauckler

2004-01-01

123

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,...

124

The fractography of casting alloys  

SciTech Connect

Several types of casting alloys were fractured using various loading modes (uniaxial tension, bending, impact, and torsion, and cyclic stressing), and the corresponding mechanical properties were determined. The unetched and etched fracture surfaces and the microstructures were examined using conventional techniques. The types of casting alloys that were the subjects f these investigations include gray iron, ductile iron, cast steel, and aluminum-base alloys (A380, A356, and 319). The fractographic studies have yielded these generalizations regarding the topography of the fracture surfaces. In the case of low-ductility alloys such as gray iron and the aluminum-base alloys, the tensile edge of a fracture surface produced by a stress system with a strong bending-moment component has a highly irregular contour, whereas the compressive edge of the fracture surface is quite straight and parallel to the bend axis. On the other hand, the periphery of a fracture surface produced by uniaxial tension has a completely irregular contour. The fracture surface produced by cyclic loading of a gray iron does not display any macroscopic evidence (such as a thumb nail) of the loading mode. However, the fracture surface of each of the other casting alloys displays clear, macroscopic evidence of failure induced by fatigue. The aluminum-base alloys fracture completely within the interdendritic region of the microstructure when subjected to monotonic loading by uniaxial tension or bending, whereas a fatigue crack propagates predominantly through the primary crystals of the microstructure.

Powell, G.W. (Ohio State Univ., Columbus, OH (United States))

1994-10-01

125

Machine Casting of Ferrous Alloys.  

National Technical Information Service (NTIS)

This report covers the research for the period of the eighteenth to the thirthieth month of a four-year program. During this period the 'Continuous Rheocaster' has been greatly improved and a machine casting system using semi-solid alloys 'Thixocasting' h...

M. C. Flemings R. Mehrabian J. R. Melcher R. G. Riek K. P. Young

1975-01-01

126

Tape casting of magnesium oxide.  

SciTech Connect

A tape casting procedure for fabricating ceramic magnesium oxide tapes has been developed as a method to produce flat sheets of sintered MgO that are thin and porous. Thickness of single layer tapes is in the range of 200-400 {micro}m with corresponding surface roughness values in the range of 10-20 {micro}m as measured by laser profilometry. Development of the tape casting technique required optimization of pretreatment for the starting magnesium oxide (MgO) powder as well as a detailed study of the casting slurry preparation and subsequent heat treatments for sintering and final tape flattening. Milling time of the ceramic powder, plasticizer, and binder mixture was identified as a primary factor affecting surface morphology of the tapes. In general, longer milling times resulted in green tapes with a noticeably smoother surface. This work demonstrates that meticulous control of the entire tape casting operation is necessary to obtain high-quality MgO tapes.

Ayala, Alicia; Corral, Erica L.; Loehman, Ronald E.; Bencoe, Denise Nora; Reiterer, Markus; Shah, Raja A.

2008-02-01

127

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

128

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.

2008-10-25

129

Advanced Lost Foam Casting Technology  

SciTech Connect

This report describes the research done under the six tasks to improve the process and make it more functional in an industrial environment. Task 1: Pattern Pyrolysis Products and Pattern Properties Task 2: Coating Quality Control Task 3: Fill and Solidification Code Task 4: Alternate Pattern Materials Task 5: Casting Distortion Task 6: Technology Transfer

Charles E. Bates; Harry E. Littleton; Don Askeland; Taras Molibog; Jason Hopper; Ben Vatankhah

2000-11-30

130

Investment casting of gold jewellery  

Microsoft Academic Search

Measurements made by a very simple method have shown that many of the factors which affect the quality of castings are sensitive\\u000a to surface and interfacial energies during the pouring of the melt. The results of a number of measurements of these parameters\\u000a are presented and discussed.

Dieter Ott; Christoph J. Raub

1985-01-01

131

Investment casting of gold jewellery  

Microsoft Academic Search

The efficiency with which the moulds are filled is one of the most important aspects in the lost wax procedure for casting\\u000a jewellery. The factors which affect it are briefly discussed and the results of a number of experiments aimed at increasing\\u000a knowledge of the complex interrelationships between them are presented.

Dieter Ott; Christoph J. Raub

1986-01-01

132

Restoration of Castings of Compressor and Refrigerating Units  

Microsoft Academic Search

At present, cast iron [mainly grey cast iron SCh (GCI) 20)] is the chief structural material of compressor and refrigerating equipment. In the cast-making process, the loss due to defects is about 9%. In order to raise output of castings of a satisfactory quality, a variety of cast restoration techniques are applied. The techniques for repair of defects in cast

A. I. Lyubich

2002-01-01

133

Prototype casting fabrication by stereolithography  

SciTech Connect

A new product development technology is emerging which could have a major impact on the investment casting industry. It's identified by several names, the most common of which is STEREOLITHOGRAPHY.'' This technology involves a three-dimensional printing process which will yield plastic parts (polymer models) from solid, surface, or wireframe CAD files. The concept links a CAD database to a process which guides a laser beam to solidify liquid photo-curable polymer into a programmed shaped. The process can produce models in far less time and at far less cost than can be done by other known (conventional) model producing methods. Parts that would normally require weeks or months to prototype with conventional processes can be produced in a matter of hours by Stereolithography. The Allied-Signal Inc., Kansas City Division, is engaged in a development project (funded by the Department of Energy) which is aimed at establishing this process as a practical, expedient, and cost-effective method fabricating prototype investment castings. The early phases of the project include procurement of a special designed test unit for several companies (Service Centers) involved in fabrication of models. These models are produced in various materials and used in experimental casting programs being conducted with four casting suppliers (two ferrous and two non-ferrous). This presentation will cover the objectives of the project and the results obtained up to this time. We will also briefly review future plans for the continuation of the project, until this new technology has been proven as a viable process for rapid development of investment castings.

Cromwell, W.E.

1990-11-01

134

Land-based turbine casting initiative  

SciTech Connect

To meet goals for the ATS program, technical advances developed for aircraft gas turbine engines need to be applied to land-based gas turbines. These advances include directionally solidified and single crystal castings, alloys tailored to exploit these microstructures, complex internal cooling schemes, and coatings. The proposed program to scale aircraft gas turbine casting technology up to land based gas turbine size components is based on low sulfur alloys, casting process development, post-cast process development, and establishing casting defect tolerance levels. The inspection side is also discussed.

Mueller, B.A.; Spicer, R.A. [Howmet Corp., Whitehall, MI (United States)

1995-12-31

135

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

136

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

137

Emulsion based cast booster - a priming system  

SciTech Connect

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

Gupta, R.N.; Mishra, A.K. [National Institute of Rock Mechanics, KGF (India)

2005-07-01

138

The cast structure of a 7075 alloy produced by a water-cooling centrifugal casting method  

SciTech Connect

A water-cooling centrifugal casting method was applied to cast the 7075 Al alloy to generate a much finer cast structure than that produced by conventional ingot casting methods. The effects of casting parameters, i.e., rotation speed, pouring temperature, water flow, and grain refiner, on casting structure were systematically studied so that the optimum casting condition and the solidification mechanism could be established. The typical cast structure along the thickness direction of a cast ring could be divided into four equiaxed zones, including the chill zone which is in contact with the mold wall. All zones have their characteristic grain size, morphology, and relative thickness, which are all dependent on the casting condition. The optimum casting condition yielding the finest structure available was found to be 3,000 rpm, 650 C, and sufficient water cooling. A uniform portion occupying 90 pct of the whole thickness and having a grain size of 17 [mu]m could be achieved under such a casting condition. When a grain refiner was added, the whole ring became further concentrated with grains of fine structure. A mechanism concerning the overall effects of rapid solidification, turbulent flow, and centrifugal force has been proposed for the present casting method and might explain the zone-structure formation and the effects of the casting parameters on microstructural features.

Yeh, J.W. (National Tsing Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Materials Science and Engineering); Jong, S.H.

1994-03-01

139

Pressure rig for repetitive casting  

NASA Astrophysics Data System (ADS)

The invention is a pressure rig for repetitive casting of metal. The pressure rig performs like a piston for feeding molten metal into a mold. Pressure is applied to an expandable rubber diaphragm which expands like a balloon to force the metal into the mold. A ceramic cavity which holds molten metal is lined with blanket-type insulating material, necessitating only a relining for subsequent use and eliminating the lengthy cavity preparation inherent in previous rigs. In addition, the expandable rubber diaphragm is protected by the insulating material thereby decreasing its vulnerability to heat damage. As a result of the improved design the life expectancy of the pressure rig contemplated by the present invention is more than doubled. Moreover, the improved heat protection has allowed the casting of brass and other alloys with higher melting temperatures than possible in the conventional pressure rigs.

Vasquez, Peter; Hutto, William R.; Philips, Albert R.

1989-09-01

140

Investment casting of gold jewellery  

Microsoft Academic Search

The lost wax or investment casting process used extensively in gold jewellery fabrication is subject to the effects of a large\\u000a number of process variables. One consequence of this is that where problems arise or exist in its application, they can be\\u000a difficult to understand and solve. In order to promote optimization of the process the authors have studied the

Dieter Ott; Christoph J. Raub

1985-01-01

141

Tape casting of lanthanum chromite  

Microsoft Academic Search

Solid oxide fuel cells (SOFCs) are currently being developed for a variety of applications such as stationary on-site power plants and cogeneration. The effects of process additives, ball milling, and solids loading were evaluated for tape casting suspensions of glycine-nitrate-synthesized La{sub 0.7}Ca{sub 0.31}CrOâ powder. An optimized formulation was obtained based on rheological characterization, electrokinetic sonic amplitude measurements, qualitative examination of

Michael W. Murphy; Timothy R. Armstrong; Peter A. Smith

1997-01-01

142

Tape casting of lanthanum chromite  

SciTech Connect

Solid oxide fuel cells (SOFCs) are currently being developed for a variety of applications such as stationary on-site power plants and cogeneration. The effects of process additives, ball milling, and solids loading were evaluated for tape casting suspensions of glycine-nitrate-synthesized La{sub 0.7}Ca{sub 0.31}CrO{sub 3} powder. An optimized formulation was obtained based on rheological characterization, electrokinetic sonic amplitude measurements, qualitative examination of green tapes, and the sintered microstructure. The tape casting formulation incorporated 66:34 methyl ethyl ketone/ethyl alcohol solvent, an aliphatic phosphate ester dispersant, and 80 wt% (35 vol%) solids. The best binder/plasticizer system was 12 wt% (15 vol%) poly(isobutyl methacrylate) and 5 wt% (6.3 vol%) benzyl butyl phthalate plasticizer (binder:plasticizer = 2.3). Cast tapes were sintered at 1300 C for 2 h, producing a bulk density of 96.2% theoretical, with linear shrinkage of 22% and an approximate grain size of 1.3 {micro}m.

Murphy, M.W.; Armstrong, T.R.; Smith, P.A. [Pacific Northwest National Lab., Richland, WA (United States)

1997-01-01

143

Clean Cast Steel Technology, Phase IV  

SciTech Connect

The objective of the Clean Cast Steel Technology Program was to improve casting product quality by removing or minimizing oxide defects and to allow the production of higher integrity castings for high speed machining lines. Previous research has concentrated on macro-inclusions that break, chip, or crack machine tool cutters and drills and cause immediate shutdown of the machining lines. The overall goal of the project is to reduce the amount of surface macro-inclusions and improve the machinability of steel castings. Macro-inclusions and improve the machinability of steel castings. Macro-inclusions have been identified by industrial sponsors as a major barrier to improving the quality and marketability of steel castings.

Charles E. Bates

2003-02-24

144

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

145

A novel method for vacuum casting titanium.  

PubMed

A new method for vacuum casting titanium is described. The device allows decontamination of the mold before placing it into the casting machine. After wax elimination, the mold is placed into the device and sealed with a thin film of titanium. The air is evacuated from the mold, and it is flushed with helium. The process is repeated, and the casting is made when convenient. PMID:2133381

Hruska, A R

146

Casts and crusts of the tympanic membrane.  

PubMed

Casts and crusts of the tympanic membrane were removed from patients with previous otitis media. Casts are formed of adherent keratinocytes in a matrix of dried exudate. Detachment from the drumhead leaves the underlying epidermis intact. Casts are defined as those crusts that have detached spontaneously from the surface of the drum. A mechanism based on epithelial proliferation induced by inflammation within the middle ear, with subsequent keratinocyte retention and thickening, is proposed. PMID:2426916

Weinberger, J; Proops, D W; Hawke, M

147

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

148

Aging degradation of cast stainless steel  

Microsoft Academic Search

A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450°C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term

O. K. Chopra; H. M. Chung

1985-01-01

149

Gating of Permanent Molds for ALuminum Casting  

Microsoft Academic Search

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

David Schwam; John F. Wallace; Tom Engle; Qingming Chang

2004-01-01

150

The Effects of Scaphoid and Colles Casts on Hand Function  

Microsoft Academic Search

Although necessary for bone healing, immobilisation temporarily prevents hand function and may necessitate corrective physiotherapy later. Scaphoid and Colles casts are both commonly used to immobilize scaphoid fractures. Non-union rates are comparable with both casts. The Scaphoid cast incorporates the thumb, whereas the Colles cast leaves the thumb free. We compared the effect of the two casts on hand function

A. KARANTANA; M. J. DOWNS-WHEELER; K. WEBB; C. A. PEARCE; A. JOHNSON; G. C. BANNISTER

2006-01-01

151

Investment cast AISI H13 tooling for automotive applications  

Microsoft Academic Search

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

M. C. Maguire; M. D. Baldwin; P. W. Hochanadel; G. R. Edwards

1995-01-01

152

Cast Process Simulation for the Rapid Tooling.  

NASA Astrophysics Data System (ADS)

A major use for RP (Rapid Prototyping) now is in the foundry industry. It is so called RT (Rapid Tooling). Models are used as patterns for sand and plaster casting or used as sacrificial models in investment casting in the RT. In order to improve casting quality, a cast process simulation program for the RT has been made. This simulation depends on analysis of size accuracy parameters. The result could be came back into the CAD forming program. After that a new CAD data have been adopted in RT process. Then the RT technology could have sufficient accuracy in fabrication. Work supported by the Natural Science Foundation of China (NSFC).

Zhang, Renji; Jiang, Rui; Liu, Yuan; Yan, Yongnian

1997-03-01

153

Microstructured metal molds fabricated via investment casting  

NASA Astrophysics Data System (ADS)

This paper describes an investment casting process to produce aluminum molds having integrated microstructures. Unlike conventional micromolding tools, the aluminum mold was large and had complex curved surfaces. The aluminum was cast from curved microstructured ceramic molds which were themselves cast from curved microstructured rubber. The aluminum microstructures had an aspect ratio of 1:1 and sizes ranging from 25 to 50 µm. Many structures were successfully cast into the aluminum with excellent replication fidelity, including circular, square and triangular holes. We demonstrate molding of large, curved surfaces having surface microstructures using the aluminum mold.

Cannon, Andrew H.; King, William P.

2010-02-01

154

Spray casting project final report  

SciTech Connect

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 storage and transportation canisters for high-level radioactive waste, particularly in the Multipurpose Canister (MPC) application. In addition to the waste-minimization benefits, spray casting would simplify the manufacturing process by allowing the shielding components for MPC to be produced as a single component, as opposed to multiple components with many fabrication and assembly steps. In earlier experiments, surrogate materials were used to simulate the properties (specifically reactivity and density) of DU. Based on the positive results from those studies, the project participants decided that further evaluation of the issues and concerns that would accompany spraying DU was warranted. That evaluation occupied substantially all of Fiscal Year 1995, yielding conceptual designs for both an intermediate facility and a production facility and their associated engineering estimates. An intermediate facility was included in this study to allow further technology development in spraying DU. Although spraying DU to near-net shape seems to be feasible, a number of technical, engineering, and safety issues would need to be evaluated before proceeding with a production facility. This report is intended to document the results from the spray-casting project and to provide information needed by anyone interested in proceeding to the next step.

Churnetski, S.R.; Thompson, J.E.

1996-08-01

155

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...

156

Casting Technology Relevant to the Production of High Strength Aluminum Sand Castings.  

National Technical Information Service (NTIS)

High-strength aluminum sand casting alloys such as type 201 and 224 offer yield strengths upwards of 55,000 psi on bars cut from castings. The range of properties represented expands the technical base and design strength range of aluminum castings; their...

A. G. Fleming G. B. Singh

1973-01-01

157

A Methodology to Predict Fatigue Life of Cast Iron: Uniform Material Law for Cast Iron  

Microsoft Academic Search

Mechanical, physical and manufacturing properties of cast iron make it attractive for many fields of application, such as cranks and cylinder holds. As in design of all metals, fatigue life prediction is an intrinsic part of the design process of structural sections that are made of cast iron. A methodology to predict high-cycle fatigue life of cast iron is proposed.

Sinan Korkmaz

2011-01-01

158

ASEM Analysis of Casting Defects  

NASA Astrophysics Data System (ADS)

While casting defects are a fact of life in the foundry, a method has been developed for analyzing these defects by employing analytical scanning electron microscopy (ASEM). The use of a backscattered electron detector and energy dispersive x-ray systems, available on most ASEM's, facilitates the examination of various defects. Computer storage and programming can make analysis of many particulate defects a routine procedure. Overall, the method provides a starting point from which a person with a knowledge of the process can begin to quickly diagnose the cause of defects. Examples of the usefulness of the technique are presented using case histories from a grey iron foundry.

Votava, Ward E.

1987-09-01

159

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

160

27 CFR 447.22 - Forgings, castings, and machined bodies.  

Code of Federal Regulations, 2011 CFR

...true Forgings, castings, and machined bodies. 447.22 Section 447.22 Alcohol...22 Forgings, castings, and machined bodies. Articles on the U.S. Munitions...castings, extrusions, and machined bodies) which have reached a stage in...

2011-04-01

161

WinMod: An expert advisor for investment casting.  

National Technical Information Service (NTIS)

Investment casting is an important method for fabricating a variety of high quality components in mechanical systems. Cast components, unfortunately, have a large design and gate/runner build time associated with their fabrication. In addition, casting en...

H. P. Bivens G. A. Williamson G. F. Luger R. G. Erdmann M. C. Maguire

1998-01-01

162

DE LAVAUD CASTING FACING NORTH, NOTE CORE MOUNTED IN PREPARATION ...  

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

DE LAVAUD CASTING FACING NORTH, NOTE CORE MOUNTED IN PREPARATION FOR NEXT PIPE CASTING. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

163

27 CFR 447.22 - Forgings, castings, and machined bodies.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Forgings, castings, and machined bodies. 447.22 ...Import List § 447.22 Forgings, castings, and machined bodies. Articles...partially completed state (such as forgings, castings, extrusions, and machined...

2013-04-01

164

22 CFR 121.10 - Forgings, castings and machined bodies.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Forgings, castings and machined bodies. 121.10 Section...of Articles § 121.10 Forgings, castings and machined bodies. Articles on...partially completed state (such as forgings, castings, extrusions and machined...

2013-04-01

165

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

166

Casting shape optimisation via process modelling  

Microsoft Academic Search

The paper describes the application of numerical optimisation case studies to two practical cast components. The first study highlights the potential benefit of thermal controls to achieve an optimised cast part, whereas, the second focuses on shape optimisation. In comparison with practice, it was noted that the unconstrained optimisation for thermal control identified the improvement path correctly, but the solution

R. W Lewis; M. T Manzari; R. S Ransing; D. T Gethin

2000-01-01

167

Discarding Facts: the Economics of Caste  

Microsoft Academic Search

AbstractIn contrast with previous modeling by Akerlof, the author develops a model of a caste system which utilizes the stylized facts that caste occupations are hereditary, compulsory, and endogamous. Some implications of the model are tested with data from the Census of India.

James G. Scoville

2003-01-01

168

Preparation of iron castings for enameling  

Microsoft Academic Search

The quality of enameling depends not only upon the composition of the enamel but also upon the structure, composition and properties of the metal being enameled. An increase in enameling quality and in the properties of enameled cast iron parts may be obtained by surface sheathing of cast iron parts with 08 low-carbon steel. The authors have investigated the conditions

V. V. Mironenko; A. S. Naletov; V. V. Paladich

1983-01-01

169

Automated Radioscopic Inspection of Aluminum Die Castings  

Microsoft Academic Search

Castings produced for the automotive industry are c onsidered important components for overall roadworthiness. To ensure the safety of con struction, it is necessary to check every part thoroughly using non-destructive testing . Radioscopy rapidly became the accepted way for controlling the quality of die cas t pieces. In this paper the fundamental principles of the automated detection of casting

Domingo Mery

170

Slip casting and nitridation of silicon powder  

NASA Astrophysics Data System (ADS)

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.

1985-03-01

171

Development of Titanium Alloy Casting Technology.  

National Technical Information Service (NTIS)

This program was conducted to develop the technologies necessary to establish a low-cost approach for producing titanium investment castings. This approach was based on using simpler and cheaper melting and casting techniques, common to steel and super-al...

D. R. Schuyler G. S. Hall J. A. Petrusha S. R. Seagle

1976-01-01

172

Method for Wrought and Cast Aluminum Separation.  

National Technical Information Service (NTIS)

A method of separating wrought and cast aluminum from a scrap mixture containing the two is disclosed. In this method, the scrap mixture is first heated to a temperature above the solidus temperature of the cast aluminum scrap. At this temperature, the sc...

D. Montagna H. V. Makar

1980-01-01

173

Grey Cast Iron Water Pipe Metallurgy  

Microsoft Academic Search

The results of a metallographic study of grey cast iron water pipes are reported. These pipes had been installed between 1885 and 1973 in eight different water systems. Each pipe had been extracted during scheduled maintenance or failure repairs to provide data for a larger study to produce a methodology for determining the residual life of grey cast iron pipes.

J. M. Makar; B. Rajani

174

Casting Shadows in the Science Classroom.  

ERIC Educational Resources Information Center

Uses the metaphor of shadows in a critical exploration of what it means to know and how the cultures of classrooms have shaped these images of knowing. Directs attention to objects that cast shadows on the learning and knowing of mathematics and science through the voices of preservice teachers. Discusses shadow casting toward textbooks, teachers,…

Nolan, Kathleen

2003-01-01

175

Austempering of spheroidal graphite cast iron  

Microsoft Academic Search

We study gray spherulitic cast iron, its microstructure, hardness ultimate strength in tension, elongation, and impact toughness as functions of the duration of isothermal austenitizing in the bainite region at 350 and 400°C after austenitizing at 900°C. As the temperature of quenching increases from 350 to 400°C, the microstructure of the analyzed cast iron changes from lower to higher bainite

Z. M. El-Baradie; M. M. Ibrahim; I. A. El-Sisy; A. A. Abd El-Hakeem

2004-01-01

176

Advances in shell moulding for investment casting  

Microsoft Academic Search

The casting of liquid metals to produce solid objects is a manufacturing process that has been practised for over 5000 years, with investment casting being one of the oldest known metal shaping methods. The technique itself has tremendous advantages in the production of quality components and the key benefits of accuracy, versatility and integrity. As a result the process is

S Jones; C Yuan

2003-01-01

177

Caste, Ethnicity and Poverty in Rural India  

Microsoft Academic Search

This paper analyzes the determinants of rural poverty in India, contrasting the situation of the Scheduled Caste (SC) and Schedule Tribe (ST) households with the non-scheduled population. The incidence of poverty among SC and ST households is significantly higher than non-scheduled households. Using a probit decomposition analysis, we decompose the difference in the poverty rates between the scheduled castes (or

Ira N. Gang; Myeong-Su Yun

2002-01-01

178

Is a Theory of Caste still Possible?  

Microsoft Academic Search

A theory of caste must offer a way of ordering the facts in such a way that it does not diminish the significance of some or ignore others. It must also be comparative. Caste organization is found in some parts of South Asia but not all. Equally, structural parallels may be found in many other parts of the world and

Declan Quigley

2002-01-01

179

Investment Casting Development: Ancient and Modern Approaches  

Microsoft Academic Search

The ancient art of bronze castings involved painstaking sculpturing of individual wax patterns, followed by clay covering, sun drying, dewaxing, metal pouring and manual finishing, taking several months for each casting. It required a high degree of aesthetic sensitivity and artistic skills honed over decades under the tutelage of senior craftsmen. This art is still practiced in several pockets of

B. Ravi

2003-01-01

180

Tape casting using UV curable binders  

Microsoft Academic Search

High-density tapes were obtained by tape casting of a slurry composed of alumina powder, dispersant, UV curable binder and photoinitiator, and by subsequent photopolymerization. The use of a photopolymerizable binder offers the advantage of eliminating the drying stage, which is a critical step of the tape casting process. The effects of the solid loading, of the dispersant and photoinitiator concentrations

T. Chartier; R. Penarroya; C. Pagnoux; J. F. Baumard

1997-01-01

181

Synthetic casting tapes: benefits and uses of Delta-Cast Conformable.  

PubMed

Casting is a traditional practice that has changed relatively little over thousands of years. Today, however, with the emphasis on evidence-based medicine, health professionals are examining the practice and investigating ways of improving it for the benefit of both patients and those who perform it. Most fractures and many soft tissue injuries are usually managed in a rigid cast, which brings with it complications and disadvantages. The ideal form of fracture fixation would stabilize the fracture while allowing some movement of the fracture site and soft tissue compression. This article explores the use of Delta-Cast Conformable (Johnson and Johnson), a synthetic casting tape, in both primary and secondary casting. The role of Delta-Cast Conformable with regard to focused rigidity casting, a new philosophy in fracture management, is discussed. PMID:9866464

Capper, C

182

[Casting accuracy and shrinkage of titanium castings made with zirconia investments].  

PubMed

To obtain inlay, crown and bridge types of titanium castings with sufficient size accuracy, zirconia investments with 10 mol % calcia were studied for their setting expansion, thermal expansion, total expansion, casting shrinkage compensation deficiency on fabrication method, particle size of zirconia, calcia and mixing liquid. Addition of calcia caused the change from contraction to expansion in setting and the additional thermal expansion at 900-1,200 degrees C. The choice of calcia and mixing liquid makes great influence on setting expansion, which is grouped into saturation type and delayed expansion type. By the use of the saturation type, total expansion could be controlled in the range of -2-(+)3%. Titanium castings of inlay, crown, bridge types with the values -2-(+)2% of casting shrinkage compensation deficiency could be successfully obtained. The casting shrinkage of titanium was estimated as 1.8-2%. The castings have the surface with a metallic brilliance as cast. PMID:2135548

Nishimura, F; Watari, F; Nakamura, H; Fukumoto, R; Morita, N

1990-11-01

183

The production of large structural titanium castings  

NASA Astrophysics Data System (ADS)

Titanium-alloy castings have recently become an attractive option for critical-structural applications in aerospace structures. These opportunities have occurred primarily because of the development of advanced-process technologies, such as rapid-prototyping methodology and solidification modeling, which have dramatically reduced the cost and time required to obtain first-article castings through concurrent engineering. Moreover, these technologies have lowered the risk involved in examining new applications for titanium castings. This article examines the implementation of these new technologies and the heat treatment and mechanical properties of large structural castings, particularly in relation to section size. Additionally, the production of a cast-titanium transmission adapter for the V-22 Osprey Tiltrotoraircraft is described.

Klepeisz, J.; Veeck, S.

1997-11-01

184

Final report on Expendable Pattern Casting Technology  

SciTech Connect

The Expendable Pattern Casting (EPC) process is a potential casting process breakthrough which could dramatically improve the competitiveness of the US foundry industry. Cooperatively supported by US Industry and the Department of Energy and managed by the American Foundrymen's Society, a project was started in May 1989 to develop and optimize expendable pattern casting technology. Four major tasks were conducted in the first phase of the project. Those tasks involved: (1) reviewing published literature to determine the major problems in the EPC process, (2) evaluating factors influencing sand flow and compaction, (3) evaluating and comparing factors influencing sand flow and compaction, (3) evaluating and comparing casting precision obtained in the EPC process with that obtained in other processes, and (4) identifying critical parameters that control dimensional precision and defect formation in EP castings. 26 refs., 27 figs., 11 tabs.

Not Available

1990-07-01

185

Possible segregation caused by centrifugal titanium casting.  

PubMed

The possibility of the segregation under solidification process using a centrifugal casting machine was investigated using an electron probe microanalyzer with elemental distribution map, line analysis and quantitative analysis. When a very small quantity of platinum was added to local molten titanium during the casting process, macroscopic segregation was observed under conditions of density difference of 0.1 g/cm3 at the most, confirming that the centrifugal force of the casting machine is extremely strong. When a Ti-6Al-4V alloy was cast, however, no macroscopic segregation was observed. The centrifugal force of the casting machine examined in the present study hardly results in the body-force segregation in this titanium alloy. PMID:9550020

Watanabe, K; Okawa, S; Kanatani, M; Nakano, S; Miyakawa, O; Kobayashi, M

1996-12-01

186

BMM SHAKEOUT AND VIBRATING CONVEYOR TRANSPORT SAND AND CASTINGS TO ...  

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

BMM SHAKEOUT AND VIBRATING CONVEYOR TRANSPORT SAND AND CASTINGS TO SEPARATIONS SCREENS. - Southern Ductile Casting Company, Shaking, Degating & Sand Systems, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

187

AMCC casting development. Volume 1: Executive Summary  

NASA Astrophysics Data System (ADS)

The Advanced Combustion Chamber Casting (AMCC) has been a technically challenging part due to its size, configuration, and alloy type. The height and weight of the wax pattern assembly necessitated the development of a hollow gating system to ensure structural integrity of the shell throughout the investment process. The complexity in the jacket area of the casting required the development of an innovative casting technology that PCC has termed 'TGC' or Thermal Gradient Control. This method, of setting up thermal gradients in the casting during solidification, represents a significant process improvement for PCC and has been successfully implemented on other programs. Metallurgical integrity of the final four castings was very good. Only the areas of the parts that utilized 'TGC Shape & Location System #2' showed any significant areas of microshrinkage when evaluated by non-destructive tests. Alumina oxides detected by FPI on the 'float' surfaces (top sid surfaces of the casting during solidification) of the part were almost entirely less than the acceptance criteria of .032 inches in diameter. Destructive chem mill of the castings was required to determine the effect of the process variables used during the processing of these last four parts (with the exception of the 'Shape & Location of TGC' variable).

1995-03-01

188

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

189

Deshpande: The Grammar of Caste - Economic Discrimination in Contemporary India  

Microsoft Academic Search

This book examines the contemporary nature of caste disparities in India by using a framework that integrates discussions on caste from other social science disciplines with those from within economics. It brings together quantitative evidence on different dimensions of caste disparities based on two large national-level data sets, in order to analyse the degree of change in the caste system

Ashwini Deshpande

190

Is Caste Destiny? Occupational Diversification among Dalits in Rural India  

Microsoft Academic Search

The caste system – a system of elaborately stratified social hierarchy – distinguishes India from most other societies. Among the most distinctive factors of the caste system is the close link between castes and occupations, especially in rural India, with Dalits or Scheduled Castes (SC) clustered in occupations that were the least well paid and most degrading in terms of

Ira N. Gang; Kunal Sen; Myeong-Su Yun

2012-01-01

191

Fatigue crack propagation damaging micromechanisms in ductile cast irons  

Microsoft Academic Search

Ductile iron discovery in 1948 gave a new lease on life to the cast iron family. In fact, these cast irons are characterized both by a high castability and by high toughness values, combining cast irons and steel good properties. Ductile cast irons are also characterized by high fatigue crack propagation resistance, although this property is still not widely investigated.In

M. Cavallini; O. Di Bartolomeo; F. Iacoviello

2008-01-01

192

Metal Pipe Joining with Aluminum Alloy by Ultrasonic Insert Casting  

Microsoft Academic Search

Insert casting of aluminum is widely used in industry. In order to realize better metallurgical bonding between metallic pipe and aluminum alloy castings, a new insert casting method with aided by high-power ultrasound has been developed. The bonding strength between the metal pipe and the cast aluminum alloy was evaluated by shear testing, EPMA analysis at the bonding interface was

J. Pan; M. Yoshida; G. Sasaki; H. Fukunaga

2000-01-01

193

GRINDING ROOM AT SOUTHERN DUCTILE CASTING COMPANY, BESSEMER FOUNDRY SHOWING ...  

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

GRINDING ROOM AT SOUTHERN DUCTILE CASTING COMPANY, BESSEMER FOUNDRY SHOWING WHEELABORATOR THAT IMPALE SHOT AT TUMBLING CASTINGS TO REMOVE EXCESS SURFACE METALS AND SAND; ANNEALING OVENS TO HEAT CERTAIN CASTINGS TO ACHIEVE A DESIRED CHARACTERISTIC; AND GRINDING WHEELS USED TO REMOVE GATES. - Southern Ductile Casting Company, Grinding & Shipping, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

194

Investment cast AISI H13 tooling for automotive applications.  

National Technical Information Service (NTIS)

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 mate...

M. C. Maguire M. D. Baldwin P. W. Hochanadel G. R. Edwards

1995-01-01

195

Simulating MacroPorosity in Aluminum Lost Foam Castings  

Microsoft Academic Search

Porosity in aluminum castings continues to be the leading cause of scrap in most of the foundries in the world. Research has shown methods of reducing both macro- and micro-porosity in open mold aluminum castings with varying levels of success. However, the filling behavior in Lost Foam Casting is significantly different from that in open mold casting and methods of

P. Scarber; H. Littleton

196

Modeling and control of casting and welding processes  

SciTech Connect

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

Kou, S.; Mehrabian, R.

1986-01-01

197

Fatigue behavior of A356-T6 aluminum cast alloys. Part I. Effect of casting defects  

Microsoft Academic Search

The influence of casting defects on the room temperature fatigue performance of a Sr-modified A356-T6 casting alloy has been studied using un-notched polished cylindrical specimens. The numbers of cycles to failure of materials with various secondary arm spacings (SDAS) were investigated as a function of stress amplitude, stress ratio, and casting defect size. To produce pore-free samples, HIP-ed and Densal™

Q. G Wang; D Apelian; D. A Lados

2001-01-01

198

Structure and Property Studies on Austempered and AsCast Ausferritic Gray Cast Irons  

Microsoft Academic Search

A high-strength and wear-resistant alloyed gray iron with ausferritic microstructure on solidification directly from molten\\u000a condition could be made in a Ni and Mo alloyed gray cast iron. The as-cast ausferritic cast iron was compared with two conventionally\\u000a austempered gray iron with and without Ni and Mo additions. The various phase constitution and volume fractions were analyzed\\u000a using optical, SEM

Aravind Vadiraj; G. Balachandran; M. Kamaraj

2010-01-01

199

Genetic structure of Rajaka caste and affinities with other caste populations of Andhra Pradesh, India.  

PubMed

The present study gives an account of the genetic structure in terms of distribution of a few genetic markers, viz., A1A2B0, Rh(D), G6PD deficiency and haemoglobin among the Rajaka caste population of Andhra Pradesh, India. The genetic relationships of the Rajaka caste with other Andhra caste populations were investigated in terms of genetic distance, i.e., Sq B (mn) of Balakrishnan and Sanghvi. Relatively lesser distance was established between the Rajaka and two Panchama castes. Also, the pattern of genetic distance corroborates the hierarchical order of the Hindu varna system. PMID:9428195

Parvatheesam, C; Babu, B V; Babu, M C

1997-01-01

200

WinMod: An expert advisor for investment casting  

SciTech Connect

Investment casting is an important method for fabricating a variety of high quality components in mechanical systems. Cast components, unfortunately, have a large design and gate/runner build time associated with their fabrication. In addition, casting engineers often require many years of actual experience in order to consistently pour high quality castings. Since 1989, Sandia National Laboratories has been investigating casting technology and software that will reduce the time overhead involved in producing quality casts. Several companies in the casting industry have teamed up with Sandia to form the FASTCAST Consortium. One result of this research and the formation of the FASTCAST consortium is the creation of the WinMod software, an expert casting advisor that supports the decision making process of the casting engineer through visualization and advice to help eliminate possible casting defects.

Bivens, H.P.; Williamson, G.A. Jr.; Luger, G.F. [Univ. of New Mexico, Albuquerque, NM (United States). Computer Science Dept.; Erdmann, R.G. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Materials Science and Engineering; Maguire, M.C.; Baldwin, M.D.; Anderson, D.J. [Sandia National Labs., Albuquerque, NM (United States)

1998-04-01

201

Uranium casting furnace automatic temperature control development.  

National Technical Information Service (NTIS)

Development of an automatic molten uranium temperature control system for use on batch-type induction casting furnaces is described. Implementation of a two-color optical pyrometer, development of an optical scanner for the pyrometer, determination of fur...

R. F. Lind

1992-01-01

202

Caste in India, Past and Present  

ERIC Educational Resources Information Center

Traced is the sociocultural framework for the system in Indian culture which emphasized duty and obligations rather than individual freedom and rights. Also discussed are contemporary changes in the caste system. (DB)

Bishop, Donald H.

1971-01-01

203

Advanced lost foam from casting technology  

SciTech Connect

Previous research made significant advances in understanding the Lost Foam Casting (LFC) Process and clearly identified areas where additional research was needed to improve the process and make it more functional in an industrial environment. The current project focused on five areas listed as follows: Task 1: Precision Pattern Production Task 2: Pattern Coating Consistency Task 3: Sand Fill and Compaction Effects Task 4: Pattern Gating Task 5: Mechanical Properties of Castings. This report summarizes the work done under the current contract in all five areas in the period of October 1, 1994 through December 31, 1995. Twenty-eight (28) companies jointly participate in the project. These companies represent a variety of disciplines, including pattern designers, pattern producers, coating manufacturers, plant design companies, compaction equipment manufacturers, casting producers, and casting buyers.

Bates, C.E.; Littleton, H.E.; Askeland, D., Griffin, J., Miller, B.A., Sheldon, D.S.

1996-05-01

204

Open Cast Mining: An Environmental Issue.  

ERIC Educational Resources Information Center

|Presents a case study in which students investigate the environmental issue of open cast coal mining. Students examine the issue from different perspectives; interpret the available evidence; draw appropriate conclusions; and evaluate such conclusions. (MDH)|

McPartland, Michael

1993-01-01

205

Slip casting alumina with Na-CMC  

SciTech Connect

Many forming methods are in common use for engineering ceramics. Of these, slip casting is an ideal forming method because of its low cost, simplicity and flexibility, potential for uniform particle packing and suitability to the production of articles of intricate shape. Slip casting nonclay materials, such as alumina, requires the use of both a deflocculant and a binder. There are many commercially available deflocculants and binders that can be tested in alumina casting slips. However, determination of a suitable deflocculant/binder combination and quantification of the optimal additions of the deflocculant/binder pair can be time consuming. Certain deflocculants are capable of acting as binders. One such additive is sodium carboxymethylcellulose (Na-cmc), a cellulose ether. Na-cmc is a powerful binder. It is a member of the carbohydrate binder group--the binder group with the strongest binding power. It is capable of acting as a deflocculant in glazes and nonclay casting slips.

Ruys, A.J.; Sorrell, C.C. [Univ. of New South Wales, Sydney, New South Wales (Australia)

1996-11-01

206

Roll Casting of Aluminum Alloy Clad Strip  

SciTech Connect

Casting of aluminum alloy three layers of clad strip was tried using the two sets of twin roll casters, and effects of the casting parameters on the cladding conditions were investigated. One twin roll caster was mounted on the other twin roll caster. Base strip was 8079 aluminum alloy and overlay strips were 6022 aluminum alloy. Effects of roll-load of upper and lower casters and melt temperature of the lower caster were investigated. When the roll-load of the upper and lower caster was large enough, the overlay strip could be solidified and be connected. The overlay strip could be connected when the melt of the overlay strip cast by the lower caster was low enough. Sound three layers of clad strip could be cast by proper conditions.

Nakamura, R.; Tsuge, H. [Graduate School of Osaka Institute of Technology (Japan); Haga, T. [Osaka Institute of Technology, 5-16-1 Omiya Asahiku Osaka city 535-8585 (Japan); Watari, H. [Tokyo Institute of Technology, 4259 Nagatsuda Midoriku Yokohama city 226-8502 (Japan); Kumai, S. [Gunma University, 1-5-1 tenjin cho Kiryu city 376-8515 (Japan)

2011-01-17

207

Recovery of Zircon from Investment Casting Molds.  

National Technical Information Service (NTIS)

The Bureau of Mines conducted physical and chemical beneficiation studies on three samples of waste investment casting molds to devise a method to liberate and recover zircon. Rod mill grinding, autogenous attrition grinding, and caustic leaching were lib...

C. W. Smith T. O. Llewellyn

1985-01-01

208

Future vision for the investment casting industry.  

National Technical Information Service (NTIS)

All of American industry is being subjected to increased competitive pressures due to customer needs for shorter cycle times and better quality. The investment casting industry could be in a unique position to satisfy these needs by incorporating several ...

F. J. Zanner M. C. Maguire

1993-01-01

209

Feeding and Risering Guidelines for Steel Castings.  

National Technical Information Service (NTIS)

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, a...

2002-01-01

210

Microstructural Characterization of Cast Nickel Aluminum Bronze.  

National Technical Information Service (NTIS)

The morphology and chemical analysis of the complex phases present in cast nickel aluminum bronze of nominal composition 10% aluminum, 5% nickel, and 5% iron were investigated using optical microscopy, scanning electron microscopy, and scanning transmissi...

E. A. Culpan G. Rose

1978-01-01

211

14 CFR 25.621 - Casting factors.  

Code of Federal Regulations, 2013 CFR

...castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses...berth, safety belt, and fuel and oil tank supports and attachments, and cabin pressure...

2013-01-01

212

Slip casting of advanced ceramics and composites  

NASA Astrophysics Data System (ADS)

Particle packing arrangements in slip cast (colloidal filtration) articles uniquely affect the evolution of grain size and porosity defect distributions during sintering. These particle packing arrangements are influenced by the physical properties of colloidal structures in suspension and the resulting processes of agglomerate restructuring and pore closure during consolidation. Key parameters affecting cast layer packing structures are the particle size distribution, interparticle potential, hydrodynamic stresses in suspensions, and the combined effect of hydrodynamic and compaction stresses in cast layers. Experiments with electrostatically stabilized aqueous alumina systems illustrate specific effects of interparticle potential on slip casting rates and microstructure evolution during sintering. In addition, experiments were conducted that illustrate microstructure variations caused by differential sedimentation velocities and agglomerate growth kinetic effects.

Schilling, C. H.; Aksay, I. A.

1987-03-01

213

Preparation of iron castings for enameling  

SciTech Connect

This article investigates the conditions of formation of a strong metallic bond between 08 steel and molten cast iron and of obtaining a low-carbon (ferritic) layer on the surface of a sheathed casting on the side of the iron. Points out that the quality of enameling depends not only upon the composition of the enamel but also upon the structure, composition, and properties of the metal being enameled. The results of the investigation are being used as the basis of a new method of producing cast iron enameled fittings with a surface low-carbon layer. Finds that the strength of the cast iron was increased by 1.5 times and the soundness of the enamel coating by 4 times using the new method.

Mironenko, V.V.; Naletov, A.S.; Paladich, V.V.

1983-01-01

214

Graphite Formation in Cast Iron, Phase 2.  

National Technical Information Service (NTIS)

Several types of cast irons are directionally solidified aboard the KC-135 aircraft. Also, control samples are run on Earth for comparison. Some of these samples are unusable because of various mechanical problems; the analysis and the interpretation of r...

D. M. Stefanescu M. R. Fiske

1985-01-01

215

Thermal transport properties of grey cast irons  

SciTech Connect

Thermal diffusivity and thermal conductivity of grey cast iron have been measured as a function of graphite flake morphology, chemical composition, and position in a finished brake rotor. Cast iron samples used for this investigation were cut from ``step block`` castings designed to produce iron with different graphite flake morphologies resulting from different cooling rates. Samples were also machined from prototype alloys and from production brake rotors representing a variation in foundry practice. Thermal diffusivity was measured at room and elevated temperatures via the flash technique. Heat capacity of selected samples was measured with differential scanning calorimetry, and these results were used to calculate the thermal conductivity. Microstructure of the various cast iron samples was quantified by standard metallography and image analysis, and the chemical compositions were determined by optical emission spectroscopy.

Hecht, R.L. [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.; Dinwiddie, R.B.; Porter, W.D.; Wang, Hsin [Oak Ridge National Lab., TN (United States)

1996-10-01

216

Caste and Language in Jaffna Society.  

ERIC Educational Resources Information Center

|Caste and language in the Jaffna Hindu Tamil society were correlated based on data collected from sample villages in the Jaffna peninsula, where the political and economic ascendancy of the landlords was very dominant in the recent past. (SW)|

Suseendirarajah, S.

1978-01-01

217

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

The tape casting slip composition barium titanate powder, MEK-Ethanol solvent, phosphate ester dispersant, acrylic binder, PEG and butyl-benzyl-phthalate plasticizers and cyclohexanone was studied. The nature of the dispersion mechanism for the phosphate ...

W. R. Cannon

1985-01-01

218

Beryllium-aluminum alloys for investment castings  

SciTech Connect

Beryllium-aluminum alloys containing greater than 60 wt % beryllium are very favorable materials for applications requiring light weight and high stiffness. However, when produced by traditional powder metallurgical methods, these alloys are expensive and have limited applications. To reduce the cost of making beryllium-aluminum components, Nuclear Metals Inc. (NMI) and Lockheed Martin Electronics and Missiles have recently developed a family of patented beryllium-aluminum alloys that can be investment cast. Designated Beralcast, the alloys can achieve substantial weight savings because of their high specific strength and stiffness. In some cases, weight has been reduced by up to 50% over aluminum investment casting. Beralcast is now being used to make thin wall precision investment castings for several advanced aerospace applications, such as the RAH-66 Comanche helicopter and F-22 jet fighter. This article discusses alloy compositions, properties, casting method, and the effects of cobalt additions on strength.

Nachtrab, W.T.; Levoy, N. [Nuclear Metals Inc., Concord, MA (United States)

1997-05-01

219

Feeding of high-nickel alloy castings  

Microsoft Academic Search

Feeding of the nickel-based alloys CZ-100, M-35-1, and CW-12MW, as well as of the austenitic stainless steel CN-7M, is investigated,\\u000a using a combination of casting experiments and simulation. Casting trials are performed at five foundries, to produce a total\\u000a of 55 plates of varying lengths and radiographic soundness levels. In order to develop the property databases necessary to\\u000a simulate the

Kent D. Carlson; Shouzhu Qu; Christoph Beckermann

2005-01-01

220

Ultrasonic maps of porosity in aluminum castings  

NASA Astrophysics Data System (ADS)

The use of cast aluminum in the automotive industry has grown dramatically in recent years, leading to increased need for quantitative characterization of microporosity. As previously reported in the literature, the attenuation of ultrasound can be used to measure the porosity volume fraction and the mean pore size. An immersion ultrasound system has been built utilizing this technique to scan castings with high spatial resolution. Maps of attenuation are shown to locate areas of varying porosity readily and reliably. .

Ghaffari, Bita; Potter, Timothy J.; Mozurkewich, George

2002-05-01

221

Electrochemical characterization of cast titanium alloys  

Microsoft Academic Search

A reaction layer forms on cast titanium alloy surfaces due to the reaction of the molten metal with the investment. This surface layer may affect the corrosion of the alloy in the oral environment. The objective of this study was to characterize the in vitro corrosion behavior of cast titanium alloys. ASTM Grade 2 CP titanium, Ti–6Al–4V, Ti–6Al–7Nb and Ti–13Nb–13Zr

Zhuo Cai; Ty Shafer; Ikuya Watanabe; Martha E Nunn; Toru Okabe

2003-01-01

222

Aging degradation of cast stainless steel  

Microsoft Academic Search

A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich ..cap alpha..' and Ni- and Si-rich G

O. K. Chopra; H. M. Chung

1986-01-01

223

Twin roll casting of aluminum alloy strips  

Microsoft Academic Search

Two kinds of twin roll caster for aluminum alloys were devised in the present study. Vertical type was adopted. The strip, which was thinner than 3mm, could be cast at speeds higher than 60m\\/min. Aluminum alloy, which freezing zone is very wide like A5182, could be cast using the twin roll caster of the present study at speeds up to

Toshio Haga; Kenta Tkahashi; Masaaki Ikawaand; Hisaki Watari

2004-01-01

224

Alpha case thickness modeling in investment castings  

Microsoft Academic Search

The alpha case thickness at the surface of a Ti-6Al-4V (wt pct) step wedge investment casting has been measured and successfully\\u000a predicted. The prediction uses temperature-time results obtained from a heat flow simulation of the casting. The temperature-time\\u000a results were coupled to a simple model for diffusion of oxygen into the beta phase during continuous cooling. Oxygen concentration\\u000a and microhardness

W. J. Boettinger; M. E. Williams; S. R. Coriell; U. R. Kattner; B. A. Mueller

2000-01-01

225

Bainitic high-strength cast iron with spheroidal graphite (review)  

SciTech Connect

Bainitic cast iron with spheroidal graphite (BCISG) is a new class of structural materials. The matrix structure of BCISG is bainite and residual austenite. This structure is obtained by isothermal quenching (in this case the BCISG is called isothermally-quenched high-strength cast iron-austempered ductile iron, ADI) or by continuous cooling from the casting or austenization temperature (such BCISG is called cast bainitic cast iron). 64 refs., 1 fig., 1 tab.

Voronenko, B.I.; Romatovskii, Y.I.

1992-03-01

226

Slip casting of partially stabilized zirconia  

SciTech Connect

The toughness of partially-stabilized zirconia has been studied for some time. The tetragonal phase in partially stabilized ZrO2 transforms to the monoclinic phase under the influence of stress. Partially-stabilized ZrO2 has enhanced tensile strength, good wear resistance and low friction coefficient, and has found industrial applications. This article describes the use of partially-stabilized zirconia in slip casting. Lab techniques of slip casting have been reported for nonplastic materials such as Al2O3, CaF2, CaO-stabilized ZrO2 and MgO. The article discusses the variation of slip density and firing temperature and also reports the preparation of specimens of CaOstabilized ZrO2 by slip casting from ethanol-based suspensions. The preparation of Y2O3-ZrO2 compositions by slip casting from aqueous suspension is also reported. A Y2O3 partially stabilized ZrO2 powder was used as a starting material. The densities of the cast specimens were measured from the volume and weight, and those of the sintered specimens were measured by a liquid displacement technique using distilled water. The concentation of the suspension strongly affects the relative density of the cast specimen and the firing shrinkage of the sintered specimen, while the relative density of the sintered specimen is independent of the concentration of the suspension.

Taguchi, H.; Miyamoto, H.; Takahashi, Y.

1985-02-01

227

Preparation of iron castings for enameling  

SciTech Connect

The quality of enameling depends not only upon the composition of the enamel but also upon the structure, composition and properties of the metal being enameled. An increase in enameling quality and in the properties of enameled cast iron parts may be obtained by surface sheathing of cast iron parts with 08 low-carbon steel. The authors have investigated the conditions of formation of a strong metallic bond between 08 steel and molten cast iron and of obtaining a low-carbon layer on the surface of a sheathed casting on the side of the iron. On the basis of the experimental data, a nomogram was drawn making it possible to determine the production conditions of the process. The results of the investigation are being used as the basis of a new method of producing cast iron enameled fittings with a surface low-carbon layer. The method developed specifies the preparation of halves of a thin-walled hollow nonremovable core of 08 sheet steel, diffusion butt welding of the halves prepared, shot peening, placement of the cores in the sand mold and pouring of iron at 1430-1460/sup 0/C. Production tests of experimental housings for valves showed the effectiveness of the new method in comparison with the traditional. The strength of the cast iron was increased by 1.5 times and the soundness of the enamel coating by 4 times.

Mironenko, V.V.; Naletov, A.S.; Paladich, V.V.

1983-01-01

228

Reinforcement of Aluminum Castings with Dissimilar Metals  

SciTech Connect

The project ''Reinforcement of Aluminum Casting with Dissimilar Metal'' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Cummins Inc. This project, technologies have been developed to reinforce aluminum castings with steel insert. Defect-free bond between the steel insert and the aluminum casting has been consistently obtained. The push-out experiment indicated that the bond strength is higher than that of the Al-Fin method. Two patents have been granted to the project team that is comprised of Cummins Inc. and ORNL. This report contains four sections: the coating of the steel pins, the cast-in method, microstructure characterization, and the bond strength. The section of the coating of the steel pins contains coating material selection, electro-plating technique for plating Cu and Ni on steel, and diffusion bonding of the coatings to the steel. The section of cast-in method deals with factors that affecting the quality of the metallurgical bond between the coated steel and the aluminum castings. The results of microstructure characteristics of the bonding are presented in the microstructure characterization section. A push-out experiment and the results obtained using this method is described in the section of bond strength/mechanical property.

Han, Q

2004-01-07

229

Silica exposure in hand grinding steel castings.  

PubMed

Exposure to silica dust was studied in the grinding of castings in a steel foundry that used conventional personal sampling methods and new real-time sampling techniques developed for the identification of high-exposure tasks and tools. Approximately one-third of the personal samples exceeded the National Institute for Occupational Safety and Health recommended exposure limit for crystalline silica, a fraction similar to that identified in other studies of casting cleaning. Of five tools used to clean the castings, the tools with the largest wheels, a 6-in. grinder and a 4-in. cutoff wheel, were shown to be the major sources of dust exposure. Existing dust control consisted of the use of downdraft grinding benches. The size of the casting precluded working at a distance close enough to the grates of the downdraft benches for efficient capture of the grinding dust. In addition, measurements of air recirculated from the downdraft benches indicated that less than one-half of the respirable particles were removed from the contaminated airstream. Previous studies have shown that silica exposures in the cleaning of castings can be reduced or eliminated through the use of mold coatings, which minimize sand burn-in on the casting surface; by application of high-velocity, low-volume exhaust hoods; and by the use of a nonsilica molding aggregate such as olivine. This study concluded that all these methods would be appropriate control options. PMID:1317091

O'Brien, D; Froehlich, P A; Gressel, M G; Hall, R M; Clark, N J; Bost, P; Fischbach, T

1992-01-01

230

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

231

Place of subcaste (jati) identity in the discourse on caste: examination of caste in the diaspora  

Microsoft Academic Search

Caste as a social phenomenon has undergone many changes. The most important operative unit that has exemplified caste in its discourse is subcaste (jati) identity. Both within India and certainly in the diaspora, there is now increasing evidence of the dissolution of subcaste (jati) identities giving rise to various other formations of groups replacing the endogamous relationships with other arbitrary

P. Pratap Kumar

2012-01-01

232

Introduction of mechanized manufacture of a cast lining for steel-casting ladles  

Microsoft Academic Search

The layout of the mechanized assembly is shown in Fig. I. One feature of the assembly is that during casting the ladle remains immobile, while the even cyclic supply of prepared mixture to the ladle is done by the receiving and dispensing worm of the manipulator mounted on a self-moving car. Before casting, the manipulator is moved over the ladle

N. K. Shorina; N. N. Soldatchenko; A. A. Krivosheiko; A. I. Sukhanov

1983-01-01

233

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

National Technical Information Service (NTIS)

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...

2005-01-01

234

Optimization of composition of heat-treated chromium white cast iron casting by phosphate graphite mold  

Microsoft Academic Search

In present work, the difference among orthogonal design, Fuzzy optimum design and artificial neural network ANN was performed on the basis of the optimization of chemical composition of chromium white cast iron. It is found that Fuzzy optimum design is suitable for multi-objective comprehensive evaluation, and the optimum composition of white cast iron is Cr 4%, Si 3.5%, Mn 3%

An-hui Cai; Yong Zhou; Jing-ying Tan; Yun Luo; Tie-lin Li; Min Chen; Wei-ke An

2008-01-01

235

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

Microsoft Academic Search

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

Nick Cannell; Adrian S. Sabau

2005-01-01

236

Multiscale modeling for the prediction of casting defects in investment cast aluminum alloys  

Microsoft Academic Search

Macroscopic modeling of heat transfer and fluid flow is now routinely used for the prediction of macroscopic defects in castings, while microscopic models are used to investigate the effects of alloy changes on typical microstructures. By combining these two levels of modeling it is possible to simulate the casting process over a wider range of spatial and temporal scales. This

R. W Hamilton; D See; S Butler; P. D Lee

2003-01-01

237

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

National Technical Information Service (NTIS)

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...

A. S. Sabau

2005-01-01

238

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

239

Mould design and casting process improvement on vibrator shell  

NASA Astrophysics Data System (ADS)

Vibrator shell is a part with complex structure. While the vibrator shell is designed and manufactured by traditional sand casting process, more than 80% castings are found the defects of porosity, shrinkage and pouring-shortage at the top. Aiming to the problems in traditional sand casting, this paper focused on the improvement of castings structure and the optimization of casting process. Designing process bar in the gate-channel region which is connected with the gate in castings is used to improve the castings structure, and low speed filling and solidification under high pressure are adopted to optimize the casting process which is finished by self-made four-column type hydraulic machine equipped. It can be seen that the castings quality can be greatly improved by process improvement.

Zhang, Lipan; Fang, Ligao; Chen, Zhong; Song, Kai

2011-11-01

240

Microstructure of thin-wall ductile iron castings  

SciTech Connect

The automotive industry is seeking to replace current car parts made of aluminum and iron castings with thin wall (down to 2 mm) iron castings to reduce the cost and weight of automobiles. The mechanical properties of thin wall ductile iron castings are affected strongly by the thickness of the castings. The thinner castings cool at a faster rate, and microstructural features that form during solidification, and subsequently, transform in the solid state, are strongly dependent on a geometrical parameter related to the ratio of surface area-to-volume of the casting. As this ratio becomes larger, castings cool faster. As a result, the nodule count on the observation plane of the specimens increases dramatically (>2000 nodules/mm2 in most specimens), i.e. as the thickness of castings decreases. Also, the matrix of the thin walled ductile iron castings becomes more ferritic as the ratio of surface area-to-volume decreases.

Dogan, Omer N.; Schrems, Karol K.; Hawk, Jeffrey A.; Druschitz, A.P. (Intermet Corp., Lynchburg, VA)

2001-10-01

241

Removable cast walker boots yield greater forefoot off-loading than total contact casts  

PubMed Central

Background Elevated plantar loading has been implicated in the etiology of plantar ulceration in individuals with diabetes mellitus and peripheral neuropathy. Total contact casts and cast walker boots are common off-loading strategies to facilitate ulcer healing and prevent re-ulceration. The purpose of this study was to compare off-loading capabilities of these strategies with respect to plantar loading during barefoot walking. Methods Twenty-three individuals with diabetes, peripheral neuropathy, and plantar ulceration were randomly assigned to total contact cast (N=11) or removable cast walker boot (N=12). Each subject underwent plantar loading assessment walking barefoot and wearing the off-loading device. Analysis of covariance was used to compare loading patterns in the off-loading devices for the whole foot, hindfoot, midfoot, and forefoot while accounting for walking speed and barefoot loading. Findings For the foot as a whole, there were no differences in off-loading between the two techniques. Subjects wearing cast walker boots had greater reductions in forefoot peak pressure, pressure-time integral, maximum force, and force-time integral with respect to barefoot walking. Healing times were similar between groups, but a greater proportion of ulcers healed in total contact casting compared to cast walker boots. Interpretation In subjects with diabetes, peripheral neuropathy, and plantar ulceration, cast walker boots provided greater load reduction in the forefoot, the most frequent site of diabetic ulceration, though a greater proportion of subjects wearing total contact casts experienced ulcer healing. Taken together, the less effective ulcer healing in cast walker boots despite superior forefoot off-loading suggests an important role for patient compliance in ulcer healing.

Gutekunst, David J.; Hastings, Mary K.; Bohnert, Kathryn L.; Strube, Michael J.; Sinacore, David R.

2011-01-01

242

Biliary Cast Syndrome in an Opium Inhaler  

PubMed Central

Biliary cast syndrome (BCS) is an uncommon complication which is mostly described in orthotopic liver transplantation. However, BCS has also been reported rarely in non-liver transplant patients. We describe a male long-term opium inhaler with BCS who underwent successful endoscopic cast removal by balloon enteroscopy-guided endoscopic retrograde cholangiopancreatography. A 52-year-old man, who was a known case of opium addiction, presented with the chief complaint of epigastric pain for 1 week prior to admission. Routine laboratory evaluation revealed cholestatic liver enzyme elevation. A cholestatic pattern was seen in radiographic modalities. Endoscopic retrograde cholangiopancreatography showed a linear filling defect in the intra- and extrahepatic duct. A long biliary cast was successfully removed using an extractor balloon. After removal of the biliary cast the patient is receiving ursodeoxycholic acid and does not report any problem 4 months after treatment. It seems that biliary dyskinesia due to long-term opium use can be a predisposing factor for biliary cast formation.

Dabiri, Reza; Aghdae, Hamid Asadzadeh; Rajabalinia, Hasan; Mohammad Alizadeh, Amir Houshang

2013-01-01

243

Biliary cast syndrome in an opium inhaler.  

PubMed

Biliary cast syndrome (BCS) is an uncommon complication which is mostly described in orthotopic liver transplantation. However, BCS has also been reported rarely in non-liver transplant patients. We describe a male long-term opium inhaler with BCS who underwent successful endoscopic cast removal by balloon enteroscopy-guided endoscopic retrograde cholangiopancreatography. A 52-year-old man, who was a known case of opium addiction, presented with the chief complaint of epigastric pain for 1 week prior to admission. Routine laboratory evaluation revealed cholestatic liver enzyme elevation. A cholestatic pattern was seen in radiographic modalities. Endoscopic retrograde cholangiopancreatography showed a linear filling defect in the intra- and extrahepatic duct. A long biliary cast was successfully removed using an extractor balloon. After removal of the biliary cast the patient is receiving ursodeoxycholic acid and does not report any problem 4 months after treatment. It seems that biliary dyskinesia due to long-term opium use can be a predisposing factor for biliary cast formation. PMID:24163648

Dabiri, Reza; Aghdae, Hamid Asadzadeh; Rajabalinia, Hasan; Mohammad Alizadeh, Amir Houshang

2013-09-05

244

Superplasticity in Rapidly Solidified White Cast Irons  

NASA Astrophysics Data System (ADS)

Superplastic properties of three different composition white cast irons were investigated in the temperature range of 630 to 725 °C. Fine structures consisting of 1 to 2 ?m ferrite grains were developed in these materials by consolidation of rapidly solidified powders at intermediate temperatures below the A1 critical temperature. Tensile elongations of 1410 pct were found for a 3.0 pct C + 1.5 pct Cr white cast iron, 940 pct for a 3.0 pct C white cast iron, and 480 pct for a 2.4 pct C white cast iron when tested at 700 °C and at a strain rate of 1 pct per minute. The superplastic white cast irons exhibited a high strain rate sensitivity exponent, m, of 0.5 and activation energies for plastic flow were found to be nearly equal to the activation energy for grain boundary self-diffusion in iron. These observations are in agreement with the creep behavior of superplastic materials controlled by grain boundary diffusion.

Ruano, Oscar A.; Eiselstein, Lawrence E.; Sherby, Oleg D.

1982-10-01

245

Robust digital watermarking using random casting method  

NASA Astrophysics Data System (ADS)

In this paper, a new digital watermarking scheme based-on the random casting method in the DCT domain is proposed. In the conventional watermarking methods, the DCT-transformed watermark is casting to the high frequency coefficients of the original cover image and the watermark is sequentially embedded in the casting frequency. But this kind of watermarking scheme can be attacked easily by the pirates and unlawful users, because these methods might have some structured patterns by the sequential embedding and the fixed casting domain. Also this method might get the damaged stego-image and is not robust to the image compression algorithms. Therefore, in this paper, a new robust digital watermarking scheme is proposed. In this algorithm, the frequency coefficients of the DCT-transformed original cover-image in which the watermark is inserted are randomly selected. These random position values of the casting frequencies can be used as another secret-key together with the watermark-key. From some experimental results the proposed method is found to be more robust to the possible attacks than those of the conventional methods.

Kim, Jin-Seob; Kim, Tae-Hyun; Kim, Eun-Soo

2001-12-01

246

Effect of casting methods on accuracy of peridental restorations.  

PubMed

The present study has shown that the accuracy of peridental gold alloy castings depends 1) on the type of casting machine used, 2) on the diameter of the casting sprue, and 3) on the strength properties of the investment material. The dependence between the accuracy and the three factors mentioned is based on erosion of the investment mold by the inflow of the liquid casting alloy. The vacuum casting technique proved to be a more gentle casting method than centrifugal and vacuum/pressure techniques. PMID:7051263

Finger, W; Kota, K

1982-06-01

247

Casting properties of Ni-Ti shape memory alloy.  

PubMed

A Ni-45 wt% Ti (Ni-50 at % Ti) alloy was cast into molds of magnesia and silica investments by use of a dental argon-arc pressure casting machine with a copper crucible . The castings exhibited shape memory properties. The shape recovery process was sharper in the specimens cast in magnesia investment molds than in those cast in silica (phosphate-bonded) investment molds. The latter casting had a hard region of the periphery, suggesting that shape recovery process may be affected by reaction of molten metal with silica. Furthermore, the alloy possessed the adequate mechanical properties for consideration as crown-and-bridge prostheses. PMID:6736077

Takahashi, J; Okazaki, M; Kimura, H; Furuta, Y

1984-04-01

248

Using numerical simulation with rapid prototyping and investment casting  

NASA Astrophysics Data System (ADS)

This article presents an approach to making an aluminum automobile prototype by integrating numerical simulation and rapid prototyping into investment casting. Following the integrated prototype procedure, a sound aluminum (Al-Si-7Mg) manifold prototype with excellent contour and an acceptable surface finish was made with only one casting trial. This study indicated that the potential of the rapid prototyping-investment casting coupling could be more effective with the aid of integrated numerical simulation, and numerical optimization of the casting parameters aids in minimizing the risk of casting failure and avoiding the iterative casting trials.

Wuis, M.; Schädlich-Stubenrauch, J.; Wagner, I.; Sahm, P. R.

2000-08-01

249

Salt Bath Oxinitriding of Gray Cast Iron  

NASA Astrophysics Data System (ADS)

Salt bath oxinitriding is a duplex surface treatment developed to improve tribological and corrosion properties of ferrous materials. In this research, gray cast iron samples were nitrided at the temperature range of 480°C-580°C, and then oxidized in an oxidative salt bath. The phase composition of surface layer was identified by X-ray diffraction. Using a microhardness tester, hardness of nitrided gray cast iron was measured. Corrosion behavior of treated (nitrided and oxinitrided) samples was evaluated using potentiodynamic polarization technique in 3.5% NaCl solution. XRD analyses indicate that the surface layer in nitrided and oxinitrided samples is composed of ?-iron nitride (Fe2-3N) and magnetite (Fe3O4), respectively. Results show that the corrosion resistance of gray cast iron can be improved up to 170%.

Ahmadi, M.; Teimouri, M.; Aliofkhazraee, M.; Mousavi Khoee, S. M.

250

A Diffusing Runner for Gravity Casting  

NASA Astrophysics Data System (ADS)

In gravity casting, the quality of an aluminum alloy casting relies on, among other things, the design of the runner system in which the ingate velocity into the mold cavity should be controlled to stay under a critical velocity (close to 0.5 m/s). In this study, a diffuser was proposed to reduce the velocity of liquid metal to below this critical value, while the flow rate remained almost unchanged. Flow separation and dead zones in the diffuser design were avoided. A computational modeling package and a real casting experiment (water analogy method) were employed for exploring and verifying the new design. The efficiency of the diffuser was quantified by the measurement of coefficient of discharge Cd. For this new diffuser, the pressure recovery coefficient C p and the loss coefficient K L were also estimated.

Hsu, Fu-Yuan; Lin, Huey-Jiuan

2009-12-01

251

Modeling microstructure development in gray cast irons  

NASA Astrophysics Data System (ADS)

Recent years have seen increasing use of solidification process modeling as a tool to aid in the analysis and elimination of manufacturing defects in castings. Grain size and other microstructural features such as second-phase morphology and distribution are the primary factors in determining the mechanical properties in cast metals. In this work, a representation of nucleation and growth kinetics for gray cast irons, based on a statistical description of the microstructure, has been coupled with a commercial finite-element method code for transient heat-flow calculation to determine microstructure. Features predicted include eutectic cell size, fractions of gray and white iron, graphite morphology, percent pearlite, percent ferrite, and pearlite spacing. The predicted microstructure can then be used to determine the strength and fatigue properties using published correlations. The theoretical development and results of the finite-elementbased model will be discussed and compared with experimental results.

Goettsch, David D.; Dantzig, Jonathan A.

1994-05-01

252

Variability of short arm cast application: the influence of experience using fibreglass tape and QuickCast.  

PubMed

A new short arm cast material which is heated to conform to the underlying limb was compared to conventional fibreglass tape. The time required for application, the pressures generated beneath the casts and the availability for digital motion were studied in three groups with varying lengths of casting experience. Results showed that the new immobilizer did not require additional time for application and provided similar interface pressures beneath the casts as compared to fibreglass tape. In addition, metacarpophalangeal joint motion was less restricted with the new casting experience. The shrinkable immobilizer thus offers an alternative to conventional fibreglass tape casts. PMID:9196621

Cohen, M S

1997-01-01

253

Effect of Phase Pressure on Casting Properties in Cold Chamber Die Casting Process  

NASA Astrophysics Data System (ADS)

This paper focuses on the parametric optimization of process parameter in cold chamber die casting for an industrial component (crank case). Three controllable factors of the cold chamber die casting process (namely: 1st phase pressure, 2nd phase pressure and limit switch position) were studied at three levels each by Taguchi's parametric approach and single-response optimization was conducted to identify the main factor controlling surface hardness, weight of casting and dimensional accuracy (?d). Castings were produced using aluminium alloy at recommended parameters through cold chamber die casting process. Analysis shows that in cold chamber die casting process the percentage contribution of 1st phase pressure, limit switch position and 2nd phase pressure for surface hardness is 84.17, 11.43 and 1.93 % respectively. While in the case of weight of cast component, the contribution of limit switch position is 52.26 %, followed by 1st phase pressure and 2nd phase pressure 34.77 and 9.65 % respectively. Further for ?d, contribution of 1st phase pressure is 64.55 %, limit switch position 27.71 % and 2nd phase pressure contributes 4.87 %.

Singh, R.; Kapoor, R.

2013-04-01

254

Modeling of casting microstructures and defects  

SciTech Connect

Casting is an ancient art that has been a trial-and-error process for more than 4000 years. To predict the size, shape, and quality of a cast product, casting manufacturers typically cast full-size prototypes. If one part of the process is done incorrectly, the entire process is repeated until an acceptable product is achieved. One way to reduce the time, cost, and waste associated with casting is to use computer modeling to predict not only the quality of a product on the macro- scale, such as distortion and part shape, but also on the micro-scale such as grain defects. Modeling of solidification is becoming increasingly feasible with the advent of parallel computers. There are essentially two approaches to solidification modeling.The first is that of macro-modeling where heat transfer codes model latent heat release during solidification as a constant and based solely on the local temperature. This approach is useful in predicting large scale distortion and final part shape. The second approach, micro-modeling, is more fundamental. The micro-models estimate the latent heat release during solidification using nucleation and grain growth kinetics. Micro-models give insight into cast grain morphology and show promise in the future to predict engineering properties such as tensile strength. The micro-model solidification kinetics can be evaluated using first principles or they can be evaluated using experiments. This work describes an implementation of a micro-model for uranium which uses experimental results to estimate nucleation and growth kinetics.

Shapiro, A.B.; Summers, L.T.; Eckels, D.J.; Sahai, V.

1997-09-26

255

Fluxing agent for metal cast joining  

DOEpatents

A method of joining an aluminum cast member to an aluminum component. The method includes the steps of coating a surface of an aluminum component with flux comprising cesium fluoride, placing the flux coated component in a mold, filling the mold with molten aluminum alloy, and allowing the molten aluminum alloy to solidify thereby joining a cast member to the aluminum component. The flux preferably includes aluminum fluoride and alumina. A particularly preferred flux includes about 60 wt. % CsF, about 30 wt. % AlF.sub.3, and about 10 wt. % Al.sub.2 O.sub.3.

Gunkel, Ronald W. (Lower Burrell, PA); Podey, Larry L. (Greensburg, PA); Meyer, Thomas N. (Murrysville, PA)

2002-11-05

256

The Making of Stainless Steel Shapes by Casting and Powder Metallurgy.  

National Technical Information Service (NTIS)

Contents: Production by casting; Designation and composition of alloys, Melting practice, Molding practice for static casting, Sand molds - methods, finish and tolerance, Ceramic molds - methods, finish and tolerance, Centrifugal casting, Casting characte...

J. G. Kura V. D. Barth E. T. Hall W. H. Safranek H. O. McIntire

1967-01-01

257

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

Code of Federal Regulations, 2011 CFR

... 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...

2011-07-01

258

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

Code of Federal Regulations, 2011 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...

2011-07-01

259

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

Code of Federal Regulations, 2013 CFR

... 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...

2013-07-01

260

Casting machine for grids of lead storage batteries  

SciTech Connect

A machine for the casting and subsequent stamping of grids for lead storage batteries, particularly ones consisting of low-Sb and Pb-Ca alloys, has a pouring nozzle to receive and pour a predetermined amount of melt into a casting mold arranged vertically beneath it. For removal from the mold, conveyance and machining of the castings without deformation, particularly if soft alloys are used a lifter for the casting is arranged on the casting mold, by means of which lifter the casting can be brought while remaining in its vertical position onto a conveyor device which is developed as a cooling path for hardening of the casting. At the end of the path a deflection unit repositions the casting which has been transported vertically up to this point into a horizontal position and by a feed device is advanced to a stamping machine from where the grid passes onto a conveyor belt.

Sperling, F.; Hennecke, A.

1984-06-26

261

An unusually severe case of the cast syndrome  

Microsoft Academic Search

A severe case of the cast syndrome is described following Harrington rod distraction and application of a body cast. The case was unusual as it presented late with no warning symptoms and progressed rapidly to death.

R. H. Kennedy; M. J. Cooper

1983-01-01

262

Grain Refinement of Permanent Mold Cast Copper Base Alloys.  

National Technical Information Service (NTIS)

Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot...

M. Sadayappan J. P. Thomson M. Elboujdaini G. P. Gu M. Sahoo

2004-01-01

263

Microstructural - Mechanical Property Relationships in High Strength Cast Steels.  

National Technical Information Service (NTIS)

The grain refinement of high strength steel castings by small titanium additions has been enhanced by a small particle nucleation technique. The combination of these two mechanisms makes possible the total refinement of large castings inoculated with 0.1%...

J. V. Peck R. B. Bertolo J. F. Wallace

1969-01-01

264

Producing Foils from Direct Cast Titanium Alloy Strip.  

National Technical Information Service (NTIS)

This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into ...

T. A. Stuart T. A. Gaspar I. M. Sukonnik S. L. Semiatan E. Batawi

1996-01-01

265

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

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

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

266

Final report on Expendable Pattern Casting Technology. Phase 1.  

National Technical Information Service (NTIS)

The Expendable Pattern Casting (EPC) process is a potential casting process breakthrough which could dramatically improve the competitiveness of the US foundry industry. Cooperatively supported by US Industry and the Department of Energy and managed by th...

1990-01-01

267

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

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

INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE EXTRACTING A 48' PIPE. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

268

MALLEABLE INSPECTION STATION WHERE WORKERS ELIMINATE MALFORMED CASTINGS AND SEPARATED ...  

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

MALLEABLE INSPECTION STATION WHERE WORKERS ELIMINATE MALFORMED CASTINGS AND SEPARATED GOOD CASTINGS PRIOR TO ANNEALING. - Stockham Pipe & Fittings Company, Malleable Annealing Building, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

269

FINISHED CASTINGS ARE ONLY GROUND BEFORE THEY ARE SHIPPED TO ...  

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

FINISHED CASTINGS ARE ONLY GROUND BEFORE THEY ARE SHIPPED TO CUSTOMERS WHO COMPLETE THE FINISHING IN THEIR OWN MACHINE SHOPS. - Southern Ductile Casting Company, Grinding & Shipping, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

270

INTERIOR VIEW WITH PIPE CASTING MACHINE EXTRUDING A 24' PIPE ...  

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

INTERIOR VIEW WITH PIPE CASTING MACHINE EXTRUDING A 24' PIPE AND OPERATOR JOHNNY NIXON. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

271

Vacuum-Die casting titanium for aerospace and commercial components  

NASA Astrophysics Data System (ADS)

Vacuum-die casting offers a high-quality, low-cost alternative for manufacturing titanium components. Lower costs are obtained through the elimination of processing steps that are associated with other manufacturing methods, such as investment casting. However, vacuum-die-cast component geometry is limited to single-plane, solid components weighing less than 18 kg. Initial mechanical property tests performed on vacuum-die-cast Ti-6Al-4V show properties similar to that of wrought material, which could lead to the direct substitution of vacuum-die casting components for wrought components. Additionally, the quality of vacuum-die-cast components shows improvement over investment castings through the elimination of alpha-case and the use of a ceramic-less casting system.

Larsen, Don; Colvin, Greg

1999-06-01

272

Behavior of duplex stainless steel casting defects under mechanical loadings.  

National Technical Information Service (NTIS)

Several components in the primary circuit of pressurized water reactors are made of cast duplex stainless steels. This material contains small casting defects, mainly shrinkage cavities, due to the manufacturing process. In safety analyses, the structural...

S. Jayet-Gendrot P. Gilles C. Migne

1997-01-01

273

THE USE OF QUARTZ TUBES FOR SAMPLING AND CASTING PLUTONIUM  

Microsoft Academic Search

The use of quartz tubing for sampling molten plutonium and for casting ; rods is described. These procedures offer cheap and easy-to-use methods for ; obtaining molten samples and for casting long rods with small diameters. (auth);

K. W. R. Johnson; J. W. Anderson

1958-01-01

274

SOUTHERN DUCTILE CASTING COMPANY, BACK SIDE OF FURNACE AND MOLDING ...  

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

SOUTHERN DUCTILE CASTING COMPANY, BACK SIDE OF FURNACE AND MOLDING BUILDINGS SHOWING CONNECTIONS TO LOCAL POWER GRID, PRIMARILY FOR ELECTRIC FURNACES. - Southern Ductile Casting Company, Bessemer Foundry, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

275

Enhancements in Magnesium Die Casting Impact Properties  

SciTech Connect

The need to produce lighter components in transportation equipment is the main driver in the increasing demand for magnesium castings. In many automotive applications, components can be made of magnesium or aluminum. While being lighter, often times the magnesium parts have lower impact and fatigue properties than the aluminum. The main objective of this study was to identify potential improvements in the impact resistance of magnesium alloys. The most common magnesium alloys in automotive applications are AZ91D, AM50 and AM60. Accordingly, these alloys were selected as the main candidates for the study. Experimental quantities of these alloys were melted in an electrical furnace under a protective atmosphere comprising sulfur hexafluoride, carbon dioxide and dry air. The alloys were cast both in a permanent mold and in a UBE 315 Ton squeeze caster. Extensive evaluation of tensile, impact and fatigue properties was conducted at CWRU on permanent mold and squeeze cast test bars of AZ91, AM60 and AM50. Ultimate tensile strength values between 20ksi and 30ksi were obtained. The respective elongations varied between 25 and 115. the Charpy V-notch impact strength varied between 1.6 ft-lb and 5 ft-lb depending on the alloy and processing conditions. Preliminary bending fatigue evaluation indicates a fatigue limit of 11-12 ksi for AM50 and AM60. This is about 0.4 of the UTS, typical for these alloys. The microstructures of the cast specimens were investigated with optical and scanning electron microscopy. Concomitantly, a study of the fracture toughness in AM60 was conducted at ORNL as part of the study. The results are in line with values published in the literature and are representative of current state of the art in casting magnesium alloys. The experimental results confirm the strong relationship between aluminum content of the alloys and the mechanical properties, in particular the impact strength and the elongation. As the aluminum content increases from about 5% in AM50 to over 9% in AZ91, more of the intermetallic Mg17Al12 is formed in the microstructure. For instance, for 15 increase in the aluminum content from AM50 to AM60, the volume fraction of eutectic present in the microstructure increases by 35%! Eventually, the brittle Mg17Al12 compound forms an interconnected network that reduces ductility and impact resistance. The lower aluminum in AM50 and AM60 are therefore a desirable feature in applications that call for higher impact resistance. Further improvement in impact resistance depends on the processing condition of the casting. Sound castings without porosity and impurities will have better mechanical properties. Since magnesium oxidizes readily, good melting and metal transfer practices are essential. The liquid metal has to be protected from oxidation at all times and entrainment of oxide films in the casting needs to be prevented. In this regard, there is evidence that us of vacuum to evacuate air from the die casting cavity can improve the quality of the castings. Fast cooling rates, leading to smaller grain size are beneficial and promote superior mechanical properties. Micro-segregation and banding are two additional defect types often encountered in magnesium alloys, in particular in AZ91D. While difficult to eliminate, segregation can be minimized by careful thermal management of the dies and the shot sleeve. A major source of segregation is the premature solidification in the shot sleeve. The primary solid dendrites are carried into the casting and form a heterogeneous structure. Furthermore, during the shot, segregation banding can occur. The remedies for this kind of defects include a hotter shot sleeve, use of insulating coatings on the shot sleeve and a short lag time between pouring into the shot sleeve and the shot.

David Schwam; John F. Wallace; Yulong Zhu; Srinath Viswanathan; Shafik Iskander

2000-06-30

276

Mechanical properties and microstructures of cast Ti–Cu alloys  

Microsoft Academic Search

Objectives: This study evaluated the mechanical properties of cast Ti–Cu alloys with the hope of developing an alloy for dental casting with better mechanical properties than unalloyed titanium.Methods: Ti–Cu alloys with five concentrations of copper (0.5, 1.0, 2.0, 5.0 and 10.0mass%) were made in an argon-arc melting furnace. The alloys were cast into magnesia-based molds using a centrifugal casting machine.

Masafumi Kikuchi; Yukyo Takada; Seigo Kiyosue; Masanobu Yoda; Margaret Woldu; Zhuo Cai; Osamu Okuno; Toru Okabe

2003-01-01

277

Effect of Pressure Difference on the Quality of Titanium Casting  

Microsoft Academic Search

In casting titanium using a two-compartment casting machine, Herø et al. (1993) reported that the pressure difference between the melting chamber and the mold chamber affected the soundness of the castings. This study tested the hypothesis that differences in pressure produce castings with various amounts of porosity and different mechanical properties values. Plastic dumbbell-shaped patterns were invested with an alumina-based,

I. Watanabe; J. H. Watkins; H. Nakajima; M. Atsuta; T. Okabe

1997-01-01

278

Can skin surface pressure under a cast reveal intracompartmental pressure?  

Microsoft Academic Search

Although monitoring intracompartmental pressure (IP) under a cast is very important, it is not possible to measure it in\\u000a every patient undergoing cast treatment. This study aims to answer the question of whether skin surface pressure (SSP) under\\u000a a cast can reveal IP. A plaster cast was applied to a sculpted inflatable forearm model with dorsal and volar compartments.\\u000a SSP

M. Murad Uslu; Alpaslan Apan

2000-01-01

279

Preparation of void-free casts from vinyl polysiloxane impressions  

Microsoft Academic Search

Purpose: To investigate two techniques to produce void-free casts from vinyl polysiloxane impressions.Materials and methods: Thirty casts prepared using a conventional technique were compared with 30 casts prepared using a technique involving syringing of stone in terms of numbers of surface voids.Results: Significantly fewer surface voids were observed in the casts prepared using syringing technique.Conclusion: The syringing technique investigated is

H. Sherfudhin; M. A. Abdulla

1996-01-01

280

Microabrasion of cast metal margins--a warning.  

PubMed

Plastic test patterns were milled to simulate casting margins and were cast in a variety of dental alloys. The cast specimens were exposed to horizontal and vertical streams of low-pressure microabrasion with 50 microm aluminum oxide particles. Post-exposure measurements show all specimens were affected by microabrasion. Dentists and laboratory technicians who use microabrasion must be aware of the potential damage to casting margins. PMID:17362424

Mansueto, Michael A; Verrett, Ronald G; Phoenix, Rodney D

281

Microstructure and mechanical properties of high boron white cast iron  

Microsoft Academic Search

In this paper, high boron white cast iron, a new kind of wear-resistant white cast iron was developed, and its microstructure and mechanical properties were studied. The results indicate that the high boron white cast iron comprises a dendritic matrix and an interdendritic eutectic boride in as-cast condition. The distribution of eutectic boride with a chemical formula of M2B (M

Zhongli Liu; Yanxiang Li; Xiang Chen; Kaihua Hu

2008-01-01

282

Microstructures and properties of investment castings of ?-titanium aluminide  

Microsoft Academic Search

?-TiAl castings have been produced by induction skull melting (ISM), and their microstructures, hardness and tensile properties have been studied in the as-cast, hot isostatically pressed (HIPped) and HIPped+heat treated conditions. The equiaxed rosette grains found in the cast structure suggest that the alloy was cast in a partially solid condition. HIPping and heat treatment for 24 h at 1300°C

J. P Kuang; R. A Harding; J Campbell

2002-01-01

283

Fluid flow and heat transfer modeling for castings  

Microsoft Academic Search

Casting is fundamental to manufacturing many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of

H. M. Domanus; Y. Y. Liu; W. T. Sha

1986-01-01

284

Application of TRIZ Theory in Patternless Casting Manufacturing Technique  

NASA Astrophysics Data System (ADS)

The ultimate goal of Patternless Casting Manufacturing (referred to as PCM) is how to obtain the casts by casting the sand mold directly. In the previous PCM, the resin content of sand mold is much higher than that required by traditional resin sand, so the casts obtained are difficult to be sound and qualified products, which limits the application of this technique greatly. In this paper, the TRIZ algorithm is introduced to the innovation process in PCM systematically.

Yang, Weidong; Gan, Dequan; Jiang, Ping; Tian, Yumei

285

Some regional characteristics of Muslim caste systems in India  

Microsoft Academic Search

There already exists a mass of literature on the Hindu Caste Systems and some work has also been done on the Muslim castes in India. A closer analysis indicates, however, an interesting regional variation in the social stratification among Muslims lending a complex castes system in different parts of India. The objective of this paper is to analyze the regional

S. Shamim Ahmad; A. K. Chakravarti

1981-01-01

286

DOES CASTE MATTER FOR WAGES IN THE INDIAN LABOR MARKET?  

Microsoft Academic Search

This paper explores whether pay gaps on the basis of caste are still evident in the Indian labor market using data from the most recent round of the nationally representative National Sample Survey. Caste in India is the primary source of stratificatio n. The hypothesis is that the hierarchical nature of the caste system and the strong association of ritual

PUJA VASUDEVA DUTTA

287

The effect of hot isostatic pressing on cast aluminum  

NASA Astrophysics Data System (ADS)

Aluminum-silicon alloys are the most important commercial aluminum casting alloys, primarily because of their superior casting characteristics. This article discusses the effect of hot isostatic pressing on the mechanical properties of cast aluminum alloy A356. The effect of low-cost Densal hotisostatic pressing is also examined.

Lei, C. S. C.; Frazier, W. E.; Lee, E. W.

1997-11-01

288

Study on a CAD\\/CAE system of die casting  

Microsoft Academic Search

Increasing demans for premium quality, high productivity and cost-saving products provide powerful incentives to improve the way that die castings are made today. Research has shown that the fluid flow of the liquid metal and the temperature distribution of the dies and the die castings have a critical influence on the quality of the cast products, on the production rate

Zhang Weishan; Xiong Shoumei; Liu Baicheng

1997-01-01

289

ANALYSIS OF CASTING DEFECT THROUGH DEFECT DIAGNOSTIC STUDY APPROACH  

Microsoft Academic Search

Production of casting involves various processes like pattern making, moulding, core making and melting etc. It is very difficult to produce defect free castings. A defect may be the result of a single cause or a combination of causes. The castings may have one or more defects. These can be minimized by taking correct remedial actions in the tools like

B. CHOKKALINGAM; S. S. MOHAMED NAZIRUDEEN

290

Numerical simulation of casting solidification in permanent metallic molds  

Microsoft Academic Search

Casting solidification is actually the transformation of liquid phase to solid phase with the liberation of latent heat of fusion. During this metallurgical process, it induces casting defects like shrinkage, porosity and hot tears. To eradicate and eliminate these problems, accurate casting design and proper design of gating system is necessary. This can be predicted and designed by means of

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

2006-01-01

291

The structure and properties of rapidly cooled cast steels  

SciTech Connect

The results of a new rapid cooling process for the production of cast steel components are presented. The process, known as the mold-chill-casting-with-intense-cooling-rate (MCIC) technology, allows for the development of refined structure and improved properties in a wide range of cast steel components.

Vinokur, B.B. [Ukrainian Academy of Science, Kiev (Ukraine). Inst. of Casting Problems

1997-02-01

292

Clean Cast Steel Technology - Machinability and Technology Transfer  

SciTech Connect

There were two main tasks in the Clean Cast Steel Technology - Machinability and Technology Transfer Project. These were (1) determine the processing facts that control the machinability of cast steel and (2) determine the ability of ladle stirring to homogenize ladle temperature, reduce the tap and pouring temperatures, and reduce casting scrap.

C. E. Bates; J. A. Griffin

2000-05-01

293

INTERIOR VIEW WITH PIPE CASTING MACHINE WITH OPERATOR JOHNNY NIXON ...  

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

INTERIOR VIEW WITH PIPE CASTING MACHINE WITH OPERATOR JOHNNY NIXON SETTING A CORE IN THE CASTING OF A 24' PIPE. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

294

Structural features of atomized white cast iron powder  

Microsoft Academic Search

White cast iron powder rapidly quenched from the liquid condition with presence of the same phases and structural components differs markedly in structure from normally cast white iron.2.With an increase in cooling rate vcool during solidification the amount of eutectic decreases. However, with an increase in carbon content this tendency is weakened and with 3.9% the structure of powder cast

A. P. Gulyaev; S. I. Astakhov

1991-01-01

295

Wear-corrosion study of white cast irons  

Microsoft Academic Search

A US Bureau of Mines study to quantify synergism between wear and corrosion of white cast iron in an aqueous sulfate environment was conducted using a rotating cylinder-anvil apparatus. A commercial 13.5% Cr white cast iron sample and the individual constituents of a white cast iron were studied to determine the role of each phase in the degradation processes of

S. W. Watson; B. W. Madsen; S. D. Cramer

1995-01-01

296

Status of investment cast gamma titanium aluminides in the USA  

Microsoft Academic Search

Investment casting of gamma titanium aluminide alloys has become the near-term process of choice for component manufacture. This is largely due to its near-net shape processing capabilities which allow cast gamma components to be manufactured at a lower cost when compared with wrought or powder methods. Casting processes have been developed that are capable of producing aerospace quality components as

Donald E. Larsen

1996-01-01

297

Preparation of alumina membranes by tape casting and dip coating  

Microsoft Academic Search

The preparation of an alumina ultrafiltration membrane with a mean pore size of 6.5 nm was performed by slip casting or tape casting of the support, dip coating or tape casting of the intermediate layer, followed by dip coating of the top layer. Controlled porosity and pore size in the support were obtained by the addition of starch particles which

Karin Lindqvist; Eva Lidén

1997-01-01

298

The effect on cast post dimensions of casting investment and airborne particle abrasion.  

PubMed

Cast posts can sometimes prove difficult to seat fully during fitting. This study compared two different liquid/water dilutions for phosphate bonded investment and the effect of controlled airborne particle abrasion on resulting post diameter. After measuring polymeric post patterns (n = 18), 3 groups were invested using concentrated solution and 3 groups using dilute solution. After casting they were weighed and remeasured then exposed to airborne particle abrasion. Both solutions produced oversized cast posts. Mean diameter reduction during airborne particle abrasion was 8 microm/10s taking an average of 41s to reach precast size. Where a post pattern fits tightly, airborne particle abrasion for 70s should reduce the casting sufficiently to accommodate the cement lute. PMID:22645794

Hashem, Danya; German, Matthew J; Wassell, Robert W

2011-09-01

299

Transient altitude-induced compartment syndrome associated with fiberglass casts using waterproof cast padding.  

PubMed

Changes in aircraft cabin pressure and its interplay with a fixed diameter fiberglass cylindrical cast and the closed air cells in waterproof cast padding may cause a transient altitude-induced compartment syndrome. In this case series, 2 patients reported transient compartment syndromes that resolved with aircraft decent. As proof of concept, this work displays photographic and video evidence showing the difference in air cell volume from experimental data in a vacuum chamber as well as real-world volume changes at cruise altitude in a commercial airliner. Transient altitude-induced compartment syndromes associated with fiberglass casts using waterproof cast padding are real and surgeons and patients should be advised of this potentially devastating complication. PMID:23431541

Kadzielski, John; Bae, Donald S

2013-01-01

300

Computing Direct Shadows Cast by Convex Polyhedra  

Microsoft Academic Search

We present an exact method to compute the bound- aries between umbra, penumbra and full-light regions cast on a plane by a set of disjoint convex polyhedra, some of which are light sources. This method builds on a recent characterization of topological visual event surfaces presented in a companion paper.

Julien Demouth; Xavier Goaoc

2009-01-01

301

Centrifugal Vacuum Casting Machine - Feasibility Study.  

National Technical Information Service (NTIS)

The objective is development of a prototype-production process for making aircraft-aerospace quality precision castings. The process would use powdered metals as a charge to be inductively melted directly in 'lost wax' molds (with integral 'make-up' hoppe...

M. D. Boyer

1974-01-01

302

Casting shadows: Dalit assertion in Indian literature  

Microsoft Academic Search

This dissertation tracks the emergence of literary narratives by and about Dalit communities in India from the 1950s to the 1990s. Examining the literary texts from a historical materialist perspective, I explore their articulation of self-identity and resistance against the caste system. The materialist methodology enables discussion of the literature's focus on labor and the body, while centrally posing the

Shalini Ramachandran

2003-01-01

303

Die Soldering in Aluminium Die Casting.  

National Technical Information Service (NTIS)

Two types of tests, dipping tests and dip-coating tests were carried out on small steel cylinders using pure aluminum and 380 alloy to investigate the mechanism of die soldering during aluminum die casting. Optical and scanning electron microscopy were us...

Q. Han E. A. Kenik S. Viswanathan

2000-01-01

304

Simulation of the stir casting process  

Microsoft Academic Search

Non-homogeneous particle distribution is one of the greatest problems in casting metal matrix composites (MMCs). To optimise some of the parameters for uniform particle distribution for batch compocasting the present simulation studies were conducted. The simulation involves visualisation experiments. In the visualisation experiments liquid and semisolid aluminium are replaced by other fluids with similar characteristics. SiC reinforcement particulate similar to

S Naher; D Brabazon; L Looney

2003-01-01

305

Arsenic Removal from Drinking Water - Web cast  

EPA Science Inventory

Web cast presentation covered six topics: (1) Arsenic Chemistry, (2) Technology Selection/Arsenic Demonstration Program, (3) Case Study 1, (4) Caser Study 2, (5) Case Study 3, and (6) Media Regeneration Project. The presentation was considered a training session and consist of m...

306

Durability and Damage Tolerance of Aluminum Castings.  

National Technical Information Service (NTIS)

A durability and damage tolerance property data base for D357-T6 and B201-T7 cast by three commercial foundries was developed. The specifications for the two alloys were selected based on the results of screening evaluations which are included in the firs...

G. R. Turk M. W. Ozelton

1988-01-01

307

New coatings for continuous casting rolls  

Microsoft Academic Search

Rolls in the steel industry withstand very high loads, thermal cycling leading to thermal fatigue, and severe environmental attack. The fatigue behavior of coatings is not only dependant on the Hertzian contact pressure alone, but it is highly influenced by the machine characteristics. Rolls in a continuous casting machine (CCM) are mainly exposed to: (a) thermal fatigue due to high

Alejandro Sanz

2004-01-01

308

Method for casting epoxy tensile coupons  

Microsoft Academic Search

A method is described for producing silicone rubber molds and casting epoxy tensile coupons in these molds. The resulting epoxy coupons have smooth, glossy surfaces and are dimensionally reproducible. The process uses no release agents, coolants, or other possible contaminants and yields high-quality epoxy coupons.

Dale L. Fanter

1978-01-01

309

Oriented growth of cast silicon sheets  

NASA Astrophysics Data System (ADS)

Casting of silicon sheets in molds, using a mold releasing agent, is shown to result in the attainment of a large size columnar grain structure normal to the sheet surface, and a predominantly 110 surface orientation. A possible oriented growth mechanism is proposed on the basis of dendritic grain growth.

Saito, T.; Shimura, A.; Matsui, J.

1985-09-01

310

Oriented growth of cast silicon sheets  

Microsoft Academic Search

Casting of silicon sheets in molds, using a mold releasing agent, is shown to result in the attainment of a large size columnar grain structure normal to the sheet surface, and a predominantly 110 surface orientation. A possible oriented growth mechanism is proposed on the basis of dendritic grain growth.

T. Saito; A. Shimura; J. Matsui

1985-01-01

311

Slip-Cast Coating of Alumina Crucibles.  

National Technical Information Service (NTIS)

The development of a process for coating alumina crucibles with MgO protective coat in a two-step slip casting operation is described. The best milling conditions for the alumina used were set ball milling for 24 hr. MgO had to be calcined at 1200 exp 0 C...

N. A. Haroun M. A. A. El-Masry

1980-01-01

312

Periclase ceramics obtained by water slip casting  

Microsoft Academic Search

Conclusions Studies were made of the colloidal-rheological rules for forming concentrated water suspensions of periclase in relation to the method of obtaining them, the degree of hydration of MgO, and the amount of rare-earth oxides added. This work resulted in the production of dense ceramics using the slip casting method and water suspensions.

L. A. Skomorovskaya; V. B. Zlatkovskii; I. I. Nemets

1991-01-01

313

Roll Casting of Al-25%Si  

SciTech Connect

Strip casting of Al-25%Si strip was tried using an unequal diameter twin roll caster. The diameter of the lower roll (large roll) was 1000 mm and the diameter of the upper roll (small roll) was 250 mm. Roll material was mild steel. The sound strip could be cast at the speeds ranging from 8 m/min to 12 m/min. The strip did not stick to the roll without the parting material. The primary Si, which existed at centre area of the thickness direction, was larger than that which existed at other area. The size of the primary Si was smaller than 0.2 mm. Eutectic Si was smaller 5 {mu}m. The as-cast strip was ranging from 2 mm to 3 mm thick and its width was 100 mm. The as-cast strip could be hot rolled down to 1 mm. The hot rolled strip was cold rolled. The primary Si became smaller and the pore occurred around the primary Si after the rolling.

Haga, Toshio [Osaka Institute of Technology, Omiya Asahiku Osaka city 535-8585 (Japan); Harada, Hideto [Graduate School of Osaka Institute of Technology, Omiya Asahiku Osaka city 535-8585 (Japan); Watari, Hisaki [Gunma University, Kiryu city, 376-8515 (Japan)

2011-05-04

314

Squeeze Casting of Steel Weapon Components.  

National Technical Information Service (NTIS)

The project was initiated to study the feasibility of applying the squeeze casting process to produce two specific steel weapon components - the receiver base and the barrel support of the M85 weapon. Dies were designed and fabricated for both components ...

D. A. Stawarz K. M. Kulkarni K. R. Iyer R. B. Miclot

1974-01-01

315

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

316

APPARATUS AND METHOD FOR INJECTION CASTING  

DOEpatents

S>A single-chamber metal casting apparatus is described wherein molten metal in a vertically movable container can be brought directly into contact with molds. By increasing the gas pressure within the chamber the metal is forced upward into the molds.

Shuck, A.B.

1960-09-13

317

CAST: Collaborative Agents for Simulating Teamwork  

Microsoft Academic Search

Psychological studies on teamwork have shown that an effective team often can anticipate information needs of teammates based on a shared mental model. Existing multi-agent models for teamwork are limited in their ability to support proactive information exchange among teammates. To address this issue, we have developed and implemented a multi-agent architecture called CAST that simulates teamwork and supports proactive

John Yen; Jianwen Yin; Thomas R. Ioerger; Michael S. Miller; Dianxiang Xu; Richard A. Volz

2001-01-01

318

Erosion of White Cast Irons and Stellite.  

National Technical Information Service (NTIS)

The erosion behavior of dual-phase alloys containing large, hard carbides has been investigated. A series of high Cr-Mo white cast irons with a systematic variation of carbide volume fraction (CVF) and powder metallurgy specimens of Stellite 6 were eroded...

S. S. Aptekar T. H. Kosel

1985-01-01

319

Economically alloyed wrought white cast irons  

Microsoft Academic Search

1.In analyzing the deformation curves of cast irons with a ledeburite eutectic based on vanadium supersaturated and chromium alloyed cementite and of normal white irons a difference including oscillation of the flow stress was observed.2.In addition to relaxation stresses in the matrix the character of the yield curves is determined by the phase transformations in the alloyed cementite occurring during

Yu. N. Taran; P. F. Nizhnikovskaya; O. R. Danichek; T. M. Mironova; M. A. Loiferman; S. I. Belorusov; G. F. Demchenko; D. D. Khizhnyak

1989-01-01

320

The CERN Axion Solar Telescope (CAST)  

SciTech Connect

A decommissioned LHC test magnet is being prepared as the CERN Axion Solar Telescope (CAST) experiment. The magnet has a field of 9.6 Tesla and length of 10 meters. It is being mounted on a platform to track the sun over plus or minus 8 to the sixth power vertically and plus or minus 45 to the sixth power, horizontally.

Aalseth, Craig E. (BATTELLE (PACIFIC NW LAB)); Arik, E (Bogazici Universitesi); Autiero, D (European Organization for Nuclear Research); Avignone, Frank T. (UNKNOWN); Barth, K (European Organization for Nuclear Research); Bowyer, Sonya M. (BATTELLE (PACIFIC NW LAB)); Brauninger, H (Max-Planck-Institut fur Extraterrestrische Physik); Brodzinski, Ronald L. (BATTELLE (PACIFIC NW LAB)); Carmona, J. M. (Universidad de Zaragoza); Cebrian, S (Unknown); Celebi, S (Universidad de Zaragoza); Cetin, S (Bogazici Universitesi); Collar, J I. (Chicago, University Of); Creswick, R (South Carolina, Univ Of); Delbart, A (Centre d'Etudes de Saclay); Delattre, M (European Organization for Nuclear Research); DiLella, L (European Organization for Nuclear Research); De Oliveira, R (European Organization for Nuclear Research); Eleftheriadis, Ch (Aristotle University of Thessaloniki); Erdutan, N (European Organization for Nuclear Research); Fanourakis, G (National Research Center for Physical Sciences, Demokritos, Greece); Farach, H A. (South Carolina, Univ Of); Fiorini, C (Politecnico di Milano, Italy); Geralis, Th. (National Research Center for Physical Sciences, Demokritos, Greece); Giomataris, I (Centre d'Etudes de Saclay, Gif-Sur-Yvette, France); Girard, Thomas A. (VISITORS); Gninenko, S. N. (Institue for Nuclear Research, Moscow, Russia); Golubev, N. A. (Institute for Nuclear Research, Moscow, Russia); Hasinoff, M (British Columbia,University of); Hoffmann, D (Technische Universitat Darmstadt); Irastorza, I. G. (Universidad de Zaragoza); Jacoby, J (Technische Universitat Darmstadt); Jeanneau, F (Centre d'Etudes de Saclay, Gif-Sur-Yvette, France); Knopf, Michael A. (BATTELLE (PACIFIC NW LAB)); Kovzelev, A. V. (Institute for Nuclear Reserach, Moscow, Russia); Kotthaus, R (Max-Planck-Institut fur Physik, Muenchen, Germany); Krcmar, M (Ruder Boskovic Institute); Krecak, Z (Ruder Boskovic Institute, Zagreb, Croatia); Lakic, B (Ruder Boskovic Institute, Zagreb, Croatia); Liolios, A (Universidade de Li

2002-10-10

321

Modelling of the investment casting process  

Microsoft Academic Search

The aim of this paper is to present the modelling work carried for the FOCAST project in order to acquire a better understanding of the physical phenomena which control the investment casting processes.The paper will first present the general approach used by the authors. Then, for each process stage studied, the models used and their hypotheses are presented and discussed.

Jean-Christophe Gebelin; Mark R Jolly

2003-01-01

322

Refining of the Copper and investment casting  

Microsoft Academic Search

The present work deals with the problems of vacuum metallurgy and the method of exact casting of refined copper. Copper refining comprises deoxidation and removal of hydrogen, oxygen as well as some volatile components. The non-solubility of nitrogen in molten metal is also considered.The refining theory in high vacuum copper melting by evaporation is dealt with. On the basis of

1995-01-01

323

Efficient Runner Networks for Investment Castings  

Microsoft Academic Search

We present a computational method that finds an efficient runner network for an investment casting, once the gate locations have been established. The method seeks to minimize a cost function that is based on total network volume. The runner segments are restricted to lie in the space not occupied by the part itself. The collection of algorithms has been coded

RICHARD C. GIVLER; DAVID B. SAYLORS

2000-01-01

324

An Update on ToxCast?  

EPA Science Inventory

In its first phase, ToxCast? is profiling over 300 well-characterized chemicals (primarily pesticides) in over 400 HTS endpoints. These endpoints include biochemical assays of protein function, cell-based transcriptional reporter assays, multi-cell interaction assays, transcripto...

325

Robotic Deburring of Small Series of Castings  

Microsoft Academic Search

Robotic cleaning of castings is currently limited to large series of parts with small burrs. The costs for fixtures and clamping and for online programming of the robot largely exceed the potential savings of using robots for small series. Less expensive fixtures only add to the positioning uncertainties by which the use of online programmed robots becomes prohibitive.The paper presents

H. Van Brussel; W. Persoons

1996-01-01

326

High performance presence-accelerated ray casting  

Microsoft Academic Search

We present a novel presence acceleration for volumetric ray casting. A highly accurate estimation for object presence is obtained by projecting all grid cells associated with the object boundary on the image plane. Memory space and access time are reduced by run-length encoding of the boundary cells, while boundary cell projection time is reduced by exploiting projection templates and multiresolution

Ming Wan; Arie E. Kaufman; Steve Bryson

1999-01-01

327

Caste, sexuality and labour: The troubled connection  

Microsoft Academic Search

This article examines the troubled connection between feminist research and activism. As a member of the autonomous feminist collective Forum Against Oppression of Women, in Mumbai, the author draws on her participation in the ongoing discussions and dialogue, both within the group and with other organizations, and uses the case of feminist thinking on caste and sexual labour to discuss

Meena Gopal

2012-01-01

328

Scintillating fiber calorimeters with cast absorbers  

Microsoft Academic Search

The technology to construct cast lead-eutectic scintillating fiber calorimeters for measuring the energy of hadron and electromagnetic showers is discussed. The lead eutectic injection process, mold construction and release equipment, and fiber preform are described, along with beam test results on prototypes. Novel extensions of the technique include liquid fiber forward calorimeters, and shot-loading of the molten eutectic to achieve

D. Brown; R. Carey; S. T. Dye; E. Hazen; D. Higby; J. P. Miller; B. L. Roberts; L. Sulak; C. Wang; W. Worstell; D. Boccuzzi; D. Scrofani; K. Segall; D. Wall; D. R. Winn; C. Bromberg; J. Huston; R. Miller; C. Yosef; A. David; N. Diaczenko; S. Zaman; A. Sanzgiri; R. Webb; D. Acosta; J. Branson; B. Ong; H. Paar; M. Sivertz; D. Thomas; F. Ayer; C. Elder; D. Sullivan

1991-01-01

329

Epigenetics: the making of ant castes.  

PubMed

Social insects represent a unique model for how the same genome can give rise to entirely different phenotypes - soldiers, common labourers, and queens. New research on ants and honeybees points to DNA methylation as a crucial factor in determining the caste of a developing individual. PMID:23058801

Chittka, Alexandra; Wurm, Yannick; Chittka, Lars

2012-10-01

330

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

A typical nonaqueous tape casting system based on a commercial acrylic binder was studied to understand the system in more depth. The following conclusions were drawn: The best surfactants for dispersing barium titanate in the MEK-ethanol solvent system a...

W. R. Cannon

1988-01-01

331

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

332

A new freeze casting technique for ceramics  

NASA Astrophysics Data System (ADS)

A new freeze casting technique for ceramics capable of manufacturing near room temperature with a sublimable vehicle has been developed in order to eliminate expensive processes under extremely cold temperatures in the conventional freeze casting. Fluid concentrated slurries of Al2O 3 powder in molten camphene (C10H16) were successfully prepared at 55°C with a small amount of a dispersant. These slurries were quickly solidified (frozen) at room temperature to yield a rigid solid green body, where the frozen camphene was easily removed by sublimation (freeze-drying) with negligible shrinkage. Sintering was successfully conducted without any special binder burnout process to yield dense sintered bodies (over 98% T.D). An organic alloy with a eutectic composition in the naphthalene (C 10H8)-camphor (C10H16O) binary system with a eutectic temperature of 31°C was also found to be a successful vehicle for the new ceramic freeze casting. The fabrication processes are almost the same as those with camphene. It was found that vehicles with off-eutectic compositions resulted in large voids in the sintered body due to the ceramic particle rejection by pro-eutectic crystals during freezing. At the eutectic composition, fine lamellar microstructure in the solidified vehicle inhibits the particle rejection. The proposed advantages of the new freeze casting technique with a sublimable vehicle include; (1) elimination of extremely cold temperatures used in conventional freeze casting; (2) elimination of troublesome binder burnout process; and (3) fast manufacturing cycle due to quick solidification. Porous ceramic bodies with unique interconnected pore channels were fabricated by the new freeze casting with lower solid content. The unique channels surrounded by fully dense walls have nearly circular cross-sections unlike conventional aqueous freeze casting. The porosity and the channel diameters are controllable by the solid content in the slurry. The unique channels are replicas of entangled dendrites of frozen camphene, which sublimes during freeze-drying process. The unique porous structure with interconnected pore channels, which is completely new, is considered potentially useful in many applications such as filters and implantable bone scaffolds.

Araki, Kiyoshi

333

The Fit of Gold-alloy Full-crown Castings Made with Ceramic Casting Ring Liners  

Microsoft Academic Search

Measurements were made of the fit of gold-alloy full-crown castings produced with dry ceramic ring liners. When used with vacuum investing, these liners absorb relatively large amounts of water from the investment mix (thereby reducing its original W\\/P ratio) and then function as wet liners, thus increasing the investment's potential expansion and giving castings which are consistently larger than when

R. Earnshaw; E. F. Morey

1992-01-01

334

Mechanical properties of as-cast microalloyed steels produced via investment casting  

Microsoft Academic Search

Tensile and room temperature Charpy V-notch impact tests were used to evaluate the variations in the as-cast mechanical properties of a low-carbon steel produced via shell mould investment casting and containing combinations of vanadium, niobium and titanium. Tensile results indicate that the yield strength and ultimate tensile strength (UTS) have increased up to respectively 615MPa and 770MPa due to the

H. Najafi; J. Rassizadehghani; S. Norouzi

2011-01-01

335

Structure and Property Studies on Austempered and As-Cast Ausferritic Gray Cast Irons  

NASA Astrophysics Data System (ADS)

A high-strength and wear-resistant alloyed gray iron with ausferritic microstructure on solidification directly from molten condition could be made in a Ni and Mo alloyed gray cast iron. The as-cast ausferritic cast iron was compared with two conventionally austempered gray iron with and without Ni and Mo additions. The various phase constitution and volume fractions were analyzed using optical, SEM and XRD analyses. The various aspects of the alloy chemistry and processing conditions have been correlated with the microstructure and mechanical properties obtained. The analysis showed that the Ni-Mo alloyed austempered gray iron and the directly as-cast austempered gray iron had similar phase constitutions. The strength of the direct as-cast alloy with ausferritic microstructure was higher than the others due to its higher austenite content and carbide distribution. The wear rate of the conventionally austempered Ni and Mo containing alloy and direct as-cast ausferritic alloys is 20% of the austempered gray iron without Ni and Mo with friction coefficient less than 0.4.

Vadiraj, Aravind; Balachandran, G.; Kamaraj, M.

2010-10-01

336

Kin, caste and kisan movement in Marwar: Some questions to the conventional sociology of kin and caste  

Microsoft Academic Search

The basic flaw of conventional sociology in India has been that it studies caste and kinship in isolation from the economic and political structure. Consequently, it fails to understand the basis of unity in kin and caste groups. We have argued that unity between members of the same kin and caste groups depends, in the last analysis, on an identity

Hira Singh

1979-01-01

337

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

Microsoft Academic Search

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

Nick Cannell; Mark Samonds; Adi Sholapurwalla; Sam Scott

2008-01-01

338

Caste in 21st Century India: Competing Narratives  

PubMed Central

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

Desai, Sonalde; Dubey, Amaresh

2012-01-01

339

Effect of internal microblasting on retention of cemented cast crowns.  

PubMed

Microblasting of cast mental crowns is considered a standard procedure in most laboratories and an effective alternative to acid pickling. During the process of devesting and finishing, the surfaces of cast restorations are microblasted with an abrasive agent. This investigation measured the retention of type III cast gold crowns after cleansing with pickling solution (group I) or microblasting with 50-micron aluminum oxide (group II) or 50-micron glass beads (group III). Microblasting the internal surface of cast crowns with 50-micron aluminum oxide significantly improved the retention of castings luted with zinc phosphate cement. PMID:2090815

O'Connor, R P; Nayyar, A; Kovarik, R E

1990-11-01

340

Die Casting Part Distortion: Prediction and Attenuation  

SciTech Connect

The goal of this research was to predict the part deformation and residual stresses after ejection from the die and cooling to room temperature. A finite element model was built to achieve this goal and several modeling techniques were investigated throughout this research. Die-casting is a very complex process and the researchers are faced with a large number of hard to solve physical problems when modeling the process. Several assumptions are made in our simulation model. The first significant assumption is the instantaneous cavity filling. This means that the cavity filling stage is not considered in our model. Considering the cavity filling stage increases the modeling complexity as a result of different flow patterns. expected in the shot sleeve, gate, runner and different cavity features. The flow of gas from the cavity through the vents is another problem that is ignored in our model as a result of this assumption. Our second assumption is that the cast metal has uniform temperature distribution inside the cavity, at the starting point of simulation. This temperature is assumed to be over liquidus limit, i.e. the solid fraction is 0.0% of the cast metal. The third assumption is due to ABAQUS (commercial software used in this research) limitations. ABAQUS cannot deal with multi-phase models; therefore we use solid elements to define the casting instead of multi-phase (liquid/solid) elements. Liquid elements can carry the hydrostatic pressure from the shot sleeve and apply it on the cavity surfaces, while the solid elements do not have this capability. To compensate for this assumption we add the cavity pressure as a boundary condition and apply it on the cavity surface separately from the part. Another issue with this assumption is that, liquid casting can follow the cavity shape when it distorts. With the use of solid elements to represent the casting during its liquid state, it loses this capability to follow the cavity. Several techniques were tested to overcome this problem.

Dr, R. Allen Miller

2002-02-12

341

Genetic Evidence on the Origins of Indian Caste Populations  

PubMed Central

The origins and affinities of the ?1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in ?265 males from eight castes of different rank to ?750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%–30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements) in all of the caste and continental populations (?600 individuals). Analysis of these data demonstrated that the upper castes have a higher affinity to Europeans than to Asians, and the upper castes are significantly more similar to Europeans than are the lower castes. Collectively, all five datasets show a trend toward upper castes being more similar to Europeans, whereas lower castes are more similar to Asians. We conclude that Indian castes are most likely to be of proto-Asian origin with West Eurasian admixture resulting in rank-related and sex-specific differences in the genetic affinities of castes to Asians and Europeans.

Bamshad, Michael; Kivisild, Toomas; Watkins, W. Scott; Dixon, Mary E.; Ricker, Chris E.; Rao, Baskara B.; Naidu, J. Mastan; Prasad, B.V. Ravi; Reddy, P. Govinda; Rasanayagam, Arani; Papiha, Surinder S.; Villems, Richard; Redd, Alan J.; Hammer, Michael F.; Nguyen, Son V.; Carroll, Marion L.; Batzer, Mark A.; Jorde, Lynn B.

2001-01-01

342

Genetic evidence on the origins of Indian caste populations.  

PubMed

The origins and affinities of the approximately 1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in approximately 265 males from eight castes of different rank to approximately 750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%-30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements) in all of the caste and continental populations (approximately 600 individuals). Analysis of these data demonstrated that the upper castes have a higher affinity to Europeans than to Asians, and the upper castes are significantly more similar to Europeans than are the lower castes. Collectively, all five datasets show a trend toward upper castes being more similar to Europeans, whereas lower castes are more similar to Asians. We conclude that Indian castes are most likely to be of proto-Asian origin with West Eurasian admixture resulting in rank-related and sex-specific differences in the genetic affinities of castes to Asians and Europeans. PMID:11381027

Bamshad, M; Kivisild, T; Watkins, W S; Dixon, M E; Ricker, C E; Rao, B B; Naidu, J M; Prasad, B V; Reddy, P G; Rasanayagam, A; Papiha, S S; Villems, R; Redd, A J; Hammer, M F; Nguyen, S V; Carroll, M L; Batzer, M A; Jorde, L B

2001-06-01

343

Full-crown castings made with water-saturated and dry casting ring liners.  

PubMed

The carcinogenic potential of asbestos has led to the development of non-asbestos materials for use as casting ring liners. Cellulose paper are replacing asbestos paper. The brass die and crown were made to produce full crowns. The standardized wax pattern was replicated twenty-nine times. Two grooves were marked on the die and wax patterns. The marginal gaps between wax pattern and die shoulder were measured. Then, the wax specimens were divided into three groups. The dry ring liner and the water-saturated ring liner were used, in the third group, any liner was used. The castings were fabricated and were fitted on the die. Measurements were made of the distance separating the gingival margin of the castings from the shoulder on the die. Measurement points (X and Y) were the same points used for wax pattern measurement. The difference between wax pattern and casting was found to be statistically significant in all the groups (p = 0.0051). There was no statistically significant difference between groups on the comparative fit of the castings. The mean marginal space in the water-saturated liner group was 0.51 +/- 0.12 mm (X), 0.51 +/- 0.11 mm (Y), and in the dry liner group, the mean marginal space was 0.47 +/- 0.09 mm (X), 0.49 +/- 0.08 mm (Y). In the unlined group, they were 0.52 +/- 0.18 mm (X), 0.55 +/- 0.17 mm (Y). Use of dry ring lining material resulted in smaller marginal spaces between castings and the die than use of water-saturated cellulose ring lining material. The results demonstrated that the use of dry liners may improve the fit of castings to dies. PMID:10794510

Keyf, F; Erman, G

2000-04-01

344

Numerical and Experimental Study on Residual Stress in Gray Cast Iron Stress Lattice Shape Casting  

NASA Astrophysics Data System (ADS)

The prediction of residual stress in a stress lattice shape casting (stress lattice) has been conducted and discussed by some researchers via the Finite Element Method (FEM). However, most of the previous studies used the first-order tetrahedral element, which has poor analysis accuracy in problems including bending. The use of the first-order tetrahedral element makes the verification of these studies uncertain because the bending deformation essentially occurs in the stress lattice casting. This study first shows that the thermal stress analysis for the stress lattice should use the element that can represent the bending deformation in principle for bending of the thin parts. Second, the simulated residual stress was compared with the measured value. The thermal stress analysis successfully predicted the residual stress of the stress lattice casting with and 11 pct difference. In addition to the prediction of the residual stress, it is important from the viewpoint of the productivity of castings to reveal the effect of the shake-out temperature on the residual stress. However, in the previous studies, conclusions concerning the effect of the shake-out temperature on the residual stress were not consistent ( i.e., the one study said the higher shake-out temperature decreased the residual stress, and another study said a higher shake-out temperature increased the residual stress). Therefore, the current study first discusses the reason for the inconsistent conclusions in the previous studies. Second, stress lattice castings were cast and shaken out at various shake-out temperatures. Then, the current study validated the effect of the shake-out temperature on the residual stress. Consequently, the experimental results supported the conclusion of Kasch and Mikelonis that the shake-out at higher temperature contributed to the increase of the residual stress in the casting.

Motoyama, Yuichi; Takahashi, Hiroki; Okane, Toshimitsu; Fukuda, Yoya; Yoshida, Makoto

2013-07-01

345

Wavelet-assisted volume ray casting.  

PubMed

Volume rendering is an important technique for computational biology. In this paper we propose a new wavelet-assisted volume ray casting algorithm. The main idea is to use the wavelet coefficients for detecting the local frequency, and decide the appropriate sampling rate along the ray according to the maximum frequency. Our algorithm is to first apply the 3D discrete wavelet transform on the volume, then create an index volume to indicate the necessary sampling distance at each voxel. During ray casting, the original volume is traversed in the spatial domain, while the index volume is used to decide the appropriate sampling distance. We demonstrate that our algorithm provides a framework for approximating the volume rendering at different levels of quality in a rapid and controlled way. PMID:9697179

He, T

1998-01-01

346

Phase Transformation in Cast Superaustenitic Stainless Steels  

SciTech Connect

Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.

Nathaniel Steven Lee Phillips

2006-12-12

347

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

348

Foam Filters Used in Gravity Casting  

NASA Astrophysics Data System (ADS)

Ceramic foam filters are normally used for reducing the velocity of liquid metal in the design of runner systems. In this study, four designs of the runner system with various orientations of foam filters were explored, and their effect on the velocity of the melt was estimated by a casting experiment and computational modeling. In the casting experiment, the free-fall trajectory and metal weighing methods were employed for measuring apparent velocity and flow rate, respectively. Using Forchheimer's equation, a porous material such as a foam filter was simulated. The modeling result was validated by the experiment. For the efficient use of a foam filter in a running system with a high flow rate but low exit velocity, an optimized design is recommended.

Hsu, Fu-Yuan; Lin, Huey-Jiuan

2011-12-01

349

The USAMP magnesium powertrain cast components project  

NASA Astrophysics Data System (ADS)

Despite the demonstrated ability of magnesium alloys to significantly reduce weight at acceptable costs in many areas of an automobile, powertrain components have not benefited from this metal, primarily because the high-temperature alloys that are required for engines and transmissions are too expensive. However, the U.S. Department of Energy and the U.S. Automotive Materials Partnership have launched a project to evaluate several new, potentially low-cost magnesium alloys, design several pre-competitive power-train components for the best alloy properties, cast and dynamometer or vehicle test the components in assembled powertrains, develop a powertrain magnesium alloy design database and common alloy specification, and identify andpromote the funding of fundamental research into improved magnesium alloys and casting processes.

Powell, Bob R.

2002-02-01

350

Microporosity prediction in aluminum alloy castings  

Microsoft Academic Search

A comprehensive methodology that takes into account solidification, shrinkage-driven interdendritic fluid flow, hydrogen precipitation,\\u000a and porosity evolution has been developed for the prediction of the microporosity fraction and distribution in aluminum alloy\\u000a castings. The approach may be used to determine the extent of gas and shrinkage porosity, i.e., the resultant microporosity which occurs due to gas precipitation and that which

A. S. Sabau; S. Viswanathan

2002-01-01

351

Salt Bath Oxinitriding of Gray Cast Iron  

Microsoft Academic Search

Salt bath oxinitriding is a duplex surface treatment developed to improve tribological and corrosion properties of ferrous materials. In this research, gray cast iron samples were nitrided at the temperature range of 480°C-580°C, and then oxidized in an oxidative salt bath. The phase composition of surface layer was identified by X-ray diffraction. Using a microhardness tester, hardness of nitrided gray

M. Ahmadi; M. Teimouri; M. Aliofkhazraee; S. M. Mousavi Khoee

2008-01-01

352

Efficient Runner Networks for Investment Castings  

SciTech Connect

We present a computational method that finds an efficient runner network for an investment casting, once the gate locations have been established. The method seeks to minimize a cost function that is based on total network volume. The runner segments are restricted to lie in the space not occupied by the part itself. The collection of algorithms has been coded in C and runner designs have been computed for several real parts, demonstrating substantial reductions in rigging volume.

GIVLER,RICHARD C.; SAYLORS,DAVID B.

2000-07-18

353

Innovative method for casting steel armorplate  

SciTech Connect

The US Bureau of Mines, through an Interagency Agreement with the US Tank-Automotive Command (TACOM), has successfully developed a steel expendable pattern casting process (EPC) for the manufacture of armorplate. The new armor is lighter and more ballistically effective than conventional rolled homogeneous armor (RHA), and costs less. An applique armor spinoff from the program was field-tested during the Gulf War. The applique armor withstood direct impacts from enemy munitions without failure.

Turner, P.C.; Hansen, J.S.

1993-01-01

354

Repair welding of gamma titanium aluminide castings  

NASA Astrophysics Data System (ADS)

This paper examines the GTA repair welding of cast Ti-48Al-2Cr-2Nb gamma titanium aluminide. Pre-weld heat treatment, preheat and welding parameters are evaluated and discussed. A wide range of GTAW parameters is demonstrated for use with this alloy and the resulting weld structure is examined. The effects of postweld heat treatment on the structure of the weld deposit is also determined.

Kelly, T. J.

355

Hypereutectic aluminum-silicon casting alloy  

Microsoft Academic Search

An engine block is described for an internal combustion engine, comprising a cast block composed of a hypereutectic aluminium silicon alloy and having at least one cylinder bore therein. The alloys consists essentially of 16% to 19% by weight of silicon, 0.4% to 0.7% by weight of magnesium, up to 1.4% by weight of iron, up to 0.3% by weight

W. G. Hesterberg; R. J. Donahue; B. L. Sheaffer

1986-01-01

356

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

357

Slip casting of partially stabilized zirconia  

Microsoft Academic Search

The toughness of partially-stabilized zirconia has been studied for some time. The tetragonal phase in partially stabilized ZrO2 transforms to the monoclinic phase under the influence of stress. Partially-stabilized ZrO2 has enhanced tensile strength, good wear resistance and low friction coefficient, and has found industrial applications. This article describes the use of partially-stabilized zirconia in slip casting. Lab techniques of

H. Taguchi; H. Miyamoto; Y. Takahashi

1985-01-01

358

An Integrated procedure for modeling investment castings  

NASA Astrophysics Data System (ADS)

A major roadblock preventing the widespread use of casting simulation technology is the intensive effort required by a highly skilled-professional to construct a finite-element model. To address this situation, this article proposes an integrated-model construction procedure that reduces model construction time for a typical aeropropulsion component from two weeks to two days. It also describes another step toward the accurate and practical prediction of the coating process through coupled heat transfer, fluid flow, and stress calculation.

Tu, John S.; Kelly Foran, R.; Hines, Albert M.; Aimone, Paul R.

1995-10-01

359

Review: aqueous tape casting of ceramic powders  

Microsoft Academic Search

Slurry formulations and processing parameters of the water-based tape casting of ceramic powders are reviewed. Additives include binders, like cellulose ethers, vinyl or acrylic-type polymers; plasticizers, like glycols; and dispersants, like ammonium salts of poly(acrylic acids). Mostly alumina powders have been employed. Hydrophobing of ceramic powders permits the aqueous processing even of water-reactive powders, like aluminium nitride. Non-toxicity and non-inflammability

D. Hotza; P. Greil

1995-01-01

360

Superplasticity in Rapidly Solidified White Cast Irons  

Microsoft Academic Search

Superplastic properties of three different composition white cast irons were investigated in the temperature range of 630\\u000a to 725 C. Fine structures consisting of 1 to 2 ?m ferrite grains were developed in these materials by consolidation of rapidly\\u000a solidified powders at intermediate temperatures below the A1 critical temperature. Tensile elongations of 1410 pct were found for a 3.0 pct

Oscar A. Ruano; Lawrence E. Eiselstein; Oleg D. Sherby

1982-01-01

361

A transformation toughening white cast iron  

Microsoft Academic Search

An experimental white cast iron with the unprecedented fracture toughness of 40 MPa m1\\/2 is currently being studied to determine\\u000a the mechanisms of toughening. This paper reports the investigation of the role of strain-induced martensitic (SIM) transformation.\\u000a The dendritic microconstituent in the toughened alloy consists primarily of retained austenite, with precipitated M7C3 carbides\\u000a and some martensite. Refrigeration experiments and differential

S. K. HANN; J. D. GATES

1997-01-01

362

AUSTEMPERING OF A SILICON MANGANESE CAST STEEL  

Microsoft Academic Search

The influence of austempering on the microstructure and mechanical properties of an alloyed cast steel containing high silicon (3.00%) and high manganese (2.00%) was studied. The influence of microstructure on the plain strain fracture toughness of this new steel was also examined. The test results show that by using a suitable austempering process, i.e., by austenitizing at 1010°C (1850°F) for

Susil K. Putatunda

2001-01-01

363

Advances in nickel-based cast superalloys  

Microsoft Academic Search

Nickel-based superalloys have served as the most competitive high temperature structural materials under highly stressed and\\u000a aggressive operating conditions in a variety of applications for more than 60 years. The most demanding among all the applications\\u000a has been the gas turbine aerofoil castings of modern aero-engines. These turbine parts operate in extremely aggressive environment\\u000a of high velocity hot combustion gas-air

Niranjan Das

2010-01-01

364

SILICA EXPOSURE IN HAND GRINDING STEEL CASTINGS  

Microsoft Academic Search

Exposure to silica dust was studied in the grinding of castings in a steel foundry that used conventional personal sampling methods and new real-time sampling techniques developed for the identification of high-exposure tasks and tools. Approximately one-third of the personal samples exceeded the National Institute for Occupational Safety and Health recommended exposure limit for crystalline silica, a fraction similar to

Dennis OBrien; Phillip A. Froehlich; Michael G. Gressel; Ronald M. Hall; Nancy J. Clark; Patrick Bost; Thomas Fischbach

1992-01-01

365

INDUSTRIALIZATION OF CAST ALUMINUM MATRIX COMPOSITES (AMCCs)  

Microsoft Academic Search

This paper briefly describes the main research points and activities which have been considered toward industrialization of cast aluminum matrix composites (AMCCs). First, the issues in liquid processing of metal matrix composites are reviewed. The different requirements for successful AMCCs are then described. Post-processingsuch as heat treatment, forming, and machining, which can beperformed on AMCCs, are discussed. The up-to-date, specially

Mohamed A. Taha

2001-01-01

366

INVESTMENT CASTING OF ALLVAC® 718PLUS™ ALLOY  

Microsoft Academic Search

Many jet engine structural components are fabricated using investment castings, generally a lower-cost material alternative to built-up structures. Waspaloy is a nickel-base, age-hardenable superalloy with excellent high-temperature strength and good oxidation resistance, utilized in rotating aero engine components up to 704°C and higher temperatures for static components in modern jet engines. Typical applications include casings, frames and rings. Waspaloy has

T. D. Bayha; M. Lu; K. E. Kloske

367

[Studies on titanium casting. (1) Influence of the mold temperature on titanium castings].  

PubMed

Pure titanium and titanium alloys have excellent biocompatibility, excellent corrosion tarnish resistance, a quarter of the specific gravity of gold base alloys and suitable mechanical properties for dental clinical use. However, titanium has some undesirable characteristics. For example, it has a high melting temperature and chemical reactivity at high temperatures. The investigate influence of the mold temperature on castability and mechanical properties of the titanium castings was study. The castability was found to be good at various mold temperatures, but the higher the mold temperature during casting, the greater the adhesive phenomenon between titanium surface and the investment. From the EPMA observation of the surface layer on the titanium castings, an Si- rich layer whose thickness increased considerably with increasing temperature was observed. The Vickers hardness in the surface layer was greater than that in the inner part. At a higher mold temperature during casting the thickness of the high Vickers hardness layer was increased. There was a relationship between the Vickers hardness value and the thickness of Si rich layer. In the tensile strength test of titanium castings, elongation values decrease and tensile strength values increased with the rise in mold temperature. PMID:2135519

Kuroiwa, A; Wada, K; Hibino, Y; Yoshida, O; Kakumoto, Y; Kouchi, H; Nagayama, K; Hashimoto, H

1990-03-01

368

Aging degradation of cast stainless steel  

SciTech Connect

A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450/sup 0/C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the ..cap alpha..' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450/sup 0/C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450/sup 0/C. 18 refs., 13 figs.

Chopra, O.K.; Chung, H.M.

1985-10-01

369

Grindability of cast Ti-Hf alloys.  

PubMed

As part of our systematic studies characterizing the properties of titanium alloys, we investigated the grindability of a series of cast Ti-Hf alloys. Alloy buttons with hafnium concentrations up to 40 mass% were made using an argon-arc melting furnace. Each button was cast into a magnesia-based mold using a dental titanium casting machine; three specimens were made for each metal. Prior to testing, the hardened surface layer was removed. The specimens were ground at five different speeds for 1 min at 0.98 N using a carborundum wheel on an electric dental handpiece. Grindability was evaluated as the volume of metal removed per minute (grinding rate) and the volume ratio of metal removed compared to the wheel material lost (grinding ratio). The data were analyzed using ANOVA. A trend of increasing grindability was found with increasing amounts of hafnium, although there was no statistical difference in the grindability with increasing hafnium contents. We also found that hafnium may be used to harden or strengthen titanium without deteriorating the grindability. PMID:16206203

Kikuchi, Masafumi; Takahashi, Masatoshi; Sato, Hideki; Okuno, Osamu; Nunn, Martha E; Okabe, Toru

2006-04-01

370

Die Soldering in Aluminium Die Casting  

SciTech Connect

Two types of tests, dipping tests and dip-coating tests were carried out on small steel cylinders using pure aluminum and 380 alloy to investigate the mechanism of die soldering during aluminum die casting. Optical and scanning electron microscopy were used to study the morphology and composition of the phases formed during soldering. A soldering mechanism is postulated based on experimental observations. A soldering critical temperature is postulated at which iron begins to react with aluminum to form an aluminum-rich liquid phase and solid intermetallic compounds. When the temperature at the die surface is higher than this critical temperature, the aluminum-rich phase is liquid and joins the die with the casting during the subsequent solidification. The paper discusses the mechanism of soldering for the case of pure aluminum and 380 alloy casting in a steel mold, the factors that promote soldering, and the strength of the bond formed when soldering occurs. conditions, an aluminum-rich soldering layer may also form over the intermetallic layer. Although a significant amount of research has been conducted on the nature of these intermetallics, little is known about the conditions under which soldering occurs.

Han, Q.; Kenik, E.A.; Viswanathan, S.

2000-03-15

371

Comparison of Lost Foam Casting of AM60B Alloy and A356 Alloy  

SciTech Connect

The article describes the research activities at Oak Ridge National Laboratory and Tennessee Technological University on lost foam casting of magnesium alloys. The work was focused on castings of simple geometries such as plate castings and window castings in order to compare the difference in castability between magnesium alloys and aluminum alloy using the lost foam casting process. Significant differences between lost foam aluminum casting and lost foam magnesium casting have been observed.

Han, Qingyou [ORNL; Dinwiddie, Ralph Barton [ORNL; Sklad, Philip S [ORNL; Currie, Kenneth [Tennessee Technological University; Vondra, Fred [Tennessee Technological University; Abdelrahman, Mohamed [Tennessee Technological University; Walford, Graham [Walford Technologies; Nolan, Dennis J [Foseco-Morval; Nedkova, Teodora [Kaiser Aluminum

2007-01-01

372

Anisotropic shrinkage characteristics of tape cast alumina  

NASA Astrophysics Data System (ADS)

Dimensional control during sintering is a major issue in ceramics processing to avoid high post-sintering costs associated with machining of the fired ceramic part to desired tolerances and dimensions. Ceramic forming processes such as tape casting, injection molding, and extrusion involve shear of anisotropic particles resulting in preferential alignment of the particles in the green body. This preferential alignment causes directionality in mechanical, electrical, optical, and magnetic properties and most importantly warpage or distortion during sintering. A large effort has been devoted to synthesizing ceramic green bodies with minimal density gradients and uniform packing and modeling the sintering behavior evolution but little effort has been devoted to characterizing orientation of particles and the effect of preferential alignment on sintering shrinkage anisotropy. A systematic study was initiated to study the effect of processing variables such as shear rate, solids loading, temperature, and binder content on aqueous tape cast alumina. Three different alumina systems: A16-SG, Baikowski RC-UFX DBM and RC-LS DBM were investigated. Aqueous tapes of high solids loading alumina (56 vol. %) were tape cast at various speeds and thicknesses and assuming plane Couette flow a shear rate regime of 21--270 s-1 was investigated. Higher shear rates and high solids loading resulted in higher in-plane anisotropy whereas the anisotropy in the thickness direction was higher for low solids loading systems. The anisotropy was found to be fairly constant above a certain critical shear rate (˜100 s-1) irrespective of the temperature and the solids loading and this correlated with the viscosity-shear rate relationship of the cast slips. The higher shrinkage anisotropy in the thickness direction for the low solids loading systems (35 and 45 vol. %) was attributed to the higher amount of organics in the slip required to sustain the suitable viscosity for tape casting and subsequently the strains associated with binder removal. The sintering rate in the thickness direction was significantly higher. This was attributed to more number of necks resulting from platy nature of alumina particles and the strains associated with binder removal. SEM images in the thickness direction after intermediate levels of sintering clearly revealed that the particles become more isotropic much earlier as compared to the in-plane direction. (Abstract shortened by UMI.)

Patwardhan, Jaideep Suresh

373

3D printing technique applied to rapid casting  

Microsoft Academic Search

Purpose – The purpose of this paper is to verify the feasibility and evaluate the dimensional accuracy of two rapid casting (RC) solutions based on 3D printing technology: investment casting starting from 3D-printed starch patterns and the ZCast process for the production of cavities for light-alloys castings. Design\\/methodology\\/approach – Starting from the identification and design of a benchmark, technological prototypes

Elena Bassoli; Andrea Gatto; Luca Iuliano; Maria Grazia Violante

2007-01-01

374

Cast prosthesis removal using ultrasonics and a thermoplastic resin adhesive.  

PubMed

Nonsurgical endodontic procedures are routinely performed on teeth with existing cast restorations. The internal anatomy of the tooth and location of the root canals may be obscured by a crown or fixed partial denture. Tooth morphology and canal location may, therefore, be better visualized without the cast restoration in place. This article describes a conservative technique to remove an existing cast restoration to facilitate nonsurgical root canal treatment. PMID:7996088

Parreira, F R; O'Connor, R P; Hutter, J W

1994-03-01

375

Diagnosis of oxide films in cast aluminum alloys  

Microsoft Academic Search

Aluminum (Al) alloy castings often contain many defects, such as micro-shrinkage, gas pores, shrinkage pores, hot tearing,\\u000a and oxide film entrapment. When oxide films are entrapped in Al alloy castings, they are very difficult to identify simply\\u000a by optical observation. In this study we used an auto-scanning eddy current testing method to detect oxide films entrapped\\u000a in Al alloy castings.

Yeong-Jern Chen; Hwei-Yuan Teng; Yuo-Tern Tsai

2004-01-01

376

Numerical simulation of low pressure die-casting aluminum wheel  

Microsoft Academic Search

The FDM numerical simulation software, ViewCast system, was employed to simulate the low pressure die casting (LPDC) of an aluminum wheel. By analyzing the mold-fi lling and solidifi cation stage of the LPDC process, the distribution of liquid fraction, temperature field and solidification pattern of castings were studied. The potential shrinkage defects were predicted to be formed at the rim\\/spoke

Mi Guofa; Liu Xiangyu; Wang Kuangfei; Fu Hengzhi

377

Prof. John Campbell's ten rules for making reliable castings  

NASA Astrophysics Data System (ADS)

John Campbell’s “Casting Rules” were developed over a lifetime of work in the foundry industry and later research at the University of Birmingham. Much of the research work focused on the effect of melt handling at the various transfer stages on the number of defects created and the effect on the reliability of the castings subsequently made. This article provides the author’s analysis of Campbell’s ten rules for metal casting.

Jolly, Mark

2005-05-01

378

Making castings of nonferrous alloys in bulk investment molds  

Microsoft Academic Search

The theoretical aspects and practical findings of the development and commercial implementation of new engineering processes\\u000a for making art castings of nonferrous alloys are presented. The castings weigh from 0.1 to 100 kg and reach 1.5 m in size.\\u000a They are cast into bulk filler molds of pouring mixtures based on gypsum and cement binders and can be produced individually

V. K. Dubrovin; O. M. Zaslavskaya; A. V. Karpinskii

2011-01-01

379

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

380

Sliding wear of graphite crystallized chromium white cast iron  

Microsoft Academic Search

The effects of sliding velocity, heat-treatment and graphite shape on sliding wear of graphite crystallized chromium white cast iron were studied. Two types of graphite crystallized chromium white cast irons having flaky or spheroidal and another type of 2.6C–15Cr white cast iron were prepared for this study. The effect of sliding velocity on wear resistance was studied by the Okoshi

S Aso; S Goto; Y Komatsu; W Hartono

2001-01-01

381

Investment casting of AZ91HP magnesium alloy  

Microsoft Academic Search

This paper describes AZ91HP magnesium alloy investment casting. The aim of this study is to optimize the process for magnesium\\u000a investment casting. Special attention was given to evaluating the thermal stability of oxides against molten AZ91HP magnesium\\u000a alloy. The oxides examined included CaO, CaZr03, and silica bonded A1203 and ZrSi04. Also, the microstructural features of the as-cast alloy were investigated,

Shaekwang Kim; Myounggyun Kim; Taewhan Hong; Heekook Kim; Youngjig Kim

2000-01-01

382

A novel lattice structure for SL investment casting patterns  

Microsoft Academic Search

Purpose – The purpose of this paper is to present the study of octagonal lattice structure for investment casting stereolithography (SL) patterns, and compare it with the former hexagonal structure (of the QuickCast 2.0 build style). This research aims to introduce a new internal lattice structure for investment casting SL patterns. Design\\/methodology\\/approach – Applying 3D-coupled thermal-mechanical finite element analysis; magnitudes

Sadegh Rahmati; Yousef Norouzi; Yousef Hojjat

2009-01-01

383

Alloy shrinkage factors for the investment casting process  

Microsoft Academic Search

This study deals with the experimental measurements and numerical predictions of alloy shrinkage factors (SFs) related to\\u000a the investment casting process. The dimensions of the A356 aluminum alloy casting were determined from the numerical simulation\\u000a results of solidification, heat transfer, fluid dynamics, and deformation phenomena. The investment casting process was carried\\u000a out using wax patterns of unfilled wax and shell

Adrian S. Sabau

2006-01-01

384

Aqueous suspensions for tape-casting based on acrylic binders  

Microsoft Academic Search

The use of water-based systems represents an interesting alternative to the widespread non-aqueous tape-casting but the low strength of water-based binders generally limits their applicability. A tape-casting slurry is a complex system where each organic component has a substantial effect on the rheological behaviour. In this study the effect of the dispersant and binders in alumina aqueous tape-casting slurries were

C. Pagnoux; T. Chartier; M. de F. Granja; F. Doreau; J. M. Ferreira; J. F. Baumard

1998-01-01

385

The high-quality precision casting of titanium alloys  

Microsoft Academic Search

A technique for the high-quality precision casting of titanium alloys has been developed that consists of the instantaneous\\u000a dissociation of oxide at the metal-mold interface, followed by the rapid absorption and diffusion of the dissociated oxygen\\u000a into the subsurface of the cast parts during solidification and cooling. In centrifugal casting trials using less molten alloy\\u000a than required to completely fill

Ken-Ichiro Suzuki

1998-01-01

386

Using cold-crucible melting for titanium precision castings  

NASA Astrophysics Data System (ADS)

Titanium precision castings have not kept pace with technical design requirements for demanding applications, such as the aerospace industry; advances in increased size capability have been offset by a lack of advances in metallurgical integrity and dimensional tolerances. Hence, there is a strong need for improvement in the casting process. Taramm has developed a process that combines cold-crucible induction melting and centrifugal pouring to produce viable castings.

Broihanne, Georges; Bannister, John

2000-05-01

387

Experimental study on the ice pattern fabrication for the investment casting by rapid freeze prototyping (RFP)  

Microsoft Academic Search

The process of investment casting has come to occupy a key position in the range of modern metal casting techniques. Wax pattern is widely used in the investment casting. However, there exist some problems and technical difficulties in using it such as wax pattern expanding, ceramic shell cracking, etc. A new investment casting technology, named freeze cast process (FCP), has

Qingbin Liu; Guanghua Sui; M. C. Leu

2002-01-01

388

A simplified method of total contact casting for diabetic foot ulcers.  

PubMed

A simplified method of total contact casting for diabetic plantar ulcerations is described in which a standard, well-molded short-leg walking cast is applied. Weekly cast changes are performed initially, followed by longer cast change intervals. Either fiberglass or plaster casting tape appears equally efficacious. Healing of all ulcers was demonstrated in 12 patients treated with this technique. PMID:10148327

Huband, M S; Carr, J B

1993-02-01

389

Japanese R&D on new cast alloys and materials  

SciTech Connect

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

Hayden, H.W.

1996-05-01

390

Evaluation of cast creep occurring during simulated clubfoot correction.  

PubMed

The Ponseti method is a widely accepted and highly successful conservative treatment of pediatric clubfoot involving weekly manipulations and cast applications. Qualitative assessments have indicated the potential success of the technique with cast materials other than standard plaster of Paris. However, guidelines for clubfoot correction based on the mechanical response of these materials have yet to be investigated. The current study sought to characterize and compare the ability of three standard cast materials to maintain the Ponseti-corrected foot position by evaluating cast creep response. A dynamic cast testing device, built to model clubfoot correction, was wrapped in plaster of Paris, semi-rigid fiberglass, and rigid fiberglass. Three-dimensional motion responses to two joint stiffnesses were recorded. Rotational creep displacement and linearity of the limb-cast composite were analyzed. Minimal change in position over time was found for all materials. Among cast materials, the rotational creep displacement was significantly different (p < 0.0001). The most creep displacement occurred in the plaster of Paris (2.0°), then the semi-rigid fiberglass (1.0°), and then the rigid fiberglass (0.4°). Torque magnitude did not affect creep displacement response. Analysis of normalized rotation showed quasi-linear viscoelastic behavior. This study provided a mechanical evaluation of cast material performance as used for clubfoot correction. Creep displacement dependence on cast material and insensitivity to torque were discovered. This information may provide a quantitative and mechanical basis for future innovations for clubfoot care. PMID:23636764

Cohen, Tamara L; Altiok, Haluk; Wang, Mei; McGrady, Linda M; Krzak, Joseph; Graf, Adam; Tarima, Sergey; Smith, Peter A; Harris, Gerald F

2013-04-26

391

Caste ratios affect the reproductive output of social trematode colonies.  

PubMed

Intraspecific phenotypic diversification in social organisms often leads to formation of physical castes which are morphologically specialized for particular tasks within the colony. The optimal caste allocation theory argues that specialized morphological castes are efficient at specific tasks, and hence different caste ratios should affect the ergonomic efficiency, hence reproductive output of the colony. However, the reproductive output of different caste ratios has been documented in few species of insects with equivocal support for the theory. This study investigated whether the ratios of nonreproductive and reproductive morphs affect the reproductive output of a recently discovered social trematode, Philophthalmus sp., in which the nonreproductive members are hypothesized to be defensive specialists. A census of natural infections and a manipulative in vitro experiment demonstrated a positive association between the reproductive output of trematode colonies and the ratio of nonreproductive to reproductive morphs in the presence of an intra-host trematode competitor, Maritrema novaezealandensis. On the contrary, without the competitor, reproductive output was negatively associated with the proportion of nonreproductive castes in colonies. Our findings demonstrate for the first time a clear fitness benefit associated with the nonreproductive castes in the presence of a competitor while illustrating the cost of maintaining such morphs in noncompetitive situations. Although the proximate mechanisms controlling caste ratio remain unclear in this trematode system, this study supports the prediction that the fitness of colonies is influenced by the composition of specialized functional morphs in social organisms, suggesting a potential for adaptive shifts of caste ratios over evolutionary time. PMID:23252707

Kamiya, T; Poulin, R

2012-12-17

392

Nature versus nurture in social insect caste differentiation.  

PubMed

Recent evidence for genetic effects on royal and worker caste differentiation from diverse social insect taxa has put an end to the view that these phenotypes stem solely from a developmental switch controlled by environmental factors. Instead, the relative influences of genotypic and environmental effects on caste vary among species, ranging from largely environmentally controlled phenotypes to almost purely genetic systems. Disentangling the selective forces that generate variation for caste predisposition will require characterizing the genetic mechanisms underlying this variation, and identifying particular life-history strategies and kin structures associated with strong genetic effects on caste. PMID:20106547

Schwander, Tanja; Lo, Nathan; Beekman, Madeleine; Oldroyd, Benjamin P; Keller, Laurent

2010-01-26

393

Efficient ray casting with LF-Minmax map in CUDA  

NASA Astrophysics Data System (ADS)

Ray casting is the most frequently used algorithm in direct volume rendering for displaying medical data, although it is computationally very expensive. Recent hardware improvements have allowed ray casting to be used in real-time, however, there is room for performance gains to take advantage of the recent development of general-purpose graphical processing units (GPU). The purpose of this paper is to implement the volume ray casting with the Compute Unified Device Architecture (CUDA) to obtain higher rendering performance. The experimental results show that the new algorithm is up to 15 times faster than the conventional CPU-based ray casting algorithm.

Choi, Jae

2011-03-01

394

Casting of halide and flouride alloys for laser windows  

NASA Astrophysics Data System (ADS)

The problem of residual strain in castings of alkali halides (KCl and SrCl2 doped KCl) and alkaline earth fluorides (CaF2) has been overcome by the development of proper annealing and slow cooling procedures. Large castings (5-1/2 in. diameter) of CaF2 and small castings (3 in. diameter) of SrF2 have been produced with low optical absorption coefficients at 5.25 micrometers. High quality CaF2 castings have been obtained by using as starting material either high purity single crystal chips or reagent grade powder that has been subjected to reactive atmosphere processing (RAP) in Teflon vapors.

Newberg, R. T.; Pappis, J.

1974-10-01

395

Study on the solidification condition of exudation penetration occurrence in grey cast iron castings based on solidification simulation  

NASA Astrophysics Data System (ADS)

The solidification condition of eutectic exudation penetration occurrence, a kind of casting defect in grey cast-iron castings, is studied with computer solidification simulation and experiments on specially designed castings. A hot hole refers to the solidification condition when the temperature gradient or solidifying time gradient from the centre to the surface at some location in a casting is positive during the solidification process. It is a term proposed in this paper to better describe the condition of exudation penetration occurrence and for predicting its location at hot spots in a casting. The term is useful for improving the foundry technology used for solving the penetration problem with the help of computer simulation.

Han, Jianmin; Hansen, S. F.

2000-11-01

396

Casting guidelines, tips, and techniques: proceedings from the 1997 American Burn Association PT/OT Casting Workshop.  

PubMed

Approximately 100 therapists attended the PT/OT Casting Workshop at the twenty-ninth Annual Meeting of the American Burn Association in New York City, N.Y., on March 20, 1997. The workshop consisted of four groups: two demonstrating hand/wrist casting and two demonstrating casting of the foot/ankle. Participants had the opportunity to attend one upper extremity group and one lower extremity group lasting approximately 50 minutes each. Instructors provided a demonstration of a casting procedure while addressing general guidelines, indications, contraindications, and precautions related to casting each area. Thorough handouts were provided, and each participant had the opportunity to apply two casts. The following article is a compilation of the four handouts and their bibliographies. PMID:9622472

Staley, M; Serghiou, M

397

Initial solidification phenomena in continuous casting  

NASA Astrophysics Data System (ADS)

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

Badri, Adam

398

Spray casting of steel strip: Process analysis  

NASA Astrophysics Data System (ADS)

Near-net shape manufacturing (NNSM) of thin steel sections by spray casting eliminates casting as a separate step with attendant improved microstructures and properties and significant energy savings. The process involves atomization of a stream of liquid metal and deposition of droplets in the generated spray on a moving substrate at mass flow rates of 0.25 to 2.5 kg/s. In this paper, NNSM of steel strip by the Osprey spray casting process is investigated by combining numerical simulation and experiments. Critical input parameters for the computation are quantified utilizing existing state-of-the-art mathematical models and specific experiments. Numerical computation of the consolidation of the spray at the substrate during manufacture of thin sections is conducted using both continuum and discrete event (“splat solidification”) approaches to predict: (1) variation of strip thickness in the transverse dimension and (2) isotherms and cooling rates across the strip thickness. Predicted geometries of the strip simulated by the continuum model are in good agreement with measurements. Predicted isotherms in narrow strip by the continuum approach are in reasonable agreement with thermocouple measurements for intermediate thicknesses (2 to 5 mm), and the observed microstructure is consistent with predicted cooling rates. The discrete event model predicts significantly higher cooling rates than the continuum model in the basal portion of the strip. This is consistent with the observed grain size in thin strip (

Annavarapu, Suresh; Apelian, Diran; Lawley, Alan

1990-12-01

399

Textures of strip cast Fe16%Cr  

SciTech Connect

Ferritic stainless steels with a Cr content of 16% are mainly manufactured by continuous casting, hot rolling, cold rolling and final recrystallization. The recent development of the strip casting method, which provides sheets with an equivalent geometry, i.e. thickness and width as the hot rolled band, yields significant improvements in comparison to the conventional processing. The weak initial strip texture and the homogeneous microstructure through the sample thickness have shown evidence of avoiding the well known ridging phenomenon of the finally rolled and annealed product. The occurrence of ridging in conventionally processed FeCr steel has been attributed to the collective shear of grains with (hkl)<110>, i.e. [alpha]-fibre orientations, which become oriented and topologically arranged during hot rolling. In the present paper the textures of a stainless ferritic steel with 16% Cr and 0.02% C, strip casted (SC) as well as hot rolled (HR), were thus investigated. The textures were examined by measuring the four incomplete pole figures (110), (200), (112) and (103) in the back reflection mode. The orientation distribution function (ODF) was calculated by the series expansion method (1[sup max]=22). In the case of cubic crystal symmetry and orthorhombic sample symmetry an orientation can then be presented by the three Euler angles [var phi][sub 1], [var phi], [var phi][sub 2] in the reducted Euler space. Since bcc steels tend to develop characteristic fibre textures, it is favorable to present the ODFs as isointensity diagrams in [var phi][sub 1]-sections through the Eulerspace. In this work the [alpha]-fibre and the [gamma]-fibre are of major interest.

Raabe, D.; Reher, F.; Luecke, K. (Inst. fuer Metallkunde und Metallphysik, Aachen (Germany)); Hoelscher, M. (Krupp Stahl AG, Duesseldorf-Benrath (Germany))

1993-07-01

400

Aging degradation of cast stainless steel  

SciTech Connect

A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich ..cap alpha..' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by ..cap alpha..' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 450/sup 0/C. Data from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450/sup 0/C are presented and correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed.

Chopra, O.K.; Chung, H.M.

1986-10-01

401

Modeling Coal Seam Damage in Cast Blasting  

SciTech Connect

A discrete element computer program named DMC_BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting (Preece & Taylor, 1989). This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in two dimensions. DMC_BLAST calculations compare favorably with data from actual bench blasts (Preece et al, 1993). Coal seam chilling refers to the shattering of a significant portion of the coal leaving unusable fines. It is also refereed to as coal damage. Chilling is caused during a blast by a combination of explosive shock energy and movement of the adjacent rock. Chilling can be minimized by leaving a buffer zone between the bottom of the blastholes and the coal seam or by changing the blast design to decrease the powder factor or by a combination of both. Blast design in coal mine cast blasting is usually a compromise between coal damage and rock fragmentation and movement (heave). In this paper the damage to coal seams from rock movement is examined using the discrete element computer code DMC_BLAST. A rock material strength option has been incorporated into DMC_BLAST by placing bonds/links between the spherical particles used to model the rock. These bonds tie the particles together but can be broken when the tensile, compressive or shear stress in the bond exceeds the defined strength. This capability has been applied to predict coal seam damage, particularly at the toe of a cast blast where drag forces exerted by movement of the overlying rock can adversely effect the top of the coal at the bench face. A simulation of coal mine cast blasting has been performed with special attention being paid to the strength of the coal and its behavior at t he bench face during movement of the overlying material.

Chung, S.H.; Preece, D.S.

1998-11-23

402

Fabrication of high chromium cast iron\\/low carbon steel composite material by cast and hot rolling process  

Microsoft Academic Search

A sandwich-structured composite blank containing a high chromium cast iron (HCCI) and low carbon steel (LCS) claddings was successfully fabricated by casting and hot rolling, and then a series of quenching and tempering treatments were employed. The evolution of microstructures and microhardness of as-cast, hot-rolled and heat-treated specimens were investigated. The microstructures of hot-rolled HCCI are refined and significant variations

Guoliang Xie; Hui Sheng; Jingtao Han; Jing Liu

2010-01-01

403

Evaluation of the Inertness of Investment Casting Molds Using Both Sessile Drop and Centrifugal Casting Methods  

NASA Astrophysics Data System (ADS)

The investment casting process is an economic production method for engineering components in TiAl-based alloys and offers the benefits of a near net-shaped component with a good surface finish. An investigation was undertaken to develop three new face coat systems based on yttria, but with better sintering properties. These face coat systems were mainly based on an yttria-alumina-zirconia system (Y2O3-0.5 wt pct Al2O3-0.5 wt pct ZrO2), an yttria-fluoride system (Y2O3-0.15 wt pct YF3), and an yttria-boride system (Y2O3-0.15 wt pct B2O3). After sintering, the chemical inertness of the face coat was first tested and analyzed using a sessile drop test through the metal wetting behavioral change for each face coat surface. Then, the interactions between the shell and metal were studied by centrifugal investment casting TiAl bars. Although the sintering aids in yttria can decrease the chemical inertness of the face coat, the thickness of the interaction layer in the casting was less than 10 ?m; therefore, these face coats still can be possible face coat materials for investment casting TiAl alloys.

Cheng, Xu; Yuan, Chen; Green, Nick; Withey, Paul

2013-02-01

404

Micromechanical modeling of ductile cast iron incorporating damage. Part I: Ferritic ductile cast iron  

Microsoft Academic Search

The market for ductile cast iron as a substitute material increases every year. The material structural performance is strongly dependent on the microstructure. Micromechanics can help in understanding the role played by the microstructure constituents as well as the effects associated to the shape of the spheroids, their density, surface roughness, etc. The potential of application for micromechanics modeling can

Nicola Bonora; Andrew Ruggiero

2005-01-01

405

Cast Titanium Alloy Radial Impellers: A new casting process costs less than conventional forging and machining.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. A casting process for the fabrication of Ti-6A1-4V alloy radial-compressor impellers has been developed. Impellers made by the improved process cost less than simila...

1982-01-01

406

Bronchial cast hiding a lung cancer  

PubMed Central

A 70-year-old man was admitted for severe hypoxia, haemoptysis and cough. Chest-X-ray and CT-scan indicated a right-lower-lobe collapse. Bronchoscopy showed its occlusion by whitish dense mucus. Aspiration revealed a Bronchial Cast (BC) and a stenotic and inflamed orifice of the right-lower-lobe-bronchus which was biopsied. Histopathologic examination of BC showed fibrin with lymphocytes and neutrophils, and, surprisingly, also the presence of lung cancer. Although the association between BC and benign, myxoid-soft-tissue, tracheobronchial tumors has been described, the association with lung cancer has not previously been reported, and it remains unclear whether it is causal or casual.

2012-01-01

407

Phase transformations in cast duplex stainless steels  

NASA Astrophysics Data System (ADS)

Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as sigma (sigma) and chi (chi) can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (sigma + chi) formation were analyzed using the Johnson-Mehl-Avrami (JMA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities, a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, a was stabilized with increasing Cr addition and chi by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by local composition fluctuations in the cast alloy. This may cause discrepancy between thermodynamic prediction and experimental observation.

Kim, Yoon-Jun

408

Modeling wear of cast Ti alloys  

PubMed Central

The wear behavior of Ti-based alloys was analyzed by considering the elastic–plastic fracture of individual alloys in response to the relevant contact stress field. Using the contact stresses as the process driving force, wear was computed as the wear rate or volume loss as a function of hardness and tensile ductility for Ti-based cast alloys containing an ?, ?+? or ? microstructure with or without the intermetallic precipitates. Model predictions indicated that wear of Ti alloys increases with increasing hardness but with decreasing fracture toughness or tensile ductility. The theoretical results are compared with experimental data to elucidate the roles of microstructure in wear and contrasted against those in grindability.

Chan, Kwai S.; Koike, Marie; Okabe, Toru

2007-01-01

409

Continuation of Crosscutting Technology Development at Cast  

SciTech Connect

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

Yoon, Roe-Hoan

2012-03-31

410

Reconciling the CAST and PVLAS Results  

SciTech Connect

The PVLAS experiment has recently claimed evidence for an axionlike particle in the milli-electron-volt mass range with a coupling to two photons that appears to be in contradiction with the negative results of the CAST experiment searching for solar axions. The simple axion interpretation of these two experimental results is therefore untenable and it has posed a challenge for theory. We propose a possible way to reconcile these two results by postulating the existence of an ultralight pseudoscalar particle interacting with two photons and a scalar boson and the existence of a low scale phase transition in the theory.

Mohapatra, R. N. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Nasri, Salah [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

2007-02-02

411

Directional solidification of white cast iron  

Microsoft Academic Search

Several studies of the ledeburite eutectic (Fe-Fe3C), in pure Fe-C alloys have shown that it has a lamellar morphology under plane front growth conditions. The structure of\\u000a ledeburite in white cast irons, Fe-C-Si, consists of a rod morphology. It is generally not possible to produce plane front\\u000a growth of Fe-C-Si eutectic alloys in the Fe-Fe3C form, because at the slow

J. S. Park; J. D. Verhoeven

1996-01-01

412

High Metabolic Rates in Beach Cast Communities  

Microsoft Academic Search

Metabolic hotspots at land–water interfaces are important in supporting biogeochemical processes. Here we confirm the generality\\u000a of land–aquatic interfaces as biogeochemical hot spots by extending this concept to marine beach cast materials. In situ atmospheric\\u000a pCO2, from a respiration chamber (10 cm in diameter and 20 cm high) inserted into wrack deposits, was determined using a high-precision\\u000a (±1 ppm) non-dispersive infrared gas analyzer

Grey T. Coupland; Carlos M. Duarte; Diana I. Walker

2007-01-01

413

Method and apparatus for strip casting  

DOEpatents

Casting nozzles will provide improved flow conditions with the parameters controlled according to the present invention. The gap relationships between the nozzle slot and exit orifice must be controlled in combination with converging exit passageway to provide a smooth flow without shearing and turbulence in the stream. The nozzle lips are also rounded to improve flow and increase refractory life of the lips of the nozzle. The tundish walls are tapered to provide improve flow for supplying the melt to the nozzle. The nozzle is located about 45[degree] below top dead center for optimum conditions. 2 figures.

Follstaedt, D.W.; Powell, J.C.; Sussman, R.C.; Williams, R.S.

1991-11-12

414

Method and apparatus for strip casting  

DOEpatents

Casting nozzles will provide improved flow conditions with the parameters controlled according to the present invention. The gap relationships between the nozzle slot and exit orifice must be controlled in combination with converging exit passageway to provide a smooth flow without shearing and turbulence in the stream. The nozzle lips are also rounded to improve flow and increase refractory life of the lips of the nozzle. The tundish walls are tapered to provide improve flow for supplying the melt to the nozzle. The nozzle is located about 45.degree. below top dead center for optimum conditions.

Follstaedt, Donald W. (Middletown, OH); Powell, John C. (Pittsburgh, PA); Sussman, Richard C. (West Chester, OH); Williams, Robert S. (Fairfield, OH)

1991-01-01

415

Casting of Ti-6Al-4V alloy compared with pure Ti in an Ar-arc casting machine.  

PubMed

Dental prostheses of Ti are normally cast in pure Ti. Some appliances, however, require higher yield strength. Casting of Ti alloys is of interest in such cases. The objective of the present work was to study the quality of castings made of Ti-6Al-4V compared with those made of pure Ti. Casting was made into a mold kept at room temperature using a MgO-Al2O3 investment. A standardized five-unit bridge was cast, consisting of two cylindrical crowns with sharp margins and three pontics. The overall mold filling was satisfactory. The margins of the casting alloys were, however, more rugged and incomplete than those of pure Ti. The most likely reason for this difference is the increased formation of dendrites in the alloy and thus more resistance to fluid flow. Furthermore, the sprue of the alloy was also found to contain some spherical, internal pores. Such pores were rare in the pure Ti castings. The surface reactions were found to be minimal for both of the materials. Increased casting deficiencies observed in the cast bridges of the Ti-6Al-4V alloy, compared with pure Ti, were: 1) the margins of the crowns in the bridge were less complete and 2) there was a tendency to an increased internal porosity, particularly in the sprues. PMID:8521125

Syverud, M; Okabe, T; Herø, H

1995-10-01

416

Effect of Casting Conditions and Composition on Microstructural Gradients in Roll Cast Aluminum Alloys  

SciTech Connect

Twin Roll Casting (TRC) is a process by which thin strip is produced directly from molten metal. This process has many advantages over traditional Direct Chill (DC) casting where metal is cast into large slabs or ingots and subsequently hot and cold rolled into strips. While the DC casting involves large capital investment and energy consumption, TRC produces strip with thickness in the range of 10 mm to 2.5 mm in one operation without hot rolling, with less cost, energy usage and equipment requirements. In TRC AA3105, high solidification and post-solidification cooling rates lead to high manganese supersaturation throughout the as-cast strip and very fine constituent particles near strip surface. After 90% cold rolling, the TRC material shows sluggish recrystallization kinetics and a very coarse grain structure, due to concurrent forming dispersoids and/or fine constituent particles. These particles interfere with the nucleation process by preventing migration of the boundaries associated with potential nuclei, resulting in fewer recrystallization nuclei and slower nucleation rate. In addition, the fine particles can impede grain growth by exerting a pinning pressure on moving boundaries. The current study investigated the microstructure evolution in TRC AA3105 during different thermo-mechanical treatments. A systematic study of the effects of different homogenization treatments on second phase particles was carried out. The heating rate effect on recrystallization was studies using an infrared heating furnace. The effect of second phase particles on recrystallization behavior was summarized and experimental results were presented. It was shown that a desirable, fine recrystallized grain size could be obtained by either of two means- rapid heating rate ot the annealing tempeature, or by a pre-cold work homogenization heat treatment.

Burton R. Patterson

2008-05-02

417

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

Code of Federal Regulations, 2013 CFR

...description of the cast iron basis material subcategory. 466.20 Section 466.20 Protection of Environment ENVIRONMENTAL PROTECTION...SOURCE CATEGORY Cast Iron Basis Material Subcategory § 466.20 Applicability; description of the cast iron...

2013-07-01

418

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

419

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....

2009-01-01

420

Heat-Treat Aging Practice for Shell Mold Cast 356 Aluminum.  

National Technical Information Service (NTIS)

Use of acceptable aging treatments on the basis of processing and chemistry permits attainment of near optimum physical properties for aluminum shell castings. Data developed on aging times for one aluminum casting alloy or one casting process are not alw...

E. Toledo B. Crocker

1965-01-01

421

Causes of Dimensional Distortion in DS, Cored, Turbine Blades Produced by Investment Casting of Superalloys.  

National Technical Information Service (NTIS)

The causes of dimensional distortion resulting from the various stages of the lost wax casting process affecting the outcome of blade castings are detailed. The results indicate the relative distortion at the various stages of the casting. The majority of...

N. Kumar

1988-01-01

422

75 FR 23295 - Iron Construction Castings From Brazil, Canada, and China  

Federal Register 2010, 2011, 2012, 2013

...and 265 (Third Review)] Iron Construction Castings From Brazil, Canada...duty order on ``heavy'' iron construction castings from Brazil, the antidumping...duty order on ``heavy'' iron construction castings from Canada, and...

2010-05-03

423

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 Section 464.10...GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10...

2010-07-01

424

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 Section 464.10...GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10...

2011-07-01

425

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

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the zinc casting subcategory. 464.40 Section 464.40...EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability;...

2009-01-01

426

40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.  

Code of Federal Regulations, 2010 CFR

... Applicability; description of the ferrous casting subcategory. 464.30 Section 464.30...GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Ferrous Casting Subcategory § 464.30 Applicability;...

2010-07-01

427

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

Code of Federal Regulations, 2010 CFR

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

2009-01-01

428

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 464.40...AND STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability;...

2013-07-01

429

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 Section 464.10...STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10 Applicability;...

2013-07-01

430

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 Section 464.10...GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10...

2009-01-01

431

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

432

40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.  

Code of Federal Regulations, 2011 CFR

... Applicability; description of the ferrous casting subcategory. 464.30 Section 464.30...GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Ferrous Casting Subcategory § 464.30 Applicability;...

2011-07-01

433

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

434

40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.  

Code of Federal Regulations, 2010 CFR

... Applicability; description of the ferrous casting subcategory. 464.30 Section 464.30...GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Ferrous Casting Subcategory § 464.30 Applicability;...

2009-01-01

435

40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.  

Code of Federal Regulations, 2013 CFR

... Applicability; description of the ferrous casting subcategory. 464.30 Section 464.30...STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Ferrous Casting Subcategory § 464.30 Applicability;...

2013-07-01

436

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.  

Code of Federal Regulations, 2010 CFR

...Remedial measures: Cast iron and ductile iron pipelines. 192.489 Section...Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization... Each segment of cast iron or ductile iron pipe on which general...

2010-10-01

437

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.  

Code of Federal Regulations, 2010 CFR

...Remedial measures: Cast iron and ductile iron pipelines. 192.489 Section...Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization... Each segment of cast iron or ductile iron pipe on which general...

2009-10-01

438

Nippon Kokan Technical Report No. 36, December 1982: Overseas Continuous Casting Special Issue.  

National Technical Information Service (NTIS)

Contents: The development of slab casters; Study on the solidification phenomena in continuous casting mold; Fundamental research on solidification involved in continuous casting of steel; Production of super clean steel by slab continuous casting process...

1982-01-01

439

Method for imaging inclusions in investment castings  

US Patent & Trademark Office Database

A metal or metal alloy article is cast using an investment casting mold where the mold facecoat, and perhaps one or more of the mold backup layers, comprises an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions. The facecoat preferably comprises an intimate mixture of a refractory material and the imaging agent. Intimate mixtures can be produced in a number of ways, but a currently preferred method is to cocalcine the refractory material, such as yttria, with the imaging agent, such as gadolinia. The facecoat also can comprise plural mold-forming materials and/or plural imaging agents. The difference between the linear attenuation coefficient of the article and the linear attenuation coefficient of the imaging agent should be sufficient to allow imaging of the inclusion throughout the article. The metal or metal alloy article is then analyzed for inclusions by N-ray analysis. The method also can include the step of analyzing the metal or metal alloy by X-ray analysis. The imaging agent, typically a metal oxide or salt, comprises a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, erbium, ytterbium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof.

Sturgis; David Howard (Boring, OR); Barrett; James R. (Milwaukie, OR); Springgate; Mark E. (Portland, OR); Yasrebi; Mehrdad (Clackamas, OR); Nikolas; Douglas G. (Battleground, WA)

2000-08-15

440

Capillarity in metal casting mold filling  

NASA Astrophysics Data System (ADS)

In metal casting processes, surface tension of the molten metal typically resists filling of the metal into the mold. The effects are greater for smaller mold cavities, and ultimately, the smallest cavities may not be filled. Surface tension forces can be overcome by applying pressure (head) to the molten metal, thus forcing metal into the cavities. However, a pressure-window will exist, too little pressure resulting in non-filled cavities and too much pressure resulting in penetration of the mold, which is itself porous. Filling-pressure windows are investigated for cylindrical-shaped mold cavities on both a theoretical and experimental basis. The lower bound of the filling pressure window is examined by treating cylindrical mold cavities as cylinders lined with packed spheres representing mold particles. The upper bound is examined by treating the mold as a 3-D array of close-packed spheres. The experimental work concerns industrial-scale vacuum investment casting of superalloy IN718 into molds containing various cylindrical mold cavities at various heights (heads). The experimental results are found to be in good agreement with the numerical modeling predictions for filling of rough (sphere-lined) cylindrical mold cavities.

Hilden, Jon L.

441

Directional solidification of white cast iron  

NASA Astrophysics Data System (ADS)

Several studies of the ledeburite eutectic (Fe-Fe3C), in pure Fe-C alloys have shown that it has a lamellar morphology under plane front growth conditions. The structure of ledeburite in white cast irons, Fe-C-Si, consists of a rod morphology. It is generally not possible to produce plane front growth of Fe-C-Si eutectic alloys in the Fe-Fe3C form, because at the slow growth rates required for plane front growth, the Fe3C phase is replaced by graphite. By using small additions of Te, the growth of graphite was suppressed, and the plane front growth of the ledeburite eutectic in Fe-C-Si alloys was carried out with Si levels up to 1 wt pct. It was found that the growth morphology became a faceted rod morphology at 1 wt pct Si, but in contrast to the usual rod morphology of white cast irons, the rod phase was Fe3C rather than iron. It was shown that the usual rod morphology only forms at the sides of the two-phase cellular or dendritic growth fronts in Fe-C-Si alloys. Possible reasons for the inability of plane front directional solidification to produce the usual rod morphology in Fe-C-Si alloys are discussed. Also, data are presented on the spacing of the lamellar eutectic in pure Fe-C ledeburite, which indicates that this system does not follow the usual ?2 V = constant relation of regular eutectics.

Park, J. S.; Verhoeven, J. D.

1996-08-01

442

Advanced Lost Foam Casting Technology - Phase V  

SciTech Connect

Previous research, conducted under DOE Contracts DE-FC07-89ID12869, DE-FC07-93ID12230 and DE-FC07-95ID113358 made significant advances in understanding the Lost Foam Casting (LFC) Process and clearly identified areas where additional developments were needed to improve the process and make it more functional in industrial environments. The current project focused on eight tasks listed as follows: Task 1--Computational Model for the Process and Data Base to Support the Model; Task 2--Casting Dimensional Accuracy; Task 3--Pattern Production; Task 4--Improved Pattern Materials; Task 5--Coating Control; Task 6--In-Plant Case Studies; Task 7--Energy and the Environmental Data; and Task 8--Technology Transfer. This report summarizes the work done on all tasks in the period of October 1, 1999 through September 30, 2004. The results obtained in each task and subtask are summarized in this Executive Summary and details are provided in subsequent sections of the report.

Wanliang Sun; Harry E. Littleton; Charles E. Bates

2004-04-29

443

Development of new feeding-distance rules using casting simulation: Part I. Methodology  

Microsoft Academic Search

A methodology is developed to relate measured shrinkage porosity levels in steel castings to predictions from casting simulations,\\u000a in order to determine feeding distances. Low-alloy steel casting trials were conducted to acquire a statistically meaningful\\u000a set of experimental data for top-risered cast steel sections having various ASTM shrinkage X-ray levels. Simulations of the\\u000a casting trials were then performed, using casting

Kent D. Carlson; Richard A. Hardin; Shouzhu Ou; Christoph Beckermann

2002-01-01

444

Haemoglobin Barts in Bengali Hindu Castes Studied in Calcutta  

Microsoft Academic Search

A total of 720 umbilical cord blood samples have been tested by starch gel electrophoretic method for the occur rence of haemoglobin Barts which has actually been detected in eight cord blood samples. The higher castes appear to show a lower rate of incidence of haemoglobin Barts than the other castes.Copyright © 1973 S. Karger AG, Basel

S. R. Das; S. K. Das; C. S. Dawn

1973-01-01

445

Start with Casting: What to Know before Auditions Begin.  

ERIC Educational Resources Information Center

|Outlines steps in casting a play: the group should choose a piece with the group in mind; people should be shown off to their best advantage; and ageism, sexism, or racism should not enter the casting process. Performance reality should be kept in mind. (PA)|

Carlisle, Barbara; Drapeau, Don

1997-01-01

446

Rapid Tooling via Investment Casting and Rapid Prototype Patterns  

SciTech Connect

The objective of this work to develop the materials processing and design technologies required to reduce the die development time for metal mold processes from 12 months to 3 months, using die casting of Al and Mg as the example process. Sandia demonstrated that investment casting, using rapid prototype patterns produced from Stereo lithography or Selective laser Sintering, was a viable alternative/supplement to the current technology of machining form wrought stock. A demonstration die insert (ejector halt) was investment cast and subsequently tested in the die casting environment. The stationary half of the die insert was machined from wrought material to benchmark the cast half. The two inserts were run in a die casting machine for 3,100 shots of aluminum and at the end of the run no visible difference could be detected between the cast and machined inserts. Inspection concluded that the cast insert performed identically to the machined insert. Both inserts had no indications of heat checking or degradation.

Baldwin, Michael D.

1999-06-01

447

Computer Aided Manufacturability Analysis of Die-cast Parts  

Microsoft Academic Search

Automated manufacturability analysis is an important tool with the designer which is meant to incorporate manufacturability aspects at initial stages of design. This paper deals with a system developed for automated manufacturability analysis for die-cast parts. Purpose of this system is to assist designers in their effort to come up with manufacturable die-cast parts economizing in terms of cost and

J. Madan; P. V. M. Rao; T. K. Kundra

2007-01-01

448

Mechanical characterization of cp-Ti produced by investment casting  

Microsoft Academic Search

The influence of hot swaging (SW) and annealing treatment on microstructure and mechanical properties of commercially pure titanium produced by investment casting was evaluated. The as-cast samples showed a typical microstructure consisting of a variety of ?-morphologies, while the hot swaged samples exhibited a kinked lamellar microstructure. Annealing at 500 °C did not significantly change this microstructure while annealing at

Khaled M. IBRAHIM; Mansour MHAEDE; Lothar WAGNER

2011-01-01

449

Casting titanium partial denture frameworks: A radiographic evaluation  

Microsoft Academic Search

Statement of Problem. Titanium is the most biocompatible metal available for dental castings. However, there is some concern about the castability of titanium used on a daily basis. Purpose. A radiographic evaluation of titanium partial denture frameworks was undertaken to ascertain whether these castings were technically acceptable for clinical use. Material and Methods. Three hundred Grade II titanium removable partial

Bert T. Cecconi; Raymond G. Koeppen; Rodney D. Phoenix; Mark L. Cecconi

2002-01-01

450

AERIAL VIEW OF MC WANE CAST IRON PIPE, LOOKING WEST ...  

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

AERIAL VIEW OF MC WANE CAST IRON PIPE, LOOKING WEST TO BIRMINGHAM CITY CENTER. I-20-59 RUNNING DIAGONALLY FROM RIGHT MIDDLE GROUND. L&N RAILROAD TRACKS IN FOREGROUND. - McWane Cast Iron Pipe, 1201 Vanderbilt Road , Birmingham, Jefferson County, AL

451

Castes, Migration, Immunogenetics and Infectious Diseases in South India  

Microsoft Academic Search

It has been said that the grandest genetic experiment of nature has been conducted in south India in the name of the caste system. One can expect the frequency of an infectious disease to be equal to the product of the frequencies of various indicated loci\\/alleles, whether physiological, hormonal or immunological, in an endemic area. The sympatrically isolated caste and

R. M. Pitchappan

2002-01-01

452

The Indian Caste System as a Means of Contract Enforcement  

Microsoft Academic Search

The caste system in India has been dated to approximately 1000 B.C. and still aff ects the lives of a billion people in South Asia. The persistence of this system of social stratification for 3000 years of changing economic and social environments is puzzling. This paper formalizes a model of the caste system to better understand the institution and the

Kripa Freitas

2006-01-01

453

CASTE, CLASS, AND COMMUNITY IN INDIA: AN ETHNOGRAPHIC APPROACH  

Microsoft Academic Search

The anthropology of India has been dominated by an emphasis on caste that has inhibited an integrated approach to understanding cla ss in India. Using a n ethnographic approach that takes into account the symbolic and material aspects of caste and class, this article focuses on the attempts to form a \\

Balmurli Natrajan

454

Independent origins of Indian caste and tribal paternal lineages.  

PubMed

The origins of the nearly one billion people inhabiting the Indian subcontinent and following the customs of the Hindu caste system are controversial: are they largely derived from Indian local populations (i.e. tribal groups) or from recent immigrants to India? Archaeological and linguistic evidence support the latter hypothesis, whereas recent genetic data seem to favor the former hypothesis. Here, we analyze the most extensive dataset of Indian caste and tribal Y chromosomes to date. We find that caste and tribal groups differ significantly in their haplogroup frequency distributions; caste groups are homogeneous for Y chromosome variation and more closely related to each other and to central Asian groups than to Indian tribal or any other Eurasian groups. We conclude that paternal lineages of Indian caste groups are primarily descended from Indo-European speakers who migrated from central Asia approximately 3,500 years ago. Conversely, paternal lineages of tribal groups are predominantly derived from the original Indian gene pool. We also provide evidence for bidirectional male gene flow between caste and tribal groups. In comparison, caste and tribal groups are homogeneous with respect to mitochondrial DNA variation, which may reflect the sociocultural characteristics of the Indian caste society. PMID:14761656

Cordaux, Richard; Aunger, Robert; Bentley, Gillian; Nasidze, Ivane; Sirajuddin, S M; Stoneking, Mark

2004-02-01

455

Gold jewellery casting: Technology design and defects elimination  

Microsoft Academic Search

Investment casting is widely used in the production of gold jewellery. In contrast to the state of other metal casting industry, however, their technological characteristics such as gating, melting and pouring are given little consideration. In this article, the technological characteristics of 18K (carat) gold alloys have been studied and are discussed. Some defects such as shrinkage porosity, gas porosity,

X. J. Zhang; K. K. Tong; R. Chan; M. Tan

1995-01-01

456

Ensuring adequate supply of molten metal to castings  

Microsoft Academic Search

Adequate supply of molten metal to castings must be ensured to prevent the appearance of shrinkage defects (blisters and developed porosity), which result from the formation of enclosed regions where the alloy solidifies with an inadequate supply. Cast alloys are characterized by different propensi? ties for the formation of shrinkage blisters and shrink? age porosity. The balance of these two

E. B. Ten; A. S. Drokin; D. A. Anosov

2010-01-01

457

Numerical study of porosity in titanium dental castings  

Microsoft Academic Search

A commercial software package, MAGMASOFT (MAGMA Giessereitechnologie GmbH, Aachen, Germany), was used to study shrinkage and gas porosity in titanium dental castings. A geometrical model for two simplified tooth crowns connected by a connector bar was created. Both mold filling and solidification of this casting model were numerically simulated. Shrinkage porosity was quantitatively predicted by means of a built-in feeding

M. Wu; P. R. Sahm; M. Augthun; H. Spiekermann

1999-01-01

458

Pore Formation during Decarbonization of Grey Cast Iron.  

National Technical Information Service (NTIS)

In this study, a perlitic grey cast iron containing 3.1% C, 1.5% Si, 0.35% Mn, 0.02% P, and 0.01% S was decarbonized by being held in contact with Armco iron at 1000C. The kinetics of pore formation in the cast iron was then followed by observation of the...

A. A. Baranov V. I. Movcan

1972-01-01

459

Filtration efficiency in casting of a complexly alloyed nickel melt  

NASA Astrophysics Data System (ADS)

The use of a cellular ceramic filter is shown to be effective for casting nickel superalloys in vacuum, including superalloys cast using wastes. As a result of filtration, the volume fraction of nonmetallic inclusions and their sizes and quantity in a metal decrease.

Sidorov, V. V.; Iskhodzhanova, I. V.; Rigin, V. E.; Folomeikin, Yu. I.

2012-12-01

460

Accuracy of casts generated from dual-arch impressions  

Microsoft Academic Search

Statement of problem. Dual-arch trays are often used to make simultaneous impressions of a prepared tooth and the opposing teeth. Many dentists are concerned with the accuracy of the casts generated from this type of impression. Purpose. The purpose of this investigation was to compare the accuracy of stone casts of a prepared tooth generated using 2 types of dual-arch

Larry C. Breeding; Donna L. Dixon

2000-01-01

461

The Perception and Content of Cast Shadows: An Interdisciplinary Review  

Microsoft Academic Search

Recently, psychologists have turned their attention to the study of cast shadows and demonstrated that the human perceptual system values information from shadows very highly in the perception of spatial qualities, sometimes to the detriment of other cues. However with some notable and recent exceptions, computer vision systems treat cast shadows not as signal but as noise. This paper provides

Hannah M. Dee; Paulo E. Santos

2011-01-01

462

An Improved Cast Shadow Detection Method with Edge Refinement  

Microsoft Academic Search

This paper presents an improved shadow discriminating method by dividing the cast shadow region into sub regions. We analyze the difference caused by distinct illumination condition for each sub shadow region, and then propose a classification method. We divide cast shadow into deep umbra shadow, shallow umbra shadow and penumbra shadow through gray-level and color features. For color similarity examination,

Yuqi Wang; Miao Tang; Guangxi Zhu

2006-01-01

463

Finite-element thermal modeling of casting microstructures and defects  

NASA Astrophysics Data System (ADS)

Finite-element thermal modeling offers the capability of simulating casting solidification conditions. By combining thermal modeling and inspection, a defect map can be established to enable prediction of casting microstructures and defects. Gamma-prime size, dendrite-arm spacing, equiaxed grain size, shrink, hot tearing, misrun, and other features can all be predicted.

Yu, K. O.; Nichols, J. J.; Robinson, M.

1992-06-01

464

AUTOMATED MALLEABLE ANNEALING OVENS SLOWLY HEAT AND COOL CASTINGS AS ...  

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

AUTOMATED MALLEABLE ANNEALING OVENS SLOWLY HEAT AND COOL CASTINGS AS THEY MOVE IN BINS ALONG TRACKS IN THE OVEN BOTTOM IN THE MALLEABLE ANNEALING BUILDING. THIS PROCESS TRANSFORMS BRITTLE WHITE IRON CASTINGS INTO SOFTER, STRONGER MALLEABLE IRON. - Stockham Pipe & Fittings Company, Malleable Annealing Building, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

465

Two from One Casting. Art Education: 6681.20.  

ERIC Educational Resources Information Center

Two From One Casting is a studio course dealing with exploratory applications of casting methods and materials for students in grades 7 through 12 who wish to make permanent those creations easily destroyed by time or negligence. Course rationale, enrollment guidelines, objectives, outline of content, descriptions of activities and procedures,…

Hilf, Anne

466

GUIDES TO POLLUTION PREVENTION: METAL CASTING AND HEAT TREATING INDUSTRY  

EPA Science Inventory

This guide provides an overview of the major waste generating process of metal casting and heat treating operations and presents options for reducing this waste through source reduction and recycling. ost waste generated by the metal casting, or foundry, industry is from melting ...

467

The Childhood Autism Spectrum Test (CAST): Sex Differences  

ERIC Educational Resources Information Center

|The Childhood Autism Spectrum Test (CAST) (formally known as the Childhood Asperger Screening Test) identifies autism spectrum conditions by measuring social and communication skills. The present study explored the sex distribution of scores. The CAST was distributed to 11,635 children aged 4-9 years in Cambridgeshire primary schools (UK). 3,370…

Williams, Joanna G.; Allison, Carrie; Scott, Fiona J.; Bolton, Patrick F.; Baron-Cohen, Simon; Matthews, Fiona E.; Brayne, Carol

2008-01-01

468

ICADA: Intelligent computer aided defect analysis for castings  

Microsoft Academic Search

An intelligent computer aided defect analysis (ICADA) system, based on artificial intelligence techniques, has been developed to identify design, process or material parameters which could be responsible for the occurrence of defective castings in a manufacturing campaign. The data on defective castings for a particular time frame, which is an input to the ICADA system, has been analysed. It was

R. S. Ransing; M. N. Srinivasan; R. W. Lewis

1995-01-01

469

Yield improvement and defect reduction in steel casting  

Microsoft Academic Search

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

Kent Carlson

2004-01-01

470

Production of refractory articles for bottom casting of steel  

Microsoft Academic Search

The Krasnyi Oktyabr’ Plant has introduced the production of refractory chamotte articles for bottom casting of steel. The\\u000a quality of S-88 refractory nozzles for ingot molds, MSK-9 heavy center pipes, and S-7kh150 center pipes provides casting of\\u000a structural and corrosion steel in the steel-melting shops of the plant.

V. P. Mazalova; L. I. Kiseleva; Yu. V. Druzhinin; A. D. Leonov; V. V. Portaresko; L. V. Gorlach; A. N. Matveev; V. A. Chernov

1998-01-01

471

A quick esthetic remount cast for all-ceramic restorations.  

PubMed

A technique is presented for the expedited fabrication of a remount cast for the alteration of all-ceramic crowns and fixed partial dentures. The remount cast allows the laboratory technician to know the precise location of the gingival tissues and allows modification of all-ceramic restorations. PMID:20456029

Hansen, Paul A; Gist, Julie

2010-04-29

472

29 CFR 452.131 - Casting of ballots; delegate elections.  

Code of Federal Regulations, 2013 CFR

29 Labor 2 2013-07-01 2013-07-01 false Casting of ballots; delegate elections. 452.131 Section 452...1959 Election Procedures; Rights of Members § 452.131 Casting of ballots; delegate elections. The manner in which...

2013-07-01

473

25 CFR 217.6 - Method of casting votes.  

Code of Federal Regulations, 2013 CFR

...Indians 1 2013-04-01 2013-04-01 false Method of casting votes. 217.6 Section 217.6 Indians BUREAU OF...TRIBE AND THE UTE DISTRIBUTION CORP. § 217.6 Method of casting votes. Within 30 days after an issue and any analysis...

2013-04-01

474

Corrosion resistant gray cast iron graphite flake alloys  

Microsoft Academic Search

Corrosion resistant gray cast iron alloys useful in downhole oil well environments and the like. The alloys are substantially lower in cost and substantially higher in tensile strength than high nickel-copper cast irons commonly used downhole in submergible pumps. The alloys contain substantial amounts of aluminum in combination with nickel, chromium, manganese, molybdenum, carbon, silicon, and iron. Copper, tin, vanadium,

1985-01-01

475

LUNG MODEL CASTING TECHNIQUES FOR INTERSPECIES MORPHOMETRIC COMPARISONS  

EPA Science Inventory

Techniques have been developed for casting both solid and hollow lung models from lung specimens. These techniques have been used to make casts of rat, rabbit, baboon, and human lungs and may be used for other species. An air line at a positive pressure of 25 cm of water is conne...

476

Modification of hypoeutectic low alloy white cast irons  

Microsoft Academic Search

In order to modify the continuous network of eutectic cementite normally found in low alloy white cast irons into a dispersive distribution, strategies of controlling the morphology of eutectic cementite by additives are discussed. Qualitative arguments are presented and applied to the development of a complex modifier REAINTi. With the addition of this modifier to low carbon white cast irons

Ma Qian; Wang Chaochang; Shoji Harada

1996-01-01

477

Comparison of wear resistant MMC and white cast iron  

Microsoft Academic Search

In this report, the microstructures of conventional white cast irons (WCI) and new metal matrix composites (MMC) are compared. In contrast to casting, the hot isostatic pressing (HIP) of powder mixtures offers more freedom to design specific properties like toughness and wear resistance. Both may be enhanced by a proper MMC composition. Experimental results are so convincing that special industrial

Hans Berns

2003-01-01

478

Interphase corrosion of chromium white cast irons in dynamic state  

Microsoft Academic Search

In the present paper, chromium white cast irons were prepared by the unidirectional solidification. The carbide sample was extracted for the corrosion and wear test. The inter-phase corrosion mechanism and the electrochemical behavior of chromium white cast irons in corrosion medium were discussed from the viewpoints of electrochemistry and erosion wear. The inter-phase corrosion rates between carbide and matrix were

A. F. Zhang; J. D. Xing; L. Fang; J. Y. Su

2004-01-01

479

Microstructure and mechanical properties of austempered high silicon cast steel  

Microsoft Academic Search

The influence of austempering treatment on the microstructure and mechanical properties of silicon alloyed cast steel has been studied. The experimental results show that an ausferrite structure consisting of bainitic ferrite and retained austenite can be obtained by austempering the high silicon cast steel in a large temperature range (240–400°C). No carbide would precipitate in the structure. The experimental results

Yanxiang Li; Xiang Chen

2001-01-01

480

De\\/geneticizing Caste: Population Genetic Research in South Asia  

Microsoft Academic Search

Recent years have witnessed a number of population genetics studies aiming to explore the ‘genetic profile’ of the South Asian population and of the caste system. This paper examines four genetic studies and their mass media representations, and discusses interviews with leading historians and social scientists whose work has focused on issues of the caste system. Similar to earlier commentators—from

Yulia Egorova

2009-01-01

481

Filling system for investment cast Ni-base turbine blades  

Microsoft Academic Search

In investment foundries, it is usual to pay relatively little attention to the design of the filling system of a casting. Vacuum-cast turbine blades represent a typical case, where the mould filling process is poorly controlled, the mould cavities themselves often being top-filled. The consequential surface turbulence causes the entrapment of oxide film on the liquid surface, despite the use

D. Z Li; J Campbell; Y. Y Li

2004-01-01

482

Sensitivity analysis and nonlinear programming applied to investment casting design  

Microsoft Academic Search

Finite element solidification heat transfer analysis, explicit design sensitivity analysis, and nonlinear programming are combined to examine investment casting. The theoretical formulation is presented for considering both continuous and discrete optimization. The methods are then applied to improve the design of an axisymmetric superalloy investment casting. A significant reduction in material is achieved by minimizing riser volume, while maintaining directional

S. A. Ebrahimi; D. A. Tortorelli; J. A. Dantzig

1997-01-01

483

A future vision for the investment casting industry  

SciTech Connect

All of American industry is being subjected to increased competitive pressures due to customer needs for shorter cycle times and better quality. The investment casting industry could be in a unique position to satisfy these needs by incorporating several emerging technologies into production processes. The inherent versatility and flexibility of casting make it a truly agile manufacturing process. Because of its compatibility with new rapid prototyping technologies, investment casting could be one of the key vehicles in the new ``art to part`` paradigm. Recently, dramatic advances have been made in the quality of wax and plastic patterns, parts, and tooling by investment casting on time scales unheard of today. Because design and acquisition of tooling contributes heavily to the lead time for any market, these advances will strengthen the position of investment casting manufacturers and customers, and create opportunities in traditional and non-tradition markets. Key to achieving this goal is to use the technology to remove uncertainties from investment casting process. To do this, we must collectively build the infrastructure to enable investment casting companies to make parts right the first time, every time. Integration of mature and on-the-horizon technologies will make this revolution possible and create large growth in markets for investment castings.

Zanner, F.J.; Maguire, M.C.

1993-11-01

484

A new model for caste development in social wasps  

PubMed Central

Specialization into reproductive and non-reproductive castes is one of the defining traits of eusocial insects. Knowledge of the proximal causes of caste differentiation is therefore central to achieving an understanding of the evolution of eusociality. Castes are an example of a polyphenism, multiple, discrete phenotypes arising from a single genotype in response to differing environmental conditions. Here we focus on recent work in the social wasps to provide insight into how environmental conditions may trigger the development of caste across a range from independent- to swarm-founding social species. The amount of food larvae receive has long been recognized as a key input factor in the determination of caste, but that alone is insufficient to account for the range of combinations of size, development time and caste among the female offspring of Polistes, an independent-founding wasp. Recent experimental work on P. fuscatus has shown that vibrations that are associated with the feeding of larvae are another essential environmental input in the determination of caste. we present a model of how vibrational signaling in the context of feeding larvae could interact with nutritional input to account for the developmental patterns seen in these wasps. Mapping the distribution of vibrational signaling onto a phylogeny of the social wasps suggests that this trait characterized the common ancestor of the subfamilies vespinae + Polistinae, diversified in the independent-founding species, then was superseded by caste-determining mechanisms in the swarm-founding and vespine species that function more effectively in larger colonies.

Jeanne, Robert L

2011-01-01

485

A new model for caste development in social wasps.  

PubMed

Specialization into reproductive and non-reproductive castes is one of the defining traits of eusocial insects. Knowledge of the proximal causes of caste differentiation is therefore central to achieving an understanding of the evolution of eusociality. Castes are an example of a polyphenism, multiple, discrete phenotypes arising from a single genotype in response to differing environmental conditions. Here we focus on recent work in the social wasps to provide insight into how environmental conditions may trigger the development of caste across a range from independent- to swarm-founding social species. The amount of food larvae receive has long been recognized as a key input factor in the determination of caste, but that alone is insufficient to account for the range of combinations of size, development time and caste among the female offspring of Polistes, an independent-founding wasp. Recent experimental work on P. fuscatus has shown that vibrations that are associated with the feeding of larvae are another essential environmental input in the determination of caste. we present a model of how vibrational signaling in the context of feeding larvae could interact with nutritional input to account for the developmental patterns seen in these wasps. Mapping the distribution of vibrational signaling onto a phylogeny of the social wasps suggests that this trait characterized the common ancestor of the subfamilies vespinae + Polistinae, diversified in the independent-founding species, then was superseded by caste-determining mechanisms in the swarm-founding and vespine species that function more effectively in larger colonies. PMID:21966550

Jeanne, Robert L; Suryanarayanan, Sainath

2011-07-01

486

Characterization of ductile cast iron by eddy current method  

Microsoft Academic Search

Eddy current method was applied for evaluation of material properties of ductile cast iron. Measurements of eddy current response signals from FCD 450–600 grades of cast iron demonstrated good correlation with their hardness and tensile properties. Alternative ultrasonic method was explored for assessment of hardness of the studied samples and showed its inadequacy for specimens with similar graphite nodularity.

S. Konoplyuk; T. Abe; T. Uchimoto; T. Takagi; M. Kurosawa

2005-01-01

487

Aqueous tape casting of reaction bonded aluminium oxide (RBAO)  

Microsoft Academic Search

Reaction bonding of alumina (RBAO) has been proved to be a successful route to make high-performance alumina. However, the aluminium metal in the starting mixtures prevents using aqueous processing techniques in the initial phase. Here a route is presented for aqueous tape casting of RBAO by hydrophobization of the starting powder and preparing a suitable tape cast suspension. Thermal analysis

M. D. Snel; FMM Snijkers; JJ Luyten; AA Kodentsov

2007-01-01

488

INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE AND BRIDGE CRANE ...  

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

INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE AND BRIDGE CRANE PICKING UP A 48' PIPE FOR WEIGHING AND TRANSFER TO ANNEALING OVEN. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

489

EFFECT OF MELTING TECHNIQUES ON DUCTILE IRON CASTINGS PROPERTIES  

Microsoft Academic Search

The study was designed to investigate the effects of the charge, melting conditions, nodularizing and inocula- tion on the ductile iron castings properties. Results showed that the temperature and holding time of the melt in an induction furnace and the intensity of spheroidizing effect on the carbon and residual magnesium contents in the ductile iron castings. The same grade of

S. BOCKUS; A. DOBROVOLSKIS

2006-01-01

490

A method for signature casting on digital images  

Microsoft Academic Search

Signature (watermark) casting on digital images is an important problem, since it affects many aspects of the information market. We propose a method for casting digital watermarks on images and we analyze its effectiveness. The satisfaction of some basic demands in this area is examined and a method for producing digital watermarks is proposed. Moreover, immunity to subsampling is examined

I. Pitas

1996-01-01

491

The Effects of Microalloying Elements on Cracking During Continuous Casting  

Microsoft Academic Search

SUMMARY To ensure the appropriate quality in finished products, it is important that defects in continuously cast products are minimised. As the use of hot charging and thin slab rolling coupled with direct rolling becomes more common, it is increasingly important to produce defect free continuously cast product, as inspection and repair in these situations becomes more difficult. Of the

D. N. Crowther

492

Preparation of Nonaqueous Mg Green Tapes by Tape Casting  

Microsoft Academic Search

Mg green tapes by tape casting were prepared. The effects of different powder size and shape, solid loading, the content of binder and the binder to plasticizer ratio on non-aqueous Mg slurry for tape casting and green tapes were investigated. The rheological behavior of Mg slurry and microstructure of green tapes obtained in different conditions were analyzed. The results demonstrated

Jun Li; Guoqiang Luo; Qiang Shen; Lianmeng Zhang; Hongxi Zhu; Chengji Deng

2012-01-01

493

91. VIEW NORTHWEST OF SCRAP HOUSE AND CAST HOUSE, BUILDINGS ...  

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

91. VIEW NORTHWEST OF SCRAP HOUSE AND CAST HOUSE, BUILDINGS 101 AND 72; BUILDING 101 IN THE CENTER OF THE PHOTOGRAPH HOUSED SCRAP METAL CLEANING AND PROCESSING FACILITIES; BUILDING 72 AT RIGHT CENTER HOUSED MELTING FURNACES AND CONTINUOUS CASTING MACHINERY - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

494

Nature versus nurture in social insect caste differentiation  

Microsoft Academic Search

Recent evidence for genetic effects on royal and worker caste differentiation from diverse social insect taxa has put an end to the view that these phenotypes stem solely from a developmental switch controlled by environmental factors. Instead, the relative influences of genotypic and environmental effects on caste vary among species, ranging from largely environmentally controlled phenotypes to almost purely genetic

Tanja Schwander; Nathan Lo; Madeleine Beekman; Benjamin P. Oldroyd; Laurent Keller

2010-01-01

495

49 CFR 192.275 - Cast iron pipe.  

Code of Federal Regulations, 2011 CFR

...material as the sealing medium. Each gasket must be suitably confined and retained under compression by a separate gland or follower ring. (c) Cast iron pipe may not be joined by threaded joints. (d) Cast iron pipe may not be joined by...

2011-10-01

496

Tape casting of ferroelectric, dielectric, piezoelectric and ferromagnetic materials  

Microsoft Academic Search

Tape casting is a feasible method for preparing ceramic tapes with different electrical and magnetic properties for multilayer ceramic devices. This paper describes the tape casting process for several different electroceramic materials (BST, PZT, NZF and ZSB) utilising similar organic additive and solvent systems. The properties of tapes with different ceramic compositions before and after sintering are investigated, including surface

Heli Jantunen; Tao Hu; Antti Uusimäki; Seppo Leppävuori

2004-01-01

497

Why do backward castes need their own gurus? The social and political significance of new caste-based monasteries in Karnataka  

Microsoft Academic Search

Jati matha, as people of Karnataka call it, is a monastery that culturally and religiously represents a specific caste or sub-caste group, most of which are non-Brahmin, backward castes. From the Kuruba (shepherd caste, the largest amongst other backward classes) to Dalits (former untouchables) and Adivasis (tribals), the number of such caste-mathas is believed to be more than 100 in

Aya Ikegame

2010-01-01

498

Method and apparatus for planar drag strip casting  

DOEpatents

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification.

Powell, John C. (Pittsburgh, PA); Campbell, Steven L. (Middletown, OH)

1991-01-01

499

Method and apparatus for planar drag strip casting  

DOEpatents

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification. 5 figures.

Powell, J.C.; Campbell, S.L.

1991-11-12

500

Packing of oxide ceramic powders by centrifugal casting  

NASA Astrophysics Data System (ADS)

Topical commercially available powders of silica, zinc oxide, tin oxide, and alumina were centrifugally cast. The purpose of the study was to determine the feasibility of centrifugal casting well-dispersed slips of such ceramic oxide powders to obtain high green densities and to observe the effects that deviations from an ideal monodisperse, spherical powder have on the resulting packing density. The powders were characterized by particle size distributions and microscopy. Viscosity versus pH data were obtained for those powders for which there was a sufficient quantity. The results generally showed a good correlation of centrifugal casting density with the degree of powder dispersion as measured by viscosity. However, the packing densities obtained were not higher than those which can be obtained by conventional slip casting or dry pressing. It can be concluded that centrifugal casting of typical ceramic powders does not offer any advantage over other consolidation processes.

Shaffer, G. W.; Readey, D. W.

1982-09-01