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Sample records for casting

  1. Cast

    PubMed Central

    Ohtsuka, Toshihisa; Takao-Rikitsu, Etsuko; Inoue, Eiji; Inoue, Marie; Takeuchi, Masakazu; Matsubara, Kaho; Deguchi-Tawarada, Maki; Satoh, Keiko; Morimoto, Koji; Nakanishi, Hiroyuki; Takai, Yoshimi

    2002-01-01

    The cytomatrix at the active zone (CAZ) has been implicated in defining the site of Ca2+-dependent exocytosis of neurotransmitter. We have identified here a novel CAZ protein of ∼120 kD from rat brain and named it CAST (CAZ-associated structural protein). CAST had no transmembrane segment, but had four coiled-coil domains and a putative COOH-terminal consensus motif for binding to PDZ domains. CAST was localized at the CAZ of conventional synapses of mouse brain. CAST bound directly RIM1 and indirectly Munc13-1, presumably through RIM1, forming a ternary complex. RIM1 and Munc13-1 are CAZ proteins implicated in Ca2+-dependent exocytosis of neurotansmitters. Bassoon, another CAZ protein, was also associated with this ternary complex. These results suggest that a network of protein–protein interactions among the CAZ proteins exists at the CAZ. At the early stages of synapse formation, CAST was expressed and partly colocalized with bassoon in the axon shaft and the growth cone. The vesicles immunoisolated by antibassoon antibody–coupled beads contained not only bassoon but also CAST and RIM1. These results suggest that these CAZ proteins are at least partly transported on the same vesicles during synapse formation. PMID:12163476

  2. Urinary casts

    MedlinePLUS

    ... Waxy casts; Casts in the urine; Fatty casts; Red blood cell casts; White blood cell casts ... a sign of many types of kidney diseases. Red blood cell casts mean there is a microscopic amount of ...

  3. Casting Technology.

    ERIC Educational Resources Information Center

    Wright, Michael D.; And Others

    1992-01-01

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

  4. Hair casts

    PubMed Central

    Parmar, Sweta S.; Parmar, Kirti S.; Shah, Bela J.

    2014-01-01

    Hair casts or pseudonits are circumferential concretions, which cover the hair shaft in such a way that, it could be easily removed. They are thin, cylindrical, and elongated in length. We present an unusual case of an 8-year-old girl presenting with hair casts. Occurrence of these is unusual, and they may have varied associations. This patient was suffering from developmental delay. It is commonly misdiagnosed as and very important to differentiate from pediculosis capitis. PMID:25396168

  5. CASTING FURNACES

    DOEpatents

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

    1961-01-01

    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.

  6. Paper Casting.

    ERIC Educational Resources Information Center

    Arrasjid, Dorine A.

    1980-01-01

    Describes an art project, based on the work of artist Chew Teng Beng, in the molding of wet paper on a plaster cast to create embossed paper designs. The values of such a project are outlined, including a note that its tactile approach makes it suitable to visually handicapped students. (SJL)

  7. Project CAST.

    ERIC Educational Resources Information Center

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

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

  8. Casting methods

    DOEpatents

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

    2012-12-18

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

  9. CASTING APPARATUS

    DOEpatents

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

    1958-09-23

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

  10. Casting materials

    DOEpatents

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

    2011-06-14

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

  11. Steel castings by the electroslag casting technique

    NASA Astrophysics Data System (ADS)

    Sikka, V. K.; Mitchell, A.

    1984-10-01

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

  12. Steel castings by the electroslag casting technique

    SciTech Connect

    Sikka, V.K.; Mitchell, A.

    1984-10-01

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

  13. Thin Wall Iron Castings

    SciTech Connect

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

    2001-10-31

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

  14. 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

  15. Cool Cast Facts

    MedlinePLUS

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

  16. LLNL casting technology

    NASA Astrophysics Data System (ADS)

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

    1994-01-01

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

  17. LLNL casting technology

    SciTech Connect

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

    1994-01-01

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

  18. Evaluation of electroslag castings

    SciTech Connect

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

    1985-01-01

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

  19. Advances in aluminum casting technology

    SciTech Connect

    Tiryakioglu, M.; Campbell, J.

    1998-01-01

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

  20. Improving Metal Casting Process

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Don Sirois, an Auburn University research associate, and Bruce Strom, a mechanical engineering Co-Op Student, are evaluating the dimensional characteristics of an aluminum automobile engine casting. More accurate metal casting processes may reduce the weight of some cast metal products used in automobiles, such as engines. Research in low gravity has taken an important first step toward making metal products used in homes, automobiles, and aircraft less expensive, safer, and more durable. Auburn University and industry are partnering with NASA to develop one of the first accurate computer model predictions of molten metals and molding materials used in a manufacturing process called casting. Ford Motor Company's casting plant in Cleveland, Ohio is using NASA-sponsored computer modeling information to improve the casting process of automobile and light-truck engine blocks.

  1. SLIP CASTING METHOD

    DOEpatents

    Allison, A.G.

    1959-09-01

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

  2. Evolution of halictine castes

    NASA Astrophysics Data System (ADS)

    Knerer, Gerd

    1980-03-01

    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.

  3. Casting Footprints for Eternity

    NASA Technical Reports Server (NTRS)

    1999-01-01

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

  4. Casting in sport.

    PubMed

    Decarlo, M; Malone, K; Darmelio, J; Rettig, A

    1994-03-01

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

  5. Clean Metal Casting

    SciTech Connect

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

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

  6. CENTRIFUGAL CASTING MACHINE

    DOEpatents

    Shuck, A.B.

    1958-04-01

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

  7. CASTING METHOD AND APPARATUS

    DOEpatents

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

    1958-10-01

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

  8. Adhesion Casting In Low Gravity

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Cronise, Raymond J.

    1996-01-01

    Adhesion casting in low gravity proposed as technique for making new and improved materials. Advantages of low-gravity adhesion casting, in comparison with adhesion casting in normal Earth gravity, comes from better control over, and greater uniformity of, thicknesses of liquid films that form on and adhere to solid surfaces during casting.

  9. Casting Characteristics of Aluminum Die Casting Alloys

    SciTech Connect

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

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

  10. Method of casting aerogels

    DOEpatents

    Poco, J.F.

    1993-09-07

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

  11. Method of casting aerogels

    DOEpatents

    Poco, John F.

    1993-01-01

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

  12. MOLDS FOR CASTING PLUTONIUM

    DOEpatents

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

    1962-02-27

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

  13. A Winning Cast

    NASA Technical Reports Server (NTRS)

    2001-01-01

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

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

    DOEpatents

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

    2002-01-01

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

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

    SciTech Connect

    Sikka, V.K.; Mitchell, A.

    1984-01-01

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

  16. Method for casting polyethylene pipe

    NASA Technical Reports Server (NTRS)

    Elam, R. M., Jr.

    1973-01-01

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

  17. Sealing micropores in thin castings

    NASA Technical Reports Server (NTRS)

    Mersereau, G. A.; Nitzschke, G. O.; Ochs, H. L.; Sutch, F. S.

    1981-01-01

    Microscopic pores in thin-walled aluminum castings are sealed by impregnation pretreatment. Technique was developed for investment castings used in hermetically sealed chassic for electronic circuitry. Excessively high leakage rates were previously measured in some chassis.

  18. Mix/Cast Contamination Control

    NASA Technical Reports Server (NTRS)

    Wallentine, M.

    2005-01-01

    Presented is a training handbook for Mix/Cast Contamination Control; a part of a series of training courses to qualify access to Mix/Cast facilities. Contents: List Contamination Control Requirements; Identify foreign objects debris (FOD), Control Areas and their guidelines; Describe environmental monitoring; List Contamination Control Initiatives; Describe concern for Controlled Materials; Identify FOD Controlled Areas in Mix/Cast.

  19. Casting and Angling.

    ERIC Educational Resources Information Center

    Smith, Julian W.

    As part of a series of books and pamphlets on outdoor education, this manual consists of easy-to-follow instructions for fishing activities dealing with casting and angling. The manual may be used as a part of the regular physical education program in schools and colleges or as a club activity for the accomplished weekend fisherman or the…

  20. Extrusion cast explosive

    DOEpatents

    Scribner, Kenneth J.

    1985-01-01

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants.

  1. Computer cast blast modelling

    SciTech Connect

    Chung, S.; McGill, M.; Preece, D.S.

    1994-07-01

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

  2. AMCC casting development, volume 2

    NASA Technical Reports Server (NTRS)

    1995-01-01

    PCC successfully cast and performed nondestructive testing, FPI and x-ray, on seventeen AMCC castings. Destructive testing, lab analysis and chemical milling, was performed on eleven of the castings and the remaining six castings were shipped to NASA or Aerojet. Two of the six castings shipped, lots 015 and 016, were fully processed per blueprint requirements. PCC has fully developed the gating and processing parameters of this part and feels the part could be implemented into production, after four more castings have been completed to ensure the repeatability of the process. The AMCC casting has been a technically challenging part due to its size, configuration, and alloy type. The height and weight of the wax pattern assembly necessitated the development of a hollow gating system to ensure structural integrity of the shell throughout the investment process. The complexity in the jacket area of the casting required the development of an innovative casting technology that PCC has termed 'TGC' or thermal gradient control. This method of setting up thermal gradients in the casting during solidification represents a significant process improvement for PCC and has been successfully implemented on other programs. The alloy, JBK75, is a relatively new alloy in the investment casting arena and required our engineering staff to learn the gating, processing, and dimensional characteristics of the material.

  3. Melting and casting of FeAl-based cast alloy

    SciTech Connect

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

    1998-11-01

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

  4. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-01-29

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  5. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-11-26

    Disclosed is an improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  6. Modeling of alloy casting solidification

    NASA Astrophysics Data System (ADS)

    Guo, Jianzheng; Samonds, Mark

    2011-07-01

    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.

  7. High density tape casting system

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr. (Inventor)

    1989-01-01

    A system is provided for casting thin sheets (or tapes) of particles bound together, that are used for oxygen membranes and other applications, which enables the particles to be cast at a high packing density in a tape of uniform thickness. A slurry contains the particles, a binder, and a solvent, and is cast against the inside walls of a rotating chamber. Prior to spraying the slurry against the chamber walls, a solvent is applied to a container. The solvent evaporates to saturate the chamber with solvent vapor. Only then is the slurry cast. As a result, the slurry remains fluid long enough to spread evenly over the casting surface formed by the chamber, and for the slurry particles to become densely packed. Only then is the chamber vented to remove solvent, so the slurry can dry. The major novel feature is applying solvent vapor to a rotating chamber before casting slurry against the chamber walls.

  8. Cast dielectric composite linear accelerator

    DOEpatents

    Sanders, David M.; Sampayan, Stephen; Slenes, Kirk; Stoller, H. M.

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  9. Fiber-Reinforced Slip Castings

    NASA Technical Reports Server (NTRS)

    Blome, J. C.; Drennan, D. N.; Keeser, H. M.

    1982-01-01

    Addition of silica fibers greatly reduces shrinkage and cracking during casting of ceramics. Fiber-reinforced slip-cast silica ceramics are also tougher and have lower dielectric loss. Silica fibers are hyperpure material containing only 1 part per million total metal-ion impurities. Hyperpure fibers ensure high reflectance and allow casting to be fired at temperature greater than 2,200 degrees F without loss of strength from devitrification.

  10. Casting Equipment. Casting and Angling Skills Series. Instructor Manual.

    ERIC Educational Resources Information Center

    Staton, Robert D., Jr.

    Part of a series of self-contained instructional units designed by the Missouri Department of Conservation to teach Missourians how to use outdoor resources wisely and skillfully, the instructor manual, the first in the casting and angling series, is intended both as a reference book on casting equipment and as an introduction to the sport.…

  11. Biomaterials by freeze casting.

    PubMed

    Wegst, Ulrike G K; Schecter, Matthew; Donius, Amalie E; Hunger, Philipp M

    2010-04-28

    The functional requirements for synthetic tissue substitutes appear deceptively simple: they should provide a porous matrix with interconnecting porosity and surface properties that promote rapid tissue ingrowth; at the same time, they should possess sufficient stiffness, strength and toughness to prevent crushing under physiological loads until full integration and healing are reached. Despite extensive efforts and first encouraging results, current biomaterials for tissue regeneration tend to suffer common limitations: insufficient tissue-material interaction and an inherent lack of strength and toughness associated with porosity. The challenge persists to synthesize materials that mimic both structure and mechanical performance of the natural tissue and permit strong tissue-implant interfaces to be formed. In the case of bone substitute materials, for example, the goal is to engineer high-performance composites with effective properties that, similar to natural mineralized tissue, exceed by orders of magnitude the properties of its constituents. It is still difficult with current technology to emulate in synthetic biomaterials multi-level hierarchical composite structures that are thought to be the origin of the observed mechanical property amplification in biological materials. Freeze casting permits to manufacture such complex, hybrid materials through excellent control of structural and mechanical properties. As a processing technique for the manufacture of biomaterials, freeze casting therefore has great promise. PMID:20308117

  12. Lost-Soap Aluminum Casting.

    ERIC Educational Resources Information Center

    Mihalow, Paula

    1980-01-01

    Lost-wax casting in sterling silver is a costly experience for the average high school student. However, this jewelry process can be learned at no cost if scrap aluminum is used instead of silver, and soap bars are used instead of wax. This lost-soap aluminum casting process is described. (Author/KC)

  13. Electroslag component casting. [Nickel aluminide

    SciTech Connect

    Sikka, V.K.

    1986-01-01

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

  14. Cast and splint immobilization: complications.

    PubMed

    Halanski, Matthew; Noonan, Kenneth J

    2008-01-01

    During the past three decades, internal fixation has become increasingly popular for fracture management and limb reconstruction. As a result, during their training, orthopaedic surgeons receive less formal instruction in the art of extremity immobilization and cast application and removal. Casting is not without risks and complications (eg, stiffness, pressure sores, compartment syndrome); the risk of morbidity is higher when casts are applied by less experienced practitioners. Certain materials and methods of ideal cast and splint application are recommended to prevent morbidity in the patient who is at high risk for complications with casting and splinting. Those at high risk include the obtunded or comatose multitrauma patient, the patient under anesthesia, the very young patient, the developmentally delayed patient, and the patient with spasticity. PMID:18180390

  15. Ohno continuous casting

    SciTech Connect

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

    1995-04-01

    Production of net-shape products directly from the liquid is an attractive manufacturing route for alloys that are difficult to process or that cannot be rolled, drawn, or extruded. Developed at the Chiba Institute of Technology in Japan, the Ohno Continuous Casting (OCC) approach not only provides significant cost savings, but also has the potential to create new products. OCC process equipment includes a melting furnace, crucible, mold level-control block, cooling device, and pinch rolls. OCC is currently used to produce copper rods and wires for audio and video cables, and aluminum alloy welding rods for hard-surfacing applications. For example, Mitsui Engineering and Ship Building Co. has used OCC to produce copper tubing products with internal fins and partitions for applications such as heat exchanger tubes and induction coils.

  16. Sixty Years of Casting Research

    NASA Astrophysics Data System (ADS)

    Campbell, John

    2015-11-01

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

  17. Strip casting with fluxing agent applied to casting roll

    DOEpatents

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

    1997-07-29

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

  18. Strip casting with fluxing agent applied to casting roll

    DOEpatents

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

    1997-01-01

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

  19. Biomimetic Materials by Freeze Casting

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  20. Strip casting apparatus and method

    DOEpatents

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

    1988-09-20

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

  1. Strip casting apparatus and method

    DOEpatents

    Williams, Robert S.; Baker, Donald F.

    1988-01-01

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

  2. Slip-Cast Superconductive Parts

    NASA Technical Reports Server (NTRS)

    Wise, Stephanie A.; Buckley, John D.; Vasquez, Peter; Buck, Gregory M.; Hicks, Lana P.; Hooker, Matthew W.; Taylor, Theodore D.

    1993-01-01

    Complex shapes fabricated without machining. Nonaqueous slip-casting technique used to form complexly shaped parts from high-temperature superconductive materials like YBa(2)Cu(3)O(7-delta). Such parts useful in motors, vibration dampers, and bearings. In process, organic solvent used as liquid medium. Ceramic molds made by lost-wax process used instead of plaster-of-paris molds, used in aqueous slip-casting but impervious to organic solvents and cannot drain away liquid medium. Organic-solvent-based castings do not stick to ceramic molds as they do to plaster molds.

  3. Investment casting design of experiment. Final report

    SciTech Connect

    Owens, R.

    1997-10-01

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

  4. Casting Using A Polystyrene Pattern

    NASA Technical Reports Server (NTRS)

    Vasquez, Peter; Guenther, Bengamin; Vranas, Thomas; Veneris, Peter; Joyner, Michael

    1993-01-01

    New technique for making metal aircraft models saves significant amount of time and effort in comparison with conventional lost-wax method. Produces inexpensive, effective wind-tunnel models. Metal wind-tunnel model cast by use of polystyrene pattern.

  5. Titan Casts Revealing Shadow

    NASA Astrophysics Data System (ADS)

    2004-05-01

    A rare celestial event was captured by NASA's Chandra X-ray Observatory as Titan -- Saturn's largest moon and the only moon in the Solar System with a thick atmosphere -- crossed in front of the X-ray bright Crab Nebula. The X-ray shadow cast by Titan allowed astronomers to make the first X-ray measurement of the extent of its atmosphere. On January 5, 2003, Titan transited the Crab Nebula, the remnant of a supernova explosion that was observed to occur in the year 1054. Although Saturn and Titan pass within a few degrees of the Crab Nebula every 30 years, they rarely pass directly in front of it. "This may have been the first transit of the Crab Nebula by Titan since the birth of the Crab Nebula," said Koji Mori of Pennsylvania State University in University Park, and lead author on an Astrophysical Journal paper describing these results. "The next similar conjunction will take place in the year 2267, so this was truly a once in a lifetime event." Animation of Titan's Shadow on Crab Nebula Animation of Titan's Shadow on Crab Nebula Chandra's observation revealed that the diameter of the X-ray shadow cast by Titan was larger than the diameter of its solid surface. The difference in diameters gives a measurement of about 550 miles (880 kilometers) for the height of the X-ray absorbing region of Titan's atmosphere. The extent of the upper atmosphere is consistent with, or slightly (10-15%) larger, than that implied by Voyager I observations made at radio, infrared, and ultraviolet wavelengths in 1980. "Saturn was about 5% closer to the Sun in 2003, so increased solar heating of Titan may account for some of this atmospheric expansion," said Hiroshi Tsunemi of Osaka University in Japan, one of the coauthors on the paper. The X-ray brightness and extent of the Crab Nebula made it possible to study the tiny X-ray shadow cast by Titan during its transit. By using Chandra to precisely track Titan's position, astronomers were able to measure a shadow one arcsecond in diameter, which corresponds to the size of a dime as viewed from about two and a half miles. Illustration of Crab, Titan's Shadow and Chandra Illustration of Crab, Titan's Shadow and Chandra Unlike almost all of Chandra's images which are made by focusing X-ray emission from cosmic sources, Titan's X-ray shadow image was produced in a manner similar to a medical X-ray. That is, an X-ray source (the Crab Nebula) is used to make a shadow image (Titan and its atmosphere) that is recorded on film (Chandra's ACIS detector). Titan's atmosphere, which is about 95% nitrogen and 5% methane, has a pressure near the surface that is one and a half times the Earth's sea level pressure. Voyager I spacecraft measured the structure of Titan's atmosphere at heights below about 300 miles (500 kilometers), and above 600 miles (1000 kilometers). Until the Chandra observations, however, no measurements existed at heights in the range between 300 and 600 miles. Understanding the extent of Titan's atmosphere is important for the planners of the Cassini-Huygens mission. The Cassini-Huygens spacecraft will reach Saturn in July of this year to begin a four-year tour of Saturn, its rings and its moons. The tour will include close flybys of Titan that will take Cassini as close as 600 miles, and the launching of the Huygens probe that will land on Titan's surface. Chandra's X-ray Shadow of Titan Chandra's X-ray Shadow of Titan "If Titan's atmosphere has really expanded, the trajectory may have to be changed." said Tsunemi. The paper on these results has been accepted and is expected to appear in a June 2004 issue of The Astrophysical Journal. Other members of the research team were Haroyoski Katayama (Osaka University), David Burrows and Gordon Garmine (Penn State University), and Albert Metzger (JPL). Chandra observed Titan from 9:04 to 18:46 UT on January 5, 2003, using its Advanced CCD Imaging Spectrometer instrument. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

  6. Fillability of Thin-Wall Steel Castings

    SciTech Connect

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

    2002-07-30

    The use of steel components is being challenged by lighter nonferrous or cast iron components. The development of techniques for enhancing and ensuring the filability of thin-wall mold cavities is most critical for thinner wall cast steel production. The purpose of this research was to develop thin-wall casting techniques that can be used to reliably produce thin-wall castings from traditional gravity poured sand casting processes. The focus of the research was to enhance the filling behavior to prevent misrunds. Experiments were conducted to investigate the influence of various foundry variables on the filling of thin section steel castings. These variables include casting design, heat transfer, gating design, and metal fluidity. Wall thickness and pouring temperature have the greatest effect on casting fill. As wall thickness increases the volume to surface area of the casting increases, which increases the solidification time, allowing the metal to flow further in thicker sect ions. Pouring time is another significant variable affecting casting fill. Increases or decreases of 20% in the pouring time were found to have a significant effect on the filling of thin-wall production castings. Gating variables, including venting, pouring head height, and mold tilting also significantly affected thin-wall casting fill. Filters offer less turbulent, steadier flow, which is appropriate for thicker castings, but they do not enhance thin-wall casting fill.

  7. Cast adrift: Gortex cast liners allow greater patient activity.

    PubMed

    Dubowitz, Gerald; Miller, Deborah M

    2003-01-01

    Extremity fractures are a common injury, with nearly 1.5 million cases reported in the United States in 1998. Treatment often involves lengthy periods of immobilization. This report outlines the use of a Gortex cast liner by a subject who was able to engage in swimming and scuba diving during the healing process. We report that a Gortex cast liner may be considered for an active patient who is keen to return to limited activities during fracture healing. Apparently because of a lack of knowledge of their existence, physicians currently are underutilizing this method of casting in active patients. The use of Gortex liners elsewhere has been reported to have higher patient and physician satisfaction in both use and performance, with no reported detrimental effects on outcome. PMID:14518627

  8. Instant Casting Movie Theater: The Future Cast System

    NASA Astrophysics Data System (ADS)

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

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

  9. Magnesium-lithium casting alloys

    NASA Technical Reports Server (NTRS)

    Latenko, V. P.; Silchenko, T. V.; Tikhonov, V. A.; Maltsev, V. P.; Korablin, V. P.

    1974-01-01

    The strength properties of magnesium-lithium alloys at room, low, and high temperatures are investigated. It is found that the alloys may have practical application at ambient temperatures up to 100 C, that negative temperatures have a favorable influence on the alloy strength, and that cyclic temperature variations have practically no effect on the strength characteristics. The influence of chemical coatings on corrosion resistance of the MgLi alloys is examined. Several facilities based on pressure casting machines, low-pressure casting machines, and magnetodynamic pumps were designed for producing MgLi alloy castings. Results were obtained for MgLi alloys reinforced with fibers having a volumetric content of 15%.

  10. Energy Consumption of Die Casting Operations

    SciTech Connect

    Jerald Brevick; clark Mount-Campbell; Carroll Mobley

    2004-03-15

    Molten metal processing is inherently energy intensive and roughly 25% of the cost of die-cast products can be traced to some form of energy consumption [1]. The obvious major energy requirements are for melting and holding molten alloy in preparation for casting. The proper selection and maintenance of melting and holding equipment are clearly important factors in minimizing energy consumption in die-casting operations [2]. In addition to energy consumption, furnace selection also influences metal loss due to oxidation, metal quality, and maintenance requirements. Other important factors influencing energy consumption in a die-casting facility include geographic location, alloy(s) cast, starting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting machine, related equipment (robots, trim presses), and downstream processing (machining, plating, assembly, etc.). Each of these factors also may influence the casting quality and productivity of a die-casting enterprise. In a die-casting enterprise, decisions regarding these issues are made frequently and are based on a large number of factors. Therefore, it is not surprising that energy consumption can vary significantly from one die-casting enterprise to the next, and within a single enterprise as function of time.

  11. Casting propellant in rocket engine

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  12. 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

  13. 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

  14. 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

  15. 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

  16. INTERIOR VIEW WITH CASTING MACHINE AND A 4' DUCTILE IRON ...

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

    INTERIOR VIEW WITH CASTING MACHINE AND A 4' DUCTILE IRON PIPE BEING CENTRIFUGALLY CAST, AS OPERATOR WATCHES TO ENSURE QUALITY. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

  17. Properties of electroslag castings: Part 1

    SciTech Connect

    Sikka, V.K.

    1984-11-01

    This part of several reports to be published on the properties of electroslag castings of 2 1/4 Cr-1 Mo, 9 Cr-1 Mo, and type 316 stainless steel describes the properties of three electroslag-cast valve bodies of type 316 stainless steel. These castings were electroslag cast at the University of British Columbia in Canada from ORNL-supplied electrodes. The castings have been characterized for surface finish, cracking, solidification structure, chemical analysis, hardness, ferrite distribution, tensile properties, Charpy impact properties, and creep properties. Tensile data on these castings were compared with the American Society of Mechanical Engineers (ASME) code minimum values for sand castings. The creep data were compared with the data on sand castings and the ASME code minimum curve for wrought material. 29 figures, 7 tables.

  18. Prediction of Microporosity in Shrouded Impeller Castings

    SciTech Connect

    Viswanathan, S. Nelson, C.D.

    1998-09-01

    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.

  19. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... 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...

  20. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... 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...

  1. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... 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...

  2. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in... an acceptable statistical analysis supports reduction, non-destructive inspection may be reduced...

  3. Graphite Formation in Cast Iron

    NASA Technical Reports Server (NTRS)

    Stefanescu, D. M.

    1985-01-01

    In the first phase of the project it was proven that by changing the ratio between the thermal gradient and the growth rate for commercial cast iron samples solidifying in a Bridgman type furnace, it is possible to produce all types of graphite structures, from flake to spheroidal, and all types of matrices, from ferritic to white at a certain given level of cerium. KC-135 flight experiments have shown that in a low-gravity environment, no flotation occurs even in spheroidal graphite cast irons with carbon equivalent as high as 5%, while extensive graphite flotation occurred in both flake and spheroidal graphite cast irons, in high carbon samples solidified in a high gravity environment. This opens the way for production of iron-carbon composite materials, with high carbon content (e.g., 10%) in a low gravity environment. By using KC-135 flights, the influence of some basic elements on the solidification of cast iron will be studied. The mechanism of flake to spheroidal graphite transition will be studied, by using quenching experiments at both low and one gravity for different G/R ratios.

  4. Molding A Cast Metals Program

    ERIC Educational Resources Information Center

    Trumble, Dale E.

    1975-01-01

    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)

  5. Tape casting of magnesium oxide.

    SciTech Connect

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

    2008-02-01

    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.

  6. 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,...

  7. Casting Freedom, 1860-1862

    ERIC Educational Resources Information Center

    Social Education, 2005

    2005-01-01

    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…

  8. Overview of ToxCast

    EPA Science Inventory

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

  9. Advanced Lost Foam Casting Technology

    SciTech Connect

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

    2000-11-30

    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

  10. The CAST time projection chamber

    NASA Astrophysics Data System (ADS)

    Autiero, D.; Beltrán, B.; Carmona, J. M.; Cebrián, S.; Chesi, E.; Davenport, M.; Delattre, M.; Di Lella, L.; Formenti, F.; Irastorza, I. G.; Gómez, H.; Hasinoff, M.; Lakic, B.; Luzón, G.; Morales, J.; Musa, L.; Ortiz, A.; Placci, A.; Rodrigurez, A.; Ruz, J.; Villar, J. A.; Zioutas, K.

    2007-06-01

    One of the three x-ray detectors of the CERN Axion Solar Telescope (CAST) experiment searching for solar axions is a time projection chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity x-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is set to a safe level during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62%. Shielding has been installed around the detector, lowering the background level to 4.10 × 10-5 counts cm-2 s-1 keV-1 between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion photon coupling and mass.

  11. Math: Objectives Guide. Project CAST.

    ERIC Educational Resources Information Center

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

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

  12. Diabetic Neuropathy: What is a Total Contact Cast?

    MedlinePLUS

    ... Web version Diabetic Neuropathy | What is a Total Contact Cast? What is a total contact cast? A total contact cast is a cast used to treat ulcers ( ... foot--that's why it is called a total contact cast. The cast helps to protect the skin ...

  13. Land-based turbine casting initiative

    SciTech Connect

    Mueller, B.A.; Spicer, R.A.

    1995-12-31

    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.

  14. Prediction of Part Distortion in Die Casting

    SciTech Connect

    R. Allen Miller

    2005-03-30

    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.

  15. Process development of thin strip steel casting

    SciTech Connect

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

    1990-12-01

    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.

  16. Emulsion based cast booster - a priming system

    SciTech Connect

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

    2005-07-01

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

  17. MHD technology in aluminum casting

    SciTech Connect

    Kalinichenko, I.

    1984-08-01

    The use of MHD technology in aluminum casting is discussed. Associates of the Latvian Academy of Sciences Institute of Physics developed magnetohydrodynamic units for the Siberian plant. A MHD unit made it possible to free five persons from heavy work at the plant. Labor productivity doubled in this section. With the aid of the magnetic field, the alloy silumin is obtained in only three hours. Specialists of the Irkutsk affiliate of the All-Union Scientific Research and Design Institute of the Aluminum, Magnesium and Electrode Industry are convinced that MHD technology has a bright future. However, this will necessitate the development of new MHD technology for different types of casting facilities, with their specific features taken into account.

  18. High performance, extrusion cast explosive

    SciTech Connect

    Scribner, K.J.

    1984-02-01

    The Lawrence Livermore National Laboratory has been developing a new high energy explosive system for use in precision, high performance munitions. It is a system because the composition and the manufacturing techniques are both unique. The explosive has an energy/density greater than 78% Octol. It is similar to modern type cast/cure explosives except that we can work with higher apparent viscosities since we use low pressure hydraulic systems for deaeration and casting of the explosive. We load any desired device configuration. The crystalline HMX has a nominal 60 ..mu.. particle size which contributes to an extremely smooth detonation front. This explosive is suitable for use in the most critical applications such as shaped charges and self forging fragment systems.

  19. Search for chameleons with CAST

    NASA Astrophysics Data System (ADS)

    Anastassopoulos, V.; Arik, M.; Aune, S.; Barth, K.; Belov, A.; Bruninger, H.; Cantatore, G.; Carmona, J. M.; Cetin, S. A.; Christensen, F.; Collar, J. I.; Dafni, T.; Davenport, M.; Desch, K.; Dermenev, A.; Eleftheriadis, C.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galn, J.; Garca, J. A.; Gardikiotis, A.; Garza, J. G.; Gazis, E. N.; Geralis, T.; Giomataris, I.; Hailey, C.; Haug, F.; Hasinoff, M. D.; Hoffmann, D. H. H.; Iguaz, F. J.; Irastorza, I. G.; Jacoby, J.; Jakobsen, A.; Jakov?i?, K.; Kaminski, J.; Karuza, M.; Kavuk, M.; Kr?mar, M.; Krieger, C.; Krger, A.; Laki?, B.; Laurent, J. M.; Liolios, A.; Ljubi?i?, A.; Luzn, G.; Neff, S.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M. J.; Raffelt, G.; Riege, H.; Rosu, M.; Ruz, J.; Savvidis, I.; Solanki, S. K.; Vafeiadis, T.; Villar, J. A.; Vogel, J. K.; Yildiz, S. C.; Zioutas, K.; Brax, P.; Lavrentyev, I.; Upadhye, A.

    2015-10-01

    In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter (?m) and to photons (??) via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1 keV to 400 eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600 eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of ?? ?1011 for 1

  20. Pressure rig for repetitive casting

    NASA Technical Reports Server (NTRS)

    Vasquez, Peter (Inventor); Hutto, William R. (Inventor); Philips, Albert R. (Inventor)

    1989-01-01

    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.

  1. Properties of electroslag castings. Part 2

    SciTech Connect

    Sikka, V.K.

    1985-08-01

    The quality, response to heat treatment, and mechanical properties of electroslag-cast step blocks from Cameron Iron Works and from Selectrotech, Inc., are described. The mechanical properties include Charpy impact, tensile, and creep. Properties of the electroslag castings were compared to determine the differences between casters, between wrought and electroslag cast properties, and between sand and electroslag castings. Results are presented to show that the electroslag casting process has a potential for producing properties similar to those of wrought material for 2 1/4 Cr-1 Mo and 9 Cr-1 Mo steel and similar to those of sand-cast material for type 316 stainless steel. 5 refs., 46 figs., 4 tabs.

  2. Gating of Permanent Molds for ALuminum Casting

    SciTech Connect

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

    2004-03-30

    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.

  3. Clean Cast Steel Technology, Phase IV

    SciTech Connect

    Charles E. Bates

    2003-02-24

    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.

  4. Method for casting thin metal objects

    SciTech Connect

    Pehrson, Brandon P; Moore, Alan F

    2015-04-14

    Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

  5. Directional Solidification of Nodular Cast Iron

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Stefanescu, D. M.; Hendrix, J. C.

    1987-01-01

    Cerium enhances formation of graphite nodules. Preliminary experiments in directional solidification of cast iron shows quantitative correlation of graphite microstructure with growth rate and thermal gradient, with sufficient spheroidizing element to form spheroidal graphite under proper thermal conditions. Experimental approach enables use of directional solidification to study solidification of spheriodal-graphite cast iron in low gravity. Possible to form new structural materials from nodular cast iron.

  6. A Benchmark Study on Casting Residual Stress

    SciTech Connect

    Johnson, Eric M.; Watkins, Thomas R; Schmidlin, Joshua E; Dutler, S. A.

    2012-01-01

    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.

  7. Microstructured metal molds fabricated via investment casting

    NASA Astrophysics Data System (ADS)

    Cannon, Andrew H.; King, William P.

    2010-02-01

    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.

  8. High-Density-Tape Casting System

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr.

    1987-01-01

    Centrifuge packs solids from slurry into uniform, dense layer. New system produces tapes of nearly theoretical packing density. Centrifugal system used to cast thin tapes for capacitors, fuel cells, and filters. Cylindrical rotary casting chamber mounted on high-speed bearings and connected to motor. Liquid for vapor-pressure control and casting slurry introduced from syringes through rotary seal. During drying step, liquid and vapor vented through feed tubes or other openings. Laminated tapes produced by adding more syringes to cast additional layers of different materials.

  9. Spray casting project final report

    SciTech Connect

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

    1996-08-01

    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.

  10. 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...

  11. Yield Improvement in Steel Casting (Yield II)

    SciTech Connect

    Richard A. Hardin; Christoph Beckermann; Tim Hays

    2002-02-18

    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

  12. Clean cast steel technology. Final report

    SciTech Connect

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

    1998-06-01

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

  13. Energy use in selected metal casting facilities - 2003

    SciTech Connect

    Eppich, Robert E.

    2004-05-01

    This report represents an energy benchmark for various metal casting processes. It describes process flows and energy use by fuel type and processes for selected casting operations. It also provides recommendations for improving energy efficiency in casting.

  14. Casting fine grained, fully dense, strong inorganic materials

    SciTech Connect

    Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.

    2015-11-24

    Methods and apparatuses for casting inorganic materials are provided. The inorganic materials include metals, metal alloys, metal hydrides and other materials. Thermal control zones may be established to control the propagation of a freeze front through the casting. Agitation from a mechanical blade or ultrasonic energy may be used to reduce porosity and shrinkage in the casting. After solidification of the casting, the casting apparatus may be used to anneal the cast part.

  15. The CAST (Childhood Asperger Syndrome Test)

    ERIC Educational Resources Information Center

    Williams, Jo; Scott, Fiona; Stott, Carol; Allison, Carrie; Bolton, Patrick; Baron-Cohen, Simon; Brayne, Carol

    2005-01-01

    The Childhood Asperger Syndrome Test (CAST) is a parental questionnaire to screen for autism spectrum conditions. In this validation study, the CAST was distributed to 1925 children aged 5-11 in mainstream Cambridgeshire schools. A sample of participants received a full diagnostic assessment, conducted blind to screen status. The sensitivity of…

  16. When Your Child Needs a Cast

    MedlinePLUS

    ... Your Child All About Food Allergies When Your Child Needs a Cast KidsHealth > For Parents > When Your Child Needs a Cast Print A A A Text ... is healed. Depending on the age of the child and type of break or healing needed, a ...

  17. Materials: unidirectional solidification of cast iron.

    PubMed

    Luyendijk, T; Nieswaag, H; Alsem, W H

    1984-07-13

    The segregation of sulfur in liquid cast iron was studied under conditions of microgravity on Spacelab 1. A rod of cast iron containing carbon, silicon, sulfur, and phosphorus was unidirectionally solidified at four different rates. The influence of sulfur on the graphite structure and the stability of an aluminum oxide skin deposited on the surface of the specimen were investigated. PMID:17837942

  18. Processing of IN-718 Lattice Block Castings

    NASA Technical Reports Server (NTRS)

    Hebsur, Mohan G.

    2002-01-01

    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 with only a fraction of density of the alloy. NASA Glenn Research Center has initiated research to investigate lattice block castings of high temperature Ni-base superalloys such as the model system Inconel-718 (IN-718) for lightweight nozzle applications. Although difficulties were encountered throughout the manufacturing process , a successful investment casting procedure was eventually developed. Wax formulation and pattern assembly, shell mold processing, and counter gravity casting techniques were developed. Ten IN-718 lattice block castings (each measuring 15-cm wide by 30-cm long by 1.2-cm thick) have been successfully produced by Hitchiner Gas Turbine Division, Milford, New Hampshire, using their patented counter gravity casting techniques. Details of the processing and resulting microstructures are discussed in this paper. Post casting processing and evaluation of system specific mechanical properties of these specimens are in progress.

  19. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... meet approved specifications. Paragraphs (c) and (d) of this section apply to any structural castings... structural loads. (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  20. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... meet approved specifications. Paragraphs (c) and (d) of this section apply to any structural castings... structural loads. (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  1. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... meet approved specifications. Paragraphs (c) and (d) of this section apply to any structural castings... structural loads. (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  2. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... meet approved specifications. Paragraphs (c) and (d) of this section apply to any structural castings... structural loads. (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  3. Slip casting and nitridation of silicon powder

    NASA Technical Reports Server (NTRS)

    Seiko, Y.

    1985-01-01

    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.

  4. 21 CFR 880.6185 - Cast cover.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  5. Iron/Phosphorus Alloys for Continuous Casting

    NASA Technical Reports Server (NTRS)

    Dufresne, E. R.

    1986-01-01

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

  6. Casting Shadows in the Science Classroom.

    ERIC Educational Resources Information Center

    Nolan, Kathleen

    2003-01-01

    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,…

  7. PRODUCTION OF SLIP CAST CALCIA HOLLOWWARE

    DOEpatents

    Stoddard, S.D.; Nuckolls, D.E.; Cowan, R.E.

    1963-12-31

    A method for producing slip cast calcia hollow ware in which a dense calcia grain is suspended in isobutyl acetate or a mixture of tertiary amyl alcohol and o-xylene is presented. A minor amount of triethanolamine and oleic acid is added to the suspension vehicle as viscosity adjusting agents and the suspension is cast in a plaster mold, dried, and fired. (AEC)

  8. Possible segregation caused by centrifugal titanium casting.

    PubMed

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

    1996-12-01

    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

  9. The production of large structural titanium castings

    NASA Astrophysics Data System (ADS)

    Klepeisz, J.; Veeck, S.

    1997-11-01

    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.

  10. Final report on Expendable Pattern Casting Technology

    SciTech Connect

    Not Available

    1990-07-01

    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.

  11. The role of water in slip casting

    NASA Technical Reports Server (NTRS)

    Mccauley, R. A.; Phelps, G. W.

    1984-01-01

    Slips and casting are considered in terms of physical and colloidal chemistry. Casting slips are polydisperse suspensions of lyophobic particles in water, whose degree of coagulation is controlled by interaction of flocculating and deflocculating agents. Slip casting rate and viscosity are functions of temperature. Slip rheology and response to deflocculating agents varies significantly as the kinds and amounts of colloid modifiers change. Water is considered as a raw material. Various concepts of water/clay interactions and structures are discussed. Casting is a de-watering operation in which water moves from slip to cast to mold in response to a potential energy termed moisture stress. Drying is an evaporative process from a free water surface.

  12. Subcritical Measurments Multiple HEU Metal Castings

    SciTech Connect

    Mihalczo, John T; Archer, Daniel E; Wright, Michael C; Mullens, James Allen

    2008-01-01

    Experiments with the standard annular highly enriched uranium (HEU) metal castings at the Y-12 National Security Complex were performed in which up to five castings ({approx}90 kg) were assembled in a tightly packed array with minimal spacing between castings. The fission chain multiplication process was initiated by a time-tagged {sup 252}Cf spontaneously fissioning neutron source or by time and directionally tagged neutrons from a small portable DT neutron generator. The prompt neutron time behavior was measured with plastic scintillation detectors sensitive to the fast neutron (>1 MeV) and gamma ray without distinction. These experiments were performed to provide data to benchmark methods for the calculation of the prompt neutron time behavior. Previous measurements with a single casting have been reported. This paper presents the experimental results for multiple castings.

  13. 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

  14. Bioinspired Design: Magnetic Freeze Casting

    NASA Astrophysics Data System (ADS)

    Porter, Michael Martin

    Nature is the ultimate experimental scientist, having billions of years of evolution to design, test, and adapt a variety of multifunctional systems for a plethora of diverse applications. Next-generation materials that draw inspiration from the structure-property-function relationships of natural biological materials have led to many high-performance structural materials with hybrid, hierarchical architectures that fit form to function. In this dissertation, a novel materials processing method, magnetic freeze casting, is introduced to develop porous scaffolds and hybrid composites with micro-architectures that emulate bone, abalone nacre, and other hard biological materials. This method uses ice as a template to form ceramic-based materials with continuously, interconnected microstructures and magnetic fields to control the alignment of these structures in multiple directions. The resulting materials have anisotropic properties with enhanced mechanical performance that have potential applications as bone implants or lightweight structural composites, among others.

  15. Effect of Some Parameters on the Cast Component Properties in Hot Chamber Die Casting

    NASA Astrophysics Data System (ADS)

    Singh, Rupinder; Singh, Harvir

    2016-04-01

    Hot chamber die casting process is designed to achieve high dimensional accuracy for small products by forcing molten metal under high pressure into reusable moulds, called dies. The present research work is aimed at study of some parameters (as a case study of spring adjuster) on cast component properties in hot chamber die casting process. Three controllable factors of the hot chamber die casting process (namely: pressure at second phase, metal pouring temperature and die opening time) were studied at three levels each by Taguchi's parametric approach and single-response optimization was conducted to identify the main factors controlling surface hardness, dimensional accuracy and weight of the casting. Castings were produced using aluminium alloy, at recommended parameters through hot chamber die casting process. Analysis shows that in hot chamber die casting process the percentage contribution of second phase pressure, die opening time, metal pouring temperature for surface hardness is 82.48, 9.24 and 6.78 % respectively. While in the case of weight of cast component the contribution of second phase pressure is 94.03 %, followed by metal pouring temperature and die opening time (4.58 and 0.35 % respectively). Further for dimensional accuracy contribution of die opening time is 76.97 %, metal pouring temperature is 20.05 % and second phase pressure is 1.56 %. Confirmation experiments were conducted at an optimal condition showed that the surface hardness, dimensional accuracy and weight of the castings were improved significantly.

  16. Effect of Some Parameters on the Cast Component Properties in Hot Chamber Die Casting

    NASA Astrophysics Data System (ADS)

    Singh, Rupinder; Singh, Harvir

    2015-11-01

    Hot chamber die casting process is designed to achieve high dimensional accuracy for small products by forcing molten metal under high pressure into reusable moulds, called dies. The present research work is aimed at study of some parameters (as a case study of spring adjuster) on cast component properties in hot chamber die casting process. Three controllable factors of the hot chamber die casting process (namely: pressure at second phase, metal pouring temperature and die opening time) were studied at three levels each by Taguchi's parametric approach and single-response optimization was conducted to identify the main factors controlling surface hardness, dimensional accuracy and weight of the casting. Castings were produced using aluminium alloy, at recommended parameters through hot chamber die casting process. Analysis shows that in hot chamber die casting process the percentage contribution of second phase pressure, die opening time, metal pouring temperature for surface hardness is 82.48, 9.24 and 6.78 % respectively. While in the case of weight of cast component the contribution of second phase pressure is 94.03 %, followed by metal pouring temperature and die opening time (4.58 and 0.35 % respectively). Further for dimensional accuracy contribution of die opening time is 76.97 %, metal pouring temperature is 20.05 % and second phase pressure is 1.56 %. Confirmation experiments were conducted at an optimal condition showed that the surface hardness, dimensional accuracy and weight of the castings were improved significantly.

  17. NWIS MEASUREMENTS FOR URANIUM METAL ANNULAR CASTINGS

    SciTech Connect

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

    1998-03-13

    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.

  18. Characterization of Technetium Speciation in Cast Stone

    SciTech Connect

    Um, Wooyong; Jung, Hun Bok; Wang, Guohui; Westsik, Joseph H.; Peterson, Reid A.

    2013-11-11

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Production and Long-Term Performance of Low Temperature Waste Forms” to provide additional information on technetium (Tc) speciation characterization in the Cast Stone waste form. To support the use of Cast Stone as an alternative to vitrification for solidifying low-activity waste (LAW) and as the current baseline waste form for secondary waste streams at the Hanford Site, additional understanding of Tc speciation in Cast Stone is needed to predict the long-term Tc leachability from Cast Stone and to meet the regulatory disposal-facility performance requirements for the Integrated Disposal Facility (IDF). Characterizations of the Tc speciation within the Cast Stone after leaching under various conditions provide insights into how the Tc is retained and released. The data generated by the laboratory tests described in this report provide both empirical and more scientific information to increase our understanding of Tc speciation in Cast Stone and its release mechanism under relevant leaching processes for the purpose of filling data gaps and to support the long-term risk and performance assessments of Cast Stone in the IDF at the Hanford Site.

  19. AMCC casting development. Volume 1: Executive Summary

    NASA Technical Reports Server (NTRS)

    1995-01-01

    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).

  20. Ponseti casting: a new soft option.

    PubMed

    Brewster, M B S; Gupta, M; Pattison, G T R; Dunn-van der Ploeg, I D

    2008-11-01

    We have modified the Ponseti casting technique by using a below-knee Softcast instead of an above-knee plaster of Paris cast. Treatment was initiated as soon as possible after birth and the Pirani score was recorded at each visit. Following the manipulation techniques of Ponseti, a below-knee Softcast was applied directly over a stockinette for a snug fit and particular attention was paid to creating a deep groove above the heel to prevent slippage. If necessary, a percutaneous Achilles tenotomy was performed and casting continued until the child was fitted with Denis Browne abduction boots. Between April 2003 and May 2007 we treated 51 consecutive babies with 80 idiopathic club feet with a mean age at presentation of 4.5 weeks (4 days to 62 weeks). The initial mean Pirani score was 5.5 (3 to 6). It took a mean of 8.5 weeks (4 to 53) of weekly manipulation and casting to reach the stage of percutaneous Achilles tenotomy. A total of 20 feet (25%) did not require a tenotomy and for the 60 that did, the mean Pirani score at time of operation was 2.5 (0.5 to 3). Denis Browne boots were applied at a mean of 10 weeks (4 to 56) after presentation. The mean time from tenotomy to boots was 3.3 weeks (2 to 10). We experienced one case of cast-slippage during a period of non-attendance, which prolonged the casting process. One case of prolonged casting required repeated tenotomy, and three feet required repeated tenotomy and casting after relapsing while in Denis Browne boots. We believe the use of a below-knee Softcast in conjunction with Ponseti manipulation techniques shows promising initial results which are comparable to those using above-knee plaster of Paris casts. PMID:18978275

  1. Methods for Casting Subterranean Ant Nests

    PubMed Central

    Tschinkel, Walter R.

    2010-01-01

    The study of subterranean ant nests has been impeded by the difficulty of rendering their structures in visible form. Here, several different casting materials are shown to make perfect casts of the underground nests of ants. Each material (dental plaster, paraffin wax, aluminum, zinc) has advantages and limitations, which are discussed. Some of the materials allow the recovery of the ants entombed in the casts, allowing a census of the ants to be connected with features of their nest architecture. The necessary equipment and procedures are described in the hope that more researchers will study this very important aspect of ant natural history. PMID:20673073

  2. Fractal analysis of complex microstructure in castings

    SciTech Connect

    Lu, S.Z.; Lipp, D.C.; Hellawell, A.

    1995-12-31

    Complex microstructures in castings are usually characterized descriptively which often raises ambiguity and makes it difficult to relate the microstructure to the growth kinetics or mechanical properties in processing modeling. Combining the principle of fractal geometry and computer image processing techniques, it is feasible to characterize the complex microstructures numerically by the parameters of fractal dimension, D, and shape factor, a, without ambiguity. Procedures of fractal measurement and analysis are described, and a test case of its application to cast irons is provided. The results show that the irregular cast structures may all be characterized numerically by fractal analysis.

  3. Improved Slip Casting Of Ceramic Models

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M.; Vasquez, Peter; Hicks, Lana P.

    1994-01-01

    Improved technique of investment slip casting developed for making precise ceramic wind-tunnel models. Needed in wind-tunnel experiments to verify predictions of aerothermodynamical computer codes. Ceramic materials used because of their low heat conductivities and ability to survive high temperatures. Present improved slip-casting technique enables casting of highly detailed models from aqueous or nonaqueous solutions. Wet shell molds peeled off models to ensure precise and undamaged details. Used at NASA Langley Research Center to form superconducting ceramic components from nonaqueous slip solutions. Technique has many more applications when ceramic materials developed further for such high-strength/ temperature components as engine parts.

  4. Subcritical Measurements Multiple HEU Metal Castings

    SciTech Connect

    Mihalczo, John T; Archer, Daniel E; Wright, Michael C

    2008-01-01

    Experiments with the standard annular highly enriched uranium (HEU) metal castings at Y-12 were performed in which up to 5 castings ({approx}90kg) were assembled in a tightly packed array with minimal spacing between castings. The fission chain multiplication process was initiated by a time tagged {sup 253}Cf spontaneously fissioning neutron source or time and directionally tagged neutrons from a small portable DT neutron generator and the prompt neutron time behavior measured with plastic scintillation detectors sensitive the fast neutron (>1 MeV) and gamma ray without distinction. These experiments were performed to provide data to benchmark methods for the calculation of the prompt neutron time behavior. Previous measurements with a single casting have been reported. This paper presents the experimental results for multiple castings. The prompt time decay was obtained by time coincidence correlation measurements between the detectors and the time tagged neutron source emission (equivalent to randomly pulsed neutron measurements) and between pairs of plastic scintillation detectors (equivalent to a 2-detector Rossi-alpha measurement). These standard HEU storage castings at the Y-12 plant had 5.000-in-OD, 3.500-in-ID, masses between 17,636 and 17,996 g, impurity content of 992 ppm, density of 18.75 g/cm{sup 3} and average enrichment of 93.16 wt % {sup 235}U. The castings were in tight fitting 025-in.-thick, 8.0-in-high stainless steel (SS-304) cylindrical cans for contamination control which were 8.0 in high. One can had an inside diameter of 3.0 in so that the Cf source could be located on the axes of this casting. Four 1 x 1 x 6 in plastic scintillators with the long dimension perpendicular to axes of the castings and adjacent to the outer surface of the casting cans were used. The detectors were enclosed in 1/4.-in.-thick lead shields on four 1 x 6 surfaces and on the 1 x 1 surface. The small surface of the lead shield was adjacent to the steel table. The photograph of the assembly of 5 casting with the detectors is given in Figure 1. The DT generator can be seen in the back with the time tagged neutrons aligned symmetrically around a line drawn from the generator through target spot and the center of the casting in the annular can seen in the foreground.

  5. The effect of casting temperature on the fatigue properties of cast nickel aluminide alloys

    SciTech Connect

    Gieseke, B.; Sikka, V.K.

    1991-01-01

    The results of high cycle fatigue tests at 650{degree}C on several cast Ni{sub 3}Al alloys are reported and compared to cast IN-713C. These alloys include IC-221M and several variations to the IC-221M composition. The effect of casting temperature is investigated using castings poured at three different temperatures spanning a 56{degree}C range. The results show that IC-221M cast at the highest temperature has the best fatigue strength, exceeding that for IN-713C. In these alloys, crack initiation occurs at shrinkage microporosity and the effect of casting temperature on porosity is related to the observed differences in fatigue lives. 11 refs., 4 figs.

  6. 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

  7. Basic Casting from A to Z. Student's Instruction Booklet.

    ERIC Educational Resources Information Center

    Zebco, Tulsa, OK.

    A profusely illustrated student instruction booklet contains step-by-step directions and diagrams for learning four basic casting techniques. Separate sections cover basic spin-casting, spinning, bait-casting, and fly-casting. Each section details recommended equipment (reel, rod, line, plug, tackle, lures, leaders, flies), describes specific

  8. Basic Casting from A to Z. Student's Instruction Booklet.

    ERIC Educational Resources Information Center

    Zebco, Tulsa, OK.

    A profusely illustrated student instruction booklet contains step-by-step directions and diagrams for learning four basic casting techniques. Separate sections cover basic spin-casting, spinning, bait-casting, and fly-casting. Each section details recommended equipment (reel, rod, line, plug, tackle, lures, leaders, flies), describes specific…

  9. Thermal transport properties of grey cast irons

    SciTech Connect

    Hecht, R.L.; Dinwiddie, R.B.; Porter, W.D.; Wang, Hsin

    1996-10-01

    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.

  10. Vacuum casting of thick polymeric films

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Moacanin, J.

    1979-01-01

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

  11. Advanced lost foam from casting technology

    SciTech Connect

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

    1996-05-01

    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.

  12. Beryllium-aluminum alloys for investment castings

    SciTech Connect

    Nachtrab, W.T.; Levoy, N.

    1997-05-01

    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.

  13. Slip casting alumina with Na-CMC

    SciTech Connect

    Ruys, A.J.; Sorrell, C.C.

    1996-11-01

    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.

  14. Open Cast Mining: An Environmental Issue.

    ERIC Educational Resources Information Center

    McPartland, Michael

    1993-01-01

    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)

  15. Roll Casting of Aluminum Alloy Clad Strip

    SciTech Connect

    Nakamura, R.; Tsuge, H.; Haga, T.; Watari, H.; Kumai, S.

    2011-01-17

    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.

  16. WinMod: An expert advisor for investment casting

    SciTech Connect

    Bivens, H.P.; Williamson, G.A. Jr.; Luger, G.F.; Erdmann, R.G.; Maguire, M.C.; Baldwin, M.D.; Anderson, D.J.

    1998-04-01

    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.

  17. Computed Tomography For Internal Inspection Of Castings

    NASA Technical Reports Server (NTRS)

    Hanna, Timothy L.

    1995-01-01

    Computed tomography used to detect internal flaws in metal castings before machining and otherwise processing them into finished parts. Saves time and money otherwise wasted on machining and other processing of castings eventually rejected because of internal defects. Knowledge of internal defects gained by use of computed tomography also provides guidance for changes in foundry techniques, procedures, and equipment to minimize defects and reduce costs.

  18. Generalized hair casts due to traction.

    PubMed

    Ozuguz, Pinar; Kacar, Seval; Takci, Zennure; Ekiz, Ozlem; Kalkan, Goknur; Bulbul Sen, Bilge

    2013-01-01

    Peripilar keratin casts, also called pseudonits or hair casts, are thin, elongated, greyish-white, cylindrical, sleeve-like structures that encircle the hair shaft and can easily be slid along the hair. They may be clinically misdiagnosed as nits. In addition to physical removal, keratolytic lotions or shampoos are helpful. We report an 11-year-old girl with pseudonits. Although it is not a rare condition, underdiagnosis is common. PMID:23909653

  19. Embedding Optical Fibers In Cast Metal Parts

    NASA Technical Reports Server (NTRS)

    Gibler, William N.; Atkins, Robert A.; Lee, Chung E.; Taylor, Henry F.

    1995-01-01

    Use of metal strain reliefs eliminates breakage of fibers during casting process. Technique for embedding fused silica optical fibers in cast metal parts devised. Optical fiber embedded in flange, fitting, or wall of vacuum or pressure chamber, to provide hermetically sealed feedthrough for optical transmission of measurement or control signals. Another example, optical-fiber temperature sensor embedded in metal structural component to measure strain or temperature inside component.

  20. Combination Of Investment And Centrifugal Casting

    NASA Technical Reports Server (NTRS)

    Creeger, Gordon A.

    1994-01-01

    Modifications, including incorporation of centrifugal casting, made in investment-casting process reducing scrap rate. Used to make first- and second-stage high-pressure-fuel-turbopump nozzles, containing vanes with thin trailing edges and other thin sections. Investment mold spun for short time while being filled, and stopped before solidification occurs. Centrifugal force drives molten metal into thin trailing edges, ensuring they are filled. With improved filling, preheat and pour temperatures reduced and solidification hastened so less hot tearing.

  1. High integrity castings; Proceedings of the Conference on Advances in High Integrity Castings, Chicago, IL, Sept. 24-30, 1988

    SciTech Connect

    White, C.V.; Eylon, D.; Froes, F.H.

    1988-01-01

    Papers are presented on titanium, aluminum, magnesium, and ferrous-metal castings. Particular attention is given to the titanium castings for Space Shuttle attachment fittings, the die filling and solidification of Al-Si alloys in high-pressure die casting, the 1988 investment casting industry, the crucible induction melting of magnesium alloys, and flow control technology for bottom pouring ferrous alloys.

  2. Apollo 14 composite casting demonstration

    NASA Technical Reports Server (NTRS)

    1971-01-01

    This program assisted in the design and implementation of the composite casting demonstration for the Apollo 14 mission. Both flight and control samples were evaluated. Some conclusions resulting from a comparison of the flight and control samples were: (1) Solidification in neither the flight nor control samples was truly directional. (2) Apparent intermittent contact of the melt with the container in the flight samples led to unusual nucleation and growth structures. (3) There was greater uniformity, on a macro scale, of both pores and structural features in the flight sample; presumably the result of the reduced gravity conditions. (4) It seems quite feasible to produce enhanced dispersions of gases and dense phases in a melt which is solidified in reduced gravity. (5) A two-stage heating/cooling cycle may help directional solidification. (6) Sample materials should be selected from materials in which the dispersant fully wets the matrix material. (7) Experiments should be conducted in two modes: (1) where the melt is in good thermal contact with the container, and (2) where the melt is in a free-float condition.

  3. Low Background Micromegas in CAST

    NASA Astrophysics Data System (ADS)

    Garza, J. G.; Aune, S.; Aznar, F.; Calvet, D.; Castel, J. F.; Christensen, F. E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J. A.; Giomataris, I.; Hill, R. M.; Iguaz, F. J.; Irastorza, I. G.; Jakobsen, A. C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M. J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J. K.

    2015-11-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10-6 counts/keV/cm2/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10-7 counts/keV/cm2/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as the strategies to further reduce the background level. Finally, we will describe the R&D paths to achieve sub-keV energy thresholds, which could broaden the physics case of axion helioscopes.

  4. Characterization of modified 9 Cr-1 Mo steel sand castings

    SciTech Connect

    Sikka, V.K.

    1985-04-01

    Experience with the sand casting of modified 9 Cr-1 Mo steel at several foundries is presented. The castings included simple blocks, elbows, valve bodies, and a steam chest. Castings were characterized by tensile and Charpy impact tests, for the effects of thermal aging on Charpy impact properties and hardness, and by creep, fatigue, and microstructure. Properties of the castings were compared with those observed for wrought material. In general, mechanical properties of castings were slightly lower than those of the wrought material.

  5. Reinforcement of Aluminum Castings with Dissimilar Metals

    SciTech Connect

    Han, Q

    2004-01-07

    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.

  6. The effect of upper limb casting on gait pattern.

    PubMed

    Dreyfuss, Daniel; Elbaz, Avi; Mor, Amit; Segal, Ganit; Calif, Edward

    2016-06-01

    Casting of the arm may interfere with normal walking patterns because of additional load of the cast or prevention of arm swing. This study aimed to determine the effect of applying various casts on temporospatial walking parameters, including gait velocity and cadence, step length, and single limb support. A computerized gait system was used to assess these variables for 23 healthy individuals in four walking modes: normal walking, with a cast above the elbow and a sling, and with a cast below the elbow, with and without a sling. Thirteen participants had their dominant hand casted and 10 had their nondominant hand casted. On average, casted participants took significantly smaller steps with the leg on the casted side and spent less time supported on the casted side. The least changes were noted with the arm in a cast below the elbow and no sling, and the greatest changes were noted with the arm in a cast above the elbow and in a sling. This difference was heightened when the dominant hand was casted and lessened when the nondominant hand was casted. No differences were found in walking velocity or cadence between the walking modes. Casting of the upper limb has significant effects on gait, which should be taken into consideration, especially in individuals with previous gait abnormalities. PMID:26855024

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

    SciTech Connect

    Stoddard, Nathan G

    2014-01-14

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

  8. Main results of the PISC III capability studies on cast-to-cast austenitic steel welds

    SciTech Connect

    Lemaitre, P.; Koble, T.D.; Doctor, S.R.

    1995-12-01

    In 1986 the Committee for the Safety of Nuclear Installations (CSNI) discussed the list of actions of the third phase of the Programme for the Inspection of Steel Components (PISC III). Within the framework of Action 4 of the PISC III a capability study on cast-to-cast stainless steel welds has been conducted. This study used 3 cast-to-cast stainless steel assemblies that contained a number of flaws such as mechanical fatigue cracks, lack of fusion flaws and notches of the PISC type A. Also a number of unintended flaws were present. The diameter of these assemblies varied between 838 mm and 937 mm and the wall thickness was about 68 mm. Besides a statically cast stainless steel with a rather small grain size two different types of centrifugally cast stainless steel were considered. Eleven teams from 7 different countries participated in the round robin test. A lot of information was obtained on the performance of the teams with respect to detection, false calls, depth and length sizing. Different flaw categories were considered to identify those difficult to detect. In this paper the main conclusions from the capability study on cast-to-cast austenitic steel welds will be discussed.

  9. Casting And Solidification Technology (CAST): Directional solidification phenomena in a metal model at reduced gravity

    NASA Technical Reports Server (NTRS)

    Mccay, M. H.

    1988-01-01

    The Casting and Solidification Technology (CAST) experiment will study the phenomena that occur during directional solidification of an alloy, e.g., constitutional supercooling, freckling, and dendrite coarsening. The reduced gravity environment of space will permit the individual phenomena to be examined with minimum complication from buoyancy driven flows.

  10. Methods and apparatuses for manufacturing monocrystalline cast silicon and monocrystalline cast silicon bodies for photovoltaics

    DOEpatents

    Stoddard, Nathan G.

    2011-11-01

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

  11. National Metal Casting Research Institute final report. Volume 2, Die casting research

    SciTech Connect

    Jensen, D.

    1994-06-01

    Four subprojects were completed: development and evaluation of die coatings, accelerated die life characterization of die materials, evaluation of fluid flow and solidification modeling programs, selection and characterization of Al-based die casting alloys, and influence of die materials and coatings on die casting quality.

  12. Precision Casting via Advanced Simulation and Manufacturing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A two-year program was conducted to develop and commercially implement selected casting manufacturing technologies to enable significant reductions in the costs of castings, increase the complexity and dimensional accuracy of castings, and reduce the development times for delivery of high quality castings. The industry-led R&D project was cost shared with NASA's Aerospace Industry Technology Program (AITP). The Rocketdyne Division of Boeing North American, Inc. served as the team lead with participation from Lockheed Martin, Ford Motor Company, Howmet Corporation, PCC Airfoils, General Electric, UES, Inc., University of Alabama, Auburn University, Robinson, Inc., Aracor, and NASA-LeRC. The technical effort was organized into four distinct tasks. The accomplishments reported herein. Task 1.0 developed advanced simulation technology for core molding. Ford headed up this task. On this program, a specialized core machine was designed and built. Task 2.0 focused on intelligent process control for precision core molding. Howmet led this effort. The primary focus of these experimental efforts was to characterize the process parameters that have a strong impact on dimensional control issues of injection molded cores during their fabrication. Task 3.0 developed and applied rapid prototyping to produce near net shape castings. Rocketdyne was responsible for this task. CAD files were generated using reverse engineering, rapid prototype patterns were fabricated using SLS and SLA, and castings produced and evaluated. Task 4.0 was aimed at developing technology transfer. Rocketdyne coordinated this task. Casting related technology, explored and evaluated in the first three tasks of this program, was implemented into manufacturing processes.

  13. Advanced Pattern Material for Investment Casting Applications

    SciTech Connect

    F. Douglas Neece Neil Chaudhry

    2006-02-08

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

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

    SciTech Connect

    Sabau, Adrian S

    2005-09-01

    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.

  15. Microstructure of thin-wall ductile iron castings

    SciTech Connect

    Dogan, Omer N.; Schrems, Karol K.; Hawk, Jeffrey A.; Druschitz, A.P.

    2001-10-01

    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.

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

    PubMed Central

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

    2011-01-01

    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. PMID:21496977

  17. Robust digital watermarking using random casting method

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

    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.

  18. [Reproduction of interocclusal relationship on stone casts].

    PubMed

    Arai, Y

    2000-12-01

    We fabricate a prosthesis by the indirect method. To fabricate a prosthesis functionally harmonized with the stomatognathic system, the interocclusal relationship must be reproduced on stone casts as accurately as possible. In this study, two subjects (one male, age 28; one female, age 31) were selected, and the occlusal contacts of complete arch stone casts made by three different impression methods were observed and compared with the true occlusal contacts in the intercuspal position in the mouth. To take the interocclusal records, we used a silicone bite checker. The following results were obtained. The occlusal contact points reproduced on the stone casts made by a conventional custom tray and a stock tray were rather low; that is, the number of occlusal contact points was less, and the size of the occlusal contact area was smaller, than in vivo. The states of the occlusal contact on the casts made by the same method differed from each other. On the bite-impression technique, the reproduction of occlusal contact was superior to that of the others. The shape, area, and number of contact regions under 60 micrometers were similar to contact regions under 30 micrometers in the mouth. There was no significant difference in reproduction between the custom tray and the stock tray. It is likely that the results were due to the distortion of the jaws and periodontal tissue during clenching at the intercuspal position, which could not be reproduced on the stone casts made by both the conventional custom and stock trays. PMID:11201196

  19. INDIAN CASTE SYSTEM: HISTORICAL AND PSYCHOANALYTIC VIEWS.

    PubMed

    Vallabhaneni, Madhusudana Rao

    2015-12-01

    This paper elucidates the historical origins and transformations of India's caste system. Surveying the complex developments over many centuries, it points out that three positions have been taken in this regard. One suggests that the caste one is born into can be transcended within one's lifetime by performing good deeds. The other declares caste to be immutable forever. And, the third says that one can be reborn into a higher caste if one lives a virtuous life. Moving on to the sociopolitical realm, the paper notes how these positions have been used and exploited. The paper then attempts to anchor the existence and purpose of the Hindu caste system in Freud's ideas about group psychology and Klein's proposals of splitting and projective identification. The paper also deploys the large group psychology concepts of Volkan and the culturally nuanced psychoanalytic anthropology of Roland and Kakar. It concludes with delineating some ameliorative strategies for this tragic problem in the otherwise robust democratic society of India. PMID:26611129

  20. Composites for Advanced Space Transportation Systems (CASTS)

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  1. Using recycled superalloys in precision casting

    NASA Astrophysics Data System (ADS)

    Lambergts, M.; Drapier, J. M.

    1984-04-01

    The recycling of cast scrap is not uniquely justified by fear of difficulties in supplying primary metals or by care to preserve the relationship limited natural supplies of certain of these materials: it is imperative that the smelter minimize costs. Recyling can, however, lead to a deterioration of the metallurgical properties of precision cast superalloys and to a certain chemical contamination that can affect the service life of cast parts. Recycling can be introduced only after careful control of all the consequences. The influence of recycling on composition (trace elements), solidification behavior, microstructure, and mechanical properties was investigated in various nickel alloys such as IN 100, IN 728, and Mar-M-002. Cobalt alloys such as X45 and W152 were also studied. Particular emphasis is given to inclusion content and to the tendency to microporosity. The technical occurrence and economics of an eventual hot isostatic compression cycle is evaluated.

  2. Cast Aluminum Alloy for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    2003-01-01

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

  3. Fatigue of die cast zinc alloys

    SciTech Connect

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

    2006-04-01

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

  4. On the damping capacity of cast irons

    NASA Astrophysics Data System (ADS)

    Golovin, S. A.

    2012-07-01

    The treatment of experimental data on the amplitude-dependent internal friction (ADIF) in terms of various theoretical models has revealed a staged character and the main mechanisms of the processes of energy dissipation in graphite with increasing amplitude of vibrations upon cyclic loading. It is shown that the level of the damping capacity of lamellar cast iron depends on the relationship between the elastic and strength characteristics of graphite and the matrix phase. In cast irons with a rigid matrix structure (pearlite, martensite), the energy dissipation is determined by the volume fraction and morphology of the initial graphite phase. In cast irons with a softer metallic phase (ferrite), the contact interaction of graphite inclusions with the matrix and the properties of the matrix introduce additional sources of high damping.

  5. TiC reinforced cast chromium steels

    SciTech Connect

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

    2003-11-01

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

  6. Mathematical Modeling of Surface Roughness of Castings Produced Using ZCast Direct Metal Casting

    NASA Astrophysics Data System (ADS)

    Chhabra, M.; Singh, R.

    2015-04-01

    Aim of this investigation is to develop a mathematical model for predicting surface roughness of castings produced using ZCast process by employing Buckingham's π-theorem. A relationship has been proposed between surface roughness of castings and shell wall thickness of the shell moulds fabricated using 3D printer. Based on model, experiments were performed to obtain the surface roughness of aluminium, brass and copper castings produced using ZCast process based on 3D printing technique. Based on experimental data, three best fitted third-degree polynomial equations have been established for predicting the surface roughness of castings. The predicted surface roughness values were then calculated using established best fitted equations. An error analysis was performed to compare the experimental and predicted data. The average prediction errors obtained for aluminium, brass and copper castings are 10.6, 2.43 and 3.12 % respectively. The obtained average surface roughness (experimental and predicted) values of castings produced are acceptable with the sand cast surface roughness values range (6.25-25 µm).

  7. Compound cast product and method for producing a compound cast product

    SciTech Connect

    Meyer, Thomas N.; Viswanathan, Srinath

    2002-09-17

    A compound cast product is formed in a casting mold (14) having a mold cavity (16) sized and shaped to form the cast product. A plurality of injectors (24) is supported from a bottom side (26) of the casting mold (14). The injectors (24) are in fluid communication with the mold cavity (16) through the bottom side (26) of the casting mold (14). A molten material holder furnace (12) is located beneath the casting mold (14). The holder furnace (12) defines molten material receiving chambers (36) configured to separately contain supplies of two different molten materials (37, 38). The holder furnace (12) is positioned such that the injectors (24) extend downward into the receiving chamber (36). The receiving chamber (36) is separated into at least two different flow circuits (51, 52). A first molten material (37) is received in a first flow circuit (51), and a second molten material (38) is received into a second flow circuit (52). The first and second molten materials (37, 38) are injected into the mold cavity (16) by the injectors (24) acting against the force of gravity. The injectors (24) are positioned such that the first and second molten materials (37, 38) are injected into different areas of the mold cavity (16). The molten materials (37, 38) are allowed to solidify and the resulting compound cast product is removed from the mold cavity (16).

  8. Modeling of casting microstructures and defects

    SciTech Connect

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

    1997-09-26

    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.

  9. Technetium Getters to Improve Cast Stone Performance

    SciTech Connect

    Neeway, James J.; Lawter, Amanda R.; Serne, R. Jeffrey; Asmussen, Robert M.; Qafoku, Nikolla

    2015-10-15

    The cementitious material known as Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. Two radionuclides of particular concern in these waste streams are technetium-99 (99Tc) and iodine-129 (129I). These radioactive tank waste components contribute the most to the environmental impacts associated with the cleanup of the Hanford site. A recent environmental assessment of Cast Stone performance, which assumes a diffusion controlled release of contaminants from the waste form, calculates groundwater in excess of the allowable maximum permissible concentrations for both contaminants. There is, therefore, a need and an opportunity to improve the retention of both 99Tc and 129I in Cast Stone. One method to improve the performance of Cast Stone is through the addition of “getters” that selectively sequester Tc and I, therefore reducing their diffusion out of Cast Stone. In this paper, we present results of Tc and I removal from solution with various getters with batch sorption experiments conducted in deionized water (DIW) and a highly caustic 7.8 M Na Ave LAW simulant. In general, the data show that the selected getters are effective in DIW but their performance is comprised when experiments are performed with the 7.8 M Na Ave LAW simulant. Reasons for the mitigated performance in the LAW simulant may be due to competition with Cr present in the 7.8 M Na Ave LAW simulant and to a pH effect.

  10. Lymphoplasmacytic lymphoma causing light chain cast nephropathy.

    PubMed

    Pérez, Nuria S; Garcia-Herrera, Adriana; Rosiñol, Laura; Palos, Lily; Santiago, Evelyn; Espinosa, Gerard; Solé, Manel; Campistol, Josep M; Quintana, Luis F

    2012-01-01

    Plasma cell dyscrasias are frequently associated with kidney disease through the production of monoclonal immunoglobulin but with a diverse set of pathologic renal patterns. While almost all patients with a renal biopsy showing a cast nephropathy have myeloma, kidney involvement associated with pathological immunoglobulin light chains and lymphoma is rare. To our knowledge, this is the first report of a cast nephropathy associated with lymphoplasmacytic lymphoma. We emphasize the relation between light chain deposition and renal dysfunction in this disease with production of light chains. A therapeutic approach that decreases light chain production appears to be warranted in these patients. PMID:22241794

  11. Optimal design applications in casting and welding

    SciTech Connect

    Byrne, P.E.; Michaleris, P.; Tortorelli, D.A.; Dantzig, J.A.

    1995-12-31

    In this article, the authors couple design sensitivity analysis and numerical optimization with process simulation to improve the design of castings and weldments. They first derive expressions for explicit sensitivity analysis of weakly coupled thermal stress systems. In the first of two example problems thermal analysis is used to determine an optimal riser design for a steel hammer casting. In the second example, thermal and elasto-plastic stress analyses are performed on a butt-welding process, which is then optimized to control residual stress and distortion.

  12. Caste-Selective Pheromone Biosynthesis in Honeybees

    NASA Astrophysics Data System (ADS)

    Plettner, Erika; Slessor, Keith N.; Winston, Mark L.; Oliver, James E.

    1996-03-01

    Queen and worker honeybees (Apis mellifera L.) produce a caste-related blend of functionalized 8- and 10-carbon fatty acids in their mandibular glands. The biological functions of these compounds match the queen's reproductive and the worker's nonreproductive roles in the colony. Studies with deuterated substrates revealed that the biosynthesis of these acids begins with stearic acid, which is hydroxylated at the 17th or 18th position. The 18-carbon hydroxy acid chains are shortened, and the resulting 10-carbon hydroxy acids are oxidized in a caste-selective manner, thereby determining many of the functional differences between queens and workers.

  13. Fluxing agent for metal cast joining

    DOEpatents

    Gunkel, Ronald W.; Podey, Larry L.; Meyer, Thomas N.

    2002-11-05

    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.

  14. 19. Inside the cast house at Furnace A. Molten iron ...

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

    19. Inside the cast house at Furnace A. Molten iron flowed into eight ladles. The furnace was cast (or tapped) six times each day. - Central Furnaces, 2650 Broadway, east bank of Cuyahoga River, Cleveland, Cuyahoga County, OH

  15. Molding procedure for casting a variety of alloys

    NASA Technical Reports Server (NTRS)

    Fontes, M. J.; Kourtides, D.; Leibfritz, E. R.

    1970-01-01

    General procedure and molding sand composition for preparing molds usable for casting variety of alloys are developed. Molds are prepared from mixture of sand, sodium silicate binder, and organic liquid ester. Castings of radiographic quality are produced from various alloys.

  16. Prediction of porosity in cast equiaxed alloy 718

    SciTech Connect

    Ko, Y.K.; Sahai, V.; Overfelt, R.A.; Berry, J.T.

    1995-12-31

    The prediction of porosity distribution in shaped castings is a popular topic at the present time. A number of criteria functions (CFs) have been proposed to assist in such predictions, these functions generally being obtained from computer modeling of solidification. Although considerable attention has been given to the use of CFs with plain carbon steel and aluminum castings, only limited attention has been given to superalloy castings. Using experimental data on porosity distribution in such castings for validation, various criteria functions were compared for effectiveness in predicting the level of porosity in castings of different thicknesses vacuum investment cast in alloy 718. The criteria functions concerned were obtained by interrogating the output of a simulation using commercially available software. The castings were in the form of vertically cast plates attached to a common top gating system. The problems associated with obtaining thermally accurate simulation, as well as appropriate validation are also discussed.

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

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

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

  18. Accuracy of successive casts for full-arch fixed prostheses.

    PubMed

    Dounis, Kiki S; Dounis, Georgia; Ditmyer, Marcia M; Ziebert, Gerald J

    2010-01-01

    This clinically simulated study examined the accuracy of full-arch impression materials using successive casts reproduced from single impressions. Materials tested included a polyether polyvinyl siloxane, medium viscosity material, and putty wash. Maxillary full-arch Dentoform models were created with four abutments prepared for complete crowns. Six impressions of each material produced successive first and second generation casts. Individual cast copings were then fabricated and assembled into full-arch fixed dental prostheses. Marginal discrepancies were measured on both the casts and Dentoform. Data analysis suggests insignificant differences between successive casts. However, among second generation casts, clinically similar marginal discrepancies were exhibited. Outcomes demonstrated that second generation casts enabled fabrication and assembly of full-arch restorations that were clinically equivalent to first generation casts obtained. PMID:20859561

  19. 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

  20. 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

  1. Enhancements in Magnesium Die Casting Impact Properties

    SciTech Connect

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

    2000-06-30

    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.

  2. Application of TRIZ Theory in Patternless Casting Manufacturing Technique

    NASA Astrophysics Data System (ADS)

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

    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.

  3. Improved Net-Level Filling And Finishing Of Large Castings

    NASA Technical Reports Server (NTRS)

    Johnson, Erik P.; Brown, Richard F.

    1995-01-01

    Improved method of vacuum casting of large, generally cylindrical objects to net sizes and shapes reduces amount of direct manual labor by workers in proximity to cast material. Original application for which method devised is fabrication of solid rocket-motor segments containing solid propellant, wherein need to minimize exposure of workers to propellant material being cast. Improved method adaptable to other applications involving large castings of toxic, flammable, or otherwise hazardous materials.

  4. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  5. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  6. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  7. Clean Cast Steel Technology - Machinability and Technology Transfer

    SciTech Connect

    C. E. Bates; J. A. Griffin

    2000-05-01

    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.

  8. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  9. 46 CFR 153.239 - Use of cast iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  10. 22 CFR 121.10 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Forgings, castings, and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings, and machined bodies. The U.S. Munitions List controls as defense articles those forgings, castings, and other unfinished products, such...

  11. 21 CFR 888.5960 - Cast removal instrument.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cast removal instrument. 888.5960 Section 888.5960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... A cast removal instrument is an AC-powered, hand-held device intended to remove a cast from...

  12. New methods and materials for molding and casting ice formations

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Richter, G. Paul

    1987-01-01

    This study was designed to find improved materials and techniques for molding and casting natural or simulated ice shapes that could replace the wax and plaster method. By utilizing modern molding and casting materials and techniques, a new methodology was developed that provides excellent reproduction, low-temperature capability, and reasonable turnaround time. The resulting casts are accurate and tough.

  13. Cast Stainless Steel Ferrite and Grain Structure

    SciTech Connect

    Ruud, Clayton O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Mathews, Royce; Diaz, Aaron A.; Anderson, Michael T.

    2012-09-01

    In-service inspection requirements dictate that piping welds in the primary pressure boundary of light-water reactors be subject to a volumetric examination based on the rules contained within the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI. The purpose of the inspection is the reliable detection and accurate sizing of service-induced degradation and/or material flaws introduced during fabrication. The volumetric inspection is usually carried out using ultrasonic testing (UT) methods. However, the varied metallurgical macrostructures and microstructures of cast austenitic stainless steel piping and fittings, including statically cast stainless steel and centrifugally cast stainless steel (CCSS), introduce significant variations in the propagation and attenuation of ultrasonic energy. These variations complicate interpretation of the UT responses and may compromise the reliability of UT inspection. A review of the literature indicated that a correlation may exist between the microstructure and the delta ferrite content of the casting alloy. This paper discusses the results of a recent study where the goal was to determine if a correlation existed between measured and/or calculated ferrite content and grain structure in CCSS pipe.

  14. Carburizer Effect on Cast Iron Solidification

    NASA Astrophysics Data System (ADS)

    Janerka, Krzysztof; Kondracki, Marcin; Jezierski, Jan; Szajnar, Jan; Stawarz, Marcin

    2014-06-01

    This paper presents the effect of carburizing materials on cast iron solidification and crystallization. The studies consisted of cast iron preparation from steel scrap and different carburizers. For a comparison, pig iron was exclusively used in a solid charge. Crystallization analysis revealed the influence of the carburizer material on the crystallization curves as well as differences in the solidification paths of cast iron prepared with the use of different charge materials. The carburizers' influence on undercooling during the eutectic crystallization process was analyzed. The lowest undercooling rate was recorded for the melt with pig iron, then for synthetic graphite, natural graphite, anthracite, and petroleum coke (the highest undercooling rate). So a hypothesis was formulated that eutectic cells are created most effectively with the presence of carbon from pig iron (the highest nucleation potential), and then for the graphite materials (crystallographic similarity with the carbon precipitation in the cast iron). The most difficult eutectic crystallization is for anthracite and petroleum coke (higher undercooling is necessary). This knowledge can be crucial when the foundry plant is going to change the solid charge composition replacing the pig iron by steel scrap and the recarburization process.

  15. Epigenetics: the making of ant castes.

    PubMed

    Chittka, Alexandra; Wurm, Yannick; Chittka, Lars

    2012-10-01

    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

  16. Graphite formation in cast iron, phase 2

    NASA Technical Reports Server (NTRS)

    Stefanescu, D. M.; Fiske, M. R.

    1985-01-01

    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 results on the samples that are run successfully is discussed.

  17. Language Arts: Objectives Guide. Project CAST.

    ERIC Educational Resources Information Center

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

    Intended to help special education teachers plan individualized education programs for high school special education students, this Project CAST (Community and School Together) guide presents language arts learning objectives important to independent living. Goal statements, behavioral objectives, and specialized vocabulary are outlined for the…

  18. Feature Analysis of ToxCast Compounds

    EPA Science Inventory

    ToxCast was initiated by the US Environmental Protection Agency (EPA) to prioritize environmental chemicals for toxicity testing. Phase I generated data for 309 unique chemicals, mostly pesticide actives, that span diverse chemical feature/property space, as determined by quantu...

  19. Templates Aid Removal Of Defects From Castings

    NASA Technical Reports Server (NTRS)

    Hendrickson, Robert G.

    1992-01-01

    Templates used to correlate defects in castings with local wall thicknesses. Placed on part to be inspected after coated with penetrant dye. Positions of colored spots (indicative of defects) noted. Ultrasonic inspector measures thickness of wall at unacceptable defects only - overall inspection not necessary.

  20. Roll Casting of Al-25%Si

    SciTech Connect

    Haga, Toshio; Harada, Hideto; Watari, Hisaki

    2011-05-04

    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.

  1. Casting the Spirit: A Handmade Legacy

    ERIC Educational Resources Information Center

    Rutenberg, Mona

    2008-01-01

    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…

  2. 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...

  3. Gelcasting Alumina Cores for Investment Casting

    SciTech Connect

    Janney, M A; Klug, F J

    2001-01-01

    General Electric currently uses silica investment casting cores for making superalloy turbine blades. The silica core technology does not provide the degree of dimensional control needed for advanced turbine system manufacture. The sum of the various process variables in silica core manufacturing produces cores that have more variability than is allowed for in advanced, power-generation gas turbine airfoils.

  4. Modal Vibration Analysis of Large Castings

    NASA Technical Reports Server (NTRS)

    Werlink, Rudolph J.; Margasahayam, Ravi N.

    2009-01-01

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

  5. Etched castings. An alternative approach to treatment.

    PubMed

    Wood, M

    1985-04-01

    Resin-bonded restorations are a conservative alternative with excellent patient acceptance. Improvements in retainer design and electrolytic etching of cast metal allow these restorations to be utilized in a variety of clinical situations. The article reviews the development, indications and contraindications, design, and mouth preparation as well as variations of basic techniques, esthetics, and removal of retainers. PMID:3888703

  6. Social Studies: Objectives Guide. Project CAST.

    ERIC Educational Resources Information Center

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

    The final document in a series on life skills objectives developed by Project CAST (Community and School Together), a community-based career education program for secondary special education students, this guide outlines social studies competencies needed for independent living. Goal statements, behavioral objectives, and specialized terminology…

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

    PubMed

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

    2011-09-01

    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

  8. A new freeze casting technique for ceramics

    NASA Astrophysics Data System (ADS)

    Araki, Kiyoshi

    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.

  9. Viability changes: Microbiological analysis of dental casts

    PubMed Central

    Žilinskas, Juozas; Junevičius, Jonas; Ramonaitė, Agnė; Pavilonis, Alvydas; Gleiznys, Alvydas; Sakalauskienė, Jurgina

    2014-01-01

    Background This study evaluated the survival of the most prevalent oral bacteria and fungi (Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans) in dental casts, and compared changes in the amounts of these microorganisms at different time intervals to determine how long dental casts may pose threat to the health of dental personnel and patients. Material/Methods When manufacturing the casts, regular water was replaced with sterile distilled water, where suspensions of the studied bacteria or the fungus at certain concentrations were prepared. When the dental casts were fully set (solidified), plaster shavings were examined immediately after the contact of the studied microorganism with the plaster, as well as after 1, 2, 24, 48, 72, 96, and 120 hours. Following that, we measured how the amount of the studied bacteria and fungi in 1 gram of the plaster changed within the studied period of time. Results Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05). Staphylococcus aureus remained viable in plaster for up to 4 days, and the number of these bacteria dropped after 1 day (p<0.05). Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05). Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05). Conclusions The microorganisms did not multiply in the gypsum casts and their number significantly dropped instead of increasing. PMID:24902637

  10. The cast brace and tibial plateau fractures.

    PubMed

    Delamarter, R; Hohl, M

    1989-05-01

    Three hundred six tibial plateau fractures treated at the authors' institutions and in private practice were analyzed in relation to the use of a cast brace or fracture brace. One hundred forty-one of these patients had had a cast brace or fracture brace as part of their treatment program, either as the primary fracture treatment or after open reduction or traction. The aims of this study were (1) to determine if cast bracing could maintain alignment, fracture position, and range of motion and (2) to compare its results with those of other major long-term studies of similar fractures. There were 85 lateral, 24 medial, and 32 bicondylar fractures. Cast bracing was used for one to 17 weeks, with a mean of eight weeks. Ninety-nine of the 141 patients were followed for at least one year. Eighty-two of the patients maintained alignment with less than 5 degrees of deformity, and fracture position was maintained in 85% of cases, with only 15% having 4-8 mm of loss of position. Medial plateau and subcondylar fractures had an increased incidence of fracture position loss. Ninety-seven percent of patients had greater than 90 degrees of flexion, and 90% had full extension, i.e., less than 5 degrees of contracture. Pain was minimal or absent after heavy exercise in 90% of patients using cast bracing. Arthritic changes on roentgenographic analysis were absent or mild in 93.5% and moderate or severe in 6.5% of patients. Complications, including phlebitis, pulmonary emboli, wound infection, hardware slippage, and skin slough, occurred in nine patients.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2706855

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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.

  12. Characterization of Bimetallic Castings with an Austenitic Working Surface Layer and an Unalloyed Cast Steel Base

    NASA Astrophysics Data System (ADS)

    Wróbel, Tomasz

    2014-05-01

    The paper presents the technology of bimetallic castings based on the founding method of layer coating directly in the cast process of the so-called method of mold cavity preparation. The prepared castings consist of two fundamental parts, i.e., the base and the working surface layer. The base part of the bimetallic casting is typical foundry material, i.e., unalloyed cast steel, whereas the working layer is a plate of austenitic alloy steel sort X2CrNi 18-9. The quality of the joint between the base part and the working layer was evaluated on the basis of ultrasonic non-destructive testing and structure examinations containing metallographic macro- and microscopic studies with the use of a light microscope (LOM) with microhardness measurements and a scanning electron microscope (SEM) with microanalysis of the chemical composition (energy dispersive spectroscopy—EDS). On the basis of the obtained results it was confirmed that the decisive phenomena needed to create a permanent joint between the two components of the bimetallic casting are carbon and heat transport in the direction from the high-carbon and hot base material which was poured into the mold in the form of liquid metal to the low-carbon and cold material of the working layer which was placed in the mold cavity in the form of a monolithic insert.

  13. A Modified Cast-on Method for the Reinforcement of Aluminum Castings with Dissimilar Metals

    NASA Astrophysics Data System (ADS)

    Han, Qingyou

    2016-02-01

    A modified cast-on method has been developed to reinforce aluminum castings with steel insert. Defect-free bond between the steel insert and the aluminum casting has been consistently obtained. Data obtained from a push-out experiment indicated that the bond strength was much higher than that obtained using the Al-Fin approach. This paper introduces this modified method in four sections: the coating of the steel pins, the cast-on method, microstructure characterization, and the bond strength. The section on the coating of the steel pins contains coating material selection, electroplating technique for plating Cu and Ni on steel, and diffusion bonding of the coatings to the steel. The section on cast-on 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.

  14. Caste in 21st Century India: Competing Narratives

    PubMed Central

    Desai, Sonalde; Dubey, Amaresh

    2012-01-01

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

  15. Microstructure and Elemental Distribution in a Cast Austenitic Steel

    SciTech Connect

    Kenik, Edward A; Busby, Jeremy T; Hoelzer, David T; Rowcliffe, Arthur Frederick; Vitek, John Michael

    2007-01-01

    Casting of austenitic stainless steels offers the possibility of directly producing large and/or complex structures, such as the first wall shield module or the diverter cassette for the International Tokomak Experimental Reactor. However, the resulting mechanical properties and the corrosion resistance of such cast components can be inferior compared to conventionally forged components because of the larger grain size, lower dislocation density and extensive segregation inherent in the cast material. This study examines the microstructural and compositional heterogeneities of a large casting of 316N stainless steel, as well as the possibility of improving the homogeneity and mechanical properties of such a cast material.

  16. Method of making an apertured casting. [using duplicate mold

    NASA Technical Reports Server (NTRS)

    Terray, A. (Inventor)

    1976-01-01

    An apertured casting is made by first forming a duplicate in the shape of the finished casting, positioning refractory metal bodies such as wires in the duplicate at points corresponding to apertures or passageways in finished products, forming a ceramic coating on the duplicate, removing the duplicate material, firing the ceramic in a vacuum or inert atmosphere, vacuum casting the metal in the ceramic form, removing the ceramic form, heating the cast object in an atmospheric furnace to oxidize the refractory metal bodies and then leaching the oxidized refractory bodies from the casting with a molten caustic agent or acid solution.

  17. Biliary casts after liver transplantation: Morphology and biochemical analysis

    PubMed Central

    Yang, Yu-Long; Zhang, Cheng; Lin, Mei-Ju; Shi, Li-Jun; Zhang, Hong-Wei; Li, Jing-Yi; Yu, Qiang

    2013-01-01

    AIM: To investigate the pathogenesis of biliary casts after liver transplantation relative to their morphology and biochemical markers. METHODS: The microstructure of biliary casts was assessed using scanning electron microscopy and Hematoxylin and eosin staining assessed their histology. The expression levels of CD3, CD5, CD34, CD68 and CD79a in these biliary casts were evaluated immunohistochemically. RESULTS: Biliary casts differed widely in their microstructure, with some containing blood vessels positive for CD34 and collagen fibers with positive Masson staining. Large numbers of neutrophils and other inflammatory cells were present, but only on the edge of the biliary casts; although the boundaries were clear without crossover. None of the biliary casts contained T-lymphocytes, B-lymphocytes, macrophages and other inflammatory cells. CONCLUSION: The microcostructure of biliary casts differed. Bacteria and acute rejection are not clearly related to their formation. PMID:24282366

  18. Metallic Fuel Casting Development and Parameter Optimization Simulations

    SciTech Connect

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

    2013-03-01

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

  19. An investigation of squeeze-cast alloy 718

    NASA Technical Reports Server (NTRS)

    Gamwell, W. R.

    1993-01-01

    Alloy 718 billets produced by the squeeze-cast process have been evaluated for use as potential replacements for propulsion engine components which are normally produced from forgings. Alloy 718 billets were produced using various processing conditions. Structural characterizations were performed on 'as-cast' billets. As-cast billets were then homogenized and solution treated and aged according to conventional heat-treatment practices for this alloy. Mechanical property evaluations were performed on heat-treated billets. As-cast macrostructures and microstructures varied with squeeze-cast processing parameters. Mechanical properties varied with squeeze-cast processing parameters and heat treatments. One billet exhibited a defect free, refined microstructure, with mechanical properties approaching those of wrought alloy 718 bar, confirming the feasibility of squeeze-casting alloy 718. However, further process optimization is required, and further structural and mechanical property improvements are expected with process optimization.

  20. Die Casting Part Distortion: Prediction and Attenuation

    SciTech Connect

    Dr, R. Allen Miller

    2002-02-12

    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.

  1. Grain structure and segregation in microgravity castings

    NASA Astrophysics Data System (ADS)

    Gandin, Charles-André; Billa, Bernard; Zimmermann, Gerhard; Browne, David; Fautrelle, Yves; Grün, Gerd-Ulrich; Steiler, Jean-Marc

    2005-10-01

    The main objective of this MAP project is the investigation of the formation of the transition from columnar to equiaxed macrostructure that takes place in casting. Indeed, grain structures observed in most casting processes of metallic alloys are the result of a competition between the growth of several arrays of dendrites that develop under constrained and unconstrained conditions, leading to the columnar to equiaxed transition. A dramatic effect of buoyancy-driven flow on the transport of equiaxed crystals on Earth is acknowledged. This leads to difficulties in conducting precise investigations of the origin of the formation of the equiaxed crystals and their interaction with the development of the columnar grain structure. Consequently, critical benchmark data to test fundamental theories of grain structure formation are required, which benefit from microgravity investigations. These objectives are of direct interest to the project's industrial partners.

  2. Process for slip casting textured tubular structures

    DOEpatents

    Steinlage, Greg A.; Trumble, Kevin P.; Bowman, Keith J.

    2002-01-01

    A process for centrifugal slip casting a textured hollow tube. A slip made up of a carrier fluid and a suspended powder is introduced into a porous mold which is rotated at a speed sufficient to create a centrifugal force that forces the slip radially outward toward the inner surface of the mold. The suspended powder, which is formed of particles having large dimensional aspect ratios such as particles of superconductive BSCCO, settles in a textured fashion radially outward toward the mold surface. The carrier fluid of the slip passes by capillary action radially outward around the settled particles and into the absorbent mold. A layer of mold release material is preferably centrifugally slip cast to cover the mold inner surface prior to the introduction of the BSCCO slip, and the mold release layer facilitates removal of the BSCCO greenbody from the mold without fracturing.

  3. Phase Transformation in Cast Superaustenitic Stainless Steels

    SciTech Connect

    Nathaniel Steven Lee Phillips

    2006-12-12

    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.

  4. Volatile Species Retention During Metallic Fuel Casting

    SciTech Connect

    Randall S. Fielding; Douglas L. Proter

    2013-10-01

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

  5. Refractory films from spin-cast polyacrylonitrile

    SciTech Connect

    Renschler, C.L.; Sylwester, A.P.

    1987-01-01

    Polyacrylonitrile (PAN) films have been spin-cast and pyrolyzed to produce thin (500 to 1500 A) carbon films. These films have higher electrical conductivities than carbon films produced by other methods at similar temperatures. The conductivity can be varied by at least four orders of magnitude by changing the pyrolysis temperature. UV, IR, and Raman spectroscopies were used to investigate the chemical structure of the films during different stages of processing.

  6. IMPROVED MAGNESIUM OXIDE SLIP CASTING METHOD

    DOEpatents

    Stoddard, S.D.; Nuckolls, D.E.

    1963-12-31

    A process for making an aqueous magnesium oxide slip casting slurry comprising the steps of mixing finely ground fused magnesium oxide with water, milling the slurry for at least 30 hours at a temperature of 2-10 deg C (the low temperature during milling inhibiting the formation of hydrated magnesium oxide), discharging the slurry from the mill, adding hydrochloric acid as a deflocculent, and adding a scum inhibitor is presented. (AEC)

  7. Thin Wall Cast Iron: Phase II

    SciTech Connect

    Doru M. Stefanescu

    2005-07-21

    The development of thin-wall technology allows the designers of energy consuming equipment to select the most appropriate material based on cost/material properties considerations, and not solely on density. The technology developed in this research project will permit the designers working for the automotive industry to make a better informed choice between competing materials and thin wall cast iron, thus decreasing the overall cost of the automobile.

  8. Mold For Casting Radius-Inspection Specimens

    NASA Technical Reports Server (NTRS)

    Ball, Robert N.

    1988-01-01

    Thin replicas viewed on comparator without sectioning. New mold machined from piece of transparent poly(methyl methacrylate). Fits around base of post. Two slots machined into inner surface form channels for casting inspection sections. Bottom of mold fits flush against surface around bottom of post. When surface slanted, mold automatically aligns in proper orientation. Time required to inspect elliptical radii located at bottoms of series of small posts reduced from 18 hours to 3 hours.

  9. Influence of casting solvent on phenyl ordering at the surface of spin cast polymer thin films.

    PubMed

    Myers, John N; Zhang, Chi; Chen, Chunyan; Chen, Zhan

    2014-06-01

    Controlling the surface molecular structure of spin cast polymer films is important for the rational design of surface properties. However, the relationship between spin casting parameters and film surface molecular structure is poorly understood. We report that the surface molecular structure of spin cast homopolymers which contain phenyl groups is influenced by the solvent aromaticity, investigated by a nonlinear optical spectroscopy, sum frequency generation (SFG) vibrational spectroscopy. When phenyl groups were located in a linear polymer backbone, spin casting with aromatic solvents enhanced the phenyl SFG signal relative to when a non-aromatic solvent was used which suggests that the aromatic solvent induced the surface phenyl groups to be more ordered and/or to lie more perpendicular to the film surface. In addition, when alkyl structures were believed to be present at the solvent/air interface, alkyl structures were observed at the film/air interface which suggests that molecular structure at the solvent/air interface was carried to the film surface. The effects of solvent aromaticity on phenyl ordering at spin cast film surfaces can be explained by different molecular structures of polymer chains at solvent/air interfaces, preferential solvation of functional groups during evaporation, and re-orientation of bulky side groups at the polymer film/air interface. PMID:24703669

  10. Symposium on electroslag component casting: proceedings

    SciTech Connect

    Judkins, R.R.; Hobday, J.M.

    1984-03-01

    The US Department of Energy (DOE), Office of Fossil Energy, Office of Surface Coal Gasification, has established a Materials Program to develop and apply appropriate materials to coal gasification plant components. The overall goals of the Surface Gasification Materials Program (SGMP) are to improve operational reliability and system durability and to reduce fabrication and operating costs of coal gasification plant components. The SGMP Electroslag Component Casting Project is directed to 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 to develop a sufficient data base to permit ESC to become an ASME Code-accepted process. It is also intended to transfer the ESC process technology to private industry. This symposium was planned to discuss not only the SGMP Electroslag Component Casting Project but the activities and experiences of other organizations as well. The symposium addressed descriptions of electroslag processes; a worldwide perspective on the status of ESC technology; and details of production, mechanical properties, economics, and use of ESC for coal gasification components. Ten papers were presented, and a panel discussion was held to provide participants an opportunity to express their opinions and to offer recommendations on the content of the DOE program. This document constitutes the proceedings of that symposium. The papers included here are minimally edited transcripts of the presentations made at the symposium. All papers have been processed for inclusion in the Energy Data Base.

  11. Aging degradation of cast stainless steel

    SciTech Connect

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

    1985-10-01

    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.

  12. Fisher Matrix Preloaded — FISHER4CAST

    NASA Astrophysics Data System (ADS)

    Bassett, Bruce A.; Fantaye, Yabebal; Hlozek, Renée; Kotze, Jacques

    The Fisher Matrix is the backbone of modern cosmological forecasting. We describe the Fisher4Cast software: A general-purpose, easy-to-use, Fisher Matrix framework. It is open source, rigorously designed and tested and includes a Graphical User Interface (GUI) with automated LATEX file creation capability and point-and-click Fisher ellipse generation. Fisher4Cast was designed for ease of extension and, although written in Matlab, is easily portable to open-source alternatives such as Octave and Scilab. Here we use Fisher4Cast to present new 3D and 4D visualizations of the forecasting landscape and to investigate the effects of growth and curvature on future cosmological surveys. Early releases have been available at since mid-2008. The current release of the code is Version 2.2 which is described here. For ease of reference a Quick Start guide and the code used to produce the figures in this paper are included, in the hope that it will be useful to the cosmology and wider scientific communities.

  13. Seal welded cast iron nuclear waste container

    DOEpatents

    Filippi, Arthur M.; Sprecace, Richard P.

    1987-01-01

    This invention identifies methods and articles designed to circumvent metallurgical problems associated with hermetically closing an all cast iron nuclear waste package by welding. It involves welding nickel-carbon alloy inserts which are bonded to the mating plug and main body components of the package. The welding inserts might be bonded in place during casting of the package components. When the waste package closure weld is made, the most severe thermal effects of the process are restricted to the nickel-carbon insert material which is far better able to accommodate them than is cast iron. Use of nickel-carbon weld inserts should eliminate any need for pre-weld and post-weld heat treatments which are a problem to apply to nuclear waste packages. Although the waste package closure weld approach described results in a dissimilar metal combination, the relative surface area of nickel-to-iron, their electrochemical relationship, and the presence of graphite in both materials will act to prevent any galvanic corrosion problem.

  14. Comparison of Lost Foam Casting of AM60B Alloy and A356 Alloy

    SciTech Connect

    Han, Qingyou; Dinwiddie, Ralph Barton; Sklad, Philip S; Currie, Kenneth; Vondra, Fred; Abdelrahman, Mohamed; Walford, Graham; Nolan, Dennis J; Nedkova, Teodora

    2007-01-01

    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.

  15. X-ray computed tomography for casting development

    NASA Astrophysics Data System (ADS)

    Georgeson, Gary E.; Crews, Alan R.; Bossi, Richard H.

    1992-09-01

    Computed tomography (CT) has been used to evaluate specific sand casting product examples for technical and economic benefits. The representative results are applicable to other casting technologies as well. CT has been shown to be cost effective in the development of new castings. The areas which would benefit include internal dimensional measurements (eliminating destructive sectioning), specific region inspections, flaw characterization in critical regions (to allow passing or informed repair of castings), and geometric acquisition for CAD/CAM. The quantitative capability of CT allows an engineering evaluation of castings based upon a correlation with performance. This quantitative measurement capability has also been used to measure the benefit of hot isostatic pressing in casting production. CT is also cost effective for engineering design and analysis by providing rapid geometry acquisition for input to computer aided design systems. This is particularly beneficial for components that do not have existing drawings or cannot be adequately defined until they are made for any reason. Presently CT can serve as an engineering aid to casting manufacturing. In order for CT evaluation to become routine in foundry applications, however, casting designers need to call it out as a measurement technique in the original casting design drawings, specifications on the application of CT must be written, contracts must include CT evaluation as a means for accepting casting quality, and lower cost CT systems must be available.

  16. Physical Simulation of Investment Casting of Complex Shape Parts

    NASA Astrophysics Data System (ADS)

    Rahimian, Mehdi; Milenkovic, Srdjan; Maestro, Laura; De Azua, Aitor Eguidazu Ruiz; Sabirov, Ilchat

    2015-05-01

    Development of investment casting process has been a challenge for manufacturers of complex shape parts. Numerous experimental casting trials are typically carried out to determine the optimum casting parameters for fabrication of high-quality products. In this work, it is demonstrated that physical simulation of investment casting can successfully predict microstructure and hardness in as-cast complex shape parts. The physical simulation tool consists of a thermal model and melting/solidification experiments in thermo-mechanical simulator. The thermal model is employed to predict local cooling rate during solidification at each point of a casting. Melting/solidification experiments are carried out under controlled cooling rates estimated by the thermal model. Microstructural and mechanical characterization of the solidified specimens is performed; the obtained results predict the local microstructure and mechanical properties of the casting. This concept is applied to investment casting of complex shape nozzle guide vanes from Mar-M247 Ni-based superalloy. Experimental casting trials are performed and the outcomes of physical simulation tool are validated against experimental results. It is shown that phase composition, secondary dendrite arm spacing, grain size, γ/ γ' eutectic size and volume fraction, size and shape of carbide particles, and local microhardness can be predicted at each point of the casting via physical simulation.

  17. Centrifugal Casting Features/Metallurgical Characterization of Aluminum Alloys

    SciTech Connect

    Chirita, G.; Soares, D.; Cruz, D.; Silva, F. S.; Stefanescu, I.

    2008-02-15

    This paper deals with the study of centrifugal effects on aluminium castings under high G values. Most of the studies in this domain (FGMs obtained by centrifugal casting) deal with functionally graded composites reinforced with a solid phase such as silicon particles or others. However, in this study it will be shown that unreinforced aluminium alloys may be significantly influenced by the centrifugal effect and that functionally graded castings are also obtained. It has been observed that the centrifugal effect may increase in some alloys, depending on the relative position in the castings, the rupture strength by approx. 50%, and rupture strain by about 300%, as compared to the gravity casting technique. The Young's modulus may also increase by about 20%. It has also been reported that in vertical centrifugal castings there are mainly three aspects that affect the components thus obtained, namely: fluid dynamics; vibration (inherent to the system); and centrifugal force. These features have a different effect on the castings depending on the aluminium alloy. In this paper, an analysis of the most important effects of the centrifugal casting process on metallurgical features is conducted. A solidification characterization at several points along the mould will be made in order to have an accurate idea of both the fluid dynamics inside the mould during the casting and the solidification behavior in different parts of the component. These two analyses will be related to the metallurgical properties (phase distribution; SDAS; eutectic silicon content and shape, pores density and shape) along the component and mainly along the direction of the centrifugal pressure. A comparison between castings obtained by both centrifugal casting technique and gravity casting technique is made for reference (gravity casting)

  18. Anisotropic shrinkage characteristics of tape cast alumina

    NASA Astrophysics Data System (ADS)

    Patwardhan, Jaideep Suresh

    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.)

  19. Acquired localised hypertrichosis in a Chinese child after cast immobilisation.

    PubMed

    Yuen, M W; Lai, Loretta K P; Chan, P F; Chao, David V K

    2015-08-01

    Hypertrichosis refers to excessive hair growth that is independent of any androgen effect. Hypertrichosis could be congenital or acquired, localised or generalised. The phenomenon of acquired localised hypertrichosis following cast application for a fracture is well known to orthopaedic surgeons, but is rarely encountered by primary care physicians. We describe a 28-month-old Chinese boy who had fracture of right leg as a result of an injury. He had a cast applied by an orthopaedic surgeon as treatment. On removal of the cast 6 weeks later, he was noticed to have significant hair growth on his right leg compared with the left leg. The patient was reassessed 3 months after removal of the cast. The hypertrichosis resolved completely with time. This patient was one of the youngest among the reported cases of acquired localised hypertrichosis after cast application. We illustrate the significance of management of post-cast-acquired localised hypertrichosis in the primary care setting. PMID:26238136

  20. Method and mold for casting thin metal objects

    DOEpatents

    Pehrson, Brandon P; Moore, Alan F

    2014-04-29

    Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

  1. Investment cast AISI H13 tooling for automotive applications

    SciTech Connect

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

    1995-07-01

    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.

  2. Casting materials and their application in research and teaching.

    PubMed

    Haenssgen, Kati; Makanya, Andrew N; Djonov, Valentin

    2014-04-01

    From a biological point of view, casting refers to filling of anatomical and/or pathological spaces with extraneous material that reproduces a three-dimensional replica of the space. Casting may be accompanied by additional procedures such as corrosion, in which the soft tissue is digested out, leaving a clean cast, or the material may be mixed with radiopaque substances to allow x-ray photography or micro computed topography (µCT) scanning. Alternatively, clearing of the surrounding soft tissue increases transparency and allows visualization of the casted cavities. Combination of casting with tissue fixation allows anatomical dissection and didactic surgical procedures on the tissue. Casting materials fall into three categories namely, aqueous substances (India ink, Prussian blue ink), pliable materials (gelatins, latex, and silicone rubber), or hard materials (methyl methacrylates, polyurethanes, polyesters, and epoxy resins). Casting has proved invaluable in both teaching and research and many phenomenal biological processes have been discovered through casting. The choice of a particular material depends inter alia on the targeted use and the intended subsequent investigative procedures, such as dissection, microscopy, or µCT. The casting material needs to be pliable where anatomical and surgical manipulations are intended, and capillary-passable for ultrastructural investigations. PMID:24564951

  3. Evaluation of cast creep occurring during simulated clubfoot correction.

    PubMed

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

    2013-08-01

    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

  4. Advanced precision expendable pattern casting technology. 1994 Summary report

    SciTech Connect

    1995-05-01

    Casting technology is described. The following areas are reported on: precision pattern production; pattern coating; sand fill and compaction; pattern gating; mechanical properties; and technology transfer efforts.

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

    SciTech Connect

    Hayden, H.W.

    1996-05-01

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

  6. Microporosity Prediction and Validation for Ni-based Superalloy Castings

    NASA Astrophysics Data System (ADS)

    Guo, J.; Beckermann, C.; Carlson, K.; Hirvo, D.; Bell, K.; Moreland, T.; Gu, J.; Clews, J.; Scott, S.; Couturier, G.; Backman, D.

    2015-06-01

    Microporosityin high performance aerospace castings can reduce mechanical properties and consequently degrade both component life and durability. Therefore, casting engineers must be able to both predict and reduce casting microporosity. A dimensionless Niyama model has been developed [1] that predicts local microporosity by accounting for local thermal conditions during casting as well as the properties and solidification characteristics of the cast alloy. Unlike the well-known Niyama criterion, application of the dimensionless Niyama model avoids the need to find a threshold Niyama criterion below which shrinkage porosity forms - a criterion which can be determined only via extensive alloy dependent experimentation. In the present study, the dimensionless Niyama model is integrated with a commercial finite element casting simulation software, which can now more accurately predict the location-specific shrinkage porosity volume fraction during solidification of superalloy castings. These microporosity predictions are validated by comparing modelled results against radiographically and metallographically measured porosity for several Ni-based superalloy equiaxed castings that vary in alloy chemistry with a focus on plates of changing draft angle and thickness. The simulation results agree well with experimental measurements. The simulation results also show that the dimensionless Niyama model can not only identify the location but also the average volume fraction of microporosity distribution in these equiaxed investment cast Ni-based superalloy experiments of relatively simple geometry.

  7. Tribological Properties of Al-SiC Metal Matrix Composites: A Comparison Between Sand Cast and Squeeze Cast Techniques

    NASA Astrophysics Data System (ADS)

    Ghosh, S.; Sahoo, P.; Sutradhar, G.

    2014-10-01

    Tribological behaviour of Al-SiC metal matrix composites prepared using two different fabrication techniques, viz. sand cast and squeeze cast techniques are studied in a multi- tribotester (TR-25, DUCOM, India) under dry sliding conditions and ambient atmosphere for varying volume fraction of reinforcement, applied load and sliding speed. Friction increases with increase in applied load and sliding speed and volume fraction of reinforcement. Wear test results show increased wear rates at higher load and speed, while increase in SiC volume fraction yields decrease in wear rate. Corrosion study conducted in 3.5 % NaCl solution shows that squeeze cast composites have better corrosion resistance than sand cast composites. Vickers's microhardness test shows improved hardness properties for squeeze cast composites compared to sand cast ones. The microstructure study of wear tracks reveals domination of abrasive wear with minor traces of adhesive wear.

  8. Initial solidification phenomena in continuous casting

    NASA Astrophysics Data System (ADS)

    Badri, Adam

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

  9. Modeling Coal Seam Damage in Cast Blasting

    SciTech Connect

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

    1998-11-23

    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.

  10. Electromagnetic continuous casting project: Final report

    SciTech Connect

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

    1988-10-01

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

  11. Refractory films from spin-cast carbon

    SciTech Connect

    Renschler, C.L.; Sylwester, A.P.

    1988-01-01

    A method is described to produce thin films of carbon by the pyrolysis of spin-cast polyacrylonitrile. Uv, ir, and Raman spectroscopies were employed to investigate the chemical structure of the films during pyrolysis. The electrical conductivity of films made in this way can be varied over several decades by changing the final temperature of carbonization. These films can also be photolithographically patterned and manipulated by wet and dry transfer techniques. As such, these films may have utility in microelectronic and hybrid microcircuit applications. 7 refs., 4 figs.

  12. Phase Transformations in Cast Duplex Stainless Steels

    SciTech Connect

    Yoon-Jun Kim

    2004-12-19

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

  13. Method and apparatus for strip casting

    DOEpatents

    Follstaedt, Donald W.; Powell, John C.; Sussman, Richard C.; Williams, Robert S.

    1991-01-01

    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.

  14. Method and apparatus for strip casting

    DOEpatents

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

    1991-11-12

    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.

  15. Phase transformations in cast duplex stainless steels

    NASA Astrophysics Data System (ADS)

    Kim, Yoon-Jun

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

  16. An investment mold for titanium casting

    NASA Astrophysics Data System (ADS)

    Calvert, E. D.

    1981-07-01

    The Bureau of Mines, in its effort to promote greater utilization of domestically abundant materials, conducted research on an alternate mold material that has commercial potential for titanium investment casting. Using variations of the conventional lost wax molding process, investment shell molds were formed entirely of fused, calcia-stabilized ZrO2-forming binder. Optimization of binder/slurry properties, stucco grain size and distribution, and curing practices resulted in a structurally sound investment shell that was distortion free and thermally stable.

  17. Continuation of Crosscutting Technology Development at Cast

    SciTech Connect

    Yoon, Roe-Hoan

    2012-03-31

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

  18. Microstructurally toughened articles and casting thereof

    SciTech Connect

    Divecha, A.P.; Karmarkar, S.D.

    1991-01-01

    The present invention relates in general to articles reinforced with discontinuous composites and the like, and a process of making the same, and in particular, to the use of preforms which can be used to form articles such as microstructurally toughened tubes by casting. Discontinuous metal matrix composites (MMC) have relatively recently been used industrially. The most widely used discontinuous composites are silicon carbide whiskers (SiC) and silicon carbide particles (SiCp) or (SiCw). Discontinuously reinforced aluminum is commonly designated as SiC/Al and SiCp/Al, respectively. Patent applications.

  19. INTERNAL ADAPTATION OF CAST TITANIUM CROWNS

    PubMed Central

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

    2007-01-01

    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°C, 515°C and 600°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 (mm2). 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°C/100%: (7.25 mm2 ±1.59) and 600°C/100% (8.8 mm2 ±2.25) groups, which presented statistically similar levels of internal misfit. PMID:19089139

  20. Sputtered protective coatings for die casting dies

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  1. Nonaqueous slip casting of high temperature ceramic superconductors using an investment casting technique

    NASA Astrophysics Data System (ADS)

    Hooker, Matthew W.; Taylor, Theodore D.; Wise, Stephanie A.; Buckley, John D.; Vasquez, Peter; Buck, Gregory M.; Hicks, Lana P.

    1993-08-01

    A process for slip casting ceramic articles that does not employ parting agents and affords the casting of complete, detailed, precision articles that do not possess parting lines is presented. This process is especially useful for high temperature superconductors and water-sensitive ceramics. A wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell mold of the calcium sulfate-bonded investment material. The shell mold is cooled to room temperature, and a ceramic slip, created by dispersing a ceramic powder in an organic liquid, is poured therein. After a ceramic shell of desired thickness or a solid article has set up in the shell mold, excess ceramic slip is poured out. The shell mold is misted with water and peeled away from the ceramic article, after which the ceramic is fired to provide a complete, detailed, precision, high temperature superconductive ceramic article without parting lines. The casting technique may take place in the presence of a magnetic field to orient the ceramic powders during the casting process.

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

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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 μm; therefore, these face coats still can be possible face coat materials for investment casting TiAl alloys.

  3. Slip casting and pressure slip casting of Si{sub 3}N{sub 4} aqueous suspensions

    SciTech Connect

    Castanho, S.M.; Moreno, R.; Salomoni, A.; Stamenkovic, I.

    1995-09-01

    The stability of silicon nitride aqueous slips has been studied in order to obtain Si{sub 3}N{sub 4} pressureless sintered compacts. High solid content slips (up to 65 wt%) have been prepared by using tetramethylammonium hydroxide as dispersing agent. The effect of sintering aids on the rheology and casting conditions has been studied by slip casting and uniaxial pressure filtration. The casting rate, the green density and the microstructure of samples obtained from both slurry consolidation techniques have been compared taking into account the role of the sintering additives. Sintering of cast green specimens has been performed at 1750{degrees}C in N{sub 2} atmosphere.

  4. Spall behavior of cast iron with varying microstructures

    NASA Astrophysics Data System (ADS)

    Plume, Gifford; Rousseau, Carl-Ernst

    2014-07-01

    The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94-1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.

  5. Comparative study of two commercially pure titanium casting methods

    PubMed Central

    RODRIGUES, Renata Cristina Silveira; FARIA, Adriana Claudia Lapria; ORSI, Iara Augusta; de MATTOS, Maria da Gloria Chiarello; MACEDO, Ana Paula; RIBEIRO, Ricardo Faria

    2010-01-01

    The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior. Objective This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure. Material and Methods 72 frameworks were cast from CP Ti (n=36) and Co-Cr alloy (n=36; control group). For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6) were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey's to compare materials and cast methods (α=0.05). Results Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (p<0.05) were observed only for the Co-Cr alloy with 0.25 mm and 0.50 mm undercuts. Significant differences were found for the 0.25 mm and 0.75 mm undercuts dependent on the material used. For the 0.50 mm undercut, significant differences were found when the materials were induction casted. Conclusion Although both casting methods produced satisfactory CP Ti RPD frameworks, the occurrence of porosities was greater in the plasma/vacuum-pressure than in the induction/centrifugation method, the latter resulting in higher clasp rigidity, generating higher retention force values. PMID:21085805

  6. Spall behavior of cast iron with varying microstructures

    SciTech Connect

    Plume, Gifford; Rousseau, Carl-Ernst

    2014-07-21

    The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94–1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.

  7. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  8. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  9. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  10. Shallow water model for horizontal centrifugal casting

    NASA Astrophysics Data System (ADS)

    Boháček, J.; Kharicha, A.; Ludwig, A.; Wu, M.

    2012-07-01

    A numerical model was proposed to simulate the solidification process of an outer shell of work roll made by the horizontal centrifugal casting technique. Shallow water model was adopted to solve the 2D average flow dynamics of melt spreading and the average temperature distribution inside the centrifugal casting mould by considering the centrifugal force, Coriolis force, viscous force due to zero velocity on the mould wall, gravity, and energy transport by the flow. Additionally, a 1D sub-model was implemented to consider the heat transfer in the radial direction from the solidifying shell to the mould. The solidification front was tracked by fulfilling the Stefan condition. Radiative and convective heat losses were included from both, the free liquid surface and the outer wall of the mould. Several cases were simulated with the following assumed initial conditions: constant height of the liquid metal (10, 20, and 30 mm), uniform temperature of the free liquid surface (1755 K). The simulation results have shown that while the solidification front remained rather flat, the free surface was disturbed by waves. The amplitude of waves increased with the liquid height. Free surface waves diminished as the solidification proceeded.

  11. Advanced Lost Foam Casting Technology - Phase V

    SciTech Connect

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

    2004-04-29

    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.

  12. Rapid processing of cast and attached shadows.

    PubMed

    Elder, James H; Trithart, Sherry; Pintilie, Gregor; MacLean, Donald

    2004-01-01

    We used a visual-search method to investigate the role of shadows in the rapid discrimination of scene properties. Targets and distractors were light or dark 2-D crescents of identical shape and size, on a mid-grey background. From the dark stimuli, illusory 3-D shapes can be created by blurring one arc of the crescent. If the inner arc is blurred, the stimulus is perceived as a curved surface with attached shadow. If the outer arc is blurred, the stimulus is perceived as a flat surface casting a shadow. In a series of five experiments, we used this simple stimulus to map out the shadow properties that the human visual system can rapidly detect and discriminate. To subtract out 2-D image factors, we compared search performance for dark-shadow stimuli with performance for light-shadow stimuli which generally do not elicit strong 3-D percepts. We found that the human visual system is capable of rapid discrimination based upon a number of different shadow properties, including the type of the shadow (cast or attached), the direction of the shadow, and the displacement of the shadow. While it is clear that shadows are not simply discounted in rapid search, it is unclear at this stage whether rapid discrimination is acting upon shadows per se or upon representations of 3-D object shape and position elicited by perceived shadows. PMID:15693674

  13. Software Computes Tape-Casting Parameters

    NASA Technical Reports Server (NTRS)

    deGroh, Henry C., III

    2003-01-01

    Tcast2 is a FORTRAN computer program that accelerates the setup of a process in which a slurry containing metal particles and a polymeric binder is cast, to a thickness regulated by a doctor blade, onto fibers wound on a rotating drum to make a green precursor of a metal-matrix/fiber composite tape. Before Tcast2, setup parameters were determined by trial and error in time-consuming multiple iterations of the process. In Tcast2, the fiber architecture in the final composite is expressed in terms of the lateral distance between fibers and the thickness-wise distance between fibers in adjacent plies. The lateral distance is controlled via the manner of winding. The interply spacing is controlled via the characteristics of the slurry and the doctor-blade height. When a new combination of fibers and slurry is first cast and dried to a green tape, the shrinkage from the wet to the green condition and a few other key parameters of the green tape are measured. These parameters are provided as input to Tcast2, which uses them to compute the doctor-blade height and fiber spacings needed to obtain the desired fiber architecture and fiber volume fraction in the final composite.

  14. Horizontal electromagnetic casting of thin metal sheets

    DOEpatents

    Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

    1988-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  15. Horizontal electromagnetic casting of thin metal sheets

    DOEpatents

    Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

    1987-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  16. Aluminum Alloy and Article Cast Therefrom

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A. (Inventor); Chen, Po-Shou (Inventor)

    2003-01-01

    A cast article from an aluminum alloy, which has improved mechanical properties at elevated temperatures, has the following composition in weight percent: Silicon 14 - 25.0, Copper 5.5 - 8.0, Iron 0.05 - 1.2, Magnesium 0.5 - 1.5, Nickel 0.05 - 0.9, Manganese 0.05 - 1.0, Titanium 0.05 - 1.2, Zirconium 0.05 - 1.2, Vanadium 0.05 - 1.2, Zinc 0.05 - 0.9, Phosphorus 0.001 - 0.1, and the balance is Aluminum, wherein the silicon-to-magnesium ratio is 10 - 25, and the copper-to-magnesium ratio is 4 - 15. The aluminum alloy contains a simultaneous dispersion of three types of Al3X compound particles (X=Ti, V, Zr) having a LI2, crystal structure, and their lattice parameters are coherent to the aluminum matrix lattice. A process for producing this cast article is also disclosed, as well as a metal matrix composite, which includes the aluminum alloy serving as a matrix and containing up to about 60% by volume of a secondary filler material.

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

    SciTech Connect

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

    2008-11-21

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

  18. Heat treatment study of aluminum casting alloy M45

    NASA Technical Reports Server (NTRS)

    Lovoy, C. V.

    1967-01-01

    Study determines the heat treatment cycle of aluminum casting alloy M-45 which will increase the strength levels of the alloy while maintaining optimum stress corrosion resistance. Evidence indicates that present production castings are overaged too severely to take full advantage of the strength of the alloy.

  19. A future vision for the investment casting industry

    SciTech Connect

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

    1993-11-01

    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.

  20. 126. EXTERIOR VIEW, LOOKING NORTH, SHOWING CAST SHED NO. 2, ...

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

    126. EXTERIOR VIEW, LOOKING NORTH, SHOWING CAST SHED NO. 2, FURNACE NO. 2, STOVES, POWER HOUSE, STACKS, FURNACE NO. 1 CAST SHED. FURNACE NO. 2 IS IN PROCESS OF RESTORATION. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  1. Casting Porosity-Free Grain Refined Magnesium Alloys

    SciTech Connect

    Schwam, David

    2013-08-12

    The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings. 

  2. Rapid Tooling via Investment Casting and Rapid Prototype Patterns

    SciTech Connect

    Baldwin, Michael D.

    1999-06-01

    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.

  3. QUENCHING TUMBLING MILL TUMBLES CASTINGS OVER EACH OTHER TO REMOVE ...

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

    QUENCHING TUMBLING MILL TUMBLES CASTINGS OVER EACH OTHER TO REMOVE RUNNERS AND SPRUES WHILE QUICKLY COOLING THEM WITH WATER IN THE MALLEABLE ANNEALING BUILDING. THIS PROCESS ENSURES CASTINGS FORM WHITE IRON PRIOR TO BEING ASSEMBLED. - Stockham Pipe & Fittings Company, Malleable Annealing Building, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  4. The Childhood Autism Spectrum Test (CAST): Sex Differences

    ERIC Educational Resources Information Center

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

    2008-01-01

    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…

  5. Refining cast implant-retained restorations by electrical discharge machining.

    PubMed

    Schmitt, S M; Chance, D A; Cronin, R J

    1995-03-01

    The UCLA abutment was developed to create implant-retained restorations with ideal contours, excellent esthetics, and minimal vertical space requirements for restorative materials. A major drawback of this abutment is that casting inaccuracies in the lost-wax process are difficult to control. This article describes a method of refining cast implant-retained restorations by use of electrical discharge machining. PMID:7760278

  6. 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 ...

  7. Properties of a hybrid plaster-fibreglass cast

    PubMed Central

    Charles, Mark N.; Yen, David

    2000-01-01

    Objective To examine the suitability of a plaster-fibreglass hybrid cast for orthopedic applications, comparing them to plaster of Paris (POP) and fibreglass constructs. Method Groups of 10 standardized hybrid, POP and fibreglass casts were studied. An Instron servo-hydraulic system was used to test the casts in 3-point bending and shear. Outcome measures Strength, stiffness, weight, thickness and cost of the 3 types of cast, and shear strength at the interface between the POP and fibreglass in the hybrid casts. Results The hybrid casts were twice as strong as the POP constructs, were stiffer and weighed 14% less but were thicker and cost 2.5 times more. They were almost as strong as and less than half the cost of the fibreglass constructs but were thicker, not as stiff, and weighed 42% more. The shear strength of the POPfibreglass interface in the hybrid casts was higher than the 3-point bending strength of this construct by a factor of 3. Conclusions Plaster-fibreglass hybrid casts should be considered for orthopedic use on the basis of their strength, stiffness, weight and cost, combined with their acknowledged advantages of good moulding ability and water resistance. PMID:11045095

  8. 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

  9. 22 CFR 121.10 - Forgings, castings and machined bodies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles on the U.S. Munitions List include articles in a partially completed state (such as...

  10. 22 CFR 121.10 - Forgings, castings and machined bodies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles on the U.S. Munitions List include articles in a partially completed state (such as...

  11. 22 CFR 121.10 - Forgings, castings and machined bodies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles on the U.S. Munitions List include articles in a partially completed state (such as...

  12. 22 CFR 121.10 - Forgings, castings and machined bodies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles on the U.S. Munitions List include articles in a partially completed state (such as...

  13. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles on the U.S. Munitions Import List include articles in a partially completed state (such as...

  14. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles on the U.S. Munitions Import List include articles in a partially completed state (such as...

  15. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles on the U.S. Munitions Import List include articles in a partially completed state (such as...

  16. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles on the U.S. Munitions Import List include articles in a partially completed state (such as...

  17. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles on the U.S. Munitions Import List include articles in a partially completed state (such as...

  18. RAW COPPER SLABS USED IN CASTING OPERATIONS AT BUFFALO PLANT ...

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

    RAW COPPER SLABS USED IN CASTING OPERATIONS AT BUFFALO PLANT OF AMERICAN BRASS COMPANY. MATERIALS STORAGE FOR THE CAST SHOP NOW OCCUPIES A PORTION OF THE ORIGINAL BRASS MILL BUILT BY THE BUFFALO COPPER AND BRASS ROLLING MILL IN 1906-07 AND EXPANDED IN 1911. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  19. High-resolution airway morphometry from polyurethane casts

    NASA Astrophysics Data System (ADS)

    Neufeld, Gordon R.; Vargas, John; Hoford, John D.; Craft, Jeanne; Shroff, Sunil; McRae, Karen M.

    1995-05-01

    An airway cast was made and imbedded in a solid polyurethane block of a contrasting color. The block was sequentially milled and photographed. The sequential photographs were scanned to create an image database which was analyzed on VIDA; a multidimensional image analysis software package. The technique shows promise as a semi-automated process for generating a high resolution morphometric database from airway casts.

  20. 29 CFR 452.131 - Casting of ballots; delegate elections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 2 2011-07-01 2011-07-01 false Casting of ballots; delegate elections. 452.131 Section 452.131 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR... REPORTING AND DISCLOSURE ACT OF 1959 Election Procedures; Rights of Members § 452.131 Casting of...

  1. 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...

  2. Filtration efficiency in casting of a complexly alloyed nickel melt

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  3. 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

  4. Fiberglass versus plaster casts. How to choose between them.

    PubMed

    Silfverskiold, J P

    1989-10-01

    Both fiberglass and plaster of Paris casts have advantages and disadvantages, and the choice of material depends on the individual situation. Fiberglass is used most often, but plaster of Paris, with its molding capabilities, is the first choice for fresh extremity fractures. "Hybrid" casts offer no advantages. PMID:2636865

  5. Two from One Casting. Art Education: 6681.20.

    ERIC Educational Resources Information Center

    Hilf, Anne

    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,…

  6. 8. VIEW OF A MOLD FOR PRECISION CASTING. THE MOLD ...

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

    8. VIEW OF A MOLD FOR PRECISION CASTING. THE MOLD WAS USED IN FOUNDRY OPERATIONS THAT CAST PLUTONIUM EITHER AS INGOTS SUITABLE FOR ROLLING AND FURTHER WROUGHT PROCESSING OR INTO SHAPES AMENABLE TO DIRECT MACHINING OPERATIONS. (5/6/59) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  7. Mold with improved core for metal casting operation

    DOEpatents

    Gritzner, Verne B.; Hackett, Donald W.

    1977-01-01

    The present invention is directed to a mold containing an improved core for use in casting hollow, metallic articles. The core is formed of, or covered with, a layer of cellular material which possesses sufficient strength to maintain its structural integrity during casting, but will crush to alleviate the internal stresses that build up if the normal contraction during solidification and cooling is restricted.

  8. Start with Casting: What to Know before Auditions Begin.

    ERIC Educational Resources Information Center

    Carlisle, Barbara; Drapeau, Don

    1997-01-01

    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)

  9. Prediction of ALLOY SHRINKAGE FACTORS FOR THE INVESTMENT CASTING PROCESS

    SciTech Connect

    Sabau, Adrian S

    2006-01-01

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

  10. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    SciTech Connect

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

    2005-04-01

    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 tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  11. Tundish Technology for Casting Clean Steel: A Review

    NASA Astrophysics Data System (ADS)

    Sahai, Yogeshwar

    2016-03-01

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

  12. Tensile-property characterization of thermally aged cast stainless steels.

    SciTech Connect

    Michaud, W. F.; Toben, P. T.; Soppet, W. K.; Chopra, O. K.; Energy Technology

    1994-03-03

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  13. Method and apparatus for planar drag strip casting

    DOEpatents

    Powell, John C.; Campbell, Steven L.

    1991-01-01

    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.

  14. Method and apparatus for planar drag strip casting

    DOEpatents

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

    1991-11-12

    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.

  15. The Influence of Casting Conditions on the Microstructure of As-Cast U-10Mo Alloys: Characterization of the Casting Process Baseline

    SciTech Connect

    Nyberg, Eric A.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2013-12-13

    Sections of eight plate castings of uranium alloyed with 10 wt% molybdenum (U-10Mo) were sent from Y-12 to the Pacific Northwest National Laboratory (PNNL) for microstructural characterization. This report summarizes the results from this study.

  16. Relationship Between Casting Distortion, Mold Filling, and Interfacial Heat Transfer in Sand Molds

    SciTech Connect

    J. K. Parker; K. A. Woodbury; T. S. Piwonka; Y. Owusu

    1999-09-30

    This project sought to determine the relationship between casting dimensions and interfacial heat transfer in aluminum alloy sand castings. The program had four parts; measurement of interfacial heat transfer coefficients in resin bonded and green sand molds, the measurement of gap formation in these molds, the analysis of castings made in varying gatings, orientations and thicknesses, and the measurement of residual stresses in castings in the as-cast and gate removed condition. New values for interfacial heat transfer coefficients were measured, a novel method for gap formation was developed, and the variation of casting dimensions with casting method, gating, and casting orientation in the mold was documented.

  17. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2014-02-28

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leachability indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited range of the factors in the test matrix hindered the identification of individual component effects. Future work should involve broader factor ranges to identify the roles played by each of the components in the mix via thermal analyses, analytical microscopy, and characterization of phase formation.

  18. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect

    Fox, K. M.; Edwards, T. A.; Roberts, K. B.

    2013-10-02

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited range of the factors in the test matrix hindered the identification of individual component effects. Future work should involve broader factor ranges to identify the roles played by each of the components in the mix via thermal analyses, analytical microscopy, and characterization of phase formation.

  19. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2013-09-17

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited range of the factors in the test matrix hindered the identification of individual component effects. Future work should involve broader factor ranges to identify the roles played by each of the components in the mix via thermal analyses, analytical microscopy, and characterization of phase formation.

  20. Gating of Permanent Molds for Aluminum Casting

    SciTech Connect

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

    2004-01-01

    This report summarizes a two-year project, DE-FC07-011D13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. Other studies have been conducted using water flow and behavior of liquid aluminum in sand mold using real time photography. This investigation utilizes graphite molds transparent to X-Rays making it possible to observe the flow pattern through a number of vertically oriented grating systems. These have included systems that are choked at the base of a rounded vertical sprue and vertical gating systems with a variety of different ingates into the bottom of a mold cavity. These systems have also been changed to include gating systems with vertical and horizontal gate configurations. Several conclusions can be derived from this study. A sprue-well, as designed in these experiments, does not eliminate the vena contracta. Because of the swirling at the sprue-base, the circulating metal begins to push the entering metal stream toward the open runner mitigating the intended effect of the sprue-well. Improved designs of sprue-wells should be evaluated. In order for a runner extension to operate efficiently, it must have a small squared cross-section. If it is tapered, the first metal to enter the first metal to enter the system is not effectively trapped. If the cross section is large, there is less turbulence when the aluminum enters the mold cavity in comparison to the smaller cross sectioned, squared runner. However, a large runner reduces yield. In bottom-feeding gating systems, a filter can significantly improve the filling of the casting. The filter helps to slow the metal flow rate enough to reduce jetting into the mold cavity. In top feeding gating systems, a filter can initially slow the metal flow rate, but because the metal drops after passing the filter, high velocities are achieved during free fall when a filter is in place. Side feeding gating systems provide less turbulent flow into the mold cavity. The flow is comparable to a bottom-feeding gating system with a filter. Using properly designed side-gating system instead of a bottom-feeding system with a filter can potentially save the cost of the filter. Rough coatings promote better fill than smooth coatings. This conclusion seems at first counter intuitive. One tends to assume a rough coating creates more friction resistance to the flow of molten metal. In actuality the molten aluminum stream flows inside an oxide film envelope. When this film rests on top of the ridges of a rough coating the microscopic air pockets between the coating and the oxide film provide more thermal insulation than in a smooth coating. This insulation promotes longer feeding distances in the mold as demonstrated in the experiments. Much of this work is applicable to vertically parted sand molds as well, although the heat transfer conditions do vary from a metal mold generally used in permanent molding of aluminum. The flow measurements were conducted using graphite molds and real time X-Ray radiography recorded at a rate of 30 images per second through those molds. The facilities at Arrow Aluminum Foundry were used in the study. The results will be employed to demonstrate to the American Foundry Industry how molten aluminum flows in permanent molds of different designs and characteristics. The results of these experiments were compared with computer mold and simulation models. The Procast and Magmasoft flow and solidification simulation programs were employed to predict the flow behavior under the different conditions that can prevail in permanent mold gating. The development of a valid computer model that can correctly and accurately predict this flow is much more intricate than generally realized. To provide accurate predictions such programs require significant adjustments and verification with experimental data.

  1. Methods and apparatuses for manufacturing geometric multicrystalline cast silicon and geometric multicrystalline cast silicon bodies for photovoltaics

    SciTech Connect

    Stoddard, Nathan G

    2015-02-10

    Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of geometrically ordered multi-crystalline silicon may be formed that is free or substantially free of radially-distributed impurities and defects and having at least two dimensions that are each at least about 10 cm is provided.

  2. Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

    NASA Astrophysics Data System (ADS)

    Lim, Sang-Sub; Mun, Jae-Chul; Kim, Tae-Won; Kang, Chung-Gil

    2014-12-01

    In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

  3. Method of casting silicon into thin sheets

    DOEpatents

    Sanjurjo, Angel; Rowcliffe, David J.; Bartlett, Robert W.

    1982-10-26

    Silicon (Si) is cast into thin shapes within a flat-bottomed graphite crucible by providing a melt of molten Si along with a relatively small amount of a molten salt, preferably NaF. The Si in the resulting melt forms a spherical pool which sinks into and is wetted by the molten salt. Under these conditions the Si will not react with any graphite to form SiC. The melt in the crucible is pressed to the desired thinness with a graphite tool at which point the tool is held until the mass in the crucible has been cooled to temperatures below the Si melting point, at which point the Si shape can be removed.

  4. Spin-cast carbon films from polyacrylonitrile

    SciTech Connect

    Renschler, C.L.; Sylwester, A.P.

    1987-01-01

    Carbon films have been made by a variety of techniques, including evaporation, sputtering, and laser or thermal pyrolysis of organic polymers. Polyacrylonitrile (PAN) is often used as a carbon precursor, since low-temperature thermo-oxidative pretreatment produces a material which can be pyrolyzed without loss of shape. This is the basis for the production of carbon fibers with good mechanical properties. We report here the formation of very thin films of carbon (500 to 1500 A) by pyrolysis of spin-cast PAN. Using this technique, large, conductive films can be made which are sufficiently robust to allow intact lift-off and transfer of the films from one substrate to another. Such films are chemically inert, but can be photolithographically patterned and etched with an oxygen plasma.

  5. CENTER FOR ADVANCED SEPARATION TECHNOLOGY (CAST) PROGRAM

    SciTech Connect

    Yoon, Roe-Hoan; Hull, Christopher

    2014-09-30

    The U.S. is the largest producer of mining products in the world. In 2011, U.S. mining operations contributed a total of $232 billion to the nation’s GDP plus $138 billion in labor income. Of this the coal mining industry contributed a total of $97.5 billion to GDP plus $53 billion in labor income. Despite these contributions, the industry has not been well supported with research and development funds as compared to mining industries in other countries. To overcome this problem, the Center for Advanced Separation Technologies (CAST) was established to develop technologies that can be used by the U.S. mining industry to create new products, reduce production costs, and meet environmental regulations.

  6. Acoustic energy transmission in cast iron pipelines

    NASA Astrophysics Data System (ADS)

    Kiziroglou, Michail E.; Boyle, David E.; Wright, Steven W.; Yeatman, Eric M.

    2015-12-01

    In this paper we propose acoustic power transfer as a method for the remote powering of pipeline sensor nodes. A theoretical framework of acoustic power propagation in the ceramic transducers and the metal structures is drawn, based on the Mason equivalent circuit. The effect of mounting on the electrical response of piezoelectric transducers is studied experimentally. Using two identical transducer structures, power transmission of 0.33 mW through a 1 m long, 118 mm diameter cast iron pipe, with 8 mm wall thickness is demonstrated, at 1 V received voltage amplitude. A near-linear relationship between input and output voltage is observed. These results show that it is possible to deliver significant power to sensor nodes through acoustic waves in solid structures. The proposed method may enable the implementation of acoustic - powered wireless sensor nodes for structural and operation monitoring of pipeline infrastructure.

  7. General requirement for effective overburden casting

    SciTech Connect

    Cook, J.D.; McCutchen, D.

    1994-12-31

    Effective overburden casting requires the efficient use of todays explosives and initiations systems if a mine is to survive. This paper uses a major coal stripping operation as an example of the proper application of explosives and initiation system to their conditions. High speed photography, rock analysis and computer modeling were used to assist in determining the effective use of the explosives and the initiation systems. The high speed photography confirmed the computer modeling done by SABREX, the Scientific Approach to Blasting Rock with Explosives developed by ICI Explosives world group of companies. The major coal company used in this paper mines the 36 inch Sewanee coal seam in Tennessee for TVA steam generation. The overburden is usually in excess of 100 ft. of sandstone.

  8. Casting inorganic structures with DNA molds

    PubMed Central

    Sun, Wei; Boulais, Etienne; Hakobyan, Yera; Wang, Wei Li; Guan, Amy; Bathe, Mark; Yin, Peng

    2014-01-01

    We report a general strategy for designing and synthesizing inorganic nanostructures with arbitrarily prescribed three-dimensional shapes. Computationally designed DNA strands self-assemble into a stiff “nano-mold” that contains a user-specified three-dimensional cavity and encloses a nucleating gold “seed”. Under mild conditions, this seed grows into a larger cast structure that fills and thus replicates the cavity. We synthesized a variety of nanoparticles with three nanometer resolution: three distinct silver cuboids with three independently tunable dimensions, silver and gold nanoparticles with diverse cross sections, and composite structures with homo-/heterogeneous components. The designer equilateral silver triangular and spherical nanoparticles exhibited plasmonic properties consistent with electromagnetism-based simulations. Our framework is generalizable to more complex geometries and diverse inorganic materials, offering a range of applications in biosensing, photonics, and nanoelectronics. PMID:25301973

  9. Casting of HgCdTe

    NASA Astrophysics Data System (ADS)

    Alexiades, V.

    1991-03-01

    Mercury-Cadmium-Telluride is a technologically important electronic material, used primarily as an infrared-detector. In such applications, large crystals of uniform concentration are desirable, which is difficult to achieve when the crystal is grown under gravity. Modeling and numerical simulation can help us gain insight, in the interpretation of experiments, and in designing future earth-bound and microgravity experiments. In this report we present a compilation of the relevant thermophysical properties of the pseudo-binary (HgTe)(1-x)(CdTe)(x), as functions of composition, x, and temperature, for both the solid and liquid phases, at the high temperatures (approximately 600 to 1100 C) relevant in the casting process.

  10. TiC reinforced cast Cr steels

    SciTech Connect

    Dogan, O.N.; Hawk, J.A.; Schrems, K.K.

    2006-06-01

    A new class of materials, namely TiC-reinforced cast chromium (Cr) steels, was developed for applications requiring high abrasion resistance and good fracture toughness. The research approach was to modify the carbide structure of commercial AISI 440C steel for better fracture resistance while maintaining the already high abrasion resistance. The new alloys contained 12Cr, 2.5–4.5Ti, and 1–1.5C (wt.%) and were melted in a vacuum induction furnace. Their microstructure was composed primarily of a martensitic matrix with a dispersion of TiC precipitates. Modification of TiC morphology was accomplished through changing the cooling rate during solidification. Wear rates of the TiC-reinforced Cr steels were comparable to that of AISI 440C steel, but the impact resistance was much improved.

  11. Erosion of white cast irons and stellite

    SciTech Connect

    Aptekar, S.S.; Kosel, T.H.

    1985-01-01

    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 with alumina, crushed quartz and rounded quartz particles. These erodents were chosen because quartz has a hardness between that of the matrix and the Cr-rich carbides, whereas the hardness of alumina is comparable to that of the carbides. In addition, comparison of the results with crushed quartz and alumina allows an evaluation of the effect of particle hardness while the differences between the rounded and crushed quartz results can be attributed to the shape difference. For all erodents and alloys, the dependence of erosion on angle of incidence was weak. With alumina and rounded quartz erodents, the erosion rate increased with increasing CVF, while the reverse was true with crushed quartz. The crushed quartz erodent gave an erosion rate only slightly lower than that of alumina, indicating that the carbide erosion resistance is not a strong function of erodent particle hardness in this range of hardness. Scanning electron microscope (SEM) observations of the eroded surfaces showed that erosion of the highest-CVF white cast iron alloy with alumina or rounded quartz resulted in depression of the large primary carbides, while with crushed quartz many of the carbides protruded above the matrix. The SEM and erosion rate observations show that with crushed quartz the carbides are more erosion resistant than the eutectic matrix and that the carbides therfore contribute to erosion resistance, while with the other erodents the reverse is true. 17 refs., 15 figs., 2 tabs.

  12. Size Effect on Magnesium Alloy Castings

    NASA Astrophysics Data System (ADS)

    Li, Zhenming; Wang, Qigui; Luo, Alan A.; Zhang, Peng; Peng, Liming

    2016-03-01

    The effect of grain size on tensile and fatigue properties has been investigated in cast Mg alloys of Mg-2.98Nd-0.19Zn (1530 μm) and Mg-2.99Nd-0.2Zn-0.51Zr (41 μm). The difference between RB and push-pull fatigue testing was also evaluated in both alloys. The NZ30K05-T6 alloy shows much better tensile strengths (increased by 246 pct in YS and 159 pct in UTS) and fatigue strength (improved by ~80 pct) in comparison with NZ30-T6 alloy. RB fatigue testing results in higher fatigue strength compared with push-pull fatigue testing, mainly due to the stress/strain gradient in the RB specimen cross section. The material with coarse grains could be hardened more in the cyclic loading condition than in the monotonic loading condition, corresponding to the lower σ f and the higher σ f/σ b or σ f/σ 0.2 ratio compared to the materials with fine grains. The fatigue crack initiation sites and failure mechanism are mainly determined by the applied stress/strain amplitude. In LCF, fatigue failure mainly originates from the PSBs within the surface or subsurface grains of the samples. In HCF, cyclic deformation and damage irreversibly caused by environment-assisted cyclic slip is the crucial factor to influence the fatigue crack. The Coffin-Manson law and Basquin equation, and the developed MSF models and fatigue strength models can be used to predict fatigue lives and fatigue strengths of cast magnesium alloys.

  13. Near-congruent solidification of castings

    NASA Astrophysics Data System (ADS)

    Chaput, Kevin J.

    A study on the microstructure development of as-cast Cu-Mn alloys based around the congruent minimum at 34.6 wt % Mn and 873 °C was performed. Initially, this was to evaluate the alloy as an alternative to wide freezing range Pb and Sn bronzes that are plagued with porosity. The shallow minimum and associated narrow freezing ranges around the congruent point result in a completely cellular (non-dendritic) solidification morphology for a composition range ~3 wt % Mn about the congruent composition (C c). The degree of cellular solidification was found to depend on the mold material. Increased mold conductivity lead to a narrower composition range of complete cellular solidification. By casting alloys of different compositions into a composite mold, the effect of the mold conductivity allowed an evaluation of the congruent point reported by Gokcen. These results fit well with the constitutional supercooling criterion. While solidification at a point ideally would be planar, this was not observed even with minor deviations from the Cc. An additional study of the microstructure development along the minimum trough in the liquidus surface between the Cu-Mn and Ni-Mn binary congruent points of the Cu-Mn-Ni ternary system was conducted. This study revealed that alloys near the binary congruent minima were more cellular than alloys near the middle of the phase diagram, along the trough. As the composition approached the center of the Cu-Mn-Ni diagram, the morphology became more dendritic, characteristic of an isomorphous system. Even though these alloys did not solidify in a completely cellular manner, they were free of any microshrinkage porosity. The alloys in this study (Cu-Mn and Cu-Mn-Ni) show promise for use in structural applications due to the lack of microshrinkage porosity, potent solution strengthening of manganese and strong aging response.

  14. Thermal investigation of compound cast steel tools

    NASA Astrophysics Data System (ADS)

    Schaper, Mirko; Haferkamp, Heinz; Niemeyer, Matthias; Pelz, Christoph; Viets, Roman

    1999-03-01

    Tools for hot forging are exposed to complex stresses during their life-cycle. Therefore, forging dies should have a high wear resistance and toughness on the surface, combined with excellent thermal conductivity in the die body. Hot-work tool steel is appropriate for this application except from its thermal conductance. Hence, a tool consisting of hot-work tool steel in the area of contact and heat-treatable steel as die body is favorable. A smoothly graded microstructure in the joint zone between the two steel alloys is needed to match with the requirements. Fabrication of such functionally graded dies by sand casting exhibits high sensitivity to temperature and geometry dependent parameters. To melt on the inlay's surface must be ensured without destroying this region according to overheat coarsening and mixing of alloying elements. Instead of empirical methods to optimize the process parameters, a thermographic CCD-device is used for visualization of the heat flow while pouring the melt on the inlay. In fact the molten metal flow can be directed homogeneously across the bonding surface at adequate temperatures after evaluation of thermography data. The use of a silica-aerogel sheet as opaque window beneath the inlay in the mold enables systematic development of gating and risering, whereas undesirable scaling of the inlay due to the change of emissivity is retarded. Infrared image sequences clearly demonstrate the influence of different ring gating systems concerning the filling properties. Non-joined cavities may even be classified from image data. Compound cast steel tools have been manufactured and examined in forging trials validating life-cycle prolongation.

  15. Size Effect on Magnesium Alloy Castings

    NASA Astrophysics Data System (ADS)

    Li, Zhenming; Wang, Qigui; Luo, Alan A.; Zhang, Peng; Peng, Liming

    2016-06-01

    The effect of grain size on tensile and fatigue properties has been investigated in cast Mg alloys of Mg-2.98Nd-0.19Zn (1530 μm) and Mg-2.99Nd-0.2Zn-0.51Zr (41 μm). The difference between RB and push-pull fatigue testing was also evaluated in both alloys. The NZ30K05-T6 alloy shows much better tensile strengths (increased by 246 pct in YS and 159 pct in UTS) and fatigue strength (improved by ~80 pct) in comparison with NZ30-T6 alloy. RB fatigue testing results in higher fatigue strength compared with push-pull fatigue testing, mainly due to the stress/strain gradient in the RB specimen cross section. The material with coarse grains could be hardened more in the cyclic loading condition than in the monotonic loading condition, corresponding to the lower σ f and the higher σ f/ σ b or σ f/ σ 0.2 ratio compared to the materials with fine grains. The fatigue crack initiation sites and failure mechanism are mainly determined by the applied stress/strain amplitude. In LCF, fatigue failure mainly originates from the PSBs within the surface or subsurface grains of the samples. In HCF, cyclic deformation and damage irreversibly caused by environment-assisted cyclic slip is the crucial factor to influence the fatigue crack. The Coffin-Manson law and Basquin equation, and the developed MSF models and fatigue strength models can be used to predict fatigue lives and fatigue strengths of cast magnesium alloys.

  16. The influence of master cast technique on the cast precision of implant-retained fixed prostheses.

    PubMed

    Rodrigues, Mariana Agustinho; Luthi, Leonardo Flores; Henriques, Guilherme Elias Pessanha

    2012-01-01

    The aim of this study was to evaluate the precision of three different mold filling techniques in order to obtain a cast simulating a three-unit, implant-retained, fixed prosthesis. Thirty casts (n = 10) were obtained using three different mold filling techniques. Group 1 used a unique fulfillment technique, Group 2 used a two-step fulfillment technique, and Group 3 used a latex cylinder technique. Using a metallic matrix, a titanium substructure was created to simulate a three-unit fixed prosthesis used as reference to evaluate the marginal misfit and tension forces in each cast. The vertical misfit was measured by an optical microscope with an increase of 120X and by an analysis unit using the one-screw test. The tension was quantified using strain gauges. The strain results showed a statistical difference between Group 3 and the other groups. The Tukey test showed no difference between the different treatment groups (p = 0.05). All three techniques were deemed efficient; however, considering that the cylinder latex technique induced less force toward the implants, it is the preferable technique for daily clinical practice. PMID:22414505

  17. Irradiation response of delta ferrite in as-cast and thermally aged cast stainless steel

    NASA Astrophysics Data System (ADS)

    Li, Zhangbo; Lo, Wei-Yang; Chen, Yiren; Pakarinen, Janne; Wu, Yaqiao; Allen, Todd; Yang, Yong

    2015-11-01

    To enable the life extension of Light Water Reactors (LWRs) beyond 60 years, it is critical to gain adequate knowledge for making conclusive predictions to assure the integrity of duplex stainless steel reactor components, e.g. primary pressure boundary and reactor vessel internal. Microstructural changes in the ferrite of thermally aged, neutron irradiated only, and neutron irradiated after being thermally aged cast austenitic stainless steels (CASS) were investigated using atom probe tomography. The thermal aging was performed at 400 °C for 10,000 h and the irradiation was conducted in the Halden reactor at ˜315 °C to 0.08 dpa (5.6 × 1019 n/cm2, E > 1 MeV). Low dose neutron irradiation at a dose rate of 5 × 10-9 dpa/s was found to induce spinodal decomposition in the ferrite of as-cast microstructure, and further to enhance the spinodal decomposition in the thermally aged cast alloys. Regarding the G-phase precipitates, the neutron irradiation dramatically increases the precipitate size, and alters the composition of the precipitates with increased, Mn, Ni, Si and Mo and reduced Fe and Cr contents. The results have shown that low dose neutron irradiation can further accelerate the degradation of ferrite in a duplex stainless steel at the LWR relevant condition.

  18. Melting and casting characteristics of aluminum alloy A356-SiC particulate reinforced cast composites

    SciTech Connect

    Yarandi, F.M.

    1991-01-01

    Melting and casting characteristics of A356 (Al 7% Si) alloy reinforced with 10, 15, and 20 vol. % SiC particles were studied. Remelting followed by holding and solidification of these composites leads to settling of the SiC particles to the bottom of the mold. The height of the SiC particle-free zone formed at the top of the mold, as a result of settling, is referred to as the denuded zone. A356 with 20 vol. % SiC ({approximately}14-{mu} particle size) showed larger denuded zones for a given settling time compared to the system with 10 or 15 vol. % SiC. The permanent mold and sand mold spiral fluidities, and permanent mold casting fluidity of Al A356-SiC particle melt slurry generally decrease with increasing vol. % of a given size SiC. The fluidity values increase with temperature until a temperature range of 740-760C. Solidification microstructures formed during static settling and during flow along the length of the casting fluidity for SiC particle composites were analyzed. Influences of cooling rate, settling time, and oxide films on solidification microstructures were investigated.

  19. Geographic variation of caste structure among ant populations.

    PubMed

    Yang, Andrew S; Martin, Christopher H; Nijhout, H Frederik

    2004-03-23

    Morphologically distinct worker castes of eusocial insects specialize in different tasks. The relative proportions of these castes and their body sizes represent the demography of a colony that is predicted to vary adaptively with environments. Despite strong theoretical foundations, there has been little empirical evidence for the evolution of colony demography in nature. We show that geographically distinct populations of the ant Pheidole morrisi differ in worker caste ratios and worker body sizes in a manner consistent with microevolutionary divergence. We further show that the developmental mechanism for caste determination accounts for the unique pattern of covariation observed in these two traits. Behavioral data reveal that the frequency of different tasks performed by workers changes in a caste-specific manner when caste ratios are altered and demonstrate the importance of the major caste in colony defense. The population-level variation documented here for P. morrisi colonies supports the predictions of adaptive demography theory and illustrates that developmental mechanisms can play a significant role in shaping the evolution of phenotype at the colony level. PMID:15043818

  20. Development of a thin steel strip casting process. Final report

    SciTech Connect

    Williams, R.S.

    1994-04-01

    This is a comprehensive effort to develop direct strip casting to the point where a pilot scale program for casting carbon steel strip could be initiated. All important aspects of the technology were being investigated, however the program was terminated early due to a change in the business strategy of the primary contractor, Armco Inc. (focus to be directed at specialty steels, not low carbon steel). At termination, the project was on target on all milestones and under budget. Major part was casting of strip at the experiment casting facility. A new caster, capable of producing direct cast strip of up to 12 in. wide in heats of 1000 and 3000 lb, was used. A total of 81 1000-1200 lb heats were cast as well as one test heat of 3000 lb. Most produced strip of from 0.016 to 0.085 in. thick. Process reliability was excellent for short casting times; quality was generally poor from modern hot strip mill standards, but the practices necessary for good surface quality were identified.

  1. Development of a CFD code for casting simulation

    NASA Technical Reports Server (NTRS)

    Murph, Jesse E.

    1993-01-01

    Because of high rejection rates for large structural castings (e.g., the Space Shuttle Main Engine Alternate Turbopump Design Program), a reliable casting simulation computer code is very desirable. This code would reduce both the development time and life cycle costs by allowing accurate modeling of the entire casting process. While this code could be used for other types of castings, the most significant reductions of time and cost would probably be realized in complex investment castings, where any reduction in the number of development castings would be of significant benefit. The casting process is conveniently divided into three distinct phases: (1) mold filling, where the melt is poured or forced into the mold cavity; (2) solidification, where the melt undergoes a phase change to the solid state; and (3) cool down, where the solidified part continues to cool to ambient conditions. While these phases may appear to be separate and distinct, temporal overlaps do exist between phases (e.g., local solidification occurring during mold filling), and some phenomenological events are affected by others (e.g., residual stresses depend on solidification and cooling rates). Therefore, a reliable code must accurately model all three phases and the interactions between each. While many codes have been developed (to various stages of complexity) to model the solidification and cool down phases, only a few codes have been developed to model mold filling.

  2. Predicting Pattern Tooling and Casting Dimensions for Investment Casting, Phase III

    SciTech Connect

    Sabau, Adrian S

    2008-04-01

    Efforts during Phase III focused mainly on the shell-alloy systems. A high melting point alloy, 17-4PH stainless steel, was considered. The experimental part of the program was conducted at ORNL and commercial foundries, where wax patterns were injected, molds were invested, and alloys were poured. Shell molds made of fused-silica and alumino-silicates were considered. A literature review was conducted on thermophysical and thermomechanical properties alumino-silicates. Material property data, which were not available from material suppliers, was obtained. For all the properties of 17-4PH stainless steel, the experimental data available in the literature did not cover the entire temperature range necessary for process simulation. Thus, some material properties were evaluated using ProCAST, based on CompuTherm database. A comparison between the predicted material property data and measured property data was made. It was found that most material properties were accurately predicted only over several temperature ranges. No experimental data for plastic modulus were found. Thus, several assumptions were made and ProCAST recommendations were followed in order to obtain a complete set of mechanical property data at high temperatures. Thermal expansion measurements for the 17-4PH alloy were conducted during heating and cooling. As a function of temperature, the thermal expansion for both the alloy and shell mold materials showed different evolution on heating and cooling. Numerical simulations were performed using ProCAST for the investment casting of 17-4PH stainless steel parts in fused silica molds using the thermal expansion obtained on heating and another one with thermal expansion obtained on cooling. Since the fused silica shells had the lowest thermal expansion properties in the industry, the dewaxing phase, including the coupling between wax-shell systems, was neglected. The shell mold was considered to be a pure elastic material. The alloy dimensions were obtained from numerical simulations. For 17-4PH stainless steel parts, the alloy shrinkage factors were over-predicted, as compared with experimental data. Additional R&D focus was placed on obtaining material property data for filled waxes, waxes that are common in the industry. For the first time in the investment casting industry, the thermo-mechanical properties of unfilled and filled waxes were measured. Test specimens of three waxes were injected at commercial foundries. Rheometry measurement of filled waxes was conducted at ORNL. The analysis of the rheometry data to obtain viscoelastic properties was not completed due to the reduction in the budget of the project (approximately 50% funds were received).

  3. A study of interfacial heat transfer and process parameters in squeeze casting and low pressure permanent mold casting

    NASA Astrophysics Data System (ADS)

    Krishna, Prasad

    2001-08-01

    With the emerging demand for energy efficient and environment-friendly automobiles, cast aluminum alloys are increasingly being used in their manufacture. In this context, two permanent mold casting processes, namely, Squeeze Cast Permanent Mold and Low Pressure Permanent Mold (LPPM) have become very popular in the production of high integrity shape-cast aluminum components. However, many industries are yet to benefit from the full potential of these processes due to limited understanding of the effect of process parameters on casting quality and the necessary boundary conditions for computer modeling and simulation so as to minimize costly field trials. This dissertation attempts to address some of these concerns facing today's foundry industry. An experimental investigation of the Indirect Squeeze Casting Process was conducted by pouring molten Al-7Si-0.3Mg (A356) alloy into a specially designed and instrumented mold, mounted on a horizontal clamped-vertical shot squeeze caster (HVSC). Temperature measurements close to the metal/mold interface were made and compared with the results of the numerical simulation of heat flow during solidification and cooling of castings. The Heat Transfer Coefficient (HTC), a critical parameter essential for any solidification simulation, was estimated based on the simulation that gave the best fit to the experimental temperature data. During the solidification process, the HTC is relatively uniform over the entire casting and on reaching a critical solidification pressure, the HTC is close to 4500 W/m2 K. The work has also provided a correlation of Secondary Dendrite Arm Spacing (SDAS) with cooling rate for a modified A356 alloy. Low Pressure Permanent Mold Casting experiments were conducted by pouring a nearly identical aluminum alloy into an instrumented, coated mold mounted on a low pressure casting machine. The pressure levels, along with the time required to achieve complete filling, were microprocessor controlled in the casting machine. The HTC evaluation and SDAS-Cooling Rate Correlation were made in a similar manner to the Squeeze Casting study. A novel approach to estimating the HTC, accounting for the temporal and spatial temperature and thermal property variations, is presented. The maximum and minimum values of the HTC in this case were close to 2000 W/m2 K with no air gap and 400 W/m2 K with an air gap formation. The influences of air gap formation and mold coatings in controlling interfacial heat transfer were also modeled. It is expected that the HTCs and SDAS-Cooling Rate Correlations for the two casting processes will assist foundry engineers in deriving maximum benefits from each process.

  4. Stress Corrosion Cracking Behavior of Cast Stainless Steels

    SciTech Connect

    Teysseyre, Sebastien; Busby, Jeremy T; Was, Gary

    2009-01-01

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

  5. Shrinkage Prediction for the Investment Casting of Stainless Steels

    SciTech Connect

    Sabau, Adrian S

    2007-01-01

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

  6. Melting and casting processes for high-temperature intermetallics

    SciTech Connect

    Sen, Subhayu; Stefanescu, D.M. )

    1991-05-01

    Most of the metallic systems thus far identified as promising from the commercial viewpoint are composed of elements which are either susceptible to oxidation, such as Al, or highly reactive, such as Ti; these characteristics entail the use of such melting and casting techniques as vacuum-induction melting, vacuum-arc remelting, electroslag refining, plasma-arc melting, spray casting, and directional solidification. Spray casting is noteworthy both in its ability to produce near-net-shape components and its inherent reduction of the oxygen and hydrogen pickup which has been associated with the embrittlement of aluminides. 24 refs.

  7. Filler metal alloy for welding cast nickel aluminide alloys

    DOEpatents

    Santella, M.L.; Sikka, V.K.

    1998-03-10

    A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

  8. Design and Analysis for Melt Casting Metallic Fuel Pins

    SciTech Connect

    Wu, Xiaolong; Clarksean, Randy; Chen, Yitung; Meyer, Mitchell K.

    2002-07-01

    A concept for the casting of metallic fuels pins containing low vapor pressure materials is presented and discussed. The important physics of this concept include the mass transport of americium from the melt, the induction heating and stirring of the melt, plus the casting of long slender fuel rods. This paper discusses and presents preliminary modeling results for the casting of long, slender fuel rods. The model considers the flow of the melt into the molds, heat transfer into the molds, and the impact of process parameters on the formation of the fuel rod. (authors)

  9. Method to prevent/mitigate steam explosions in casting pits

    DOEpatents

    Taleyarkhan, Rusi P.

    1996-01-01

    Steam explosions can be prevented or mitigated during a metal casting process by the placement of a perforated flooring system in the casting pit. An upward flow of compressed gas through this perforated flooring system is introduced during the casting process to produce a buffer layer between any spilled molten metal and the cooling water in the reservoir. This buffer layer provides a hydrodynamic layer which acts to prevent or mitigate steam explosions resulting from hot, molten metal being spilled into or onto the cooling water.

  10. Method to prevent/mitigate steam explosions in casting pits

    DOEpatents

    Taleyarkhan, R.P.

    1996-12-24

    Steam explosions can be prevented or mitigated during a metal casting process by the placement of a perforated flooring system in the casting pit. An upward flow of compressed gas through this perforated flooring system is introduced during the casting process to produce a buffer layer between any spilled molten metal and the cooling water in the reservoir. This buffer layer provides a hydrodynamic layer which acts to prevent or mitigate steam explosions resulting from hot, molten metal being spilled into or onto the cooling water. 3 figs.

  11. Numerical Simulation of Cast Distortion in Gas Turbine Engine Components

    NASA Astrophysics Data System (ADS)

    Inozemtsev, A. A.; Dubrovskaya, A. S.; Dongauser, K. A.; Trufanov, N. A.

    2015-06-01

    In this paper the process of multiple airfoilvanes manufacturing through investment casting is considered. The mathematical model of the full contact problem is built to determine stress strain state in a cast during the process of solidification. Studies are carried out in viscoelastoplastic statement. Numerical simulation of the explored process is implemented with ProCASTsoftware package. The results of simulation are compared with the real production process. By means of computer analysis the optimization of technical process parameters is done in order to eliminate the defect of cast walls thickness variation.

  12. Freeze Tape Casting of Functionally Graded Porous Ceramics

    NASA Technical Reports Server (NTRS)

    Sofie, Stephen W.

    2007-01-01

    Freeze tape casting is a means of making preforms of ceramic sheets that, upon subsequent completion of fabrication processing, can have anisotropic and/or functionally graded properties that notably include aligned and graded porosity. Freeze tape casting was developed to enable optimization of the microstructures of porous ceramic components for use as solid oxide electrodes in fuel cells: Through alignment and grading of pores, one can tailor surface areas and diffusion channels for flows of gas and liquid species involved in fuel-cell reactions. Freeze tape casting offers similar benefits for fabrication of optimally porous ceramics for use as catalysts, gas sensors, and filters.

  13. Corrosive wear of cast iron under reciprocating lubrication

    SciTech Connect

    Yahagi, Y.; Nagasawa, Y.; Hotta, S.; Mizutani, Y.

    1986-01-01

    In order to study the wear of cylinder bore fundamentally, a reciprocating friction tester was produced and utilized. The friction between a cast iron and a piston-ring and the wear of the cast iron were examined under the corrosive oil with sulphuric acid. The findings indicate that the friction and wear around TDC and BDC was confirmed to be greater than between these reversal points and the friction and wear around the reversal points increased with the sulphuric acid which has caused the deficiency of oil film and the corrosion of the cast iron.

  14. Advanced rotary engine components utilizing fiber reinforced Mg castings

    NASA Technical Reports Server (NTRS)

    Goddard, D.; Whitman, W.; Pumphrey, R.; Lee, C.-M.

    1986-01-01

    Under a two-phase program sponsored by NASA, the technology for producing advanced rotary engine components utilizing graphite fiber-reinforced magnesium alloy casting is being developed. In Phase I, the successful casting of a simulated intermediate housing was demonstrated. In Phase II, the goal is to produce an operating rotor housing. The effort involves generation of a material property data base, optimization of parameters, and development of wear- and corrosion-resistant cast surfaces and surface coatings. Results to date are described.

  15. A combined experimental and modeling approach to uranium casting

    SciTech Connect

    Korzekwa, D.; Dunn, P.

    1994-08-01

    U casting was studied using a combined experimental and modeling approach; the U is cast into graphite molds using vacuum induction melting. Mold design and process parameters were varied. FLOW-3D and ABAQUS codes were used. Temperature predictions were compared with experimental data from thermcouples in the mold; initial metal and mold temperatures were used in input to FLOW-3D. Fluid flow predictions were validated using static and dynamic radiographic data. Dynamic radiographic videos of gold castings were compared to 3D simulations.

  16. An accelerated clinical chairside technique for casting overdenture attachment copings.

    PubMed

    Scherer, Michael D; Campagni, Wayne V

    2011-11-01

    An accelerated technique for casting a direct-pattern post and core restoration for use in fixed prosthodontics has been previously described. Similar techniques for use in removable prosthodontics show potential for clinical use, specifically for the fabrication of radicular stud overdenture attachments and their corresponding copings. The procedure uses a chairside technique and readily available components to fabricate a direct, acrylic resin pattern combining the elements of a cast coping with a fixed radicular attachment. This pattern can subsequently be invested, cast, finished and polished, luted, and attached to the removable prosthesis in a single clinical appointment. PMID:22024184

  17. Hanford's Simulated Low Activity Waste Cast Stone Processing

    SciTech Connect

    Kim, Young

    2013-08-20

    Cast Stone is undergoing evaluation as the supplemental treatment technology for Hanford’s (Washington) high activity waste (HAW) and low activity waste (LAW). This report will only cover the LAW Cast Stone. The programs used for this simulated Cast Stone were gradient density change, compressive strength, and salt waste form phase identification. Gradient density changes show a favorable outcome by showing uniformity even though it was hypothesized differently. Compressive strength exceeded the minimum strength required by Hanford and greater compressive strength increase seen between the uses of different salt solution The salt waste form phase is still an ongoing process as this time and could not be concluded.

  18. Fabricating an Accurate Implant Master Cast: A Technique Report.

    PubMed

    Balshi, Thomas J; Wolfinger, Glenn J; Alfano, Stephen G; Cacovean, Jeannine N; Balshi, Stephen F

    2015-12-01

    The technique for fabricating an accurate implant master cast following the 12-week healing period after Teeth in a Day® dental implant surgery is detailed. The clinical, functional, and esthetic details captured during the final master impression are vital to creating an accurate master cast. This technique uses the properties of the all-acrylic resin interim prosthesis to capture these details. This impression captures the relationship between the remodeled soft tissue and the interim prosthesis. This provides the laboratory technician with an accurate orientation of the implant replicas in the master cast with which a passive fitting restoration can be fabricated. PMID:26215098

  19. Working-class royalty: bees beat the caste system.

    PubMed

    Wenseleers, Tom; Ratnieks, Francis L W; de F Ribeiro, Marcia; de A Alves, Denise; Imperatriz-Fonseca, Vera-Lucia

    2005-06-22

    The struggle among social classes or castes is well known in humans. Here, we show that caste inequality similarly affects societies of ants, bees and wasps, where castes are morphologically distinct and workers have greatly reduced reproductive potential compared with queens. In social insects, an individual normally has no control over its own fate, whether queen or worker, as this is socially determined during rearing. Here, for the first time, we quantify a strategy for overcoming social control. In the stingless bee Schwarziana quadripunctata, some individuals reared in worker cells avoid a worker fate by developing into fully functional dwarf queens. PMID:17148145

  20. Prosthetic management of malpositioned implant using custom cast abutment

    PubMed Central

    Chatterjee, Aishwarya; Ragher, Mallikarjuna; Patil, Sanket; Chatterjee, Debopriya; Dandekeri, Savita; Prabhu, Vishnu

    2015-01-01

    Two cases are reported with malpositioned implants. Both the implants were placed 6–7 months back. They had osseointegrated well with the surrounding bone. However, they presented severe facial inclination. Case I was restored with custom cast abutment with an auto polymerizing acrylic gingival veneer. Case II was restored with custom cast UCLA type plastic implant abutment. Ceramic was directly fired on the custom cast abutments. The dual treatment strategy resulted in functional and esthetic restorations despite facial malposition of the implants. PMID:26538957

  1. X-ray detectors of the CAST experiment

    NASA Astrophysics Data System (ADS)

    Yildiz, S. C.

    2014-03-01

    CERN Axion Solar Telescope (CAST) is an experiment probing hypothetical particles: the axions, created in the solar core. Inside the transverse magnetic field of the CAST magnet, axions can be converted into x-rays, and be detected by four x-ray detectors at CAST. The expected x-ray signal in CAST is in 1-10 keV range, intensity depending strongly on the coupling constant of axion-photon conversion gaγ, which is expected to be low. This requires CAST to have detectors with very low background levels. The CAST Experiment makes use of three Micromesh Gaseous Structure (micromegas) detectors, which are gaseous detectors, derived from ideas of Multiwire Proportional Chambers (MWPC). CAST Micromegas detectors show perfect stability, good spatial and energy resolution. The intense study on Micromegas has enabled CAST to understand the nature of its background level, and improve it by a factor of 102 over ten years. New detector design, new readout system, better cosmic veto and addition of x-ray telescope will further improve the background in the next data taking of the experiment. The Charge-Coupled Device (CCD) of CAST is a pn-CCD detector with 200 × 64 pixels. The CAST CCD is coupled to an X-ray telescope, focusing all the parallel x-rays into a 9 mm diameter spot. The CCD will be replaced by the InGrid detector, a special manufactured micromegas detector. It is able to detect single electrons, and the low energy capabilities will open new frontiers on search of axions and other exotic particles. Another option is the Silicon Drift Detector (SDD), which is being tested in 2013, and has an energy threshold as low as 250 eV. The CAST experiment is the pioneering helioscope that excludes an important part of axion mass-coupling constant parameter space, and expects to exclude more in the following years. To succeed CAST, a new experiment, the International AXion Observatory (IAXO) is being designed and optimised, comprising the construction of a magnet specially built for axion search as well as new detectors that will enable to improve the actual limits by 1-1.5 orders of magnitude.

  2. Optimization of Squeeze Casting for Aluminum Alloy Parts

    SciTech Connect

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

    2002-07-30

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

  3. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  4. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  5. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  6. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  7. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  8. Advanced lost foam casting quarterly report, October 1, 1995--December 31, 1995

    SciTech Connect

    1995-12-31

    Objective is to advance the state of the art in lost foam casting technology, in order to improve the competitiveness of the US metals casting industries. The following tasks are reported on pyrolysis defects and sand distortion, bronze casting technology, steel casting technology, sand filling and compaction, coating technology, precision pattern production, and computational modeling.

  9. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... line which extends through the building wall must be of steel pipe. (c) A cast iron or ductile iron... 49 Transportation 3 2011-10-01 2011-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile...

  10. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... line which extends through the building wall must be of steel pipe. (c) A cast iron or ductile iron... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile...

  11. 40 CFR 464.20 - Applicability; description of the copper casting subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION... Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory. The... introduction of pollutants into publicly owned treatment works resulting from copper casting operations...

  12. 40 CFR 464.20 - Applicability; description of the copper casting subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION... Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory. The... introduction of pollutants into publicly owned treatment works resulting from copper casting operations...

  13. Clean ferrous casting technology research. Final technical report, September 29, 1993--December 31, 1995

    SciTech Connect

    Piwonka, T.S.

    1996-01-01

    This report details results of a 30-month program to develop methods of making clean ferrous castings, i.e., castings free of inclusions and surface defects. The program was divided into 3 tasks: techniques for producing clean steel castings, electromagnetic removal of inclusions from ferrous melts, and study of causes of metal penetration in sand molds in cast iron.

  14. 40 CFR 464.20 - Applicability; description of the copper casting subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory... introduction of pollutants into publicly owned treatment works resulting from copper casting operations...

  15. 40 CFR 464.20 - Applicability; description of the copper casting subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory... introduction of pollutants into publicly owned treatment works resulting from copper casting operations...

  16. 40 CFR 464.20 - Applicability; description of the copper casting subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory... introduction of pollutants into publicly owned treatment works resulting from copper casting operations...

  17. 40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... aluminum casting subcategory. 464.10 Section 464.10 Protection of Environment ENVIRONMENTAL PROTECTION... Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The... introduction of pollutants into publicly owned treatment works resulting from aluminum casting operations...

  18. 40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... aluminum casting subcategory. 464.10 Section 464.10 Protection of Environment ENVIRONMENTAL PROTECTION... Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The... introduction of pollutants into publicly owned treatment works resulting from aluminum casting operations...

  19. Study of FES/CAST/HGS

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Cummings, Rick; Jones, Brian

    1992-01-01

    The microgravity materials processing program has been instrumental in providing the crystal growth community with an experimental environment to better understand the phenomena associated with the growing of crystals. In many applications one may pursue the growth of large single crystals which cannot be grown on earth due to convective driven flows. A microgravity environment is characterized by neither convection of buoyancy. Consequently superior crystals are able to be grown in space. On the other hand, since neither convection nor buoyancy dominates the fluid flow in a microgravity environment, then lesser dominating phenomena can affect crystal growth, such as surface driven flows or diffusion limited solidification. In the case of experiments that are to be flown in space using the Fluid Experiments System (FES), diffusion limited growth should be the dominating phenomenon. The use of holographic and Schlieren optical techniques for studying the concentration gradients in solidification processes has been used by several investigators over the years. The Holographic Ground System (HGS) facility at MSFC has been a primary resource in researching this capability. Consequently scientific personnel have been able to utilize these techniques in both ground based research and in space experiments. An important event in the scientific utilization of the HGS facilities was the TGS (triglycine sulfate) Crystal Growth and the Casting and Solidification Technology (CAST) experiments that were flown on the International Microgravity Lab (IML) mission in March of this year. The preparation and processing of these space observations are the primary experiments reported in this work. This project provides some ground-based studies to optimize on the holographic techniques used to acquire information about the crystal growth processes flown on IML. Since the ground-based studies will be compared with the space-based experimental results, it is necessary to conduct sufficient ground based studies to best determine how the experiment in space worked. The current capabilities in computer based systems for image processing and numerical computation have certainly assisted in those efforts. As anticipated, this study has certainly shown that these advanced computing capabilities are helpful in the data analysis of such experiments.

  20. Assessment of thermal embrittlement of cast stainless steels

    SciTech Connect

    Chopra, O.K.; Shack, W.J.

    1994-05-01

    A procedure and correlations are presented for assessing thermal embrittlement and predicting Charpy-impact energy and fracture toughness J-R curve of cast stainless steel components under Light Water Reactor operating conditions from known material information. The ``saturation`` impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Fracture properties as a function of time and temperature of reactor service are estimated from the kinetics of embrittlement, which are also determined from chemical composition. A common ``predicted lower-bound`` J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature. Examples of estimating fracture toughness of cast stainless steel components during reactor service are presented.

  1. 41. Casting floor, "B" furnace, pour in progress; mudgun is ...

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

    41. Casting floor, "B" furnace, pour in progress; mudgun is to right of furnace; photo taken from furnace operator's booth. Looking south/southwest - Rouge Steel Company, 3001 Miller Road, Dearborn, Wayne County, MI

  2. Nuclear-waste encapsulation by metal-matrix casting

    SciTech Connect

    Nelson, R.G.; Nesbitt, J.F.; Slate, S.C.

    1981-05-01

    Several encapsulation casting processes are described that were developed or used at the Pacific Northwest Laboratory to embed simulated high-level wastes of two different forms (glass marbles and ceramic pellets) in metal matrices. Preliminary evaluations of these casting processes and the products are presented. Demonstrations have shown that 5- to 10-mm-dia glass marbles can be encapsulated on an engineering scale with lead or lead alloys by gravity or vacuum processes. Marbles approx. 12 mm in dia were successfully encapsulated in a lead alloy on a production scale. Also, 4- to 9-mm-dia ceramic pellets in containers of various sizes were completely penetrated and the individual pellets encased with aluminum-12 wt % silicon alloy by vacuum processes. Indications are that of the casting processes tested, aluminum 12 wt % silicon alloy vacuum-cast around ceramic pellets had the highest degree of infiltration or coverage of pellet surfaces.

  3. Casting Simulation of an Austrian Bronze Age Sword Hilt

    NASA Astrophysics Data System (ADS)

    Pola, Annalisa; Mödlinger, Marianne; Piccardo, Paolo; Montesano, Lorenzo

    2015-07-01

    Bronze Age swords with a metal hilt can be considered the peak of Bronze Age casting technologies. To reconstruct the casting techniques used more than 3000 years ago, a metal hilted sword of the Schalenknauf type from Lower Austria was studied with the aid of macroscopic analyses and simulation of mold filling and casting solidification. A three-dimensional model of the hilt was created based on optical scanner measurements performed on a hilt recently discovered during archaeological excavations. Three different configurations of the gating system were considered, two on the pommel disk and one on the knob, and the effect of its location on the formation of casting defects was investigated. Three-dimensional computed tomography was used to detect internal defects, such as gas and shrinkage porosity, which were then compared with those calculated by simulation. The best match between actual and predicted hilt quality demonstrated the location of the gating system, which turned out to be on the pommel disk.

  4. 4. INTERIOR, FOUNDRY CA. 1919 SHOWING CASTINGS READY FOR CLEANING ...

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

    4. INTERIOR, FOUNDRY CA. 1919 SHOWING CASTINGS READY FOR CLEANING AND FOUNDRY FLASKS TO RIGHT. - Hardie-Tynes Manufacturing Company, Workshop, 800 Twenty-eighth Street North, Birmingham, Jefferson County, AL

  5. 10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR ...

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

    10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR STOREFRONT, SHOWING MANUFACTURER'S STAMP: IOWA IRON WOKS CO. DUBUQUE. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Dubuque Seed Company Warehouse, 169-171 Iowa Street, Dubuque, Dubuque County, IA

  6. 25. Detail of cast iron lamp post base with fluted ...

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

    25. Detail of cast iron lamp post base with fluted wooded post at top, located at north end of bridge. VIEW NORTHEAST - Chelsea Street Bridge & Draw Tender's House, Spanning Chelsea River, Boston, Suffolk County, MA

  7. Advanced lost foam casting technology. 1995 summary report

    SciTech Connect

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

    1996-05-01

    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; and Task 5: Mechanical Properties of Castings. This report summarizes the work done under the current contract in all five areas. 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. This report summarizes the work done in the past two years and the conclusions drawn from the work.

  8. Adjustable hinge permits movement of knee in plaster cast

    NASA Technical Reports Server (NTRS)

    Maley, W. E.

    1967-01-01

    Metal knee hinge with an adjustable sleeve worn on the outside of a leg cast facilitates movement of the knee joint. This helps eliminate stiffness of the knee and eliminates bulkiness and adjustment difficulty.

  9. Adhesive Wear Behavior of Heat Treated Spheroidal Graphite Cast Iron

    NASA Astrophysics Data System (ADS)

    Salim, M.; Shama, S.; Mozumder, Y. H.; Behera, R. K.; P, Sindhoora L.; Pattanaik, A.; Mishra, S. C.; Sen, S.

    2015-02-01

    Spheroidal graphite cast iron is one of the most favorable materials in cast iron family due to its wide range of mechanical and tribological properties. In the current research priority is given towards the investigation of wear system response of spheroidal graphite cast iron subjected to various heat treatment conditions. Pearlitic/ferritic and upper bainitic matrix was obtained through normalizing and austempering treatment for an austenitizing temperature of 1000°C. Dry sliding wear test was performed at 10N, 20N, 30N for a sliding distance of 7.54m. With increase in load weight loss was observed for as-cast specimen whereas normalized specimen showed very less weight loss with increasing load. On the other hand the austempered specimen observed to lose weight when operated at 10N, whereas at 20N and 30N drastic gain in weight was observed.

  10. Structural Factors Affecting Formability of Continuous Cast Aluminum Alloys

    SciTech Connect

    2001-10-01

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

  11. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-iron pipelines. When an operator has knowledge that the support for a segment of a buried cast-iron... blasting; (2) Impact forces by vehicles; (3) Earth movement; (4) Apparent future excavations near...

  12. 49 CFR 192.755 - Protecting cast-iron pipelines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-iron pipelines. When an operator has knowledge that the support for a segment of a buried cast-iron... blasting; (2) Impact forces by vehicles; (3) Earth movement; (4) Apparent future excavations near...

  13. Development Program for Natural Aging Aluminum Casting Alloys

    SciTech Connect

    Dr. Geoffrey K. Sigworth

    2004-05-14

    A number of 7xx aluminum casting alloys are based on the ternary Al-Zn-Mg system. These alloys age naturally to high strength at room temperature. A high temperature solution and aging treatment is not required. Consequently, these alloys have the potential to deliver properties nearly equivalent to conventional A356-T6 (Al-Si-Mg) castings, with a significant cost saving. An energy savings is also possible. In spite of these advantages, the 7xx casting alloys are seldom used, primarily because of their reputation for poor castibility. This paper describes the results obtained in a DOE-funded research study of these alloys, which is part of the DOE-OIT ''Cast Metals Industries of the Future'' Program. Suggestions for possible commercial use are also given.

  14. Awareness Programs and Change in Taste-Based Caste Prejudice

    PubMed Central

    Banerjee, Ritwik; Datta Gupta, Nabanita

    2015-01-01

    Becker's theory of taste-based discrimination predicts that relative employment of the discriminated social group will improve if there is a decrease in the level of prejudice for the marginally discriminating employer. In this paper we experimentally test this prediction offered by Garry Becker in his seminal work on taste based discrimination, in the context of caste in India, with management students (potential employers in the near future) as subjects. First, we measure caste prejudice and show that awareness through a TV social program reduces implicit prejudice against the lower caste and the reduction is sustained over time. Second, we find that the treatment reduces the prejudice levels of those in the left tail of the prejudice distribution - the group which can potentially affect real outcomes as predicted by the theory. And finally, a larger share of the treatment group subjects exhibit favorable opinion about reservation in jobs for the lower caste. PMID:25902290

  15. Awareness programs and change in taste-based caste prejudice.

    PubMed

    Banerjee, Ritwik; Datta Gupta, Nabanita

    2015-01-01

    Becker's theory of taste-based discrimination predicts that relative employment of the discriminated social group will improve if there is a decrease in the level of prejudice for the marginally discriminating employer. In this paper we experimentally test this prediction offered by Garry Becker in his seminal work on taste based discrimination, in the context of caste in India, with management students (potential employers in the near future) as subjects. First, we measure caste prejudice and show that awareness through a TV social program reduces implicit prejudice against the lower caste and the reduction is sustained over time. Second, we find that the treatment reduces the prejudice levels of those in the left tail of the prejudice distribution--the group which can potentially affect real outcomes as predicted by the theory. And finally, a larger share of the treatment group subjects exhibit favorable opinion about reservation in jobs for the lower caste. PMID:25902290

  16. Web Cast on Arsenic Demonstration Program: Lessons Learned

    EPA Science Inventory

    Web cast presentation covered 10 Lessons Learned items selected from the Arsenic Demonstration Program with supporting information. The major items discussed include system design and performance items and the cost of the technologies.

  17. 42. Casting floor, "B" furnace, pour in progress; mudgun is ...

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

    42. Casting floor, "B" furnace, pour in progress; mudgun is to right of furnace; operator takes temperature of iron in trough during pout. Looking south - Rouge Steel Company, 3001 Miller Road, Dearborn, Wayne County, MI

  18. 3. FOURTH FLOOR OF OIL HOUSE (NOTICE CAST IRON SUPPORT ...

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

    3. FOURTH FLOOR OF OIL HOUSE (NOTICE CAST IRON SUPPORT POSTS AND OIL PRESS IN THE CENTER) - Wilson's Oil House, Lard Refinery, & Edible Fats Factory, Oil House, 2801 Southwest Fifteenth Street, Oklahoma City, Oklahoma County, OK

  19. 56. DETAIL OF BASE OF STEEL WINDMILL TOWER WITH CAST ...

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

    56. DETAIL OF BASE OF STEEL WINDMILL TOWER WITH CAST IRON HAND PUMP OVER WELL HEAD ON HIGHWAY L44 IN IOWA JUST EAST OF NEBRASKA CITY, NEBRASKA. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  20. Residual stress in spin-cast polyurethane thin films

    SciTech Connect

    Zhang, Hong; Zhang, Li

    2015-01-19

    Residual stress is inevitable during spin-casting. Herein, we report a straightforward method to evaluate the residual stress in as-cast polyurethane thin films using area shrinkage measurement of films in floating state, which shows that the residual stress is independent of radial location on the substrate and decreased with decreasing film thickness below a critical value. We demonstrate that the residual stress is developed due to the solvent evaporation after vitrification during spin-casting and the polymer chains in thin films may undergo vitrification at an increased concentration. The buildup of residual stress in spin-cast polymer films provides an insight into the size effects on the nature of polymer thin films.

  1. Casting Stainless-Steel Models Around Pressure Tubes

    NASA Technical Reports Server (NTRS)

    Vasquez, Peter; Micol, John R.

    1992-01-01

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

  2. An Energy Savings Model for the Heat Treatment of Castings

    SciTech Connect

    Y. Rong; R. Sisson; J. Morral; H. Brody

    2006-12-31

    An integrated system of software, databases, and design rules have been developed, verified, and to be marketed to enable quantitative prediction and optimization of the heat treatment of aluminum castings to increase quality, increase productivity, reduce heat treatment cycle times and reduce energy consumption. The software predicts the thermal cycle in critical locations of individual components in a furnace, the evolution of microstructure, and the attainment of properties in heat treatable aluminum alloy castings. The model takes into account the prior casting process and the specific composition of the component. The heat treatment simulation modules can be used in conjunction with software packages for simulation of the casting process. The system is built upon a quantitative understanding of the kinetics of microstructure evolution in complex multicomponent alloys, on a quantitative understanding of the interdependence of microstructure and properties, on validated kinetic and thermodynamic databases, and validated quantitative models.

  3. Bifilm Defects in Ni-Based Alloy Castings

    NASA Astrophysics Data System (ADS)

    Campbell, John; Tiryakioğlu, Murat

    2012-08-01

    The Ni-base superalloys, which are normally melted and cast in a vacuum, entrain their surface-oxide film during turbulent pouring of the melt; unfortunately at this time, this process is universally practiced for investment castings of these materials. The entrained film becomes a bifilm crack automatically, so that cast alloys have a large population of cracks that controls their failure behavior. The problems of the growth of single crystals and the welding of polycrystalline alloys are reviewed to illustrate the central role of bifilms in the cracking of turbine blades, the heat-affected zones of welds, and the reliability of properties. It has been demonstrated that improved gravity pouring systems can reduce these problems significantly, but only countergravity filling of molds is expected to result in defect-free castings. Recent cases in which turbine blades failed in service are examined, and the central role of bifilm defects in these failures is discussed.

  4. Section, Cast Iron Stair Detail and Window Details St. ...

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

    Section, Cast Iron Stair Detail and Window Details - St. Elizabeths Hospital, Atkins Hall, 2700 Martin Luther King Jr. Avenue, Southeast, 518-542 Redwood Street, Southeast, Washington, District of Columbia, DC

  5. Study Casts Doubt on Effectiveness of COPD Drug

    MedlinePLUS

    ... 157039.html Study Casts Doubt on Effectiveness of COPD Drug Research finds acetazolamide may not help patients ... help to breathe, a new study suggests. COPD (chronic obstructive pulmonary disease) -- which is often related to smoking -- includes emphysema, ...

  6. INTERIOR VIEW LOOKING WEST, CAST HOUSE OF BLAST FURNACE NO. ...

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

    INTERIOR VIEW LOOKING WEST, CAST HOUSE OF BLAST FURNACE NO. 1 AND BLAST FURNACE NO. 2. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 1 & No. 2, Donner Avenue, Monessen, Westmoreland County, PA

  7. 67. INTERIOR VIEW OF THE CAST HOUSE OR DOROTHY SIX ...

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

    67. INTERIOR VIEW OF THE CAST HOUSE OR DOROTHY SIX BLAST FURNACE LOOKING NORTHEAST. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  8. 13. SOUTHWEST VIEW OF CAST HOUSE No. 1, BLAST FURNACE ...

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

    13. SOUTHWEST VIEW OF CAST HOUSE No. 1, BLAST FURNACE No. 1, AND HOIST HOUSE No. 1. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  9. 56. LOOKING NORTH AT DOROTHY SIX BLAST FURNACE WITH CAST ...

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

    56. LOOKING NORTH AT DOROTHY SIX BLAST FURNACE WITH CAST HOUSE IN FOREGROUND AND DUSTCATCHER AT RIGHT OF FURNACE (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  10. BRASS FOUNDRY MACHINE ROOM USED TO MACHINE CAST BRONZE PIECES ...

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

    BRASS FOUNDRY MACHINE ROOM USED TO MACHINE CAST BRONZE PIECES FOR VALVES AND PREPARE BRONZE VALVE BODIES FOR ASSEMBLY. - Stockham Pipe & Fittings Company, Brass Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  11. Method of casting articles of a bulk-solidifying amorphous alloy

    DOEpatents

    Lin, Xianghong; Johnson, William L.; Peker, Atakan

    1998-01-01

    A casting charge of a bulk-solidifying amorphous alloy is cast into a mold from a temperature greater than its crystallized melting temperature, and permitted to solidify to form an article. The oxygen content of the casting charge is limited to an operable level, as excessively high oxygen contents produce premature crystallization during the casting operation. During melting, the casting charge is preferably heated to a temperature above a threshold temperature to eliminate heterogeneous crystallization nucleation sites within the casting charge. The casting charge may be cast from above the threshold temperature, or it may be cooled to the casting temperature of more than the crystallized melting point but not more than the threshold temperature, optionally held at this temperature for a period of time, and thereafter cast.

  12. Method of casting articles of a bulk-solidifying amorphous alloy

    DOEpatents

    Lin, X.; Johnson, W.L.; Peker, A.

    1998-08-25

    A casting charge of a bulk-solidifying amorphous alloy is cast into a mold from a temperature greater than its crystallized melting temperature, and permitted to solidify to form an article. The oxygen content of the casting charge is limited to an operable level, as excessively high oxygen contents produce premature crystallization during the casting operation. During melting, the casting charge is preferably heated to a temperature above a threshold temperature to eliminate heterogeneous crystallization nucleation sites within the casting charge. The casting charge may be cast from above the threshold temperature, or it may be cooled to the casting temperature of more than the crystallized melting point but not more than the threshold temperature, optionally held at this temperature for a period of time, and thereafter cast. 8 figs.

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

    SciTech Connect

    Nick Cannell; Adrian S. Sabau

    2005-09-30

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

  14. Procedure for flaw detection in cast stainless steel

    DOEpatents

    Kupperman, David S.

    1988-01-01

    A method of ultrasonic flaw detection in cast stainless steel components incorporating the steps of determining the nature of the microstructure of the cast stainless steel at the site of the flaw detection measurements by ultrasonic elements independent of the component thickness at the site; choosing from a plurality of flaw detection techniques, one such technique appropriate to the nature of the microstructure as determined and detecting flaws by use of the chosen technique.

  15. Social interactions affecting caste development through physiological actions in termites

    PubMed Central

    Watanabe, Dai; Gotoh, Hiroki; Miura, Toru; Maekawa, Kiyoto

    2014-01-01

    A colony of social insects is not only an aggregation of individuals but also a functional unit. To achieve adaptive social behavior in fluctuating environmental conditions, in addition to coordination of physiological status in each individual, the whole colony is coordinated by interactions among colony members. The study on the regulation of social-insect colonies is termed “social physiology.” Termites, a major group of social insects, exhibit many interesting phenomena related to social physiology, such as mechanisms of caste regulation in a colony. In their colonies, there are different types of individuals, i.e., castes, which show distinctive phenotypes specialized in specific colony tasks. Termite castes comprise reproductives, soldiers and workers, and the caste composition can be altered depending on circumstances. For the regulation of caste compositions, interactions among individuals, i.e., social interactions, are thought to be important. In this article, we review previous studies on the adaptive meanings and those on the proximate mechanisms of the caste regulation in termites, and try to understand those comprehensively in terms of social physiology. Firstly, we summarize classical studies on the social interactions. Secondly, previous studies on the pheromone substances that mediate the caste regulatory mechanisms are overviewed. Then, we discuss the roles of a physiological factor, juvenile hormone (JH) in the regulation of caste differentiation. Finally, we introduce the achievements of molecular studies on the animal sociality (i.e., sociogenomics) in terms of social physiology. By comparing the proximate mechanisms of social physiology in termites with those in hymenopterans, we try to get insights into the general principles of social physiology in social animals. PMID:24782780

  16. Hydrophobic aluminum nitride powder for aqueous tape casting

    SciTech Connect

    Hotza, D.; Janssen, R.; Claussen, N.; Greil, P.

    1995-09-01

    Hydrophobic AlN powder was prepared by adsorption of octadecanoic acid. The surface modified AlN powder was then used in aqueous tape casting. A statistical experimental design was employed. A comparative study of aqueous slurries and cast tapes for hydrophobic AlN and Al{sub 2}O{sub 3} was made. The effect of slurry components on slurry viscosity, tensile strength and strain to failure of green tapes was discussed.

  17. Promising method of producing cast billets from superalloys

    NASA Astrophysics Data System (ADS)

    Eremin, E. N.; Filippov, Yu. O.; Eremin, A. E.

    2010-12-01

    A new method is proposed for electroslag casting of products made of superalloys. A melt is modified by ultradispersed refractory particles, and the accumulation of a metal in a melting vessel and its pouring into a mold are performed in an argon atmosphere. The equipment designed for this method is described. The results of comparative analysis of the properties of the cast metal are presented, and the advantages of the method are shown.

  18. Extended Leach Testing of Simulated LAW Cast Stone Monoliths

    SciTech Connect

    Serne, R. Jeffrey; Westsik, Joseph H.; Williams, Benjamin D.; Jung, H. B.; Wang, Guohui

    2015-07-09

    This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.

  19. Cast Metal Coalition Research and Development Closeout Report

    SciTech Connect

    Allen, D.

    2000-08-01

    The Cast Metal Coalition, composed of more than 22 research providers and universities and 149 industrial partners, has completed a four-year research and development partnership with the Department of Energy. This report provides brief summaries of the 29 projects performed by the Coalition. These projects generated valuable information in such aspects of the metals industry as process prediction technologies, quality control, improved alloys, product machinability, and casting process improvements.

  20. Orientation of Microdomains of Block Copolymers by Zone casting

    NASA Astrophysics Data System (ADS)

    Tang, Chuanbing; Matyjaszewski, Krzysztof; Kowalewski, Tomasz

    2007-03-01

    As a ``bottom up'' method, the self-assembly of block copolymers plays a vital role in the development of soft lithography for the fabrication of microelectronic devices. A variety of methods have been developed toward better and more precise controlled patterns on solid substrates. This presentation will describe a novel solution casting technique, ``zone casting'', to induce orientation of cylindrical and lamellar microphase-separated domains of various block copolymers.

  1. Corrosion resistant gray cast iron graphite flake alloys

    SciTech Connect

    Betts, B. A.

    1985-10-22

    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, and boron may also be included. Both hardenable and non-hardenable alloys are provided.

  2. Microstructures and properties of aluminum die casting alloys

    SciTech Connect

    M. M. Makhlouf; D. Apelian; L. Wang

    1998-10-01

    This document provides descriptions of the microstructure of different aluminum die casting alloys and to relate the various microstructures to the alloy chemistry. It relates the microstructures of the alloys to their main engineering properties such as ultimate tensile strength, yield strength, elongation, fatigue life, impact resistance, wear resistance, hardness, thermal conductivity and electrical conductivity. Finally, it serves as a reference source for aluminum die casting alloys.

  3. Methods for manufacturing monocrystalline or near-monocrystalline cast materials

    DOEpatents

    Stoddard, Nathan G

    2014-04-29

    Methods are provided for casting one or more of a semiconductor, an oxide, and an intermetallic material. With such methods, a cast body of a monocrystalline form of the one or more of a semiconductor, an oxide, and an intermetallic material may be formed that is free of, or substantially free of, radially-distributed impurities and defects and having at least two dimensions that are each at least about 35 cm.

  4. Methods for manufacturing geometric multi-crystalline cast materials

    DOEpatents

    Stoddard, Nathan G

    2013-11-26

    Methods are provided for casting one or more of a semi-conductor, an oxide, and an intermetallic material. With such methods, a cast body of a geometrically ordered multi-crystalline form of the one or more of a semiconductor, an oxide, and an intermetallic material may be formed that is free or substantially free of radially-distributed impurities and defects and having at least two dimensions that are each at least about 10 cm.

  5. Heat Treatment Procedure Qualification for Steel Castings

    SciTech Connect

    Mariol Charles; Nicholas Deskevich; Vipin Varkey; Robert Voigt; Angela Wollenburg

    2004-04-29

    Heat treatment practices used by steel foundries have been carefully studied as part of comprehensive heat treatment procedure qualification development trials. These studies highlight the relationships between critical heat treatment process control parameters and heat treatment success. Foundry heat treatment trials to develop heat treatment procedure qualifications have shed light on the relationship between heat treatment theory and current practices. Furnace load time-temperature profiles in steel foundries exhibit significant differences depending on heat treatment equipment, furnace loading practice, and furnace maintenance. Time-temperature profiles of furnace control thermocouples can be very different from the time-temperature profiles observed at the center of casting loads in the furnace. Typical austenitization temperatures and holding times used by steel foundries far exceed what is required for transformation to austenite. Quenching and hardenability concepts were also investigated. Heat treatment procedure qualification (HTPQ) schema to demonstrate heat treatment success and to pre-qualify other alloys and section sizes requiring lesser hardenability have been developed. Tempering success is dependent on both tempering time and temperature. As such, furnace temperature uniformity and control of furnace loading during tempering is critical to obtain the desired mechanical properties. The ramp-up time in the furnace prior to the establishment of steady state heat treatment conditions contributes to the extent of heat treatment performed. This influence of ramp-up to temperature during tempering has been quantified.

  6. Cast-to-shape electrokinetic trapping medium

    DOEpatents

    Shepodd, Timothy J.; Franklin, Elizabeth; Prickett, Zane T.; Artau, Alexander

    2004-08-03

    A three-dimensional microporous polymer network material, or monolith, cast-to-shape in a microchannel. The polymer monolith, produced by a phase separation process, is capable of trapping and retaining charged protein species from a mixture of charged and uncharged species under the influence of an applied electric field. The retained charged protein species are released from the porous polymer monolith by a pressure driven flow in the substantial absence of the electric field. The pressure driven flow is independent of direction and thus neither means to reverse fluid flow nor a multi-directional flow field is required, a single flow through the porous polymer monolith can be employed, in contrast to prior art systems. The monolithic polymer material produced by the invention can function as a chromatographic medium. Moreover, by virtue of its ability to retain charged protein species and quantitatively release the retained species the porous polymer monolith can serve as a means for concentrating charged protein species from, for example, a dilute solution.

  7. Cast-to-shape electrokinetic trapping medium

    DOEpatents

    Shepodd, Timothy J.; Franklin, Elizabeth; Prickett, Zane T.; Artau, Alexander

    2006-05-30

    A three-dimensional microporous polymer network material, or monolith, cast-to-shape in a microchannel. The polymer monolith, produced by a phase separation process, is capable of trapping and retaining charged protein species from a mixture of charged and uncharged species under the influence of an applied electric field. The retained charged protein species are released from the porous polymer monolith by a pressure driven flow in the substantial absence of the electric field. The pressure driven flow is independent of direction and thus neither means to reverse fluid flow nor a multi-directional flow field is required, a single flow through the porous polymer monolith can be employed, in contrast to prior art systems. The monolithic polymer material produced by the invention can function as a chromatographic medium. Moreover, by virtue of its ability to retain charged protein species and quantitatively release the retained species the porous polymer monolith can serve as a means for concentrating charged protein species from, for example, a dilute solution.

  8. Phase Transformations in Cast Superaustenitic Stainless Steels

    NASA Astrophysics Data System (ADS)

    Phillips, Nathaniel S. L.; Scott Chumbley, L.; Gleeson, Brian

    2009-12-01

    The goal of this investigation was to study phase transformations in cast superaustenitic stainless steels. Experiments were performed to determine the phase transformation behavior for alloys CN3MN and CK3MCuN. Samples were taken from keel bars that were heat treated between 1160 and 1230 °C and then isothermally held for times ranging from 1 min to 2040 h at temperatures in the range of 700-900 °C. The resulting microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy and wavelength dispersive spectroscopy. The microstructures, composed primarily of sigma- and Laves-phases within a purely austenitic matrix, showed relatively slow transformation kinetics, with transformation not completed even after the longest anneals. SEM and TEM analysis of superaustenitic samples reveal that precipitation takes place initially on grain boundaries and proceeds intragranularly. The results of these SEM and TEM investigations, along with volume fractions and number densities as a function of time and temperature, will be presented and discussed.

  9. Restoring Functional Areas of Continuously Casted Cylinders

    NASA Astrophysics Data System (ADS)

    Brezinov, Janette; Balog, Peter; Vi?, Jn

    2012-12-01

    the paper proposes the fourth restoration of a roller in continuous casting production lines which can enhance production efficiency and lowers costs. The roller was forged from the material 24CrMoV55 - DIN 17240. The roller has been restored three times and is chosen for further restoration. The roller was restored by submerged arc welding (SAW) where the first layer was made from UP-5-200-CZ wire and the covering layers made from UP-5-45-CZ wire. Quality of the weld deposits were evaluated by measuring the hardness, mixing the weld with basic material and by setting the basic mechanical properties in the critical under-weld deposit area. Structures of the weld deposits were evaluated by light microscopy and their chemical composition was determined by EDX analysis. Based on experiments it can be concluded that rollers can be restored for the fourth time, but the limiting factor is the extent of damage.

  10. A finite element method for casting simulations

    SciTech Connect

    Hetu, J.F.; Ilinca, F.

    1999-11-26

    The rapid growth in the use of advanced materials in a large number of highly demanding automotive, electronic, and consumer applications has promoted the development of new and more complex material forming processes. A good understanding of the interaction between material and processing conditions is now very important in order to comply with stricter tolerances and demanding service conditions. This is particularly important in the case of castings involving the filling of a die where the coupled phenomena of fluid flow and heat transfer determine, to a large extent the final properties of the part. This paper presents a finite element model for the three-dimensional simulation of industrial mold filling and solidification problems. The finite element solutions of mold filling problems involve highly convective fluid flow coupled with free surface, heat transfer, nonconstant material properties, and complex three-dimensional geometries. They present unusual challenges for both the finite element modeling and numerical solution algorithms. In this work a segregated algorithm is proposed to solve Navier-Stokes, energy, and front tracking equations. The streamline upwind Petrov-Galerkin formulation is used to obtain stable solutions. The position of the free surface is modeled using a level-set approach. The whole procedure is shown to present the accuracy, robustness, and cost-effectiveness needed for complex three-dimensional industrial applications.

  11. Determination of Bulk Dimensional Variation in Castings

    SciTech Connect

    Dr. James F. Cuttino Dr. Edward P. Morse

    2005-04-14

    The purpose of this work is to improve the efficiency of green sand foundries so that they may continue to compete as the most cost-effective method of fabrication while meeting tightening constraints on near-net shape manufacturing. In order to achieve this objective, the study is divided into two major components. The first component concentrated on identifying which processes control surface finish on the castings and which provide potential reductions in variations. The second component identified metrological methods that effectively discern between the geometry of bulk material versus surface finish in order to more accurately determine the quality of a part. The research resulted in the determination of an empirical relationship relating pouring parameters to dimensional variation, with an R2 value of greater than 0.79. A significant difference in variations obtained from vertical vs. horizontal molding machines was also noticed. When analyzed separately, however, the resulting empirical relationships for horizontal and vertical machines had reduced R2 values, probably due to the reduced data sets. Significant parameters when considering vertical and horizontal molding machines together included surface roughness, pattern type, iron type, pouring rate, copper content, amount of Western Bentonite, and permeability.

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

    NASA Technical Reports Server (NTRS)

    Frankhouser, W. L.

    1980-01-01

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

  13. Mechanical properties and microstructure of centrifugally cast alloy 718

    SciTech Connect

    Michel, D.J.; Smith, H.H.

    1985-07-01

    The relationship between the microstructure and mechanical properties of alloy 718 was investigate for two discs centrifugally cast at 50 and 200 rpm and given a duplex age heat treatment. The results of mechanical property tests at temperatures from 426 to 649/sup 0/C showed that the tensile, yield and ultimate strength levels of both castings were similar. However, the creep-rupture properties were considerably enhanced for the casting produced at 200 rpm. Comparison of the radial and transverse creep properties of each disc indicated that creep life was generally independent of orientation, but ductility was greatest for specimens oriented transverse to the radial direction of the casting. Fatigue crack propagation performance was not greatly influenced by orientation or mold speed parameters and is comparable to wrought alloy 718 when compared on the basis of stress intensity factor range. The centrifugal casting process was found to produce a homogeneous microstructure free of porosity but with the expected segregation of solute alloying elements to Laves and carbide phases. The effect of the as-cast microstructure on the mechanical behavior and the potential influence of hot isostatic pressing to improve the microstructure are discussed.

  14. Mechanical properties and microstructure of centrifugally cast alloy 718

    NASA Astrophysics Data System (ADS)

    Michel, D. J.; Smith, H. H.

    1985-07-01

    The relationship between the microstructure and mechanical properties of alloy 718 was investigated for two discs centrifugally cast at 50 and 200 rpm and given a duplex age heat treatment. The results of mechanical property tests at temperatures from 426 to 649 °C showed that the tensile yield and ultimate strength levels of both castings were similar. However, the creep-rupture properties were considerably enhanced for the casting produced at 200 rpm. Comparison of the radial and transverse creep properties of each disc indicated that creep life was generally independent of orientation, but ductility was greatest for specimens oriented transverse to the radial direction of the casting. Fatigue crack propagation performance was not greatly influenced by orientation or mold speed parameters and was comparable to wrought alloy 718 when compared on the basis of stress intensity factor range. The centrifugal casting process was found to produce a homogeneous microstructure free of porosity but with the expected segregation of solute alloying elements to Laves and carbide phases. The effect of the as-cast microstructure on the mechanical behavior and the potential influence of hot isostatic pressing to improve the microstructure are discussed.

  15. A new method of producing casts for anatomical studies.

    PubMed

    De Sordi, Nadia; Bombardi, Cristiano; Chiocchetti, Roberto; Clavenzani, Paolo; Trerè, Claudio; Canova, Marco; Grandis, Annamaria

    2014-09-01

    The objective of the present study was to verify if polyurethane foam is a suitable material to make accurate casts of vessels and viscera, and to develop a method based on its use for anatomical studies. This new technique has been tested primarily on the lungs of different animals, but also on the renal, intestinal and equine digital vessels. It consisted of three steps: specimen preparation, injection of the foam and corrosion of the cast. All structures injected with foam were properly filled. The bronchial tree and the vessels could be observed up to their finer branches. The method is inexpensive, simple and requires no special equipment. The pre-casting procedure does not require perfusion of the specimens with formalin, or prolonged flushing with carbon dioxide gas or air for drying. The polyurethane foam does not need a catalyst. It is simply diluted with acetone, which does not cause shrinkage of the cast due to evaporation during hardening. The foam naturally expands into the cavities without high pressure of the inoculum, and hardens in just 2 or 3 h at room temperature. Only two drawbacks were observed. The first is the fact that multiple injections cannot be made in the same cavity since the foam solidifies quickly; the second is the slight brittleness of the cast, due to the low elasticity of polyurethane foam. In conclusion, polyurethane foam was a suitable material for producing accurate casts of vessels and viscera. PMID:24788383

  16. Quantitative biomechanical comparison of ankle fracture casting methods.

    PubMed

    Shipman, Alastair; Alsousou, Joseph; Keene, David J; Dyson, Igor N; Lamb, Sarah E; Willett, Keith M; Thompson, Mark S

    2015-06-01

    The incidence of ankle fractures is increasing rapidly due to the ageing demographic. In older patients with compromised distal circulation, conservative treatment of fractures may be indicated. High rates of malunion and complications due to skin fragility motivate the design of novel casting systems, but biomechanical stability requirements are poorly defined. This article presents the first quantitative study of ankle cast stability and hypothesises that a newly proposed close contact cast (CCC) system provides similar biomechanical stability to standard casts (SC). Two adult mannequin legs transected at the malleoli, one incorporating an inflatable model of tissue swelling, were stabilised with casts applied by an experienced surgeon. They were cyclically loaded in torsion, measuring applied rotation angle and resulting torque. CCC stiffness was equal to or greater than that of SC in two measures of ankle cast resistance to torsion. The effect of swelling reduction at the ankle site was significantly greater on CCC than on SC. The data support the hypothesis that CCC provides similar biomechanical stability to SC and therefore also the clinical use of CCC. They suggest that more frequent re-application of CCC is likely required to maintain stability following resolution of swelling at the injury site. PMID:25719278

  17. ToxCast: Developing Predictive Signatures of Chemically Induced Toxicity (Developing Predictive Bioactivity Signatures from ToxCasts HTS Data)

    EPA Science Inventory

    ToxCast, the United States Environmental Protection Agencys chemical prioritization research program, is developing methods for utilizing computational chemistry, bioactivity profiling and toxicogenomic data to predict potential for toxicity and prioritize limited testing resour...

  18. ToxCast: Developing Predictive Signatures of Chemically Induced Toxicity (Developing Predictive Bioactivity Signatures from ToxCasts HTS Data)

    EPA Science Inventory

    ToxCast, the United States Environmental Protection Agency’s chemical prioritization research program, is developing methods for utilizing computational chemistry, bioactivity profiling and toxicogenomic data to predict potential for toxicity and prioritize limited testing resour...

  19. Letter Report: LAW Simulant Development for Cast Stone Screening Test

    SciTech Connect

    Russell, Renee L.; Westsik, Joseph H.; Swanberg, David J.; Eibling, Russell E.; Cozzi, Alex; Lindberg, Michael J.; Josephson, Gary B.; Rinehart, Donald E.

    2013-03-27

    More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in the HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second facility will be needed for the expected volume of additional LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with waste acceptance criteria for the IDF disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long term performance of the waste form in the IDF disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. A testing program was developed in fiscal year (FY) 2012 describing in some detail the work needed to develop and qualify Cast Stone as a waste form for the solidification of Hanford LAW (Westsik et al. 2012). Included within Westsik et al. (2012) is a section on the near-term needs to address Tri-Party Agreement Milestone M-062-40ZZ. The objectives of the testing program to be conducted in FY 2013 and FY 2014 are to: • Determine an acceptable formulation for the LAW Cast Stone waste form. • Evaluate sources of dry materials for preparing the LAW Cast Stone. • Demonstrate the robustness of the Cast Stone waste form for a range of LAW compositions. • Demonstrate the robustness of the formulation for variability in the Cast Stone process. • Provide Cast Stone contaminant release data for PA and risk assessment evaluations. The first step in determining an acceptable formulation for the LAW Cast Stone waste form is to conduct screening tests to examine expected ranges in pretreated LAW composition, waste stream concentrations, dry-materials sources, and mix ratios of waste feed to dry blend. A statistically designed test matrix will be used to evaluate the effects of these key parameters on the properties of the Cast Stone as it is initially prepared and after curing. The second phase of testing will focus on selection of a baseline Cast Stone formulation for LAW and demonstrating that Cast Stone can meet expected waste form requirements for disposal in the IDF. It is expected that this testing will use the results of the screening tests to define a smaller suite of tests to refine the composition of the baseline Cast Stone formulation (e.g. waste concentration, water to dry mix ratio, waste loading).

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

    SciTech Connect

    Song, Hoon; Kim, Jong-Hwan; Kim, Ki-Hwan; Lee, Chan-Bock

    2013-07-01

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

  1. Investigation on the Interface Characteristics of Al/Mg Bimetallic Castings Processed by Lost Foam Casting

    NASA Astrophysics Data System (ADS)

    Jiang, Wenming; Li, Guangyu; Fan, Zitian; Wang, Long; Liu, Fuchu

    2016-02-01

    The lost foam casting (LFC) process was used to prepare the A356 aluminum and AZ91D magnesium bimetallic castings, and the interface characteristics of the reaction layer between aluminum and magnesium obtained by the LFC process were investigated in the present work. The results indicate that a uniform and compact interface between the aluminum and magnesium was formed. The reaction layer of the interface with an average thickness of approximately 1000 μm was mainly composed of Al3Mg2 and Al12Mg17 intermetallic compounds, including the Al3Mg2 layer adjacent to the aluminum insert, the Al12Mg17 middle layer, and the Al12Mg17 + δ eutectic layer adjacent to the magnesium base. Meanwhile, the Mg2Si intermetallic compound was also detected in the reaction layer. An oxide film mainly containing C, O, and Mg elements generated at the interface between the aluminum and magnesium, due to the decomposed residue of the foam pattern, the oxidations of magnesium and aluminum alloys as well as the reaction between the magnesium melt and the aluminum insert. The microhardness tests show that the microhardnesses at the interface were obviously higher than those of the magnesium and aluminum base metals, and the Al3Mg2 layer at the interface had a high microhardness compared with the Al12Mg17 and Al12Mg17 + δ eutectic layers, especially the eutectic layer.

  2. Investigation on the Interface Characteristics of Al/Mg Bimetallic Castings Processed by Lost Foam Casting

    NASA Astrophysics Data System (ADS)

    Jiang, Wenming; Li, Guangyu; Fan, Zitian; Wang, Long; Liu, Fuchu

    2016-05-01

    The lost foam casting (LFC) process was used to prepare the A356 aluminum and AZ91D magnesium bimetallic castings, and the interface characteristics of the reaction layer between aluminum and magnesium obtained by the LFC process were investigated in the present work. The results indicate that a uniform and compact interface between the aluminum and magnesium was formed. The reaction layer of the interface with an average thickness of approximately 1000 μm was mainly composed of Al3Mg2 and Al12Mg17 intermetallic compounds, including the Al3Mg2 layer adjacent to the aluminum insert, the Al12Mg17 middle layer, and the Al12Mg17 + δ eutectic layer adjacent to the magnesium base. Meanwhile, the Mg2Si intermetallic compound was also detected in the reaction layer. An oxide film mainly containing C, O, and Mg elements generated at the interface between the aluminum and magnesium, due to the decomposed residue of the foam pattern, the oxidations of magnesium and aluminum alloys as well as the reaction between the magnesium melt and the aluminum insert. The microhardness tests show that the microhardnesses at the interface were obviously higher than those of the magnesium and aluminum base metals, and the Al3Mg2 layer at the interface had a high microhardness compared with the Al12Mg17 and Al12Mg17 + δ eutectic layers, especially the eutectic layer.

  3. Soldier caste influences on candidate primer pheromone levels and juvenile hormone-dependent caste differentiation in workers of the termite Reticulitermes flavipes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caste systems and the division of labor they make possible are common underlying features of all social insects. Multiple extrinsic factors have been shown to impact caste differentiation; for example, primer pheromones are chemical signaling molecules produced by certain castes that impact developm...

  4. Laser drilling of cast metal matrix composites

    SciTech Connect

    Hung, N.P.; Jana, S.; Yang, L.J.; Heng, C.H.

    1995-12-31

    In spite of the enhanced mechanical properties of metal matrix composites (MMCs), full scale applications of these advanced materials are often hindered by the cost-sensitive manufacturing processes. Conventional machining processes such as turning, drilling, facing, and n-tilling have been investigated and published since the early 80`s. Polycrystalline diamond (PCD) cutting tools, which are approximately 100 times more expensive than carbide tools, are recommended for machining to overcome the high hardness of the reinforced SiC particles; however machine induced damage, high tooling cost, and the limited size and geometry of PCD tools make them less attractive. It would be a challenge, if not an impossible task, for manufacturing engineers to economically produce small holes with high aspect ratio in MMCs using the available conventional machining techniques. The need to apply non-conventional processes to MMCs was therefore justified. No paper on laser drilling of MMC was located although published papers on plasma cutting, and laser assisted cutting/joining were found. This paper investigates the feasibility of using the pulsed Nd-YAG laser to drill small holes with high aspect ratio in cast MMC reinforced with SiC particles. The process economy, hole quality, and the resulting microstructure were studied. Although high material removal rate was obtained, quality of a drilled hole could be further improved. Excessive burr, out of round, tapered holes with damaged microstructure resulted for all combinations of testing variables. Microscopic examination showed redistribution of the partially melted SiC particles, formation of the brittle aluminum carbide precipitates and aluminum oxide layer, voids, and cracks along and ahead of a blind drilled hole. Forming of these defects, the effects of assisting gas and operating parameters were theorized and discussed.

  5. Yield improvement and defect reduction in steel casting

    SciTech Connect

    Kent Carlson

    2004-03-16

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

  6. An association between the Calpastatin (CAST) gene and keratoconus

    PubMed Central

    Li, Xiaohui; Bykhovskaya, Yelena; Tang, Yongming G.; Picornell, Yoana; Haritunians, Talin; Aldave, Anthony J.; Szczotka-Flynn, Loretta; Iyengar, Sudha K.; Rotter, Jerome I.; Taylor, Kent D.; Rabinowitz, Yaron S.

    2013-01-01

    Purpose Keratoconus is a genetically heterogeneous corneal dystrophy. Previously, we performed two genome-wide linkage scans in a four generation autosomal dominant pedigree and repeatedly mapped a keratoconus locus to a genomic region located on chromosome 5q overlapping the gene encoding the inhibitor of calpains, calpastatin (CAST). To test whether variants in CAST gene are involved in genetic susceptibility to keratoconus we performed genetic testing of polymorphic markers in CAST gene in family and case-control panels of patients with keratoconus. Methods We genotyped SNPs (Single Nucleotide Polymorphisms) located in CAST gene in 262 patients in 40 Caucasian keratoconus families and in a Caucasian case-control panel with 304 cases and 518 controls. Generalized estimating equation models accounting for familial correlations implemented in GWAF program were used for association testing in families. Logistic regression models implemented in PLINK were performed to test associations in case-control samples. Results Genetic testing of first set of seven SNPs in familial samples revealed two tentative nominally significant markers (rs4869307 p=0.03; rs27654: p=0.07). Additional genotyping of twelve tightly spaced SNPs identified CAST SNP rs4434401 to be associated with keratoconus in both familial and case-control panels with p values of 0.005 and 0.05, respectively; and with combined meta p value of familial and case-control cohorts of 0.002, or, after Bonferroni correction, 0.04. Conclusions Linkage analysis and genetic association support involvement of CAST gene in the genetic susceptibility to keratoconus. In-silico analysis of CAST expression suggests differential regulation of calpain/calpastatin system in cornea as a potential mechanism of functional defect. PMID:23449483

  7. Secondary Waste Cast Stone Waste Form Qualification Testing Plan

    SciTech Connect

    Westsik, Joseph H.; Serne, R. Jeffrey

    2012-09-26

    The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the wastes into high-level waste (HLW) and low-activity waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious waste form, has been selected for solidification of this secondary waste stream after treatment in the ETF. The secondary-waste Cast Stone waste form must be acceptable for disposal in the IDF. This secondary waste Cast Stone waste form qualification testing plan outlines the testing of the waste form and immobilization process to demonstrate that the Cast Stone waste form can comply with the disposal requirements. Specifications for the secondary-waste Cast Stone waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the waste acceptance criteria for the IDF, and the waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing needed to demonstrate that the waste form can comply with these waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the secondary-waste Cast Stone waste form in the IDF

  8. Macrovoid Defect Growth during Evaporative Casting of Polymeric Membranes

    NASA Technical Reports Server (NTRS)

    Greenberg, A. R.; Khare, V. P.; Zartman, J.; Krantz, W. B.; Todd, P.

    2003-01-01

    Macrovoid (MV) formation is a significant problem in evaporatively cast polymeric membranes. MVs are large, elongated or teardrop-shaped pores (10-50 micron) that can impair membrane structural integrity. Although MVs have been extensively studied, there is no general agreement on the mechanisms governing MV growth. Recently, our research group has formulated the solutocapillary convection (SC) hypothesis, which contends that MV growth involves three principal forces: a Marangoni force generated by surface tension gradients within the MV interface, a viscous drag force, and a gravitationally induced body force. Two sets of complementary experiments were conducted to test the SC hypothesis. Ground-based videomicroscopy flow-visualization (VMFV) was utilized to measure the flow velocities at the MV-casting solution interface and deep within the casting solution. The measurements were performed with casting solutions containing 10 wt% cellulose acetate (CA), 30 wt% H2O, 60 wt% acetone, and 200- ppm TiO2 particles for flow visualization, and the surface tension was controlled by surfactant addition. Qualitatively, the experiments indicated that MV growth occurs in three distinct phases: (1) a very rapid initial growth period, (2) a much slower growth phase, and (3) absorption of selected MVs into the expanding demixed region. The presence of tracer particles inside the MVs suggests the presence of a convective flow, which transfers the particles from the bulk solution to the MV interior. Although the VMFV experiments did not establish any surfactant effect on the interfacial velocities, a statistically significant effect on the MV number density was observed. In the second set of experiments, membranes were cast aboard a KC-135 aircraft under 0-g and 2-g conditions. Despite careful attention to the design and fabrication of the membrane casting apparatus (MCA), several problems were encountered, the most significant of which was the contamination of the casting solution by the activated carbon particles used for solvent absorption.

  9. The potential of centrifugal casting for the production of near net shape uranium parts

    SciTech Connect

    Robertson, E.

    1993-09-01

    This report was written to provide a detailed summary of a literature survey on the near net shape casting process of centrifugal casting. Centrifugal casting is one potential casting method which could satisfy the requirements of the LANL program titled Near Net Shape Casting of Uranium for Reduced Environmental, Safety and Health Impact. In this report, centrifugal casting techniques are reviewed and an assessment of the ability to achieve the near net shape and waste minimization goals of the LANL program by using these techniques is made. Based upon the literature reviewed, it is concluded that if properly modified for operation within a vacuum, vertical or horizontal centrifugation could be used to safely cast uranium for the production of hollow, cylindrical parts. However, for the production of components of geometries other than hollow tubes, vertical centrifugation could be combined with other casting methods such as semi-permanent mold or investment casting.

  10. Simulation and Experiment on Direct Continuous Casting Process of Lead Frame Copper Alloy

    SciTech Connect

    Huang Guojie; Xie Shuisheng; Cheng Lei

    2010-06-15

    Direct Continuous Casting (D.C.C) is an important method in casting lead frame copper alloy. In this paper, numerical simulation is adopted to investigate the casting process in order to optimize the D.C.C technical parameters, such as the casting temperature, casting speed and cooling intensity. According to the numerical results, the reasonable parameters are that the casting temperature is between 1413 Kapprox1413 K, the casting speed is between 8 m/happrox10 m/h and the speed of cooling water is between 4.2 m/sapprox4.6 m/s. And the depth of liquid-solid boundary is measured in different casting temperature and casting speed by experiments. The results show the actual measurements have a little deviation with the numerical simulation. The results of numerical simulation provide the significant reference to the actual experiments.

  11. Method of reducing the green density of a slip cast article

    NASA Technical Reports Server (NTRS)

    Mangels, John A. (Inventor); Dickie, Ray A. (Inventor)

    1985-01-01

    The method disclosed in this specification is one of reducing the green density of an article cast in a slip casting operation. The article is cast from a casting slip containing silicon metal particles, yttrium containing particles, and a small amount of a fluoride salt which is effective to suppress flocculation of the silicon metal particles by y.sup.+3 ions derived from the yttrium containing particles. The method is characterized by the following step. A small amount of compound which produces a cation which will partly flocculate the particles of silicon metal is added to the casting slip. The small amount of this compound is added so that when the casting slip is slip cast into a casting mold, the partly flocculated particles of silicon will interrupt an otherwise orderly packing of the particles of silicon and particles of yttrium. In this manner, the green density of the slip cast article is reduced and the article may be more easily nitrided.

  12. Experimental Determination of Heat Transfer Within the Metal/Mold Gap in a DC Casting Mold: Part II. Effect of Casting Metal, Mold Material, and Other Casting Parameters

    NASA Astrophysics Data System (ADS)

    Prasad, Arvind; Bainbridge, Ian F.

    2013-07-01

    Extensive experimental studies were conducted to quantify the effect of different parameters that can affect the heat transfer from the metal to the mold during the steady-state phase of DC casting. In the first part previously published, the experimental technique was established and results were reported for the effect of gas type (atmosphere within the mold) and the gap between the metal and the mold. The results showed the significant effect of gas thermal conductivity and the metal-mold gap on the mold wall heat transfer coefficient. In this second publication on heat transfer in the mold wall region of a DC casting mold, the results from the effect of casting temperature, gas flow rate, casting alloy, mold material, and the mold insert material on the mold wall heat transfer coefficient are described. The experiments reported in the current paper show that these additional factors tested do not affect the heat flux through the mold wall to the same extent as the gap size or the gas type. The heat transfer coefficient changes by less than 5 pct when casting temperature is changed by ±25 K, less than 15 pct when the gas flow rate within the metal-mold gap flows at up to 3 LPM, and approximately 30 pct when the mold material is changed from stainless steel to AA601 to copper. Similar results were obtained when different insert materials were used. These results are explained with the help of an electrical analogy of heat transfer and are consistent with the heat transfer theory.

  13. The Effects of Casting Porosity on the Tensile Behavior of Investment Cast 17-4PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Susan, D. F.; Crenshaw, T. B.; Gearhart, J. S.

    2015-08-01

    The effect of casting porosity on the mechanical behavior of investment cast 17-4PH stainless steel was studied as well as the effect of heat treatment on the alloy's sensitivity to casting defects. Interdendritic porosity, formed during solidification and shrinkage of the alloy, reduces the yield strength and ultimate tensile strength roughly in proportion to the reduction in load bearing cross-section. The effects of casting porosity on ductility (% strain, % reduction in area) are more severe, in agreement with research on other alloy systems. In this study, 10% porosity reduced the ductility of 17-4PH stainless steel by almost 80% for the high-strength H925 condition. Tensile testing at -10°C (263 K) further reduces the alloy ductility with and without pores present. In the lower strength H1100 condition, the ductility is higher than the H925 condition, as expected, and somewhat less sensitive to porosity. By measuring the area % porosity on the fracture surface of tensile specimens, the trend in failure strain versus area % porosity was obtained and analyzed using two methods: an empirical approach to determine an index of defect susceptibility with a logarithmic fit and an analytical approach based on the constitutive stress-strain behavior and critical strain concentration in the vicinity of the casting voids. The applicability of the second method depends on the amount of non-uniform strain (necking) and, as such, the softer H1100 material did not correlate well to the model. The behavior of 17-4PH was compared to previous work on cast Al alloys, Mg alloys, and other cast materials.

  14. Rapid prototyping: A paradigm shift in investment casting

    SciTech Connect

    Atwood, C.L.; Maguire, M.C.; Baldwin, M.D.; Pardo, B.T.

    1996-09-01

    The quest for fabricating complex metal parts rapidly and with minimal cost has brought rapid prototyping (RP) processes to the forefront of the investment casting industry. Relatively recent advances in DTM Corporation`s selective laser sintering (SLS) and 3D Systems stereolithography (SL) processes have had a significant impact on the overall quality of patterns produced using these rapid prototyping processes. Sandia National Laboratories uses patterns generated from rapid prototyping processes to reduce the cycle time and cost of fabricating prototype and small lot production parts in support of a program called FASTCAST. The SLS process is used to fabricate patterns from materials such as investment casting wax, polycarbonate, and a new material called TrueForm PM{trademark}. With the timely introduction of each of these materials, the quality of patterns fabricated has improved. The development and implementation of SL QuickCast{trademark} software has enabled this process to produce highly accurate patterns for use in investment casting. This paper focuses on the successes with these new pattern materials and the infrastructure required to cast rapid prototyping patterns successfully. In addition, a brief overview of other applications of rapid prototyping at Sandia will be discussed.

  15. Producing Foils From Direct Cast Titanium Alloy Strip

    NASA Technical Reports Server (NTRS)

    Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

    1996-01-01

    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 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

  16. Metal Penetration in Sand Molds for Steel Castings: Annual Report

    SciTech Connect

    Barlow, J.O.; Stefanescu, D.M.; Lane, A.M.; Schreiber, W.C.; Owens, M.; Piwonka, T.S.

    1996-04-01

    Case studies of samples of penetration provided by consortium members showed examples of mechanical-type penetration defects and of what appeared to be chemical penetration. Sessile drop experiments of various mold substrate materials using carbon, stainless, and Mn steels showed that Mn steel wets silica strongly, indicating that silica is not a suitable mod material for this family of alloys. Contact angles were lower for steels than for cast irons. Magnesite appeared to be the best overall mold material, although zircon flour also performed well. A simplified 1-D model was developed which predicts the diffusion rates which could cause chemical penetration. It shows that, contrary to the case in cast iron, chemical penetration is a possibility in medium and low carbon steels, as diffusion of C to the casting surface may not always occur quickly enough to protect the surface from an oxidizing reaction. The mass spectrometer gas chromatograph train was modified for accurately determining the water content of gas at the mold/metal interface. Initial gas measurements indicated that the gas generated at the interface in steel castings is 80% H2-20% CO, instead of the 50% H2- 50% CO mixture found in cast iron.

  17. Fracture Toughness of CF8 Castings at Four Kelvin

    NASA Astrophysics Data System (ADS)

    Brown, E. L.; Whipple, T. A.; Tobler, R. L.

    1983-06-01

    The first fracture toughness measurements for CF8 stainless steel castings in liquid helium at 4 K are reported. Single-phase (austenite) and duplex (austenite + δ-ferrite) castings were tested. On the basis of estimates from .J-integral data, the plane-strain fracture toughness (K lc) of castings containing 3.2 to 14.5 pct δ-ferrite ranged from 84 to 179 MPa · m1/2 at 4 K. In contrast, a fully austenitic casting (0 pct (δ-ferrite) exhibited a K lc value of 331 MPa · m-2, which is nearly equivalent to the toughness of a wrought AISI 304 stainless steel of a similar strength. Light and scanning electron microscopy studies indicate that the inferior toughness of castings containing ·-ferrite may be attributed to the brittleness of this body-centered-cubic phase at cryogenic temperatures and its distribution in the microstructure. The relative stability of the austenitic phase with respect to martensitic phase transformation may also play a significant role.

  18. Computational algorithms to simulate the steel continuous casting

    NASA Astrophysics Data System (ADS)

    Ramírez-López, A.; Soto-Cortés, G.; Palomar-Pardavé, M.; Romero-Romo, M. A.; Aguilar-López, R.

    2010-10-01

    Computational simulation is a very powerful tool to analyze industrial processes to reduce operating risks and improve profits from equipment. The present work describes the development of some computational algorithms based on the numerical method to create a simulator for the continuous casting process, which is the most popular method to produce steel products for metallurgical industries. The kinematics of industrial processing was computationally reproduced using subroutines logically programmed. The cast steel by each strand was calculated using an iterative method nested in the main loop. The process was repeated at each time step (Δ t) to calculate the casting time, simultaneously, the steel billets produced were counted and stored. The subroutines were used for creating a computational representation of a continuous casting plant (CCP) and displaying the simulation of the steel displacement through the CCP. These algorithms have been developed to create a simulator using the programming language C++. Algorithms for computer animation of the continuous casting process were created using a graphical user interface (GUI). Finally, the simulator functionality was shown and validated by comparing with the industrial information of the steel production of three casters.

  19. Feasibility of a braided composite for orthopedic bone cast.

    PubMed

    Evans, Katherine R; Carey, Jason P

    2013-01-01

    A tubular braided composite bone cast for improving the efficiency and quality of bone fracture treatment is investigated. Finite element analysis was used to evaluate stress concentrations in fracture sites supported with plate and tubular casts. The stress in a plated bone is 768 % of that in a whole bone at the same location, while it is only 47 % in a bone with a tubular cast. Three unbroken synthetic humeri were mechanically tested using an in-vitro long bone testing procedure developed in-house to find their stiffness at 20° and 60° abduction; these were found to be 116.8 ± 1.5 N/mm and 20.63 ± 0.02 N/mm, respectively. A 2 cm gap osteotomy was cut through the diaphysis in each bone. The bones were casted with a Kevlar/Cold cure composite, with calculated braid angles and thicknesses that Closely matched bone propoerties. The stiffness tests were repeated, and the results were within 10 % of the unbroken bone. This novel method of bone casting is promising if other clinical challenges can be minimized. PMID:23459455

  20. Feasibility of a Braided Composite for Orthopedic Bone Cast

    PubMed Central

    Evans, Katherine R; Carey, Jason P

    2013-01-01

    A tubular braided composite bone cast for improving the efficiency and quality of bone fracture treatment is investigated. Finite element analysis was used to evaluate stress concentrations in fracture sites supported with plate and tubular casts. The stress in a plated bone is 768 % of that in a whole bone at the same location, while it is only 47 % in a bone with a tubular cast. Three unbroken synthetic humeri were mechanically tested using an in-vitro long bone testing procedure developed in-house to find their stiffness at 20° and 60° abduction; these were found to be 116.8 ± 1.5 N/mm and 20.63 ± 0.02 N/mm, respectively. A 2 cm gap osteotomy was cut through the diaphysis in each bone. The bones were casted with a Kevlar/Cold cure composite, with calculated braid angles and thicknesses that Closely matched bone propoerties. The stiffness tests were repeated, and the results were within 10 % of the unbroken bone. This novel method of bone casting is promising if other clinical challenges can be minimized. PMID:23459455

  1. Investigation of structural collapse in unidirectionally freeze cast collagen scaffolds.

    PubMed

    Clearfield, Drew; Wei, Mei

    2016-01-01

    Though unidirectional freeze casting is a facile method for the production of structurally anisotropic biomedical scaffolds, challenges exist in optimizing the drying process that are often overlooked. In particular, structural collapse may occur if the material's frozen-state glass transition temperature (Tg') is exceeded. It was discovered that unidirectionally freeze cast collagen matrices were highly deformed following lyophilization, rendering them incapable of further use. In this study, modulated differential scanning calorimetry was performed to identify Tg's of unidirectionally freeze cast collagen scaffolds, and product temperatures during sublimation were recorded. It was observed that cast matrices from 0.5 to 0.05 M acetic acid (HAc) sublimed at a lyophilizer shelf temperature of -25 °C underwent structural collapse and exceeded their Tg's for the majority of the drying cycle. The use of a low pH suspension (0.5 M HAc) promoted the formation of a non-porous surface, which in turn contributed to the increase of the product temperature above its Tg' during drying. This study has revealed that use of a low shelf temperature (-40 °C) and a low HAc concentration (0.05 M) is effective in maintaining product temperatures under Tg' thereby preventing collapse in unidirectionally freeze cast collagen scaffolds. PMID:26676861

  2. Estimation of Volume Deficit Characteristic of Cast Al-Si-Mg Alloy

    NASA Astrophysics Data System (ADS)

    Santhi, S.; Sakri, S. B.; Rao, D. Hanumantha; Sundarrajan, S.

    2013-04-01

    Volume deficit characteristic of US A356 cast aluminium alloy has been discussed in the present study. The reduction in specific volume leads to volume deficit in castings and it can be visualized as a casting defect. The information regarding the volume deficit and its distribution is essential in minimizing casting defects. The volume deficit can be classified as macro cavities, internal porosity, surface sinks and volumetric contraction. These defects are measured using mathematical formulae and the actual volume deficit of the given casting has been arrived by adding all the defects. Influence of bottom chill and casting shape on the volume deficit characteristics have been studied.

  3. Effect of Process Parameters, Casting Thickness, and Alloys on the Interfacial Heat-Transfer Coefficient in the High-Pressure Die-Casting Process

    NASA Astrophysics Data System (ADS)

    Guo, Zhi-Peng; Xiong, Shou-Mei; Liu, Bai-Cheng; Li, Mei; Allison, John

    2008-12-01

    The heat transfer at the metal-die interface is believed to have great influence on the solidification process and cast structure of the high-pressure die-casting (HPDC) process. The present article focused on the effects of process parameters, casting thickness, and alloys on the metal-die interfacial heat-transfer coefficient (IHTC) in the HPDC process. Experiment was carried out on a cold-chamber die-casting machine with two casting alloys AM50 and ADC12. A special casting, namely, “step-shape” casting, was used and cast against a H13 steel die. The IHTC was determined using an inverse approach based on the temperature measurements inside the die. Results show that the IHTC is different at different steps and changes as the solidification of the casting proceeds. Process parameters only influence the IHTC in its peak value, and for both AM50 and ADC12 alloys, a greater fast shot velocity leads to a greater IHTC peak value at steps 1 and 2. The initial die surface temperature has a more prominent influence on the IHTC peak values at the thicker steps, especially step 5. Results also show that a closer contact between the casting and die could be achieved when the casting alloy is ADC12 instead of AM50, which consequently leads to a higher IHTC.

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

    DOEpatents

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

    1990-02-20

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

  5. Effect of flask vibration time on casting integrity, Surface Penetration and Coating Inclusion in lost foam casting of Al-Si Alloy

    SciTech Connect

    Karimian, Majid; Idris, M. H.; Ourdjini, A.; Muthu, Kali

    2011-01-17

    The paper presents the result of an experimental investigation conducted on medium aluminum silicon alloy casting- LM6, using no-vacuum assisted lost foam casting process. The study is directed for establishing the relationship between the flask vibrations times developed for molded sample on the casting integrity, surface penetration and coating inclusion defects of the casting. Four different flask vibration times namely 180, 120, 90 and 60 sec. were investigated. The casting integrity was investigated in terms of fulfilling in all portions and edges. The surface penetration was measured using optical microscope whilst image analyzer was used to quantify the percentage of coating inclusion in the casting. The results show that vibration time has significant influence on the fulfilling as well as the internal integrity of the lost foam casting. It was found that the lower vibration time produced comparatively sound casing.

  6. Robust and Rapid Air-Borne Odor Tracking without Casting.

    PubMed

    Bhattacharyya, Urvashi; Bhalla, Upinder Singh

    2015-01-01

    Casting behavior (zigzagging across an odor stream) is common in air/liquid-borne odor tracking in open fields; however, terrestrial odor localization often involves path selection in a familiar environment. To study this, we trained rats to run toward an odor source in a multi-choice olfactory arena with near-laminar airflow. We find that rather than casting, rats run directly toward an odor port, and if this is incorrect, they serially sample other sources. This behavior is consistent and accurate in the presence of perturbations, such as novel odors, background odor, unilateral nostril stitching, and turbulence. We developed a model that predicts that this run-and-scan tracking of air-borne odors is faster than casting, provided there are a small number of targets at known locations. Thus, the combination of best-guess target selection with fallback serial sampling provides a rapid and robust strategy for finding odor sources in familiar surroundings. PMID:26665165

  7. Aluminum-Based Cast In Situ Composites: A Review

    NASA Astrophysics Data System (ADS)

    Pramod, S. L.; Bakshi, Srinivasa R.; Murty, B. S.

    2015-06-01

    In situ composites are a class of composite materials in which the reinforcement is formed within the matrix by reaction during the processing. In situ method of composite synthesis has been widely followed by researchers because of several advantages over conventional stir casting such as fine particle size, clean interface, and good wettability of the reinforcement with the matrix and homogeneous distribution of the reinforcement compared to other processes. Besides this, in situ processing of composites by casting route is also economical and amenable for large scale production as compared to other methods such as powder metallurgy and spray forming. Commonly used reinforcements for Al and its alloys which can be produced in situ are Al2O3, AlN, TiB2, TiC, ZrB2, and Mg2Si. The aim of this paper is to review the current research and development in aluminum-based in situ composites by casting route.

  8. CAST-10-2/DOA 2 Airfoil Studies Workshop Results

    NASA Technical Reports Server (NTRS)

    Ray, Edward J. (Compiler); Hill, Acquilla S. (Compiler)

    1989-01-01

    During the period of September 23 through 27, 1988, the Transonic Aerodynamics Division at the Langely Research Center hosted an International Workshop on CAST-10-2/DOA 2 Airfoil Studies. The CAST-10 studies were the outgrowth of several cooperative study agreements among the NASA, the NAE of Canada, the DLR of West Germany, and the ONERA of France. Both theoretical and experimental CAST-10 airfoil results that were obtained form an extensive series of tests and studies, were reviewed. These results provided an opportunity to make direct comparisons of adaptive wall test section (AWTS) results from the NASA 0.3-meter Transonic Cryogenic Tunnel and ONERA T-2 AWTS facilities with conventional ventilated wall wind tunnel results from the Canadian high Reynolds number two-dimensional test facility. Individual papers presented during the workshop are included.

  9. Deformation and fracture of cast iron with an optimized microstructure

    SciTech Connect

    He, Z.R.; Lin, G.X.; Ji, S.

    1997-04-01

    An optimized microstructure of cast iron has been developed. In situ studies with the use of scanning electron microscopy have been made of the microprocesses of deformation and fracture in tension. The surface microstructure and the corresponding fracture surface and matching fracture were observed. The optimized nodular graphite-martensite interface, in combination with the high yield strength martensite shell, has been found to delay the initiation and propagation of interfacial cracks. Subsequent propagation and the formation of cast iron cracks is hindered by the ferrite-plus-martensite matrix. During crack propagation, shear deformation, the fracture of ligaments between the crack tip and the microcracks ahead, crack deflection, and bridging take place. With the use of these observations, it is possible to explain why cast iron with this optimized microstructure has excellent strength and toughness.

  10. Advanced Lost Foam Casting technology: 1997 summary report

    SciTech Connect

    1997-12-31

    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 eight tasks listed as follows: Task 1--pyrolysis defects and sand distortion; Task 2--bronze casting technology; Task 3--steel casting technology; Task 4--sand filling and compaction; Task 5--coating technology; Task 6--precision pattern production; Task 7--computational modeling; and Task 8--project management and technology transfer. This report summarizes the work done under the current contract in all eight tasks in the period of October 1, 1995 through December 31, 1997.

  11. Fabrication of cast particle-reinforced metals via pressure infiltration

    NASA Technical Reports Server (NTRS)

    Klier, E. M.; Mortensen, A.; Cornie, J. A.; Flemings, M. C.

    1991-01-01

    A new casting process for fabrication of particle-reinforced metals is presented whereby a composite of particulate reinforcing phase in metal is first produced by pressure infiltration. This composite is then diluted in additional molten metal to obtain the desired reinforcement volume fraction and metal composition. This process produces a pore-free as-cast particulate metal-matrix composite. This process is demonstrated for fabrication of magnesium-matrix composites containing SiC reinforcements of average diameter 30, 10 and 3 microns. It is compared with the compocasting process, which was investigated as well for similar SiC particles in Mg-10 wt pct Al, and resulted in unacceptable levels of porosity in the as-cast composite.

  12. Feasibility Study for Casting of High Temperature Refractory Superalloy Composites

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    1998-01-01

    Abstract This study investigated the feasibility of using conventional casting technique to fabricate refractory wires reinforced superalloy composites. These composites were being developed for advanced rocket engine turbine blades and other high temperature applications operating up to 2000 F. Several types of refractory metal wires such as W- Th, W-Re, Mo-Hf-C and W-HF-C reinforced waspaloy were experimentally cast and heat treated at 2000 F up to 48 hrs. Scanning electron microscope analysis was conducted in regions adjacent to the wire-matrix interface to determine the reaction zone and chemical compatibility resulting from material interdiffusion. It was concluded that fabrication using conventional casting may be feasible because the wire-matrix reaction zone thickness was comparable to similar composites produced by arc-sprayed monotape with hot isostatic pressing technique, Moreover, it was also found that the chemical compatibility could be improved significantly through a slight modification of the superalloy matrix compositions.

  13. Method and apparatus for casting conductive and semiconductive materials

    DOEpatents

    Ciszek, Theodore F.

    1986-01-01

    A method and apparatus is disclosed for casting conductive and semiconduce materials. The apparatus includes a plurality of conductive members arranged to define a container-like area having a desired cross-sectional shape. A portion or all of the conductive or semiconductive material which is to be cast is introduced into the container-like area. A means is provided for inducing the flow of an electrical current in each of the conductive members, which currents act collectively to induce a current flow in the material. The induced current flow through the conductive members is in a direction substantially opposite to the induced current flow in the material so that the material is repelled from the conductive members during the casting process.

  14. (Particle deposition in human and canine tracheobronchial casts)

    SciTech Connect

    Not Available

    1990-01-01

    To predict deposition efficiency, knowledge is required of airway morphometry and the distributions of inhaled airflow. The latter are expected to vary with flow rate and detailed measurements are needed to quantitate this parameter in the human and dog models. These data should provide essential input for the development of modifying factors in incorporate flow dependent, non-homogeneous mass transfer needed for quantitative dosimetry. Full morphometric and inhalation flow distribution measurements on the human and canine airway casts were completed in the current grant period. The work provided new quantitative data of airflow distribution in a realistic central airway cast for two species and for two different airflow patterns; steady inspiratory flow and pulsatile inspiratory flow. The work is summarized in this paper. Ten cast deposition experiments have been completed to date.

  15. Development of a CFD code for casting simulation

    NASA Technical Reports Server (NTRS)

    Murph, Jesse E.

    1992-01-01

    The task of developing a computational fluid dynamics (CFD) code to accurately model the mold filling phase of a casting operation was accomplished in a systematic manner. First the state-of-the-art was determined through a literature search, a code search, and participation with casting industry personnel involved in consortium startups. From this material and inputs from industry personnel, an evaluation of the currently available codes was made. It was determined that a few of the codes already contained sophisticated CFD algorithms and further validation of one of these codes could preclude the development of a new CFD code for this purpose. With industry concurrence, ProCAST was chosen for further evaluation. Two benchmark cases were used to evaluate the code's performance using a Silicon Graphics Personal Iris system. The results of these limited evaluations (because of machine and time constraints) are presented along with discussions of possible improvements and recommendations for further evaluation.

  16. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    NASA Astrophysics Data System (ADS)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

    2016-02-01

    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  17. CASTING DEFECT MODELING IN AN INTEGRATED COMPUTATIONAL MATERIALS ENGINEERING APPROACH

    SciTech Connect

    Sabau, Adrian S

    2015-01-01

    To accelerate the introduction of new cast alloys, the simultaneous modeling and simulation of multiphysical phenomena needs to be considered in the design and optimization of mechanical properties of cast components. The required models related to casting defects, such as microporosity and hot tears, are reviewed. Three aluminum alloys are considered A356, 356 and 319. The data on calculated solidification shrinkage is presented and its effects on microporosity levels discussed. Examples are given for predicting microporosity defects and microstructure distribution for a plate casting. Models to predict fatigue life and yield stress are briefly highlighted here for the sake of completion and to illustrate how the length scales of the microstructure features as well as porosity defects are taken into account for modeling the mechanical properties. Thus, the data on casting defects, including microstructure features, is crucial for evaluating the final performance-related properties of the component. ACKNOWLEDGEMENTS This work was performed under a Cooperative Research and Development Agreement (CRADA) with the Nemak Inc., and Chrysler Co. for the project "High Performance Cast Aluminum Alloys for Next Generation Passenger Vehicle Engines. The author would also like to thank Amit Shyam for reviewing the paper and Andres Rodriguez of Nemak Inc. Research sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, as part of the Propulsion Materials Program under contract DE-AC05-00OR22725 with UT-Battelle, LLC. Part of this research was conducted through the Oak Ridge National Laboratory's High Temperature Materials Laboratory User Program, which is sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Program.

  18. Microstructures of ancient and modern cast silver–copper alloys

    SciTech Connect

    Northover, S.M.; Northover, J.P.

    2014-04-01

    The microstructures of modern cast Sterling silver and of cast silver objects about 2500 years old have been compared using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy dispersive X-ray microanalysis (EDX) and electron backscatter diffraction (EBSD). Microstructures of both ancient and modern alloys were typified by silver-rich dendrites with a few pools of eutectic and occasional cuprite particles with an oxidised rim on the outer surface. EBSD showed the dendrites to have a complex internal structure, often involving extensive twinning. There was copious intragranular precipitation within the dendrites, in the form of very fine copper-rich rods which TEM, X-ray diffraction (XRD), SEM and STEM suggest to be of a metastable face-centred-cubic (FCC) phase with a cube–cube orientation relationship to the silver-rich matrix but a higher silver content than the copper-rich β in the eutectic. Samples from ancient objects displayed a wider range of microstructures including a fine scale interpenetration of the adjoining grains not seen in the modern material. Although this study found no unambiguous evidence that this resulted from microstructural change produced over archaeological time, the copper supersaturation remaining after intragranular precipitation suggests that such changes, previously proposed for wrought and annealed material, may indeed occur in ancient silver castings. - Highlights: • Similar twinned structures and oxidised surfaces seen in ancient and modern cast silver • General precipitation of fine Cu-rich rods apparently formed by discontinuous precipitation is characteristic of as-cast silver. • The fine rods are cube-cube related to the matrix in contrast with the eutectic. • The silver-rich phase remains supersaturated with copper. • Possibly age-related grain boundary features seen in ancient cast silver.

  19. Ultra Large Castings to Produce Low Cost Aluminum Vehicle Structures

    SciTech Connect

    T. N. Meyer; M. J. Kinosz; E. M. Bradac; M. Mbaye; J. T. Burg; M. A. Klingensmith

    1999-04-26

    Through a cooperative effort with the U.S. Department of Energy (DOE) Office of Heavy Vehicle Technologies (OHVT), Alcoa is developing a casting process to produce ultra large thin wall components. The casting process is a low pressure, metal mold, multiport injection vertical casting process. The specific system for demonstration of the process is located at Alcoa's Technology Center and will be capable of producing parts extending 3 M long, 1.7 M wide and 0.4 M high. For example, single castings of car floor pan frames or side wall aperture structures are candidates for this installation. This shall provide a major opportunity to reduce the cost of lightweight transportation vehicle structures by (a) reducing the components or part count and (b) reducing the cost of assembly. To develop and demonstrate the process, an inner panel of the Chrysler minivan liftgate will be first produced on this system. Through computer analyses, the cast inner panel design was developed to satisfy both structural performance and casting process requirements. Currently, this is an 11 part assembly of steel components. At the time of this abstract, the numerous system components are in various phases of fabrication and site preparation is fully underway, with system shakedown beginning in the second quarter of 1999. Successful demonstration of caster system operation is anticipated to occur during the third quarter and production of a high quality product during the fourth quarter. Although the process is targeted toward reducing the cost of lightweight trucks, buses and autos, consideration is being given to application in the aircraft industry.

  20. Benchmark testing the flow and solidification modeling of AI castings

    NASA Astrophysics Data System (ADS)

    Sirrell, B.; Holliday, M.; Campbell, J.

    1996-03-01

    Although the heat flow aspects of the simulation of castings now appears to be tolerably well advanced, a recent exercise has revealed that computed predictions can, in fact, be widely different from experimentally observed values. The modeling of flow, where turbulence is properly taken into account, appears to be good in its macroscopic ability. However, better resolution and the possible general incorporation of surface tension will be required to simulate the damaging effect of air entrainment common in most metal castings. It is envisaged that the results of this excercise will constitute a useful benchmark test for computer models of flow and solidification for the foreseeable future.