Sample records for die casting applications

  1. Vacuum Die Casting of Silicon Sheet for Photovoltaic Applications

    NASA Technical Reports Server (NTRS)

    1979-01-01

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

  2. Application of High-Temperature Mold Materials to Die Cast Copper Motor Rotor for Improved Efficiency

    SciTech Connect

    John G. Cowie; Edwin F. Brush, Jr.; Dale T. Peters; Stephen P. Midson; Darryl J. Van Son

    2003-05-01

    The objective of the study, Application of High-Temperature Mold Materials to Die Cast Copper Motor Rotor for Improved Efficiency, was to support the Copper Development Association (CDA) in its effort to design, fabricate and demonstrate mold technologies designed to withstand the copper motor rotor die casting environment for an economically acceptable life. The anticipated result from the compiled data and tests were to: (1) identify materials suitable for die casting copper, (2) fabricate motor rotor molds and (3) supply copper rotor motors for testing in actual compressor systems. Compressor manufacturers can apply the results to assess the technical and economical viability of copper rotor motors.

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

    SciTech Connect

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

    1995-12-31

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

  4. Casting Characteristics of Aluminum Die Casting Alloys

    Microsoft Academic Search

    Makhlouf M. Makhlouf; Diran Apelian

    2002-01-01

    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

  5. 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.

  6. Case study of lean manufacturing application in a die casting manufacturing company

    NASA Astrophysics Data System (ADS)

    Ching, Ng Tan; Hoe, Clarence Chan Kok; Hong, Tang Sai; Ghobakhloo, Morteza; Pin, Chen Kah

    2015-05-01

    The case study of lean manufacturing aims to study the application of lean manufacturing in a die casting manufacturing company located in Pulau Penang, Malaysia. This case study describes mainly about the important concepts and applications of lean manufacturing which could gradually help the company in increasing the profit by studying and analyzing their current manufacturing process and company culture. Many approaches of lean manufacturing are studied in this project which includes: 5S housekeeping, Kaizen, and Takt Time. Besides, the lean tools mentioned, quality tool such as the House of Quality is being used as an analysis tool to continuously improve the product quality. In short, the existing lean culture in the company is studied and analyzed, with recommendations written at the end of this paper.

  7. Die Soldering in Aluminium Die Casting

    SciTech Connect

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

    2000-03-15

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

  8. 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.

  9. Application of Nonlinear Superposition to Creep and Relaxation of Commercial Die-Casting Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Oza, Ashish; Jaglinski, Tim; Vanderby, Ray; Lakes, Roderic S.

    2004-12-01

    Die-cast aluminum alloys are heavily used in small engines, where they are subjected to long-term stresses at elevated temperatures. The resulting time-dependent material responses can result in inefficient engine operation and failure. A method to analytically determine the stress relaxation response directly from creep tests and to accurately interpolate between experimental time-history curves would be of great value. Constant strain, stress relaxation tests and constant load, creep tests were conducted on aluminum die-casting alloys: B-390, eutectic Al Si and a 17% Si Al alloy. A nonlinear superposition integral was used to (i) interpolate between empirical primary inelastic creep-strain and stress-relaxation time histories and (ii) to determine the stress relaxation response from corresponding creep data. Using isochronal stress-strain curves, prediction of the creep response at an intermediate stress level from empirical creep curves at higher and lower stresses resulted in a correlation (R) of 0.98. Similarly for relaxation, correlations of 0.98 were obtained for the prediction of an intermediate strain level curve from higher and lower empirical relaxation curves. The theoretical prediction of stress relaxation from empirical creep curves fell within 10% of experimental data.

  10. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  12. Use of RSP Tooling to Manufacture Die Casting Dies

    SciTech Connect

    Kevin McHugh

    2004-07-01

    The technology and art used to construct die casting dies has seen many improvements over the years. However, the time lag from when a design is finalized to the time a tool is in production has remained essentially the same. The two main causes for the bottleneck are the need to qualify a part design by making prototypes (usually from an alternative process), and the production tooling lead time after the prototypes are approved. Production tooling costs are high due to the labor and equipment costs associated with transforming a forged block of tool steel into a finished tool. CNC machining, sink EDM, benching, engraving and heat treatment unit operations are typically involved. As a result, there is increasing interest in rapid tooling (RT) technologies that shorten the design-to-part cycle and reduce the cost of dies. There are currently more than 20 RT methods being developed and refined around the world (1). The "rapid" in rapid tooling suggests time compression for tool delivery, but does not address robustness as nearly all RT approaches are intended for low-volume prototype work, primarily for molding plastics. Few options exist for die casting. An RT technology suitable for production-quality tooling in the time it normally takes for prototype tooling is highly desirable. In fact, there would be no need for a distinction between prototype and production tooling. True prototype parts could be made using the same processing conditions and materials intended for production. Qualification of the prototype part would allow the manufacturer to go directly into production with the same tool. A relatively new RT technology, Rapid Solidification Process (RSP) Tooling, is capable of making production-quality tooling in an RT timeframe for die casting applications. RSP Tooling, was developed at the Idaho National Engineering and Environmental Laboratory (INEEL), and commercialized with the formation of RSP Tooling, LLC (2). This paper describes the process, and summarizes properties of H13 tool steel dies.

  13. Wear Properties of Thixoformed and High Pressure Die Cast Aluminium Alloys for Connecting Rod Applications in Compressors

    SciTech Connect

    Birol, Yuecel [Materials Institute, Marmara Research Center, TUeBITAK, Kocaeli (Turkey); Birol, Feriha [R and D Center, ARCELIK, Tuzla, Istanbul (Turkey)

    2007-04-07

    Hypereutectic aluminium casting alloys are attractive candidates for connecting rod applications in compressors. The wear properties of these alloys are largely controlled by their microstructural features which in turn are affected by the processing route. Several hypo- and hypereutectic Al-Si alloys were produced by high pressure die casting and thixoforming in the present work. The former route produced a very fine microstructure while relatively coarser, globular {alpha}-Al matrix dominated in thixoformed grades. A modified Falex Block on Ring equipment was employed to investigate the wear properties of these alloys. Wear tests were carried out under service conditions in the lubricated state at 75 deg. C. The superior wear properties of hypereutectic alloys produced by high pressure die casting with respect to the thixoformed variety is accounted for by the very fine microstructure with a fine dispersion of primary Si particles in the former. Of the two production routes employed, thixoforming had a favorable effect on wear properties at equal Si levels.

  14. Applications for the strontium treatment of wrought and die-cast Al

    NASA Astrophysics Data System (ADS)

    Kulunk, B.; Zuliani, D. J.

    1996-10-01

    Strontium is well known for its ability to modify the eutectic silicon phase in aluminum-silicon foundry alloys. More recently, however, it has been established that strontium also stabilizes the more desirable ? iron-bearing intermetallic phase in 6XXX series wrought aluminum alloys. As a result, lengthy billet homogenization times that are normally required to transform the acicular ? iron-bearing intermetallic phase to the ? phase can be shortened significantly. In the case of the foundry alloys, strontium additions to a 380 alloy were found to increase the pressure tightness of high-pressure die castings by as much as 60%. This improvement is believed to occur as a result of improved metal flow with the strontium addition causing a reduction in the size of the entrapped air pores and the refinement of sludge particles.

  15. Development of a non-intrusive heat transfer coefficient gauge and its application to high pressure die casting

    Microsoft Academic Search

    G. Dour; M. Dargusch; C. Davidson; A. Nef

    2005-01-01

    A heat transfer coefficient gauge has been built, obeying particular rules in order to ensure the relevance and accuracy of the collected information. The gauge body is made out of the same materials as the die casting die (H13). It is equipped with six thermocouples located at different depths in the body and with a sapphire light pipe. The light

  16. Numerical simulation of low pressure die casting of magnesium wheel

    Microsoft Academic Search

    Ying-chun Wang; Da-yong Li; Ying-hong Peng; Xiao-qin Zeng

    2007-01-01

    The application of magnesium in the automotive industry contributes to reduced fuel consumption and CO2 emissions. Nowadays, most magnesium components in automobiles are manufactured by die casting. In this paper, simulation\\u000a of the low pressure die casting process of a magnesium wheel that adopts FDM (finite difference method) is presented. Through\\u000a calculating the temperature and velocity fields during filling and

  17. Modeling the Mechanical Performance of Die Casting Dies

    SciTech Connect

    R. Allen Miller

    2004-02-27

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

  18. 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.

  19. Automated Radioscopic Inspection of Aluminum Die Castings

    Microsoft Academic Search

    Domingo Mery

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

  20. Formation of defect bands in high pressure die cast magnesium alloys

    Microsoft Academic Search

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

    2001-01-01

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

  1. Spray-formed tooling for injection molding and die casting applications

    SciTech Connect

    K. M. McHugh; B. R. Wickham

    2000-06-26

    Rapid Solidification Process (RSP) Tooling{trademark} is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described.

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

    SciTech Connect

    Jensen, D. [University of Northern Iowa, Cedar Falls, IA (United States). Dept. of Industrial Technology] [comp.

    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.

  3. Characterization of Spray Lubricants for the Die Casting Process

    SciTech Connect

    Sabau, Adrian S [ORNL

    2008-01-01

    During the die casting process, lubricants are sprayed in order to cool the dies and facilitate the ejection of the casting. The cooling effects of the die lubricant were investigated using Thermogravimetric analysis (TGA), heat flux sensors (HFS), and infrared imaging. The evolution of the heat flux and pictures taken using a high speed infrared camera revealed that lubricant application was a transient process. The short time response of the HFS allows the monitoring and data acquisition of the surface temperature and heat flux without additional data processing. A similar set of experiments was performed with deionized water in order to assess the lubricant effect. The high heat flux obtained at 300 C was attributed to the wetting and absorbant properties of the lubricant. Pictures of the spray cone and lubricant flow on the die were also used to explain the heat flux evolution.

  4. Integrated optimization system for high pressure die casting processes

    Microsoft Academic Search

    L. X. Kong; F. H. She; W. M. Gao; S. Nahavandi; P. D. Hodgson

    2008-01-01

    High pressure die casting (HPDC) is a versatile process for producing engineered metal parts by forcing molten metal under high pressure into reusable steel dies. However there are a large number of attributes involved which contribute to the complexity of the process. A novel integrated approach is developed to optimize the high pressure die casting processes. The die temperature profiles

  5. Heat-Transfer Coefficient and In-Cavity Pressure at the Casting-Die Interface during High-Pressure Die Casting of the Magnesium Alloy AZ91D

    Microsoft Academic Search

    A. Hamasaiid; G. Dour; M. S. Dargusch; T. Loulou; C. Davidson; G. Savage

    2008-01-01

    The present article deals with the application of a new measurement method to determine the heat-transfer coefficient (HTC)\\u000a and the heat flux density at the casting-die interface during high-pressure die casting (HPDC) and solidification of the magnesium\\u000a AZ91D alloy. The main measurements during the trial included velocity and the position of the piston that delivers the metal\\u000a into the die,

  6. Vacuum assisted high pressure die casting of aluminium alloys

    Microsoft Academic Search

    X. P. Niu; B. H. Hu; I. Pinwill; H. Li

    2000-01-01

    High pressure die castings usually contain gas porosity due mainly to the entrapment of air or gas in the melt during the very high speed injection of the molten metal into the cavity. In this paper, the advantages of using an evacuated die cavity during mould filling were evaluated. ASTM standard die casting tensile specimens of three Al alloys, Al–5%Si,

  7. Effect of process parameters on porosity distributions in high-pressure die-cast AM50 Mg-alloy

    Microsoft Academic Search

    S. G. Lee; A. M. Gokhale; G. R. Patel; M. Evans

    2006-01-01

    High-pressure die-casting is the preferred manufacturing process for cast Mg-alloy components used for numerous applications. High-pressure die-cast components usually contain micro-porosity that adversely affects their mechanical properties. In this contribution, the effects of three important process parameters, gate velocity, intensification pressure, and melt temperature on the micro-porosity distributions in high-pressure die-cast AM50 Mg-alloy are quantitatively characterized. The amounts of total

  8. High-pressure die casting: effect of fluid flow on the microstructure of LM24 die-casting alloy

    Microsoft Academic Search

    M. R. Ghomashchi

    1995-01-01

    The effect of fluid flow rate on the microstructure of LM24 high pressure die-casting alloy was studied using a fully controlled cold chamber high-pressure die-casting machine and casting a series of rectangular coupons of 65 × 130 × 4 mm. All castings showed a bimodal distribution of dendrites in which the morphology of dendrites was completely different to the classic

  9. Performance enhancements of die casting tools trough PVD nanocoatings

    Microsoft Academic Search

    M. Rosso; D. Ugues; E. Torres; M. Perucca; P. Kapranos

    2008-01-01

    Wear and failure of die casting dies involve a complex interaction between various mechanisms. The most important wear and\\u000a failure modes are summarized as follows: (i) the so-called washout damages on working die surfaces are attributed to erosion,\\u000a corrosion and soldering; (ii) thermal fatigue is the most important failure mode in die casting. The sector of surface thin\\u000a PVD coatings

  10. Performance evaluation of PVD coatings for high pressure die casting

    Microsoft Academic Search

    S. Gulizia; M. Z. Jahedi; E. D. Doyle

    2001-01-01

    During high-pressure die-casting (HPDC) of aluminium alloys, there is a tendency for the molten alloy to react with the tool steel die, core pins and inserts. This occurrence within the high pressure die casting (HPDC) industry is referred to as ‘soldering’. It is of concern to high-pressure die casters because of down-time due to the regular removal of the soldered

  11. Die erosion and its effect on soldering formation in high pressure die casting of aluminium alloys

    Microsoft Academic Search

    Z. W Chen; M. Z Jahedi

    1999-01-01

    Erosion of the die material during die filling has long been regarded as a possible damage mechanism of dies in high pressure die casting (HPDC) of aluminium alloys. Melt impingement and erosion have also been proposed to be an important step leading to die soldering. However, there is little information in the literature on the direct measurement of any kind

  12. Development of Thin Section Zinc Die Casting Technology

    SciTech Connect

    Goodwin, Frank [International Lead Zinc Research Org., Inc.] [International Lead Zinc Research Org., Inc.

    2013-10-31

    A new high fluidity zinc high pressure die casting alloy, termed the HF alloy, was developed during laboratory trials and proven in industrial production. The HF alloy permits castings to be achieved with section thicknesses of 0.3 mm or less. Technology transfer activities were conducted to develop usage of the HF high fluidity alloy. These included production of a brochure and a one-hour webinar on the HF alloy. The brochure was then sent to 1,184 product designers in the Interzinc database. There was excellent reception to this mailing, and from this initial contact 5 technology transfer seminars were conducted for 81 participants from 30 companies across a wide range of business sectors. Many of the successful applications to date involve high quality surface finishes. Design and manufacturing assistance was given for development of selected applications.

  13. Creep studies of AZ91D pressure die casting

    Microsoft Academic Search

    M. Regev; E. Aghion; A. Rosen

    1997-01-01

    Creep properties of pressure die cast AZ91D magnesium alloy (9% Al-1% Zn) were investigated in the temperature range of 150–180 °C and load range of 30–100 MPa. The pressure die cast material is characterized by a small grain size of about 10 ?m. Creep tests were performed under constant load and under varying load. Creep rates were found to be

  14. A reclassification of the die-filling stages in pressure die-casting processes

    Microsoft Academic Search

    Y. B. Lui; W. B. Lee; B. Ralph

    1996-01-01

    Traditionally, the die-filling process in pressure die-casting is divided into three stages. This paper initiates the concept of a ‘five-stage’ process for one-shot pressure die-casting processes. The concept of a ‘five-stage’ process retains the familiar first and second stages, breaks down the third stage into two and adds a fifth ‘residual stage’. It is shown that the maximum metal pressure

  15. Formation and progression of die soldering during high pressure die casting

    Microsoft Academic Search

    Z. W. Chen

    2005-01-01

    High pressure die casting experiments have been conducted and detailed metallurgical examination of the soldered samples was made to study the formation and early progression of die soldering. It was found that soldering formed initially with a build-up of cast alloy on the samples (named mechanical soldering). Two major build-up modes were identified. One was a sudden build-up of a

  16. Low-pressure die casting of magnesium alloy AM50: Response to process parameters

    Microsoft Academic Search

    Penghuai Fu; Alan A. Luo; Haiyan Jiang; Liming Peng; Yandong Yu; Chunquan Zhai; Anil K. Sachdev

    2008-01-01

    Low-pressure die casting (LPDC) process has been successfully used to produce sound magnesium alloy AM50 castings. The influence of process parameters: filling time, pressure holding time, die temperature, holding pressure and casting temperature, on the mechanical properties, microstructure and density of LPDC castings were studied. The optimal process parameters for LPDC casting have been experimentally determined as follows: filling time

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

    SciTech Connect

    Shivpuri, R.

    1997-09-18

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

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

    PubMed

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

    2014-10-01

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

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

    E-print Network

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

    1999-01-01

    Die casting is a common method of light metal processing which is used to produce accurately dimensioned, sharply defined metal parts. Most die casting machines in use today utilize a complex hydraulic system to perform the necessary work required...

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

    E-print Network

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

    Die casting is a common method of light metal processing which is used to produce accurately dimensioned, sharply defined metal parts. Most die casting machines in use today utilize a complex hydraulic system to perform the necessary work required...

  1. Turbine blade casting die design method based on FBS theory

    Microsoft Academic Search

    Zhou Tong; Wang Wenhu; Wang Hong

    2010-01-01

    This paper put forward a method which is based on function-behavior-structure (FBS) according to the characters and demands of turbine blade die design. Through the analysis of the designing process of cavity, the paper researched on the mapping method of FBS which realized the automatic design of the cavity of precision casting mould on the basis of rule deduction and

  2. Microstructures and properties of aluminum die casting alloys

    Microsoft Academic Search

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

    1998-01-01

    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

  3. REVIEW OF NEW PROCESS TECHNOLOGIES IN THE ALUMINUM DIE-CASTING INDUSTRY

    Microsoft Academic Search

    Jean Collot

    2001-01-01

    There have been many challenges in aluminum die casting to establish casting processes to produce high-integrity components from aluminum alloys. Advances in new casting technology mainly have been in pressure die casting; in particular, to obtain mold filling at low speed. This can be achieved by using innovative filling processes with aluminum alloys in the liquid or semisolid state. Different

  4. A neural network system for the prediction of process parameters in pressure die casting

    Microsoft Academic Search

    Prasad K. D. V. Yarlagadda; Eric Cheng Wei Chiang

    1999-01-01

    In this work an artificial intelligent neural network system is developed to generate the process parameters for the pressure die casting process. The scope of this work includes analysing a physical model of the pressure die casting filling stage based on the governing equations of die cavity filling, and the collection of feasible casting data for the training of the

  5. Die casting die deflections: Prediction and attenuation. Final report, July 1, 1995--September 30, 1997

    SciTech Connect

    Miller, R.A.; Ahuett-Garza, H.; Choudhury, A.K.; Dedhia, S.

    1998-05-01

    This report summarizes two years of research intended to develop methods to model and predict the deflection patterns in die casting dies. No comprehensive analysis of this type had previously been completed. The die casting process is complex and involves numerous mechanical and thermal phenomena that effect the mechanical behavior of the die. A critical activity in this work was sorting out and evaluating the relative contributions of the various mechanisms to die deflections. This evaluation was accomplished through a series of simple engineering analyses based primarily on the order of magnitude of the influence of each load considered on die deflections. A modeling approach incorporating commercially available finite element analysis software was developed and tested. The model evolved by testing simple models against more comprehensive models and against the limited experimental data that is available. The development of the modeling approach lead to consideration of the die casting machine in more detail than was originally anticipated. The machine is critical and cannot be ignored. A simplified model described as a spring/platen model was developed to account for the machine platens, tie bars, and toggles. The characteristics of this model are described and predictions based on this model are compared against full machine models and measured deflections of machine platens. Details of the modeling approach and the various case studies are provided in the report and in several publications that have resulted from the work.

  6. Corrosion behaviour of high pressure die-cast and semi-solid cast AZ91D alloys

    Microsoft Academic Search

    S Mathieu; C Rapin; J Hazan; P Steinmetz

    2002-01-01

    The microstructure and the corrosion behaviour of high pressure die-cast and semi-solid cast AZ91D magnesium alloys have been investigated. Semi-solid processing leads to a structure with large rounded grains of a solid solution of magnesium (? phase) whereas die-cast alloys are more homogeneous. Electrochemical measurements, particularly with impedance spectroscopy, have shown that the semi-solid cast alloy possesses a corrosion rate

  7. Soldering mechanisms in materials and coatings for aluminum die casting

    Microsoft Academic Search

    Eduardo K. Tentardini; Augusto O. Kunrath; Cesar Aguzzoli; Maria Castro; John J. Moore; Israel J. R. Baumvol

    2008-01-01

    The stability against reaction with aluminum of materials and coatings commonly used in aluminum die casting was investigated. The materials considered here were H13 tool steel and Anviloy® 1150, whereas the coatings were TiN and CrN. Special model, freestanding, multilayered thin film structures were used in this study, in association with complementary differential scanning calorimetry and X-ray diffraction. The nature

  8. Rule-based quotation costing of pressure die casting moulds

    Microsoft Academic Search

    B. Denkena; L.-E. Lorenzen; J. Schürmeyer

    2009-01-01

    An actual analysis in the tool and mould making sector showed that methods and programs insufficiently support the manufacturers\\u000a of pressure die casting moulds in the quotation costing process. The primary aim of quotation costing is to generate many\\u000a first-class bids in order to gain a high quantity of profitable orders. For this purpose companies have to achieve a high

  9. Onset of fracture in high pressure die casting aluminum alloys

    Microsoft Academic Search

    Dirk Mohr; Roland Treitler

    2008-01-01

    This paper deals with the development of a phenomenological criterion for the prediction of crack initiation in engineering structures made of the pressure die casting alloy Al–10Si–Mg–Mn. A custom-made biaxial testing device is employed to load a newly-designed flat specimen under various combinations of shear and normal loading. In a hybrid experimental–numerical approach, the crack initiation could be studied for

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

    SciTech Connect

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

    2007-09-01

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

  11. Determination of the metal/die interfacial heat transfer coefficient of high pressure die cast B390 alloy

    NASA Astrophysics Data System (ADS)

    Cao, Yongyou; Guo, Zhipeng; Xiong, Shoumei

    2012-07-01

    High-pressure die cast B390 alloy was prepared on a 350 ton cold chamber die casting machine. The metal/die interfacial heat transfer coefficient of the alloy was investigated. Considering the filling process, a "finger"-shaped casting was designed for the experiments. This casting consisted of five plates with different thicknesses (0.05 inch or 1.27 mm to 0.25 inch or 6.35 mm) as well as individual ingates and overflows. Experiments under various operation conditions were conducted, and temperatures were measured at various specific locations inside the die. Based on the results, the interfacial heat transfer coefficient and heat flux were determined by solving the inverse heat transfer problem. The influence of the mold-filling sequence, sensor locations, as well as processing parameters including the casting pressure, die temperature, and fast/slow shot speeds on the heat transfer coefficient were discussed.

  12. The Effects of Externally Solidified Product on Wave Celerity and Quality of Die Cast Products

    SciTech Connect

    Carroll Mobley; Yogeshwar Sahai; Jerry Brevick

    2003-10-10

    The cold chamber die casting process is used to produce essentially all the die cast aluminum products and about 50% of the die cast magnesium products made today. Modeling of the cold chamber die casting process and metallographic observations of cold chamber die cast products indicate that typically 5 to 20% of the shot weight is solidified in the shot sleeve before or during cavity filling. The protion of the resulting die casting which is solidified in the shot sleeve is referred to as externally solidified product, or, when identified as a casting defect, as cold flakes. This project was directed to extending the understanding of the effects of externally solidified product on the cold chamber die casting process and products to enable the production of defect-free die castings and reduce the energy associated with these products. The projected energy savings from controlling the fraction of externally solidified product in die cast components is 40 x 10 Btu through the year 2025.

  13. Notched bar Izod impact properties of zinc die castings

    SciTech Connect

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

    2007-03-01

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

  14. High-Pressure Die-Casting: Contradictions and Challenges

    NASA Astrophysics Data System (ADS)

    Bonollo, Franco; Gramegna, Nicola; Timelli, Giulio

    2015-05-01

    High-pressure die casting (HPDC) is particularly suitable for high production rates and it is applied in several industrial fields; actually, approximately half of the world production of light metal castings is obtained by this technology. An overview of the actual status of HPDC technology is described in the current work, where both critical aspects and potential advantages are evidenced. Specific attention is paid to the quality requirements from the end users, as well as to the achievable production rate, the process monitoring and control, and the European and worldwide scenario. This overview leads to individuate the most relevant challenges for HPDC industry: "zero-defect" production, real-time process control, understanding the role of the process variables, process optimization, introduction of research and development activities, and disseminating the knowledge about HPDC technology. Performing these actions, HPDC foundries could achieve a more mature and efficient approach to large end users and exploit their really relevant potential.

  15. Heat Treatment of High-Pressure Die Castings

    Microsoft Academic Search

    R. N. Lumley; R. G. O’Donnell; D. R. Gunasegaram; M. Givord

    2007-01-01

    High-pressure die-cast Al alloys cannot normally be heated at high temperatures due to the presence of pores containing entrapped\\u000a gases, which lead to the formation of surface blisters. It has been found that blistering can be avoided by using considerably\\u000a shorter solution-treatment times and lower temperatures. Experiments with alloys 360 (Al-9.5Si-0.5Mg) and 380 (Al-8.5Si-3.5Cu)\\u000a have shown that strong responses to

  16. Investment cast AISI H13 tooling for automotive applications

    SciTech Connect

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

    1995-07-01

    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.

  17. Die casting die deflections: Prediction and attenuation. Final report, July 1, 1995--September 30, 1997

    SciTech Connect

    Miller, R.Allen; Ahuett-Garza, Horacio; Choudhury, Aswin K.; Dedhia, Sanjay

    1998-05-01

    The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects or problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information from the voxel model for display to the user.

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

    E-print Network

    Ozel, Tugrul

    High-speed machining of cast iron and alloy steels for die and mold manufacturing P. FallboÈhmer, C of cast iron and alloy steels used in die and mold manufacturing. This work covers: (a) theoretical to machining of aluminum alloys for manufacturing complicated parts used in the aircraft industry. This tech

  19. Optimization of a Wear Property of Die Cast AZ91D Components via a Neural Network

    Microsoft Academic Search

    Jeong-Lian Wen; Jie-Ren Shie; Yung-Kuang Yang

    2009-01-01

    This study integrated a trained general regression neural network (GRNN) and a sequential quadratic programming (SQP) method to determine an optimal parameter setting for a die casting process of AZ91D. Nine experiments were prepared under different die casting processes by selecting slurry pressure, the fusion slurry velocity and the mold temperature as three controlled parameters and the wear mass loss

  20. Modelling the pressure die casting process using boundary and finite element methods

    Microsoft Academic Search

    K. Davey; S. Bounds

    1997-01-01

    This paper is concerned with an investigation into the benefits and problems of modelling the pressure die casting process using a finite element solidification model for the casting and boundary element model for the die. Linking boundary and finite element methods is beset with difficulties with each method requiring different mesh, time-step and other requirements for accurate results. The numerical

  1. WARM WATER SCALE MODEL EXPERIMENTS FOR MAGNESIUM DIE CASTING

    SciTech Connect

    Sabau, Adrian S [ORNL

    2006-01-01

    High-pressure die casting (HPDC) involves the filling of a cavity with the molten metal through a thin gate. High gate velocities yield jet break-up and atomization phenomena. In order to improve the quality of magnesium parts, the mold filling pattern, including atomization phenomena, needs to be understood. The goal of this study was to obtain experimental data on jet break-up characteristics for conditions similar to that of magnesium HPDC, and measure the droplet velocity and size distribution. A scale analysis is first presented in order to identify appropriate analogue for liquid magnesium alloys. Based on the scale analysis warm water was chosen as a suitable analogue and different nozzles were manufactured. A 2-D component phase Doppler particle analyzer (PDPA) and 2-D component particle image velocimetry (PIV) were then used to obtain fine particle diameter and velocity distributions in 2-D plane.

  2. Feeding Mechanisms in High-Pressure Die Castings

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

    This work focuses on understanding the feeding behavior during high-pressure die casting (HPDC). The effects of intensification pressure (IP) and gate thickness on the transport of material through the gate during the latter stages of HPDC were investigated using an AlSi3MgMn alloy. Microstructural characterization of the gate region indicated a marked change in feeding mechanism with increasing IP and gate size. Castings produced with a high IP or thick gate contained a relatively low fraction of total porosity, and shear band-like features existed through the gate, suggesting that semisolid strain localization in the gate is involved in feeding during the pressure intensification stage. When a low IP is combined with a thin gate, no shear band is observed in the gate and feeding is less effective, resulting in a higher level of porosity in the HPDC component. Although shear banding through the gate was found to reduce porosity in HPDC parts, if gates are not properly designed, deformation of the mushy zone through the gate can cause severe macrosegregation, large pores, and large cracks, which could severely reduce the performance of the component.

  3. Die Materials for Critical Applications and Increased Production Rates

    SciTech Connect

    David Schwam; John Wallace; Sebastian Birceanu

    2002-11-30

    Die materials for aluminum die-casting need to be resistant to heat checking, and have good resistance to washout and to soldering in a fast flow of molten aluminum. To resist heat checking, die materials should have a low coefficient of thermal expansion, high thermal conductivity, high hot yield strength, good temper softening resistance, high creep strength, and adequate ductility. To resist the washout and soldering, die materials should have high hot hardness, good temper resistance, low solubility in molten aluminum and good oxidation resistance. It is difficult for one material to satisfy with all above requirements. In practice, H13 steel is the most popular material for aluminum die casting dies. While it is not an ideal choice, it is substantially less expensive to use than alternative materials. However, in very demanding applications, it is sometimes necessary to use alternative materials to ensure a reasonable die life. Copper-base, nickel-base alloys and superalloys, titanium-,molybdenum-, tungsten-base alloys, and to some extent yttrium and niobium alloys, have all been considered as potential materials for demanding die casting applications. Most of these alloys exhibit superior thermal fatigue resistance, but suffer from other shortcomings.

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

    SciTech Connect

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

    2010-10-26

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

  5. Characterisation of the spray cooling heat transfer involved in a high pressure die casting process

    Microsoft Academic Search

    Guang Wei Liu; Yosry Sadeik Morsi; Brian Robert Clayton

    2000-01-01

    A systematic experimental study was conducted to examine the heat transfer characteristics from the hot die surface to the water spray involved in high pressure die casting processes. Temperature and heat flux measurements were made locally in the spray field using a heater made from die material H-13 steel and with a surface diameter of 10 mm. The spray cooling

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

    SciTech Connect

    Jerald Brevick; R. Allen Miller

    2004-03-15

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

  7. Investigation of the interface phenomena and its effect on erosion and corrosion in aluminum die casting

    NASA Astrophysics Data System (ADS)

    Chu, Yeou-Li

    When performing an aluminum die casting operation, hot molten metal is injected into the die cavity. The die locks for part solidification. After the part solidifies, the casting will eject from the die. During this operation, the die surface experiences thermal cycling, high velocity impingement, chemical attack and interface friction. Thermal cycling leads to heat checking wear, high velocity impingement to erosive wear, chemical attack to soldering, and interface friction to the part bending and/or galling during ejection. The die casting process is a very capital intensive operation. All the above problems result in down time of the die casting shop. This down time results in loss of production and ultimately loss of capital. The purpose of this study is to (a) investigate the physical and chemical phenomena active at the die-cast aluminum metal interface, and (b) understand the performance of selected die surface treatments in protecting the interface from aluminum foundry alloy. Four laboratory tests were selected to study the aluminum die casting stages: (a) molten metal injection stage (erosive test), (b) filling and solidification (dissolution and wettability tests), and (c) parts ejection stage (friction test). Both qualitative and quantitative results were generated. This research produced many interesting discussions. In erosive testing, in addition to impingement velocity, the melt superheat and alloy types also found to play an important role in the erosion of the die steel. In the past, die casters believed that the higher molten aluminum temperature would cause higher erosive wear loss. However, this study found lower melt temperatures to result in greater erosive wear. In dissolution testing, the alloy elements were found to play an important role. In the past, die casters thought that Fe (Iron) was the main element which affects the dissolution of the die steel into the molten aluminum. This was found not to be necessary true. The Mn and Si content in the alloy also affects the die steel dissolution to a great extent. In wettability testing, the contact angle of the die steel surface was found to correlate well to the soldering phenomena. The friction coefficients of different surface treatments and cast alloy pairs were measured. There was no significant difference among all the surface coatings or treatments. The results of this investigation help explain the interface mechanisms present during a die casting operation and that effect on the die wear and machine down time related problem. It also provides guidelines for further research in the study and control of these mechanisms.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  9. Hot compression behavior of the AZ91 magnesium alloy produced by high pressure die casting

    Microsoft Academic Search

    E. Cerri; P. Leo; P. P. De Marco

    2007-01-01

    The hot deformation behavior of a Mg–9Al–1Zn alloy produced by high pressure die casting has been investigated by means of compression tests in the temperature and strain rate ranges of 125–300°C and 1.6×10?5 to 10?1s?1, respectively. The samples were deformed in the high pressure die casting state or after an exposure at 415°C for 2h to evaluate any different response

  10. The influence of pressure during solidification of high pressure die cast aluminium telecommunications components

    Microsoft Academic Search

    Matthew S. Dargusch; G. Dour; N. Schauer; C. M. Dinnis; G. Savage

    2006-01-01

    The effects of process variables on the quality of high-pressure die cast components was determined with the aid of in-cavity pressure sensors. In particular, the effects of set intensification pressure, delay time, and casting velocity have been investigated. The in-cavity pressure sensor has been used to determine how conditions within the die-cavity are related to the process parameters regulated by

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

    Microsoft Academic Search

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

    2008-01-01

    The heat transfer at the metal-die interface is believed to have great influence on the solidification process and cast structure\\u000a of the high-pressure die-casting (HPDC) process. The present article focused on the effects of process parameters, casting\\u000a thickness, and alloys on the metal-die interfacial heat-transfer coefficient (IHTC) in the HPDC process. Experiment was carried\\u000a out on a cold-chamber die-casting machine

  12. Steady state thermal model for the hot chamber injection system in the pressure die casting process

    Microsoft Academic Search

    I. Rosindale; K. Davey

    1998-01-01

    This paper describes a three-dimensional numerical model that is used to predict the steady state thermal behaviour of the metal injection system of a hot chamber pressure die casting machine. The behaviour of the injection system is considered in conjunction with that of the die. The boundary element method (BEM) is employed, as surface temperatures are of primary importance. The

  13. Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Development of Surface Engineered Coating Systems for Aluminum Pressure Die Casting Dies: Towards a 'Smart' Die Coating

    SciTech Connect

    Dr. John J. Moore; Dr. Jianliang Lin,

    2012-07-31

    The main objective of this research program was to design and develop an optimal coating system that extends die life by minimizing premature die failure. In high-pressure aluminum die-casting, the die, core pins and inserts must withstand severe processing conditions. Many of the dies and tools in the industry are being coated to improve wear-resistance and decrease down-time for maintenance. However, thermal fatigue in metal itself can still be a major problem, especially since it often leads to catastrophic failure (i.e. die breakage) as opposed to a wear-based failure (parts begin to go out of tolerance). Tooling costs remain the largest portion of production costs for many of these parts, so the ability prevent catastrophic failures would be transformative for the manufacturing industry.The technology offers energy savings through reduced energy use in the die casting process from several factors, including increased life of the tools and dies, reuse of the dies and die components, reduction/elimination of lubricants, and reduced machine down time, and reduction of Al solder sticking on the die. The use of the optimized die coating system will also reduce environmental wastes and scrap parts. Current (2012) annual energy saving estimates, based on initial dissemination to the casting industry in 2010 and market penetration of 80% by 2020, is 3.1 trillion BTU's/year. The average annual estimate of CO2 reduction per year through 2020 is 0.63 Million Metric Tons of Carbon Equivalent (MM TCE).

  14. SPH based modelling of oxide and oxide film formation in gravity die castings

    NASA Astrophysics Data System (ADS)

    Ellingsen, K.; Coudert, T.; M'Hamdi, M.

    2015-06-01

    Gravity die casting is an important casting process which has the capability of making complicated, high-integrity components for e.g. the automotive industry. Oxides and oxide films formed during filling affect the cast product quality. The Smoothed particle hydrodynamics (SPH) method is particularly suited to follow complex flows. The SPH method has been used to study filling of a gravity die including the formation and transport of oxides and oxide films for two different filling velocities. A low inlet velocity leads to a higher amount of oxides and oxide films in the casting. The study demonstrates the usefulness of the SPH method for an increased understanding of the effect of different filling procedures on the cast quality.

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

    NASA Astrophysics Data System (ADS)

    Sce, Andrea; Caporale, Lorenzo

    2014-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

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

    Microsoft Academic Search

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

    2007-01-01

    Bands of positive macrosegregation and porosity commonly follow the surface contour of components produced by high-pressure\\u000a die casting (HPDC). In this article, Al alloy AlSi7Mg and Mg alloys AZ91 and AM60 were cast into tensile test bars using cold-chamber\\u000a (cc) HPDC. Microstructural characterization revealed that externally solidified crystals (ESCs) are not necessary for defect\\u000a band formation, and that defect bands

  18. Skin solidification during high pressure die casting of Al–11Si–2Cu–1Fe alloy

    Microsoft Academic Search

    Z. W. Chen

    2003-01-01

    Surface regions of Al–11Si–2Cu–1Fe alloy castings produced by high pressure die casting (HPDC) were examined and three microstructural features were observed. In locations of direct melt impingement, there was not an ?-Al rich layer. In most surface locations, a porosity-free ?-Al rich layer was observed. However, in surface locations of low impact of melt, a porosity-free layer being a mixture

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

    Microsoft Academic Search

    P.. Cavaliere; P. P. De Marco

    2007-01-01

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

  20. Final report to USAMP on the use of EBPVD in the light metal die casting industry

    SciTech Connect

    Heestand, G.M.

    1996-02-02

    This is the final report to the United States Automotive Materials Partnership (USAMP) on the use of Electron Beam Physical Vapor Deposition (EBPVD) to make rapid tooling for functional prototyping of metal mold processes. Historically this process has been successfully applied to the production of mold inserts for the plastics injection mold industry. Our approach for this project was to use the same technique to produce dies which could be used to make a few thousand light metal (aluminum and magnesium) prototype parts. The difficulty encountered in this project was that the requirements for the die casting industry, both in size and material requirements, were considerably more stringent than those encountered in the plastics injection industry. Consequently our technique, within the allotted time and budget constraints, was not able to meet the requirements set forth by USAMP. The remainder of this report is organized into five sections. The first discusses the technique in some detail while the second discusses a successful application. The third section discusses issues with this process while the fourth specifically discusses the work done in this project. The last is a short summary and conclusion section.

  1. Simple visualization techniques for die casting part and die design. Final report, July 1, 1995--September 30, 1997

    SciTech Connect

    Miller, R.A.; Lu, S.C.; Rebello, A.B.

    1998-05-01

    The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects of problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information form the voxel model for display to the user.

  2. Numerical simulation of mold-filling capability for a thin- walled aluminum die casting

    NASA Astrophysics Data System (ADS)

    Sun, L.; Subasic, E.; Jakumeit, J.

    2015-06-01

    Mold-filling capability is an important property of casting materials. Especially in thin-walled die casting, fast cooling of the melt by contact to the die makes complete filling difficult to ensure. Simulation is an important tool enabling investigation of filling problems, even before the die is manufactured. However, the prediction of misruns is challenging. Flow and solidification have to be computed as closely coupled. The effects of surface tension, the wetting angle and reduced melt flow due to solidification must be modeled with high precision. To meet these requirements, a finite-volume method using arbitrary polyhedral control volumes is used to solve flow and solidification as closely coupled. The Volume-of-Fluid approach is used to capture the phase separation between gas, melt and solid in connection with a High-Resolution Interface-Capturing scheme to obtain sharp interfaces between phases. To model the resistance of the dendrite network to the melt flow, an additional source term in the momentum equation was implemented. The Bolt test was performed for A356 alloys at a range of different casting temperatures. Numerical prediction of incomplete filling in the bottleneck regions agreed well with experimental findings using 3D camera scanning. The simulation enables derivation of the dependence of critical wall-thickness, i.e. the thickness which is fillable, on casting temperature and metallostatic pressure. This could prove useful in predicting filling problems ahead of casting.

  3. Predicting compositions and properties of aluminum die casting alloys using artificial neural network

    Microsoft Academic Search

    L. Wang; D. Apelian; M. Ma; W. Huang

    Despite the large numbe r of ex isting alloys and alloy databases, identifying proper alloys for spe cific ap plicat io ns still remains a challenge. In order to facilitate the selection and prediction of aluminum die casting alloys and their properties, an electronic database - \\

  4. Three defect types in friction stir welding of aluminum die casting alloy

    Microsoft Academic Search

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

    2006-01-01

    For different tool plunge downforces, the optimum FSW conditions of aluminum die casting alloy were examined. The higher the tool plunge downforce is, the wider the range of the optimum FSW conditions is. The following three different types of defects are formed, depending on the FSW conditions. (1) A large mass of flash due to the excess heat input; (2)

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

    Microsoft Academic Search

    P. Fallböhmer; C. A. Rodr??guez; T. Özel; T. Altan

    2000-01-01

    This paper gives a brief overview of HSC technology and presents current progress in high performance machining of cast iron and alloy steels used in die and mold manufacturing. This work covers: (a) theoretical and experimental studies of tool failure and tool life in high-speed milling of hard materials, (b) optimization of CNC programs by adjusting spindle RPM and feed

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

    Microsoft Academic Search

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

    2006-01-01

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

  7. On the optimum plunger acceleration law in the slow shot phase of pressure die casting machines

    Microsoft Academic Search

    F Faura; J López; J Hernández

    2001-01-01

    The objective of this paper is to analyse a plunger acceleration law that is expected to minimize air entrapment in the slow shot phase of pressure die casting in horizontal cold chambers, and thus to reduce porosity in manufactured parts. The study is carried out using results from an analytical model of the flow of molten metal in the shot

  8. 3D SPH flow predictions and validation for high pressure die casting of automotive components

    Microsoft Academic Search

    P. W. Cleary; J. Ha; M. Prakash; T. Nguyen

    2006-01-01

    The geometric complexity and high fluid speeds involved in high pressure die casting (HPDC) combine to give strongly three-dimensional fluid flow with significant free surface fragmentation and splashing. A Lagrangian simulation technique that is particularly well suited to modelling HPDC is smoothed particle hydrodynamics (SPH). Materials are approximated by particles that are free to move around rather than by fixed

  9. Modelling the environmental impact of an aluminium pressure die casting plant and options for control

    Microsoft Academic Search

    Belmira Neto; Carolien Kroeze; Leen Hordijk; Carlos Costa

    2008-01-01

    This study describes a model (MIKADO) to analyse options to reduce the environmental impact of aluminium die casting. This model will take a company perspective, so that it can be used as a decision-support tool for the environmental management of a plant. MIKADO can be used to perform scenario analyses to analyse the impact on the environment of different strategies,

  10. Superplastic behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die cast

    Microsoft Academic Search

    P. Cavaliere; P. P. De Marco

    2007-01-01

    The room temperature and hot tensile properties of AZ91 magnesium alloy produced by high pressure die cast after friction stir processing (FSP) were studied in the present paper. Such process is a modification of classical friction stir welding one in which the sheets are not joined but the stirring action of the tool, on the bulk material, is used to

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

    NASA Astrophysics Data System (ADS)

    Ferraro, Stefano; Timelli, Giulio

    2015-04-01

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

  12. Die-casting effect on surface characteristics of thin-walled AZ91D magnesium components

    NASA Astrophysics Data System (ADS)

    Hu, Lifang; Chen, Shaoping; Miao, Yang; Meng, Qingsen

    2012-11-01

    Filling trace, filling time and temperature distribution during the die-casting process were simulated using commercial software (MAGMA). The surface microstructure and phase distribution in thin-walled AZ91D magnesium components cast on a hot-chamber die-casting machine were investigated by means of optical microscopy and scanning electron microscopy. The depth profile of alloying elements was examined using a glow discharge optical emission spectrometer. The outer skin microstructure consists of more ?-phase and less eutectic ?-phase than the interior region. The elemental content of C, Si, and Fe in the outer skin increased along the filling trace, and they decreased with increasing distance from the surface to the interior region, while the Al had an inverse trend. The corrosion resistance decreased along the filling trace.

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

    NASA Astrophysics Data System (ADS)

    Wu, Mengwu; Xiong, Shoumei

    2012-07-01

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

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

    SciTech Connect

    David Schwam

    2012-12-15

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

  15. Development of materials for the rapid manufacture of die cast tooling

    NASA Astrophysics Data System (ADS)

    Hardro, Peter Jason

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

  16. Compressive strain-rate sensitivity of magnesium–aluminum die casting alloys

    Microsoft Academic Search

    Wei Qian Song; Peter Beggs; Mark Easton

    2009-01-01

    Compressive properties of three die cast magnesium alloys (AM20, AM50, and AM60) have been investigated at a nominal strain rate range from 0.001s?1 to approximately 1700s?1. The high strain rate experiments were conducted using a Split Hopkinson Bar apparatus. The strain rate sensitivity decreased with increasing Al content at the low strain rates. At strain rates above 1500s?1 there was

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

    Microsoft Academic Search

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

    2006-01-01

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

  18. Endurance limit and threshold stress intensity of die cast magnesium and aluminium alloys at elevated temperatures

    Microsoft Academic Search

    H. Mayer; M. Papakyriacou; B. Zettl; S. Vacic

    2005-01-01

    High cycle fatigue properties of the high-pressure die-cast magnesium alloys AZ91 hp, AS21 hp and AE42 hp and of the aluminium alloy AlSi9Cu3 are investigated at elevated temperatures. Fatigue tests are performed at ultrasonic cyclic frequency and load ratio R=?1. Compared with ambient air environment, the S–N curves determined in warm air of 125°C (magnesium alloys) and 150°C (aluminium alloy)

  19. Nondestructive Quantitative Evaluation of Porosity Volume Distribution in Aluminum Alloy Die Castings by Fractal Analysis

    Microsoft Academic Search

    Yoshihiko Hangai; Shota Maruhashi; Soichiro Kitahara; Osamu Kuwazuru; Nobuhiro Yoshikawa

    2009-01-01

    The nondestructive and three-dimensional quantitative evaluation of porosity in aluminum alloy die castings is proposed to\\u000a identify whether the predominant cause of pore formation is shrinkage or entrapped gas. The validity of this method of evaluation\\u000a was shown by comparing two different regions with different ratios of pores formed by shrinkage and gas. It was shown that\\u000a the proposed evaluation

  20. Galvanic corrosion properties of differently PVD-treated magnesium die cast alloy AZ91

    Microsoft Academic Search

    H. Hoche; C. Blawert; E. Broszeit; C. Berger

    2005-01-01

    Different types of PVD coatings and plasma treatments were applied for the surface treatment of magnesium die cast alloy AZ91 specimens. The different types of surface treatment were all developed by the authors and the fundamental properties are described elsewhere. The coating systems were:•9 ?m CrN hard coating•3 ?m TiN coating•0.5 ?m plasma anodisation layer and 3 ?m Al2O3 coatingThe

  1. Exergy analysis and efficiency evaluation for an aluminium melting furnace in a die casting plant

    Microsoft Academic Search

    Dennis Lee

    2003-01-01

    An aluminium melting furnace efficiency in a die casting plant was investigated using energy and exergy methods. Energy efficiency and exergy efficiency values were evaluated for the natural gas-fired furnace, and the efficiency improvement was analyzed before and after two new regenerative burners were installed on the furnace.\\u000aThe research analyzed and compared the environmental impacts attributable to the melting

  2. Multilayered chromium\\/chromium nitride coatings for use in pressure die-casting

    Microsoft Academic Search

    A Lousa; J Romero; E Mart??nez; J Esteve; F Montalà; L Carreras

    2001-01-01

    Chromium nitride coatings are known to give reasonable solutions to the requirements of semisolid forming tools and of pressure die-casting of low-melting-point metals and alloys. These hard coatings have good mechanical behavior when working at high temperatures. They show enhanced hardness and good wear and corrosion resistance, as well as reduced adhesion to the molten or semisolid metal. We have

  3. Microstructure of a pressure die cast magnesium—4wt.% aluminium alloy modified with rare earth additions

    Microsoft Academic Search

    G. Pettersen; H. Westengen; R. Høier; O. Lohne

    1996-01-01

    Addition of cerium-rich mixtures of rare earth (RE) elements to aluminium-containing magnesium pressure die cast alloys is known to improve the creep properties at elevated temperatures. In the present investigation, a detailed description of the microstructure of a magnesium-4 wt.% aluminium alloy containing 1.4 wt.% of a cerium-rich mixture of RE elements is presented. Particle types occurring and their distribution

  4. Creep deformation mechanisms in high-pressure die-cast magnesium-aluminum-base alloys

    Microsoft Academic Search

    W. Blum; Y. J. Li; X. H. Zeng; P. Zhang; B. von Großmann; C. Haberling

    2005-01-01

    Creep of die-cast Mg alloys is described as an integral part of their plastic deformation behavior in terms of stress-strain-rate-strain\\u000a relations. Creep tests yield information on yield stress, work hardening, maximum deformation resistance (minimum creep rate),\\u000a and work softening. Testing in compression avoids influences by fracture. Data on the alloy AJ52 (5Al, 2Sr) in the temperature\\u000a range between 135 °C

  5. Properties of alumina particulate reinforced aluminum alloy produced by pressure die casting

    Microsoft Academic Search

    Hüseyin Sevik; S. Can Kurnaz

    2006-01-01

    In this study, metal–matrix composites of an aluminum–silicon based alloy (LM6) and Al2O3 particles with volume fractions of 0.05, 0.10 and 0.15 and in size of 44, 85 and 125?m were produced using pressure die-casting technique. Density, hardness, tensile strength and wear properties were examined. The density values of the composites increased by adding Al2O3 particle. The hardness of the

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

    NASA Astrophysics Data System (ADS)

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

    2007-08-01

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

  7. Numerical Simulations of Jet Break-up Phenomena for the High Pressure Die Casting Process

    SciTech Connect

    Sabau, Adrian S [ORNL

    2006-01-01

    In High Pressure Die Casting a molten metal is injected through a thin gate into the cast cavity. High injection pressures and high gate velocities create atomization phenomena which can negatively affect the final quality of the cast. In order to control atomization process it is essential to understand the atomization patterns and the two-phase flowfield that exist at the gate exit. In the present work, 2D numerical simulations of the flow of molten Magnesium through a high aspect-ratio rectangular gate are performed using a water analogue for an open and closed cavity. The numerical simulations made use of VOF-type (Eulerian) physical models and Lagrangian models. Further, a sub-grid scale model was implemented that, in conjunction with VOF-type equations can efficiently predict the general atomization pattern without the need for high-resolution grids. The numerical results were compared to experimental data for validation.

  8. Precipitation Strengthening of a Mg-Al-Ca Based AXJ530 Die-cast Alloy

    NASA Astrophysics Data System (ADS)

    Suzuki, A.; Saddock, N. D.; Terbush, J. R.; Powell, B. R.; Jones, J. W.; Pollock, T. M.

    2008-03-01

    Precipitation of the Al2Ca phase in the ?-Mg phase of the Mg-Al-Ca based AXJ530 die-cast alloy and the effect of precipitation hardening on the creep resistance were studied. Precipitation of the Al2Ca phase is suppressed in the die-casting process due to its high cooling rate, but precipitation was observed during subsequent isothermal heat treatments above 448 K. The precipitate has a disk-shaped morphology parallel to the basal plane of the ?-Mg matrix phase and increases hardness by aging in the temperature range of 448 to 573 K. The creep resistance of the die-cast material at 448 K was improved by a factor of 1.5 ˜ 2, by a peak-age heat treatment at 523 K for 1 hour. Improvement in strength is limited by the low volume fraction of the precipitates; however, the precipitates are effective obstacles against dislocations gliding on nonbasal planes during creep deformation.

  9. On the influence of process variables on the thermal conditions and properties of high pressure die-cast magnesium alloys

    Microsoft Academic Search

    Nahed A. El-Mahallawy; Mohamed A Taha; Engenius Pokora; Friedrich Klein

    1998-01-01

    The influence of pressure and velocity in high-pressure magnesium die casting on the thermal conditions and on the casting properties is studied. Specimens with the shape of a tensile test plate with a thickness of 12 mm and a length of 295 mm were cast using the alloys AM20HP, AM50HP, AS41, AE42, AZ91HP. Two gate velocities of the liquid metal

  10. Microstructure Formation in AlSi4MgMn and AlMg5Si2Mn High-Pressure Die Castings

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

    Understanding microstructure formation during high-pressure die casting (HPDC) is important for the effective quality control of high-pressure diecast aluminum-alloy components for high-integrity applications. In this study, two HPDC-specific aluminum alloys, AlSi4MgMn and AlMg5Si2Mn, were cast into tensile test bars by cold-chamber (CC) HPDC. The microstructures of the tensile bar specimens were characterized at different length scales, from the scale of the casting to the scale of the eutectic interlamellar spacing. The results show that the salient as-cast microstructural features, e.g., externally solidified crystals (ESCs), defect bands, the surface layer, grain size distribution, porosity, and hot tears were similar for both alloys. The formation of these features can be understood by considering the influence of flow and solidification during each stage of the HPDC process.

  11. Detection of Cast Shadows in Surveillance Applications

    E-print Network

    's research on implementing a system for automated video surveillance. The main objectives of the DDRE video surveillance. The W4-system eectively detects moving objects, tracks them through simpleDetection of Cast Shadows in Surveillance Applications Søren Gylling Erbou 1, Helge B.D. Sørensen 2

  12. Microstructure Formation in AlSi4MgMn and AlMg5Si2Mn High-Pressure Die Castings

    Microsoft Academic Search

    S. Otarawanna; C. M. Gourlay; H. I. Laukli; A. K. Dahle

    2009-01-01

    Understanding microstructure formation during high-pressure die casting (HPDC) is important for the effective quality control\\u000a of high-pressure diecast aluminum-alloy components for high-integrity applications. In this study, two HPDC-specific aluminum\\u000a alloys, AlSi4MgMn and AlMg5Si2Mn, were cast into tensile test bars by cold-chamber (CC) HPDC. The microstructures of the tensile\\u000a bar specimens were characterized at different length scales, from the scale of

  13. Effect of viscoelastic stress state at die exit on extrusion film casting process: Theoretical study

    NASA Astrophysics Data System (ADS)

    Barborik, Tomas; Zatloukal, Martin

    2015-04-01

    In this work, viscoelastic, isothermal extrusion film casting modeling utilizing 1D membrane model and modified Leonov model was performed in order to understand the role of viscoelastic stress state at the die exit on the polymer melt film stretching in the post die area. Experimental data for LDPE and theoretical predictions based on the eXtended Pom-Pom (XPP) model taken from the open literature were used for the validation purposes. It was found that predicting capabilities of 1D membrane model utilizing XPP and modified Leonov model are comparable for the given processing conditions and material. Consequent theoretical parametric study revealed that increase in the viscoelastic stress state at the die exit, characterized as the ratio of second and first normal stress differences, -N2/N1, leads to increase in neck-in phenomenon. This suggests that specific attention should be paid to optimization of the extrusion die design in order to stabilize polymer melt film stretching in the post die area.

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

    SciTech Connect

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

    2007-03-15

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

  15. Microstructure of high pressure die cast AZ91D modified with Ca and Ce

    Microsoft Academic Search

    L. Shepeleva; M. Bamberger

    2006-01-01

    High pressure die cast (HPDC) AZ91D (Mg–8.8wt%Al–0.74wt%Zn–0.29wt%Mn) modified with Ca and Ce was investigated. Thermodynamic calculations of liquid\\/solid equilibrium were confirmed by DTA measurements and solid\\/liquid equilibrium at various temperatures between the liquidus and solidus temperatures.The solidification path of HPDC AZ91 and AZ91 modified with Ca and Ce was calculated using the Termo-Calc program. The microstructure was investigated utilizing optical

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  17. Application of New Feeding Rules To Risering of Steel Castings

    E-print Network

    Beckermann, Christoph

    1 Application of New Feeding Rules To Risering of Steel Castings Doug Smith , Tony Faivre , Shouzhu., Hardin, R.A., and Beckermann, C., "Application of New Feeding Rules to Risering of Steel Castings The importance of investigating and improving the guidelines for risering and feeding steel castings is clear

  18. Annealing of chromium oxycarbide coatings deposited by plasma immersion ion processing (PIIP) for aluminum die casting

    NASA Astrophysics Data System (ADS)

    Peters, A. M.; He, X. M.; Trkula, M.; Nastasi, M.

    2001-04-01

    Chromium oxycarbide coatings have been investigated for use as non-wetting coatings for aluminum die casting. This paper examines Cr-C-O coating stability and non-wetability at elevated temperatures for extended periods. Coatings were deposited onto 304 stainless steel from chromium carbonyl [Cr(CO) 6] by plasma immersion ion processing. The coatings were annealed in air at an aluminum die casting temperature of 700°C up to 8 h. Coatings were analyzed using resonant ion backscattering spectroscopy, nanoindentation and pin-on-disk tribometry. Molten aluminum was used to determine coating wetting and contact angle. Results indicate that the surface oxide layer reaches a maximum thickness of 900 nm. Oxygen concentrations in the coatings increased from 24% to 34%, while the surface concentration rose to almost 45%. Hardness values ranged from 22.1 to 6.7 GPa, wear coefficients ranged from 21 to 8×10 -6 mm3/ Nm and contact angles ranged from 156° to 127°.

  19. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: a scenario analysis.

    PubMed

    Neto, Belmira; Kroeze, Carolien; Hordijk, Leen; Costa, Carlos; Pulles, Tinus

    2009-02-01

    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze, C., Hordijk, L., Costa, C., 2008. Modelling the environmental impact of an aluminium pressure die casting company and options for control. Environmental Modelling & Software 23 (2) 147-168] we included the model description and explored the model by applying it to a plant in which no reduction options are assumed to be implemented (so-called zero case, reflecting the current practice in the plant). Here, we perform a systematic analysis of reduction options. We analysed seven types of reduction strategies, assuming the simultaneous implementation of different reduction options. These strategies are analysed with respect to their potential to reduce emissions, environmental impact and costs associated with the implementation of options. These strategies were found to differ largely in their potential to reduce the environmental impact of the plant (10-87%), as well as in the costs associated with the implementation of options (-268 to +277keuro/year). We were able to define 11 strategies, reducing the overall environmental impact by more than 50%. Of these, two have net negative costs, indicating that the company may in fact earn money through their implementation. PMID:18342428

  20. 40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  1. 40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  2. 40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  3. 40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  4. 40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  5. 40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  6. 40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  7. 40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  8. 40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  9. 40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  10. 40 CFR 464.20 - Applicability; description of the copper casting subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  13. 40 CFR 464.20 - Applicability; description of the copper casting subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  15. Reconstruction and visualization of complex 3D pore morphologies in a high-pressure die-cast magnesium alloy

    Microsoft Academic Search

    S. G. Lee; A. M. Gokhale; A. Sreeranganathan

    2006-01-01

    Visualization and representation of three-dimensional (3D) pore morphologies in the high-pressure die-cast Mg alloys are of significant interest for understanding and modeling processing–microstructure–properties relationships. In this contribution, an efficient and unbiased montage serial sectioning technique is applied for reconstruction of large volume (?1.24×109?m3) high-resolution (?1?m) 3D microstructure of a high-pressure die-cast AM50 Mg alloy containing gas (air) and shrinkage pores.

  16. 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.

  17. Optimization of porosity formation in AlSi 9Cu 3 pressure die castings using genetic algorithm analysis

    Microsoft Academic Search

    V. D. Tsoukalas

    2008-01-01

    In this investigation, an effective approach based on multivariable linear regression (MVLR) and genetic algorithm (GA) methods has been developed to determine the optimum conditions leading to minimum porosity in AlSi9Cu3 aluminium alloy die castings. Experiments were conducted by varying holding furnace temperature, die temperature, plunger velocities in the first and second stage, and multiplied pressure in the third stage

  18. Effect of grain refiner and grain size on the susceptibility of Al–Mg die casting alloy to cracking during solidification

    Microsoft Academic Search

    Ryosuke Kimura; Haruaki Hatayama; Kenji Shinozaki; Izumi Murashima; Jo Asada; Makoto Yoshida

    2009-01-01

    The die casting process and its alloys have been developed in recent years for automobile body parts such as B-pillars. However, it is known that die casting alloys with high ductility and fracture elongation often show a higher susceptibility to cracking during solidification than conventional Al–Si alloys. Thus, it is important to estimate and control the susceptibility to cracking during

  19. Development of a 3-D thermal model of the low-pressure die-cast (LPDC) process of A356 aluminum alloy wheels

    Microsoft Academic Search

    B. Zhang; D. M. Maijer; S. L. Cockcroft

    2007-01-01

    A mathematical model of the low-pressure die casting process for the production of A356 aluminum alloy wheels has been developed to predict the evolution of temperature within the wheel and die under the auspices of a collaborative research agreement between researchers at the University of British Columbia and a North American wheel casting facility. The heat transfer model represents a

  20. A thousandfold creep strengthening by Ca addition in die-cast AM50 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Terada, Yoshihiro; Sota, Rie; Ishimatsu, Naoya; Sato, Tatsuo; Ohori, Koichi

    2004-09-01

    The effect of calcium addition on the microstructure and creep strength of the die-cast AM50 magnesium alloy was investigated. The ?-Mg grains with the diameter of 4.9 µm are surrounded by the eutectic phases for the AM50-1.72 mass pct Ca alloy, while the ?(Mg17Al12) particles are located mainly on the grain boundaries of the ? grains for the AM50 alloy. The minimum creep rates of the AM50-1.72 mass pct Ca alloy are three orders of magnitude lower than those of the AM50 alloy at 423 K typically below 120 MPa. The thousandfold creep strengthening by the Ca addition is ascribed to the thermally stable eutectic phases appearing in the AM50-1.72 mass pct Ca alloy, which is expected to yield effective grain boundary strengthening or to resist the plastic flow of the ?-Mg grains.

  1. An experimental design criterion for minimizing meta-model prediction errors applied to die casting process design

    Microsoft Academic Search

    Theodore T. Allen; Liyang Yu; John Schmitz

    2003-01-01

    We propose the expected integrated mean-squared error (EIMSE) experimental design criterion and show how we used it to design experiments to meet the needs of researchers in die casting engineering. This criterion expresses in a direct way the researchers' goal to minimize the expected meta-model prediction errors, taking into account the effects of both random experimental errors and errors deriving

  2. Computational microstructure analyzing technique for quantitative characterization of shrinkage and gas pores in pressure die cast AZ91 magnesium alloys

    Microsoft Academic Search

    D. G. Leo Prakash; B. Prasanna; D. Regener

    2005-01-01

    Pressure die cast AZ91 magnesium alloy contains both shrinkage and gas microporosity. Quantification and characterization of shrinkage and gas microporosity is expected to be useful to understand the processing-properties-microstructure correlations. However, conventional image analysis techniques do not permit a separate quantification and characterization of shrinkage and gas microporosity. A computational microstructural (image) analyzing technique has been developed by the use

  3. Simulation-based selection of optimum pressure die-casting process parameters using neural nets and genetic algorithms

    Microsoft Academic Search

    A. Krimpenis; P. G. Benardos; G.-C. Vosniakos; A. Koukouvitaki

    2006-01-01

    Pressure die-casting condition selection mainly relies on the experience and expertise of individuals working in production industries. Systematic knowledge accumulation regarding the manufacturing process is essential in order to obtain optimal process conditions. It is not safe a priori to presume that rules of thumb, which are widely used on the shop floor, always lead to fast prototype production calibration

  4. Variability in the tensile ductility of high-pressure die-cast AM50 Mg-alloy

    Microsoft Academic Search

    S. G. Lee; G. R. Patel; A. M. Gokhale; A. Sreeranganathan; M. F. Horstemeyer

    2005-01-01

    Variability in the tensile ductility of high-pressure die-cast AM50 Mg-alloy is examined at five different test temperatures. The fracture path preferentially goes through the regions of clusters of pores. The percent ductility is correlated to area fraction of porosity in the fracture surfaces using a power law equation.

  5. Experimental and Numerical Study of Air Entrapment During the Filling of a Mould Cavity in Die Casting

    NASA Astrophysics Data System (ADS)

    Hernández-Ortega, Juan J.; Zamora, Rosendo; Palacios, Julián; López, Joaquín; Faura, Félix

    2007-04-01

    One of the most important problems encountered in die-casting processes is porosity due to air entrapment in the molten metal during the injection process. The aim of this work is to study experimentally and numerically different air entrapment mechanisms that may take place during the filling of a mould cavity (with rectangular shape) in die-casting processes. The numerical simulation of the flow in the die cavity is carried out using a CFD code (FLOW-3D), which is based on a SIMPLE-like approach to solve the coupling between the momentum and mass conservation equations and a Volume of Fluid (VOF) technique for treating the free surface. Also, filling visualization experiments are carried out on a test bench using water as working fluid in a transparent die model and a high-speed camera. The die model is specifically designed and constructed to allow an easy modification of the geometrical configuration of the gate to the die cavity. The numerical and experimental results obtained for the air-water interface evolution are compared for different inlet velocities of the fluid. The purpose is to identify the mechanisms of air entrapment during die filling.

  6. Microstructural Evolution and Solidification Behavior of Al-Mg-Si Alloy in High-Pressure Die Casting

    NASA Astrophysics Data System (ADS)

    Ji, Shouxun; Wang, Yun; Watson, D.; Fan, Z.

    2013-07-01

    Microstructural evolution and solidification behavior of Al-5 wt pct Mg-1.5 wt pct Si-0.6 wt pct Mn-0.2 wt pct Ti alloy have been investigated using high-pressure die casting. Solidification commences with the formation of primary ?-Al phase in the shot sleeve and is completed in the die cavity. The average size of dendrites and fragmented dendrites of the primary ?-Al phase formed in the shot sleeve is 43 ?m, and the globular primary ?-Al grains formed inside the die cavity is at a size of 7.5 ?m. Solidification inside the die cavity also forms the lamellar Al-Mg2Si eutectic phase and the Fe-rich intermetallics. The size of the eutectic cells is about 10 ?m, in which the lamellar ?-Al phase is 0.41 ?m thick. The Fe-rich intermetallic compound exhibits a compact morphology and is less than 2 ?m with a composition of 1.62 at. pct Si, 3.94 at. pct Fe, and 2.31 at. pct Mn. A solute-enriched circular band is always observed parallel to the surface of the casting. The band zone separates the outer skin region from the central region of the casting. The solute concentration is consistent in the skin region and shows a general drop toward the center inside the band for Mg and Si. The peak of the solute enrichment in the band zone is much higher than the nominal composition of the alloy. The die casting exhibits a combination of brittle and ductile fracture. There is no significant difference on the fracture morphology in the three regions. The band zone is not significantly detrimental in terms of the fracture mechanism in the die casting. Calculations using the Mullins and Sekerka stability criterion reveal that the solidification of the primary ?-Al phase inside the die cavity has been completed before the spherical ?-Al globules begin to lose their stability, but the ?-Al grains formed in the shot sleeve exceed the limit of spherical growth and therefore exhibit a dendritic morphology.

  7. 40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  8. 40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  9. 40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  10. 40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  11. 40 CFR 420.60 - Applicability; description of the continuous casting subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  12. 40 CFR 420.60 - Applicability; description of the continuous casting subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  13. 40 CFR 420.60 - Applicability; description of the continuous casting subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  14. 40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  15. 40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  16. 40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  17. 40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  18. 40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  19. Interface microstructure of aluminum die-casting alloy joints bonded by pulse electric-current bonding process

    Microsoft Academic Search

    Guoqiang Xie; Osamu Ohashi; Kouji Wada; Takayuki Ogawa; Minghui Song; Kazuo Furuya

    2006-01-01

    Aluminum die-casting alloy specimens were bonded by a pulse electric-current bonding (PECB) process using insert alloy powders containing 1mass% Mg into interface between two bonded specimens. Microstructure of the bonded joints was characterized and analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray energy dispersive spectroscopy (EDS). The results proposed that insert alloy powders containing Mg was

  20. Correlation of abrasive wear with microstructure and mechanical properties of pressure die-cast aluminum hard-particle composite

    Microsoft Academic Search

    S. Das; D. P. Mondal; G. Dixit

    2001-01-01

    Aluminum hard particle composites were synthesized by the solidification processing technique and the composite melt was solidified\\u000a using gravity and pressure die castings. An aluminum-silicon alloy (A 332.1) has been used as the matrix and silicon carbide\\u000a particles (quantity: 10 wt pct, and size: 50 to 80 m) have been used as reinforcement for synthesis of the composite. The microstructure

  1. An electron metallographic study of pressure die-cast commercial zinc–aluminium-based alloy ZA27

    Microsoft Academic Search

    M. DURMAN; S. MURPHY

    1997-01-01

    The microstructure of ZA27 pressure die-castings was examined by scanning and transmission electron microscopy after ageing\\u000a for 5 years at ambient temperatures. Solidification began with the formation of compact aluminium-rich ?? dendrites and tiny\\u000a rounded ?? particles, followed by the peritectic reaction whereby a zinc-rich ? phase formed around the edges of the primary\\u000a phases. The extremely high cooling rate

  2. Characterization of the effects of process parameters on macrosegregation in a high-pressure die-cast Magnesium alloy

    Microsoft Academic Search

    Soon Gi Lee; G. R. Patel; A. M. Gokhale

    2005-01-01

    Normal and inverse solute segregations have been reported to occur in several Al-alloys as well as in some other nonferrous alloys. Nonetheless, these phenomena have not been studied in high-pressure die-cast (HPDC) Mg-alloys. This contribution reports an experimental metallographic evidence of inverse surface macrosegregation in a HPDC AM60 Mg-alloy and the effects of process parameters on the extent of inverse

  3. Structures of intermetallic phases formed during immersion of H13 tool steel in an Al–11Si–3Cu die casting alloy melt

    Microsoft Academic Search

    Z. W. Chen; D. T. Fraser; M. Z. Jahedi

    1999-01-01

    The structures of intermetallic alloy layers formed during immersion of H13 tool steel into an aluminium die casting alloy melt have been studied by X-ray diffraction. Energy dispersive spectroscopy (EDS) analysis on the intermetallic phases was also conducted. A thick composite layer away from the H13 steel substrate consisted of irregular intermetallics and solidified cast alloy. A thin intermetallic layer

  4. Application of Numerical Optimization to Aluminum Alloy Wheel Casting

    NASA Astrophysics Data System (ADS)

    Duan, J.; Reilly, C.; Maijer, D. M.; Cockcroft, S. L.; Phillion, A. B.

    2015-06-01

    A method of numerically optimizing the cooling conditions in a low- pressure die casting process from the standpoint of maintaining good directional solidification, high cooling rates and reduced cycle times has been developed for the production of aluminumalloy wheels. The method focuses on the optimization of cooling channel timing and utilizes an open source numerical optimization algorithm coupled with an experimentally validated, ABAQUS-based, heat transfer model of the casting process. Key features of the method include: 1) carefully designed constraint functions to ensure directional solidification along the centerlineof the wheel; and 2) carefully formulated objective functions to maximize cooling rate. The method has been implemented on a prototype production die and the results have been tested with plant trial test.

  5. Quantitative fractographic analysis of variability in the tensile ductility of high-pressure die-cast AE44 Mg-alloy

    Microsoft Academic Search

    S. G. Lee; G. R. Patel; A. M. Gokhale; A. Sreeranganathan; M. F. Horstemeyer

    2006-01-01

    Cast magnesium alloys often exhibit large variability in fracture related mechanical properties such as ductility and strength. In this contribution, the variability in the tensile ductility of individually cast tensile test specimens of high-pressure die-cast AE44 Mg-alloy is examined at room temperature and at 394K. Significant specimen-to-specimen variations in the ductility are observed at both temperatures. The variability in the

  6. An investigation on the microstructure and tensile properties of direct squeeze cast and gravity die cast 2024 wrought Al alloy

    Microsoft Academic Search

    E. Hajjari; M. Divandari

    2008-01-01

    2024 aluminum alloy, conventionally is used for wrought products. If this alloy is subjected to cast process, a large number of shrinkage porosities will be produced within its microstructure due to its long solidification range. Therefore, in order to see the effect of pressure on the microstructure and reduction of shrinkage porosities of this type of alloy, the effect of

  7. Wear Behavior and Mechanism of a Cr-Mo-V Cast Hot-Working Die Steel

    NASA Astrophysics Data System (ADS)

    Wei, M. X.; Wang, S. Q.; Zhao, Y. T.; Chen, K. M.; Cui, X. H.

    2011-06-01

    The wear behavior and mechanisms of a Cr-Mo-V cast hot-working die steel with three microstructures (tempered martensite, troostite, and sorbite) were studied systematically through the dry-sliding wear tests within a normal load range of 50 to 300 N and an ambient temperature range of 298 K to 673 K (25 °C to 400 °C) by a pin-on-disk high-temperature wear machine. Five different mechanisms were observed in the experiments, namely adhesive, abrasive, mild oxidative, oxidative, and extrusive wear; one or more of those mechanisms would be dominant within particular ranges of load and temperature. The transition of wear mechanisms depended on the formation of tribo-oxides, which was related closely to load and temperature, and their delamination, which was mainly influenced by the matrix. By increasing the load and ambient temperature, the protective effect of tribo-oxides first strengthened, then decreased, and in some cases disappeared. Under a load ranging 50 to 300 N at 298 K (25 °C) and a load of 50 N at 473 K (200 °C), adhesive wear was the dominant wear mechanism, and abrasive wear appeared simultaneously. The wear was of mild oxidative type under a load ranging 100 to 300 N at 473 K (200 °C) and a load ranging 50 to 150 N at 673 K (400 °C) for tempered martensite and tempered troostite as well as under a load of 100 N at 473 K (200 °C) and a load ranging 50 to 100 N at 673 K (400 °C) for tempered sorbite. At the load of 200 N or greater, or the temperatures above 673 K (400 °C), oxidative wear (beyond mild oxidative wear) prevailed. When the highest load of 300 N at 673 K (400 °C) was applied, extrusive wear started to dominate for the tempered sorbite.

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

    PubMed

    Etchu, Y; Noguchi, H

    1980-10-01

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

  9. The corrosion performance of die-cast magnesium alloy MRI230D in 3.5% NaCl solution saturated with Mg(OH){sub 2}

    SciTech Connect

    Aghion, E., E-mail: egyon@bgu.ac.il; Lulu, N.

    2010-11-15

    The environmental behavior of die-cast magnesium alloy MRI230D designated for high-temperature applications was evaluated in comparison with regular AZ91D alloy. The microstructure examination was carried out using SEM, TEM, and X-ray diffraction analysis; the corrosion performance in 3.5% NaCl solution was evaluated by immersion test, salt spray testing, potentiodynamic polarization analysis, and stress corrosion behavior by Slow Strain Rate Testing (SSRT). Although the general corrosion resistance of MRI230D was slightly improved compared to that of AZ91D alloy its stress corrosion resistance was relatively reduced. The variations in the environmental behavior of the two alloys were mainly due to the differences in their chemical composition and microstructure after die casting. In particular, the differences were related to the reduced Al content in MRI230D and the addition of Ca to this alloy, which consequently affected its relative microstructure and electrochemical characteristics. - Research Highlights: {yields}Corrosion and SCC resistance of a new Mg alloy MRI230D was evaluated vs. regular AZ91D. {yields}MRI230D has a minor advantage in corrosion performance compared with AZ91D. {yields}The SCC resistance of MRI230D by SSRT analysis was relatively reduced. {yields}The reduced SCC resistance of MRI230D was due to the detrimental effect of Ca on ductility.

  10. The effect of silicon content on the microstructure and creep behavior in die-cast magnesium AS alloys

    NASA Astrophysics Data System (ADS)

    Dargusch, M. S.; Dunlop, G. L.; Bowles, A. L.; Pettersen, K.; Bakke, P.

    2004-06-01

    The effect of increasing levels of silicon on the microstructure and creep properties of high-pressure die-cast Mg-Al-Si (AS) alloys has been investigated. The morphology of the Mg2Si phase in die-cast AS alloys was found to be a function of the silicon content. The Mg2Si particles in castings with up to 1.14 wt pct Si have a Chinese script morphology. For AS21 alloys with silicon contents greater than 1.4 wt pct Si (greater than the ?-Mg2Si binary eutectic point), some Mg2Si particles have a coarse “blocky” shape. Increasing the silicon content above the eutectic level results in an increase in the number of coarse faceted Mg2Si particles in the microstructure. Creep rates at 100 hours were found to decrease with increasing silicon content in AS-type alloys. The decrease in creep rate was most dramatic for silicon contents up to 1.1 wt pct. Further additions of silicon of up to 2.64 wt pct also resulted in significant decreases in creep rate.

  11. Evaluation of soldering, washout and thermal fatigue resistance of advanced metal materials for aluminum die-casting dies

    Microsoft Academic Search

    Yulong Zhu; David Schwam; John F Wallace; Sebastian Birceanu

    2004-01-01

    Anviloy1150, H13, Mo-785, Ti–6Al–4V, Ni-718, cast iron, and copper-base alloys have been evaluated for their resistances to soldering, washout, and thermal fatigue. Anviloy1150 shows the best soldering and washout resistance, followed by Ti–6Al–4V, Mo-785, H13, and Ni-718. Anviloy1150 and Mo-785 also show the best resistance to thermal fatigue and H13 is in the middle while Ti–6Al–4V shows very bad thermal

  12. Thermal and metallographic characteristics of the Al–20% Si high-pressure die-casting alloy for monolithic cylinder blocks

    Microsoft Academic Search

    H. Yamagata; H. Kurita; M. Aniolek; W. Kasprzak; J. H. Sokolowski

    2008-01-01

    Thermal analysis data were gathered to control the hypereutectic microstructure of the die-cast Al–20% Si cylinder block at a cooling rate of 1°C\\/s. The liquidus temperature was approximately 691±2.2°C, the nucleation temperature of the Al–Si eutectic was approximately 567.1±1.9°C and the nucleation temperature of the Cu- and Mg-enriched eutectic was approximately 513.6±1.4°C. The fraction solid increases linearly from 0 to

  13. Microstructure and second-phase particles in low- and high-pressure die-cast magnesium alloy AM50

    Microsoft Academic Search

    Val Y. Gertsman; Jian Li; Su Xu; James P. Thomson; Mahi Sahoo

    2005-01-01

    The microstructure and phase composition of low-pressure die-cast (LPDC) and high-pressure diecast (HPDC) magnesium alloy\\u000a AM50 were examined by transmission electron microscopy (TEM) techniques in combination with optical microscopy, scanning electron\\u000a microscopy (SEM), and electron-probe microanalysis (EPMA). It has been established that the dimensions and morphology of the\\u000a constituent phases (?-Mg solid solution, Mg17Al12, and Al8Mn5) depend on the processing

  14. CAST

    NSDL National Science Digital Library

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

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

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

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

  16. Microstructure and corrosion behavior of die-cast AM60B magnesium alloys in a complex salt solution: A slow positron beam study

    SciTech Connect

    Liu, Y.F. [Wuhan University] [Wuhan University; Qin, Q.L. [Wuhan University] [Wuhan University; Yang, W. [Wuhan University] [Wuhan University; Wen, W. [University of Kentucky] [University of Kentucky; Zhai, T. [University of Kentucky] [University of Kentucky; Yu, B. [University of Alberta] [University of Alberta; Liu, D.Y. [University of Alberta] [University of Alberta; Luo, A. [GM Research and Development Center] [GM Research and Development Center; Song, GuangLing [ORNL] [ORNL

    2014-01-01

    The microstructure and corrosion behavior of high pressure die-cast (HPDC) and super vacuum die-cast (SVDC) AM60B magnesium alloys were investigated in a complex salt solution using slow positron beam technique and potentiodynamic polarization tests. The experiments revealed that a CaCO3 film was formed on the surface of the alloys and that the rate of CaCO3 formation for the SVDC alloy with immersion time was slower than that of the HPDC alloy. The larger volume fraction of b-phase in the skin layer of the SVDC alloy than that of the HPDC alloy was responsible for the better corrosion resistance.

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

    E-print Network

    Paris-Sud XI, Université de

    : application to ingot casting Michel Bellet, Okba Boughanmi, Grégory Fidel MINES ParisTech - CEMEF, CNRS UMR casting, or in the mould during continuous casting. The proposed approach consists of a partitioned two-step resolution strategy. 1. Introduction When modelling casting processes, one of the critical issue

  18. Application of particle method to the casting process simulation

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Zulaida, Y. M.; Anzai, K.

    2012-07-01

    Casting processes involve many significant phenomena such as fluid flow, solidification, and deformation, and it is known that casting defects are strongly influenced by the phenomena. However the phenomena complexly interacts each other and it is difficult to observe them directly because the temperature of the melt and other apparatus components are quite high, and they are generally opaque; therefore, a computer simulation is expected to serve a lot of benefits to consider what happens in the processes. Recently, a particle method, which is one of fully Lagrangian methods, has attracted considerable attention. The particle methods based on Lagrangian methods involving no calculation lattice have been developed rapidly because of their applicability to multi-physics problems. In this study, we combined the fluid flow, heat transfer and solidification simulation programs, and tried to simulate various casting processes such as continuous casting, centrifugal casting and ingot making. As a result of continuous casting simulation, the powder flow could be calculated as well as the melt flow, and the subsequent shape of interface between the melt and the powder was calculated. In the centrifugal casting simulation, the mold was smoothly modeled along the shape of the real mold, and the fluid flow and the rotating mold are simulated directly. As a result, the flow of the melt dragged by the rotating mold was calculated well. The eccentric rotation and the influence of Coriolis force were also reproduced directly and naturally. For ingot making simulation, a shrinkage formation behavior was calculated and the shape of the shrinkage agreed well with the experimental result.

  19. SiC Die Attach for High-Temperature Applications

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  20. An Application of Trapped-Air Analysis to Large Complex High-Pressure Magnesium Casting

    SciTech Connect

    Prindiville, J; Lee, S; Gokhale, A

    2004-07-08

    The usual method for simulating die-castings consists of a solidification analysis of the casting process - a computer calculation of heat transfer between the casting and the die components. The use of cyclic simulations, coupled with the geometric accuracy of the finite element method, has advanced this procedure to the point where it is routinely used for reliable prediction of shrinkage defects in die-castings. Filling analysis is also routinely used to get a glimpse of cavity filling and ensures that overflows are at their most effective location. When coupled with heat transfer, a filling analysis is also very effective in demonstrating the effects of heat loss in the fluid and how it consequentially can negatively affect filling.

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

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    2000-01-01

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

  2. Die \\

    Microsoft Academic Search

    Harald Braun

    Zu Einfluß und Wirkung Jahns Zwei herausragende Historiker des 19. Jahrhunderts, Georg Gottfried Gervinus und Heinrich von Treitschke, haben Friedrich Ludwig Jahn nicht nur rundweg eine eigenständige politische Denkfähigkeit abgesprochen, sondern auch Jahns Persönlichkeit und seine politisch- gesellschaftlichen Aktivitäten - insbesondere die von ihm gegründete und geleitete frühe Turnbewegung - durch eine Vielzahl von Negativurteilen gründlich diskreditiert. Mehrere Generationen von

  3. The effect of microstructure on the thermal fatigue resistance of investment cast and wrought AISI H13 hot work die steel

    SciTech Connect

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

    1995-07-01

    Variable thickness plate investment castings of AISI H13 hot work die steel were pour 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 steel were heat treated and characterized similarly for comparison. Microstructural differences were observed in as-cast samples poured to different section thicknesses. Dendrite cell size and carbide morphology constituted the most prominent microstructural differences observed. After a full heat treatment, however, 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 designed and built to correlate the heat checking susceptibility of AISI H13 steel to its processing and consequent microstructural condition. Surface hardness decreased significantly with thermal cycling, and heat checking was noticed 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; however, the heat-treat cast and as-cast H13 tool steel (made from standard grade wrought H13 tool steel) provided comparable resistance to heat checking in terms Of area fraction of heat checking and maximum crack length.

  4. Dry Sliding Wear Characteristics of Gravity Die-Cast Magnesium Alloys

    NASA Astrophysics Data System (ADS)

    Poddar, Palash; Das, Arpan; Sahoo, K. L.

    2014-04-01

    The paper deals with the wear behavior of conventional cast Mg-Sn-based alloys. The alloys were studied through pin- on- disk wear test under four different loading conditions; namely, 9.8, 19.6, 29.4, and 39.2 N. The study highlights the cumulative wear loss, volumetric wear loss, dry sliding wear rate, and coefficient of friction of the alloys. The volumetric wear increased with increasing applied load. The wear mechanism was studied with scanning electron microscope. The wear occurs mainly by plowing mechanism and also by delamination. During wear, extensive plastic deformation and work hardening occurred. Microstructural analysis has been carried out for all the alloys at different loading conditions.

  5. Predicting the Influence of Pore Characteristics on Ductility of Thin-Walled High Pressure Die Casting Magnesium

    SciTech Connect

    Sun, Xin; Choi, Kyoo Sil; Li, Dongsheng

    2013-06-10

    In this paper, a two-dimensional microstructure-based finite element modeling method is adopted to investigate the effects of porosity in thin-walled high pressure die casting Mg materials on their ductility. For this purpose, the cross-sections of AM50 and AM60 casting samples are first examined using optical microscope to obtain the overall information on the pore characteristics. The experimentally quantified pore characteristics are then used to generate a series of synthetic microstructures with different pore sizes, pore volume fractions and pore size distributions. Pores are explicitly represented in the synthetic microstructures and meshed out for the subsequent finite element analysis. In the finite element analysis, an intrinsic critical strain value is used for the Mg matrix material, beyond which work-hardening is no longer permissible. With no artificial failure criterion prescribed, ductility levels are predicted for the various microstructures in the form of strain localization. Mesh size effect study is also conducted, from which a mesh size dependent critical strain curve is determined. A concept of scalability of pore size effects is then presented and examined with the use of the mesh size dependent critical strain curve. The results in this study show that, for the regions with lower pore size and lower volume fraction, the ductility generally decreases as the pore size and pore volume fraction increase whereas, for the regions with larger pore size and larger pore volume fraction, other factors such as the mean distance between the pores begin to have some substantial influence on the ductility. The results also indicate that the pore size effects may be scalable for the models with good-representative pore shape and distribution with the use of the mesh size dependent critical strain curve.

  6. Strengthening Micromechanisms in Cold-Chamber High-Pressure Die-Cast Mg-Al Alloys

    NASA Astrophysics Data System (ADS)

    Yang, Kun V.; Cáceres, Carlos H.; Easton, Mark A.

    2014-08-01

    The contributions from grain boundary, solid solution, and dispersion strengthening to the yield strength of cast-to-shape specimens were calculated for seven binary alloys with compositions ranging from very dilute (0.5 mass pct Al) to concentrated (12 mass pct Al). Experimentally and theoretically determined parameters were used to explicitly account for the different microstructures at the skin and core regions of specimens' cross sections. Microhardness maps were used to identify the specimens' skin. The specimens' strength was calculated as the weighted addition of the respective strengths of skin and core. The calculated strengths reproduced well the experimental values for the dilute alloys but underestimated the strength of the most concentrated alloys by as much as ~35 MPa. It is argued that the presence of the percolating network of Mg17Al12 eutectic intermetallic, particularly in the skin region, in conjunction with highly efficient dispersion hardening due to the convoluted shape of the intermetallics, accounts for the shortfall in the calculated strength.

  7. Tape cast bioactive metal-ceramic laminates for structural application

    NASA Astrophysics Data System (ADS)

    Clupper, Daniel Christopher

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

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

    NASA Astrophysics Data System (ADS)

    Lu, You

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

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

    NASA Astrophysics Data System (ADS)

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

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

  10. Constitutive prediction and dependence of tensile properties of high-pressure die-cast AM60B and AZ91D magnesium alloy on microporosity

    Microsoft Academic Search

    Choong Do Lee

    2006-01-01

    The effect of micro-voids on the tensile property of high-pressure die-cast AM60B and AZ91D magnesium alloy was investigated\\u000a through systematic experimental approaches, with a constitutive prediction on the load carrying capacity and strain-related\\u000a factors. The strain rate sensitivity was measured through the incremental strain rate change test, and the microporosity was\\u000a measured from a comparison between the area of the

  11. Modeling and analysis of the effects of processing parameters on the performance characteristics in the high pressure die casting process of Al–SI alloys

    Microsoft Academic Search

    Ko-Ta Chiang; Nun-Ming Liu; Te-Chang Tsai

    2009-01-01

    The high pressure die casting (HPDC) process has achieved remarkable success in the manufacture of aluminum–silicon (Al–SI)\\u000a alloy components for the modern metal industry. Mathematical models are proposed for the modeling and analysis of the effects\\u000a of machining parameters on the performance characteristics in the HPDC process of Al–SI alloys which are developed using the\\u000a response surface methodology (RSM) to

  12. Experimental verification of numerical predictions for the optimum plunger speed in the slow phase of a high-pressure die casting machine

    Microsoft Academic Search

    Rosendo Zamora; Félix Faura; Joaquín López; Julio Hernández

    2007-01-01

    An experimental study of the optimum maximum plunger speed in the slow phase of a high-pressure die casting machine with horizontal\\u000a cold chamber is presented. A special apparatus that uses a photoelectric sensor to determine the instant at which the working\\u000a fluid reaches the runner was developed and installed in the injection chamber. The measured volumes of air remaining in

  13. Pressurized solidification of semi-solid aluminum die casting alloy A356

    Microsoft Academic Search

    Hong-Min Guo; Xiang-Jie Yang; Jia-Xuan Wang

    2009-01-01

    Pressurized solidification behavior of semi-solid aluminum alloy A356 slurry in relation to the final microstructures and mechanical properties has been investigated. Sound semi-solid slurry has been produced, in which the primary ?-Al presented in average diameter of 65?m and shape factor of 0.84, and featured zero-entrapped eutectic. The structural investigation revealed that application of pressure during solidification of semi-solid slurry

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

    SciTech Connect

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

    2006-08-25

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

  15. 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.

  16. Effect of Solution Heat Treatments on the Microstructure and Mechanical Properties of a Die-Cast AlSi7MgMn Alloy

    NASA Astrophysics Data System (ADS)

    Timelli, Giulio; Lohne, Otto; Arnberg, Lars; Laukli, Hans Ivar

    2008-07-01

    The influence of solution heat treatment time and temperature on the microstructure and mechanical properties and the mode of fracture of a high-pressure die-cast AlSi7MgMn alloy is reported. Metallographic and image analysis techniques have been used to quantitatively examine the microstructural changes occurring during solution heat treatment. A solution heat treatment of 15 minutes at 475 °C, or even more at 525 °C, is sufficient to spheroidize the eutectic Si, as well as coarsen and increase the interparticle distance of the eutectic Si. Increasing the solutionizing temperature from 475 °C to 525 °C improves the mechanical properties.

  17. Effect of Solid Fraction and Pressure on Microstructure and Mechanical Properties and Reduction in Liquid Segregation in the Thixo-Die-Casting Process with Al-7 Pct Si Alloy

    NASA Astrophysics Data System (ADS)

    Kang, C. G.; Lee, S. M.

    2008-05-01

    In the thixo-die-casting process, the effect of solid fraction and the applied pressure on filling behavior and mechanical properties of the thixo-die-cast product were investigated. By controlling the behavior of solid particles in thixo materials, reduction in liquid segregation during thixo-die-casting was achieved by varying gating systems and solid fractions. Therefore, a gating system with a specially designed runner and gate that controls microstructure to reduce liquid segregation was proposed. As a result, the filling behavior of the semisolid material was dominantly influenced by a solid fraction and a gating system. In addition, mechanical properties were analyzed as a function of solid fraction and applied pressure. The quality index, which assesses ultimate tensile strength (UTS) and elongation, showed that as the initial solid fraction and applied pressure increased, the quality index increased by about 100 MPa.

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

    SciTech Connect

    Sabau, Adrian S [ORNL

    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.

  19. Subclavian vein thrombosis after application of body cast.

    PubMed

    Badlani, Neil; Korenblit, Allen; Hammerberg, Kim

    2013-01-01

    Mehta-Cotrel body casting is a well-recognized and effective technique for the treatment of progressive infantile scoliosis. The treatment can be challenging to execute given the commitment required by the patient's family and treatment team, and is not without complications. In this report, we detail the occurrence of a subclavian vein thrombosis after the placement of a Mehta-Cotrel cast for the treatment of progressive infantile kyphoscoliosis. To date, this is a previously unreported complication after body casting. Expeditious and accurate diagnosis of this complication leads to effective treatment without further morbidity. Therefore, clinicians using body casting for the treatment of scoliosis should be aware of the possibility of this complication and know how to quickly diagnose and treat it. PMID:23232388

  20. 3D characterization of intermetallics in a high pressure die cast Mg alloy using focused ion beam tomography

    SciTech Connect

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

    2010-11-15

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

  1. Fastcast: Integration and application of rapid prototyping and computational simulation to investment casting

    SciTech Connect

    Maguire, M.C.; Baldwin, M.D.; Atwood, C.L.

    1996-09-01

    The emergence of several rapid prototyping and manufacturing (RP and M) technologies is having a dramatic impact on investment casting. While the most successful of the rapid prototyping technologies are almost a decade old, relatively recent process advances in their application have produced some remarkable success in utilizing their products as patterns for investment castings. Sandia National Laboratories has been developed highly coupled experimental and computational capabilities to examine the investment casting process with the intention of reducing the amount of time required to manufacture castings, and to increase the quality of the finished product. This presentation will begin with process aspects of RP and M pattern production and handling, shell fabrication, burnout, and casting. The emphasis will be on how the use of Stereolithography (SL) or Selective Laser Sintered (SLS) patterns differs from more traditional wax pattern processes. Aspects of computational simulation to couple design, thermal analysis, and mold filling will be discussed. Integration of these topics is probably the greatest challenge to the use of concurrent engineering principles with investment casting. Sandia has conducted several experiments aimed at calibrating computer codes and providing data for input into these simulations. Studies involving materials as diverse as stainless steel and gold have been conducted to determine liquid metal behavior in molds via real time radiography. The application of these experiments to predictive simulations will be described.

  2. Application in casting defect lossless examination based on surf

    NASA Astrophysics Data System (ADS)

    Fan, Youchen; Sun, Huayan; Wang, Haoxiang

    2013-08-01

    Based on the study of measures of the algorithm casting defect lossless examination and characteristics of X-ray imaging, a new automatic detection based on SURF is presented. Firstly, the algorithm detects the interested points of specifically component model in the standard image samples by SURF. Then the interested points of inspection produce are detected when the rotary worktable makes one revolution, at the same time, the interested points between model and produce are matched. The number of matched points is the basis for whether the product contains the component. Experimental results show that this method is effective in determining the component model well or not, which provides a novel method for casting defect lossless examination.

  3. Virtual aluminum castings: An industrial application of ICME

    Microsoft Academic Search

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

    2006-01-01

    The automotive product design and manufacturing community is continually besieged by Hercule an engineering, timing, and cost\\u000a challenges. Nowhere is this more evident than in the development of designs and manufacturing processes for cast aluminum\\u000a engine blocks and cylinder heads. Increasing engine performance requirements coupled with stringent weight and packaging constraints\\u000a are pushing aluminum alloys to the limits of their

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  5. An application for zirconia as a pharmaceutical die set

    Microsoft Academic Search

    Alpagut Kara; Michael J. Tobyn; Ron Stevens

    2004-01-01

    The main objective of this study was to investigate the possible use of zirconia as a material for the manufacture of punches and dies for use in tableting machines and to study its effect on ejection of tablets made from different formulations. In order to achieve this objective, the compaction properties of three commercially available direct compression excipients were examined

  6. The application of cast SiC/Al to rotary engine components

    NASA Technical Reports Server (NTRS)

    Stoller, H. M.; Carluccio, J. R.; Norman, J. P.

    1986-01-01

    A silicon carbide reinforced aluminum (SiC/Al) material fabricated by Dural Aluminum Composites Corporation was tested for various components of rotary engines. Properties investigated included hardness, high temperature strength, wear resistance, fatigue resistance, thermal conductivity, and expansion. SiC/Al appears to be a viable candidate for cast rotors, and may be applicable to other components, primarily housings.

  7. Cast Aluminum Alloys for High Temperature Applications Using Nanoparticles Al2O3 and Al3-X Compounds (X = Ti, V, Zr)

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    2009-01-01

    In this paper, the effect of nanoparticles Al2O3 and Al3-X compounds (X = Ti, V, Zr) on the improvement of mechanical properties of aluminum alloys for elevated temperature applications is presented. These nanoparticles were selected based on their low cost, chemical stability and low diffusions rates in aluminum at high temperatures. The strengthening mechanism at high temperature for aluminum alloy is based on the mechanical blocking of dislocation movements by these nanoparticles. For Al2O3 nanoparticles, the test samples were prepared from special Al2O3 preforms, which were produced using ceramic injection molding process and then pressure infiltrated by molten aluminum. In another method, Al2O3 nanoparticles can also be homogeneously mixed with fine aluminum powder and consolidated into test samples through hot pressing and sintering. With the Al3-X nanoparticles, the test samples are produced as precipitates from in-situ reactions with molten aluminum using conventional permanent mold or die casting techniques. It is found that cast aluminum alloy using nanoparticles Al3-X is the most cost effective method to produce high strength aluminum alloys for high temperature applications in comparison to nanoparticles Al2O3. Furthermore, significant mechanical properties retention in high temperature environment could be achieved with Al3-X nanoparticles, resulting in tensile strength of nearly 3 times higher than most 300- series conventional cast aluminum alloys tested at 600 F.

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

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    2005-01-01

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

  9. Urinary casts

    MedlinePLUS

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

  10. Techniques and applications for integrating a semiconductor laser on a micromachined die

    NASA Astrophysics Data System (ADS)

    Bouchard, Joseph G., Jr.; Bright, Victor M.; Burns, David M.

    1998-04-01

    This paper describes methods for attaching a vertical cavity surface emitting laser (VCSEL) on to a surface micromachined die. Techniques investigated include silver paste, soldering, wire bonding, and gold pads with integrated resistive heaters. Each technique is evaluated based on reliability, positioning tolerances, and secondary effects. Applications include single chip laser beam scanning.

  11. Design and characterization of microscale heater structures for test die and sensor applications

    SciTech Connect

    Benson, D.A.; Bowman, D.; Filter, W.; Mitchell, R. [Sandia National Labs., Albuquerque, NM (United States); Perry, J. [Philips Semiconductors, Albuquerque, NM (United States)

    1998-05-01

    The authors describe a class of microscale heaters fabricated with CMOS processes on silicon wafers. These heaters were designed to produce localized high temperatures above 400 C for test and sensor applications. The temperature levels produced for various input powers and the thermal profiles surrounding the heater for packaged and wafer-level heater structures were studied to guide the placement of microelectronics integrated with the heater structures on the same die. To show the performance of the design, they present resistance sensor measurements, IR temperature profiles, and results from a 3D thermal model of the die. This effort demonstrates that it is possible to successfully operate both a microscale heater and microcircuits on the same die.

  12. Electromagnetic casting

    SciTech Connect

    Evans, J.W.; Kageyama, R. [Univ. of California, Berkeley, CA (United States); Deepak [Motorola Corp., Phoenix, AZ (United States); Cook, D.P. [Reynolds Metals Co., Richmond, VA (United States); Prasso, D.C. [Intel Corp., Aloha, OR (United States); Nishioka, S. [NKK Corp., Kawasaki (Japan)

    1995-12-31

    Electromagnetic casting (EMC) is a technology that is used extensively in the aluminum industry to cast ingots with good surface finish for subsequent rolling into consumer product. The paper reviews briefly some investigations from the eighties wherein models for EMC were developed. Then more recent work is examined wherein more realistic 3D models have been developed, the traditional studies of electromagnetic and magnetohydrodynamic phenomena have been supplemented with research on heat transport, and the stability of the metal free surface has been examined. The paper concludes with three generalizations concerning modeling that may have wider applicability than EMC.

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

    DOEpatents

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

    1980-09-24

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

  14. Thermal fracture endurance of cast irons with application study of pig iron ingot molds

    NASA Astrophysics Data System (ADS)

    Lee, Jye-Long; Lee, Shen-Chih

    1995-06-01

    Pig iron ingot molds manufactured with flake, compacted graphite cast iron, and spheroidal graphite cast iron were installed on a pig iron casting machine and subjected to thermal cycling for studying thermal fracture endurance of the three cast irons. The effects of graphite morphology on the fracture mechanism were analyzed by examining the fracture patterns, microstructures, and microcracks in the failed molds. The determining factors of thermal fracture endurance were elucidated with thermal fracture resistance indices. Compacted graphite cast iron exhibited better thermal fracture endurance than flake and spheroidal graphite cast irons because of its higher strength-to-thermal stress ratio.

  15. The application of X-ray stereo metrology to investment casting dimensional control

    SciTech Connect

    Noble, J.A.; Mundy, J.L. [GE Corporate Research and Development Center, Schenectady, NY (United States)

    1995-12-31

    High precision investment casting designs, particularly of jet engine and turbine components, are rapidly evolving in complexity. In order to reduce the development cycle for a new design it is necessary to monitor and control the critical dimensions of the casting and associated cores and molds. In addition, detailed knowledge of the casting geometry is necessary to plan, for example, the drilling of cooling holes during airfoil manufacturing. A new approach to dimensional control of casting manufacturing operations based on X-ray metrology will be described. Precise measurements of casting dimensions and hole geometry can be achieved by a combination of conventional X-ray CT algorithms and new algorithms for radiographic stereo. Together these provide both completeness of part description as well as high throughput for production monitoring. This paper will describe a system called the QUIC (QUality Investment Casting) system being developed to implement these algorithms.

  16. Modeling and control of casting and welding processes

    SciTech Connect

    Kou, S.; Mehrabian, R.

    1986-01-01

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

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

    SciTech Connect

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

    2011-09-13

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

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

    Microsoft Academic Search

    X Dai; M Jolly; B Zeng

    2012-01-01

    All The traditional foundry usually not only uses batch melting where the aluminium alloys are melted and held in a furnace for long time, but also uses the gravity filling method in both Sand Casting Process (SCP) and Investment Casting Process (ICP). In the gravity filling operation, the turbulent behaviour of the liquid metal causes substantial entrainment of the surface

  19. Laser assisted die bending: a new application of high power diode lasers

    NASA Astrophysics Data System (ADS)

    Schuöcker, D.; Schumi, T.; Spitzer, O.; Bammer, F.; Schuöcker, G.; Sperrer, G.

    2015-02-01

    Nowadays high power lasers are mainly used for cutting of sheet metals, for welding, hardening and rapid prototyping. In the forming of sheet metals as bending or deep drawing lasers are not used. Nevertheless a few years ago a new application of high power lasers has been invented, where bending of materials that break at room temperature becomes possible by heating them along the bending edge with high power lasers thus allowing their treatment without cracks and rupture. For this purpose a large number of diode lasers are arranged in the bottom tool of a bending machine (a V-shaped die) which heat up the initially flat sheet metal during the bending process what is performed by pressing it into the die with a knife shaped upper tool where due to the laser heating the material is softened and thus cracks are avoided. For the technical realization of the new process of laser assisted die bending, modules equipped with numerous laser diodes and a total beam power of 2,5 kW are used. The light emitted by these modules enters a tool with a length of 15cm and is deflected towards the workpiece. By using ten of these modules with adjacent dies and by integrating those in a bending press a bending edge of sheet metals with a length of 1500mm can be realized. Such a bending press with laser assistance also needs energization with a power of practically 50kW, a respective water flow, a heat exchanger system and also a control for all functions of this system. Special measures have also been developed to avoid radiating of those tools that are not covered by a workpiece in the case of bending edges shorter than the full length of the bending tools whereas individual short circuiting of diode modules can be performed. Specific measures to ensure a safe operation without any harm to the operational person have been realized. Exploitation of the bending process has been carried out for titanium, where material thicknesses up to 3mm have been bent successfully.

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

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

  1. Rapid casting solutions: a review

    Microsoft Academic Search

    Munish Chhabra; Rupinder Singh

    2011-01-01

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

  2. Drop-casted polyaniline thin films on flexible substrates for supercapacitor applications

    NASA Astrophysics Data System (ADS)

    Kim, Jongmin; Sohn, J.; Jo, Yongcheol; Woo, Hyeonseok; Han, Jaeseok; Cho, Sangeun; Inamdar, A. I.; Kim, Hyungsang; Im, Hyunsik

    2014-11-01

    The PANI (polyaniline) thin films are synthesized on flexible ITO/PET (indium tin oxide/polyethylene terephthalate) substrates by using the drop-casting method. The amount of the PANI for the drop casting varies from 0.04 to 0.16 g. The morphology of the drop-casted PANI films shows a porous vermicular shape. The electrochemical supercapacitor properties of the PANI films are examined in a 0.5-M LiClO4 + PC electrolyte. The PANI films with 0.08 g of PANI show higher current density and considerably higher specific capacitance and capacity retention, compared with other PANI films. The highest specific capacitance of the films with 0.08 g of PANI is found to be ˜120 F/g, and the capacity retention is found to be as high as 70.51% after 100 charge-discharge cycles.

  3. Application of the Billet Casting Method to Determine the Onset of Incipient Melting of 319 Al Alloy Engine Blocks

    NASA Astrophysics Data System (ADS)

    Lombardi, A.; Ravindran, C.; MacKay, R.

    2015-06-01

    The increased use of Al for automotive applications has resulted from the need to improve vehicle fuel efficiency. Aluminum alloy engine blocks fulfil the need of lightweighting. However, there are many challenges associated with thermo-mechanical mismatch between Al and the gray cast iron cylinder liners, which result in large tensile residual stress along the cylinder bores. This requires improced mechanical properties in this region to prevent premature engine failure. In this study, replicating billet castings were used to simulate the engine block solution heat treatment process and determine the onset of incipient melting. Microstructural changes during heat treatment were assessed with SEM and EDX, while thermal analysis was carried out using differential scanning calorimetry. The results suggest that solution heat treatment at 500 °C was effective in dissolving secondary phase particles, while solutionizing at 515 or 530 °C caused incipient melting of Al2Cu and Al5Mg8Cu2Si6. Incipient melting caused the formation ultra-fine eutectic clusters consisting of Al, Al2Cu, and Al5Mg8Cu2Si6 on quenching. In addition, DSC analysis found that incipient melting initiated at 507 °C for all billets, although the quantity of local melting reduced with microstructural refinement as evidenced by smaller endothermic peaks and energy absorption. The results from this study will assist in improving engine block casting integrity and process efficiency.

  4. A small fatigue crack growth relationship and its application to cast aluminum

    Microsoft Academic Search

    A. Shyam; J. E. Allison; J. W. Jones

    2005-01-01

    Small fatigue crack propagation in two cast aluminum alloys – W319-T7 and A356-T6 – was investigated by initiating cracks from micronotches. It was demonstrated that an underlying relationship describes the growth behavior of these fatigue cracks. This relationship is based on a parameter which is the product of monotonic and cyclic crack tip displacements and under conditions of small scale

  5. A type of voting diffusion model and its application in defect detection in aluminum castings

    Microsoft Academic Search

    Situ Wuchao; Huang Qian; Wu Yuan

    2005-01-01

    We make use of a type of voting diffusion model for casting image processing. This model is based on an anisotropic diffusion equation driven by a diffusion tensor, whose structure depends on the coupled time-delay regularization of a matrix. The diffusion tensor determines the directions of the diffusion as well as the speed in these directions. Experimental results show that

  6. The meaning of high stress abrasion and its application in white cast irons

    Microsoft Academic Search

    J. D. Gates; G. J. Gore; M. J. P. Hermand; M. J. P. Guerineau; P. B. Martin; J. Saad

    2007-01-01

    White cast irons perform much less favourably in industrial service environments such as ball mills than would be predicted by standard laboratory abrasion tests. Pin abrasive tests are widely thought to simulate high stress abrasion, but in reality they grossly over-estimate service lives of white iron mill liners compared to pearlitic steel liners. The ‘impact-abrasion’ hypothesis has suggested that the

  7. Low Temperature Consolidation of Micro/Nanosilver Die-Attach Preforms

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

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

    SciTech Connect

    David Schwam; John F. Wallace; Quanyou Zhou

    2002-01-30

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  10. Cu wire bonding with Cu BSOB for SiP & stacked die application: Challenges & solutions

    Microsoft Academic Search

    B. Senthil Kumar; Mohandass Sivakumar; Chua Choon Wee; Li Ming; Keng Yew; J. Song

    2009-01-01

    In this paper, key challenges for copper (Cu) BSOB wire bonding process and its solutions are discussed. Cu wire bonding is an alternative interconnection technology for gold (Au) wire bonding. Cu wire is attractive because of its cost, electrical and thermo-mechanical properties. BSOB is the short form of bond-stitch-on-ball. It is used on devices that require die-die wire bonding in

  11. Application of emulsifiers in the manufacture of cast boosters and related products

    SciTech Connect

    Joginadham, C.; Shankar, P.S.; Gupta, A.N. [Premier Explosives Limited, Andhra Pradesh (India)

    1996-12-01

    Cast boosters made with pentaerythritol tetranitrate (PETN) and trinitro toluene (TNT) give high velocities of detonation and are sensitive to initiation even under high pressures. However, the manufacture of the same involves heating of TNT to its melting temperature and mixing of dry PETN in it. In the present work, wet PETN, TNT and water soluble nitrate salts were used for the manufacture of the boosters. The nitrate salt solution formed with the excess water available in wet PETN was emulsified with the aid of emulsifiers. The velocities of detonation of boosters with various percentages of water were determined. The data of explosive characters of these boosters were compared with normal pentolite cast boosters.

  12. Low Frequency Phased Array Application for Crack Detection in Cast Austenitic Piping

    Microsoft Academic Search

    Michael T. Anderson; Stephen E. Cumblidge; Steven R

    2006-01-01

    As part of a multi-year program funded by the United States Nuclear Regulatory Commission (US NRC) to address nondestructive examination (NDE) reliability of inservice inspection (ISI) programs, studies conducted at the Pacific N¬orthwest National Laboratory (PNNL) in Richland, Washington, have focused on assessing novel NDE approaches for the inspection of coarse-grained, cast stainless steel reactor components. The primary objective of

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

    NASA Astrophysics Data System (ADS)

    Elalem, Kaled

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

  14. Melting and casting of FeAl-based cast alloy

    Microsoft Academic Search

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

    1998-01-01

    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

  15. Application of statistical methods for analyzing the relationship between casting distortion, mold filling, and interfacial heat transfer in sand molds

    SciTech Connect

    Y. A. Owusu

    1999-03-31

    This report presents a statistical method of evaluating geometric tolerances of casting products using point cloud data generated by coordinate measuring machine (CMM) process. The focus of this report is to present a statistical-based approach to evaluate the differences in dimensional and form variations or tolerances of casting products as affected by casting gating system, molding material, casting thickness, and casting orientation at the mold-metal interface. Form parameters such as flatness, parallelism, and other geometric profiles such as angularity, casting length, and height of casting products were obtained and analyzed from CMM point cloud data. In order to relate the dimensional and form errors to the factors under consideration such as flatness and parallelism, a factorial analysis of variance and statistical test means methods were performed to identify the factors that contributed to the casting distortion at the mold-metal interface.

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

    PubMed

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

    2012-09-01

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

  17. van die Universiteit Stellenbosch Die kern van die beleid

    E-print Network

    Geldenhuys, Jaco

    as akademiese taal, maar neem daarmee saam die multikulturele en meertalige #12;2 Suid-Afrikaanse werklikheid- prosesse. 4. Die Taalbeleid neem die waardes en uitgangspunte wat in die Strategiese Raamwerk van die daarvan. 8. Die Taalbeleid neem die diversiteitsdoelwitte van die Universiteit in ag. 9. Die Taalbeleid

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

    E-print Network

    Paris-Sud XI, Université de

    to the simulation of Ingot Casting O. Boughanmi*1 , M. Bellet*2 *MINES ParisTech, Centre de Mise en Forme des in the context of steel casting processes, is to achieve a concurrent and efficient computation of fluid flow (ingot mould filling, nozzle jet in continuous casting) and solid mechanics (stress-strain in solidified

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

    SciTech Connect

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

    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.

  20. Melting and casting of FeAl-based cast alloy

    SciTech Connect

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

    1998-11-01

    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.

  1. Sensitivity comparison of fast integrated die-to-die T+R pattern inspection, standard database inspection, and STARlight2 contamination mode for application in mask production

    Microsoft Academic Search

    Heiko Schmalfuss; Thomas Schulmeyer; Jan Heumann; Michael Lang; Jean-Paul Sier

    2007-01-01

    'Fast Integrated Die-to-Die T+R' pattern inspection (DDTR), reflected tritone database inspection (DBRt) and STARlight2TM (SL2) contamination inspection are employed by mask makers in order to detect pattern defects and contamination defects on photomasks for in process inspection steps. In this paper we compare the detection capabilities of these modes on real production masks with a representative set of contamination and

  2. 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.

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

    E-print Network

    A. I. Karanikas; C. N. Ktorides

    2009-02-16

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

  4. The application of integrated computational material engineering (ICME) in metal castings simulation

    NASA Astrophysics Data System (ADS)

    Guo, Jianzheng; Cao, Weisheng; Samonds, Mark

    2012-07-01

    Integrated Computational Materials Engineering (ICME) is emerging as a methodology for developing advanced materials, manufacturing processing, and engineering components in a faster and more cost effective way. For casting processes, ICME involves many physical phenomena such as thermodynamics, heat transfer, fluid flow, stress, defect formation, microstructure evaluation, and thermophysical and mechanical properties. In this paper, the integration of thermodynamic calculations, thermophysical and mechanical property predictions, and the prediction of microstructure and defects during solidification and heat treatment will be presented. Such integration is helpful to understand the effects of alloy chemistry and processing conditions, and their relationship to microstructure, defect formation, and the final mechanical properties from solidification to heat treatment. Eventually the alloy chemistry and processing parameters can be optimized with the help of the integrated computational modelling.

  5. Hair casts.

    PubMed

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

    2014-10-01

    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

  6. 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

  7. Design, development, and qualification of special super N-channel MOSFET die for space applications

    NASA Astrophysics Data System (ADS)

    Joseph, Haskel M.

    1991-03-01

    The design, manufacture, processing and testing of special super Metal Oxide Semiconductor Field Effect Transistors (MOSFET) die sizers 9 and 10 (approx. 690 by 500 mils and 1022 by 772 mils respectively) are described. These sizes are developed specifically to meet the requirements of the Remote Power Controller (RPC), the Remote Bus Isolator (RBI) and the DC to DC converter of the Space Station Freedom power management and distribution system. The reliability goal is for a 15 year failure free operation in space.

  8. Die-away kinetics of aerosolized bacteria from sprinkler application of wastewater.

    PubMed Central

    Teltsch, B; Shuval, H I; Tadmor, J

    1980-01-01

    A methodology for estimating, under field conditions, the microbial die-away constant (lambda) is presented. This constant may be used in predicting the aerosolized pathogenic microorganism concentrations downwind from a wastewater spray or aeration site by means of modified atmospheric diffusion equations. The mean lambda of Escherichia coli for very early morning runs was 8.8 X 10(-3)s-1, and that for afternoon runs was 6.6 X 10(-2)s-1. PMID:6996614

  9. Pigmented casts.

    PubMed

    Miteva, Mariya; Romanelli, Paolo; Tosti, Antonella

    2014-01-01

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

  10. Thermal and Kinetic Modelling of Elastomer Flow—Application to an Extrusion Die

    NASA Astrophysics Data System (ADS)

    Launay, J.; Allanic, N.; Mousseau, P.; Deterre, R.

    2011-05-01

    This paper reports and discusses the thermal and kinetic behaviour of elastomer flow inside an extrusion die. The reaction progress through the runner was modeled by using a particle tracking technique. The aim is to analyze viscous dissipation phenomena to control scorch arisen, improve the rubber compound curing homogeneity and reduce the heating time in the mould using the progress of the induction time. The heat and momentum equations were solved in three dimensions with Ansys Polyflow. A particle tracking technique was set up to calculate the reaction progress. Several simulations were performed to highlight the influence of process parameters and geometry modifications on the rubber compound thermal and cure homogeneity.

  11. Die Milchstraße.

    NASA Astrophysics Data System (ADS)

    Henbest, N.; Couper, H.

    This book is a German translation, by M. Röser, from the English original "The guide to the Galaxy", published in 1994 (see Abstr. 61.003.065). Contents: 1. Die Entdeckung unserer Galaxis. 2. Die Lokale Gruppe. 3. Die Geographie der Galaxis. 4. Der Perseus-Arm. 5. Der Orion-Arm. 6. Unsere lokale Nachbarschaft: ein typischer Winkel der Galaxis. 7. Der Sagittarius-Arm: innerhalb der Sonnenumlaufbahn. 8. Das Zentrum der Galaxis.

  12. A comparative study of the centrifugal and vacuum-pressure techniques of casting removable partial denture frameworks.

    PubMed

    Shanley, J J; Ancowitz, S J; Fenster, R K; Pelleu, G B

    1981-01-01

    A study was undertaken to evaluate two techniques for casting accuracy on removable partial denture frameworks: centrifugal casting and vacuum-pressure casting. A standard metal die with predetermined reference points in a horizontal plane was duplicated in refractory investment. The casts were waxed, and castings of nickel-chrome alloy were fabricated by the two techniques. Both the casts and the castings were measured between the reference points with a measuring microscope. With both casting methods, the differences between the casts and the castings were significant, but no significant differences were found between castings produced by the two techniques. Vertical measurements at three designated points also showed no significant differences between the castings. Our findings indicate that dental laboratories should be able to use the vacuum-pressure method of casting removable partial denture frameworks and achieve accuracy similar to that obtained by the centrifugal method of casting. PMID:7007622

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

    NASA Astrophysics Data System (ADS)

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

    2003-07-01

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

  14. 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…

  15. Die Systemsteuerung

    Microsoft Academic Search

    Martin Grotegut

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

  16. Assisted dying.

    PubMed

    Hoffenberg, Raymond

    2006-01-01

    The Royal College of Physicians took a neutral position on the House of Lords Assisted Dying for the Terminally Ill Bill. While modern palliative care and the hospice approach have greatly reduced terminal suffering, they do not always achieve total relief of distressing symptoms--he majority of dying patients and their families probably do not receive optimal terminal care. In this article I try to rebut the common arguments against assisted dying and add some arguments in favour. I suggest that on this issue the medical professions are out of tune with majority public opinion. PMID:16521360

  17. A CAD\\/CAM system for die design and manufacture

    Microsoft Academic Search

    I. Olama; C. B. Besant; M. Ristic

    1988-01-01

    The manufacture of directionally solidified cast turbine blades relies on the precise casting of wax patterns of the actual\\u000a turbine blade. This, in turn, requires the design and manufacture of a complex die. A CAD\\/CAM system is presented specifically\\u000a for producing manufacturing information for dies based on basic data defining the shape of a turbine blade. The system is\\u000a based

  18. Application of hydrogen sensor using proton conductive ceramics as a solid electrolyte to aluminum casting industries

    Microsoft Academic Search

    Tamotsu Yajima; Kunihiro Koide; Haruki Takai; Nirihiko Fukatsu; Hiroyasu Iwahara

    1995-01-01

    A galvanic cell type of hydrogen sensor was developed using CaZrO3-based proton conductor as a solid electrolyte. It was clear that the hydrogen sensor could be used for the accurate determination of hydrogen concentration in molten aluminum alloys. The sensor probe exhibited stable EMF values and a fast response when the hydrogen concentration in the melt was changed. The application

  19. 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.

  20. 76 FR 5840 - The Basic Aluminum Castings Co., Cleveland, OH; Notice of Revised Determination on Reconsideration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

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

  1. AGARD handbook on advanced casting

    NASA Astrophysics Data System (ADS)

    Mietrach, Dietmar

    1991-03-01

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

  2. Clamshell Casting! Stefanie Wuhrer

    E-print Network

    Wuhrer, Stefanie

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

  3. Superplastic Response of Continuously Cast AZ31B Magnesium Sheet Alloys

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  5. Method and apparatus for die forming metal sheets and extrusions

    NASA Astrophysics Data System (ADS)

    Darter, John L.

    1986-06-01

    The invention comprises an apparatus for die forming metal sheets and extrusions which utilizes die blocks of low melting temperature metallic material. The die blocks are formed in an adjustable mold which comprises a mold box, a pivotable dam within the mold box and blocking means for locking the pivotable dam member in a desired angular position. Once a desired die block angle is ascertained for a particular joggle, the pivotable member of the mold box is adjusted to produce the desired angle in the die casting made in the mold box.

  6. 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.

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

    E-print Network

    Beckermann, Christoph

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

  8. Application of Film-Casting Technique to Investigate Drug-Polymer Miscibility in Solid Dispersion and Hot-Melt Extrudate.

    PubMed

    Parikh, Tapan; Gupta, Simerdeep Singh; Meena, Anuprabha K; Vitez, Imre; Mahajan, Nidhi; Serajuddin, Abu T M

    2015-07-01

    Determination of drug-polymer miscibility is critical for successful development of solid dispersions. This report details a practical method to predict miscibility and physical stability of drug with various polymers in solid dispersion and, especially, in melt extrudates by applying a film-casting technique. Mixtures of itraconazole (ITZ) with hydroxypropylmethylcellulose phthalate (HPMCP), Kollidon(®) VA 64, Eudragit(®) E PO, and Soluplus(®) were film-casted, exposed to 40°C/75% RH for 1 month and then analyzed using differential scanning calorimetry (DSC), powder X-ray diffractometry, and polarized light microscopy (PLM). ITZ had the highest miscibility with HPMCP, being miscible at drug to polymer ratio of 6:4 (w/w). There was a downward trend of lower miscibility with Soluplus(®) (miscible at 3:7, w/w, and a few microcrystals present at 4:6, w/w), Kollidon(®) VA 64 (2:8, w/w) and Eudragit(®) E PO (<1:9, w/w). PLM was found more sensitive to detect drug crystallization than DSC and powder X-ray diffractometry. There was general correlation between results of film casting and hot-melt extrusion (HME) using a twin screw extruder. For ITZ-Soluplus(®) mixtures, HME at 4:6 (w/w) resulted in a single phase, whereas drug crystallization was observed at higher drug load. HME of ITZ-Kollidon(®) VA 64 mixtures also correlated well with the miscibility predicted by film casting. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:2142-2152, 2015. PMID:25917333

  9. Relationship between casting modulus and grain size in cast A356 aluminium alloys

    NASA Astrophysics Data System (ADS)

    Niklas, A.; Abaunza, U.; Fernández-Calvo, A. I.; Lacaze, J.

    2012-01-01

    Microstructure of Al-Si alloy castings depends most generally on melt preparation and on the cooling rate imposed by the thermal modulus of the component. In the case of Al-Si alloys, emphasis is put during melt preparation on refinement of pro-eutectic (Al) grains and on modification of the Al-Si eutectic. Thermal analysis has been used since long to check melt preparation before casting, i.e. by analysis of the cooling curve during solidification of a sample cast in an instrumented cup. The conclusions drawn from such analysis are however valid for the particular cooling conditions of the cups. It thus appeared of interest to investigate how these conclusions could extrapolate to predict microstructure in complicated cast parts showing local changes in the solidification conditions. For that purpose, thermal analysis cups and instrumented sand and die castings with different thermal moduli and thus cooling rates have been made, and the whole set of cooling curves thus recorded has been analysed. A statistical analysis of the characteristic features of the cooling curves related to grain refinement in sand and die castings allowed determining the most significant parameters and expressing the cube of grain size as a polynomial of these parameters. After introduction of a further parameter quantifying melt refining an excellent correlation, with a R2 factor of 0.99 was obtained.

  10. Wege in die Zukunft

    NASA Astrophysics Data System (ADS)

    Kauermann, Göran; Mosler, Karl

    Die Zukunft stellt große Herausforderungen an die Arbeit der Deutschen Statistischen Gesellschaft. Sie betreffen die gestiegenen Anforderungen der Nutzer von Statistik, die Kommunikationsmöglichkeiten des Internets sowie die Dynamik der statistischen Wissenschaften und ihrer Anwendungsgebiete. Das Kapitel 5 beschreibt, wie sich die Gesellschaft diesen Herausforderungen stellt und welche Ziele sie sich in der wissenschaftlichen Zusammenarbeit und im Kampf gegen das Innumeratentum gesetzt hat.

  11. Development of dental casting and porcelainizing techniques for titanium alloys

    Microsoft Academic Search

    Taira

    1986-01-01

    Casting of titanium metals has been difficult due to their high chemical reactivity at elevated temperatures. Thus, special melting and mold materials are needed. This study investigated molds, Ti alloys, and porcelain applications, utilizing a new dental casting machine, Castmatic. It involved argon-arc melting and subsequent argon\\/vacuum pressurized casting. Special refractory oxides such as yttria or Zirconia A were utilized

  12. Effect of Mold Coating Materials and Thickness on Heat Transfer in Permanent Mold Casting of Aluminum Alloys

    Microsoft Academic Search

    A. Hamasaiid; M. S. Dargusch; C. J. Davidson; S. Tovar; T. Loulou; F. Rezaï-Aria; G. Dour

    2007-01-01

    In permanent mold casting or gravity die casting (GDC) of aluminum alloys, die coating at the casting-mold interface is the\\u000a most important single factor controlling heat transfer and, hence, it has the greatest influence on the solidification rate\\u000a and development of microstructure. This investigation studies the influence of coating thickness, coating composition, and\\u000a alloy composition on the heat transfer at

  13. A Benchmark Study on Casting Residual Stress

    SciTech Connect

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

    2012-01-01

    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.

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

    SciTech Connect

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

    2005-01-30

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

  15. 40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...the standards for continuous lamination/casting operations? 63.5820 Section 63...the standards for continuous lamination/casting operations? You must use one or more...continuous lamination line and each continuous casting line complies with the applicable...

  16. 40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...the standards for continuous lamination/casting operations? 63.5820 Section 63...the standards for continuous lamination/casting operations? You must use one or more...continuous lamination line and each continuous casting line complies with the applicable...

  17. 40 CFR 63.5820 - What are my options for meeting the standards for continuous lamination/casting operations?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...the standards for continuous lamination/casting operations? 63.5820 Section 63...the standards for continuous lamination/casting operations? You must use one or more...continuous lamination line and each continuous casting line complies with the applicable...

  18. Investigation on Tool Wear Rate for Modified and Unmodified Aluminium-Silicon Casting Alloy

    NASA Astrophysics Data System (ADS)

    Haque, M. M.; Khan, A. A.; Ismail, Ahmad F.

    This study demonstrates and explains the effect of strontium modification on machinability of aluminium-silicon eutectic (LM-6 type) alloy. This alloy is known to have many favourable features including weight to strength ratio, high corrosion resistance and excellent castability. However, normal unmodified LM-6 alloy has poor machinability, which reduces its applications range. In this work, various samples of LM-6 alloy were cast using sand and metallic chill mould with and without strontium addition. Machining on each cast product, was carried out using recommended cutting parameters for Al-Si alloys. Strontium modified samples have recorded a reduction in average flank wear, an increase in shear plane angles and a reduction in chip thickness. The main reason for this improvement is the refining effect of strontium, which reduces the size of the hard silicon particles. As a result, their abrasive action on the tool face has reduced a lot. Dramatic reductions in tool wear rate were recorded when the microstructures were refined. On the other hand, when no refinement of microstructure occurs, tool wear rate becomes high. Chip analysis showed that strontium modified sample produced a thinner chip thickness with a larger shear plane angle, requiring less cutting forces. The tool wear depends not only on the phases present in the work material, but also on their sizes and distribution over entire structure. Thus, strontium modification has better effect on machinability of die cast alloy compared to that of the sand cast LM-6 alloy.

  19. 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

  20. 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%.

  1. Improving Tribological Properties of Cast Al-Si Alloys through Application of Wear-Resistant Thermal Spray Coatings

    NASA Astrophysics Data System (ADS)

    Culliton, David; Betts, Anthony; Carvalho, Sandra; Kennedy, David

    2013-04-01

    Flame Spray Thermal Spray coatings are low-cost, high-wear surface-treatment technologies. However, little has been reported on their potential effects on cast automotive aluminum alloys. The aim of this research was to investigate the tribological properties of as-sprayed NiCrBSi and WC/12Co Flame Spray coatings applied to two cast aluminum alloys: high-copper LM24 (AlSi8Cu3Fe), and low-copper LM25 (AlSi7Mg). Potential interactions between the mechanical properties of the substrate and the deposited coatings were deemed to be significant. Microstructural, microhardness, friction, and wear (pin-on-disk, microabrasion, Taber abrasion, etc.) results are reported, and the performance differences between coatings on the different substrates were noted. The coefficient of friction was reduced from 0.69-0.72 to 0.12-0.35. Wear (pin-on-disk) was reduced by a factor of 103-104, which was related to the high surface roughness of the coatings. Microabrasion wear was dependent on coating hardness and applied load. Taber abrasion results showed a strong dependency on the substrate, coating morphology, and homogeneity.

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

    PubMed

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

    1990-07-01

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

  3. Cool Cast Facts

    MedlinePLUS

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

  4. MPI Must Evolve or Die

    Microsoft Academic Search

    Al Geist

    2008-01-01

    Multicore and hybrid architecture designs dominate the landscape for systems that are 1 to 20 petaflops peak performance.\\u000a As such the MPI software must evolve to effectively use these types of architectures or it will die just like the vector programming\\u000a models died. While applications may continue to use MPI, it is not business as usual in how communication libraries

  5. LLNL casting technology

    SciTech Connect

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

    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.

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

    DOEpatents

    Stoddard, Nathan G. (Gettysburg, PA)

    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.

  7. Casting and Molding

    NSDL National Science Digital Library

    Perkins School for the Blind

    2012-06-26

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

  8. Low Activation Joining of SiC/SiC Composites for Fusion Applications: Tape Casting TiC+Si Powders

    SciTech Connect

    Henager, Charles H.; Kurtz, Richard J.; Canfield, Nathan L.; Shin, Yongsoon; Luscher, Walter G.; Mansurov, Jirgal; Roosendaal, Timothy J.; Borlaug, Brennan A.

    2013-08-06

    The use of SiC composites in fusion environments likely requires joining of plates using reactive joining or brazing. One promising reactive joining method uses solid-state displacement reactions between Si and TiC to produce Ti3SiC2 + SiC. We continue to explore the processing envelope for this joint for the TITAN collaboration in order to produce optimal joints to undergo irradiation studies in HFIR. One noted feature of the joints produced using tape-calendared powders of TiC+Si has been the large void regions that have been apparently unavoidable. Although the produced joints are very strong, these voids are undesirable. In addition, the tapes that were made for this joining were produced about 20 years ago and were aging. Therefore, we embarked on an effort to produce some new tape cast powders of TiC and Si that could replace our aging tape calendared materials.

  9. Shrinkage Prediction for the Investment Casting of Stainless Steels

    SciTech Connect

    Sabau, Adrian S [ORNL

    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.

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

    SciTech Connect

    Sabau, Adrian S [ORNL

    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.

  11. 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.

  12. Faster, Less Expensive Dies Using RSP Tooling

    NASA Astrophysics Data System (ADS)

    Knirsch, James R.

    2007-08-01

    RSP Tooling is an indirect spray form additive process that can produce production tooling for virtually any forming process and from virtually any metal. In the past 24 months a significant amount of research and development has been performed. This resulted in an increase in the basic metallurgical understanding of what transpires during the rapid solidification of the metal, significant improvements in the production machine up time, ceramic developments that have improved finish, process changes that have resulted in a shorter lead time for tool delivery, and the testing of many new alloys. RSP stands for Rapid Solidification Process and is the key to the superior metallurgical properties that result from the technology. Most metals that are sprayed in the process leave the machine with the same physical properties as the same metal normally achieves through heat treatment and in some cases the properties are superior. Many new applications are being pursued including INVAR tools for aerospace composite materials, and bimetallic tools made from tool steel and beryllium copper for die casting and plastic injection molding. Recent feasibility studies have been performed with tremendous success.

  13. Internal adaptation of cast titanium crowns.

    PubMed

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

    2007-08-01

    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 degrees C, 515 degrees C and 600 degrees C. The crowns were cleaned individually in a solution (1% HF + 13% HNO3) for 10 min using a ultrasonic cleaner, with no internal adaptations, and luted with zinc phosphate cement under a 5 kg static load. The crown and die assemblies were embedded in resin and sectioned longitudinally. The area occupied by cement was observed using stereoscopic lens (10X) and measured by the Leica Qwin image analysis system (mm(2)). The data for each experimental condition (n=8) were analyzed by Kruskal-Wallis non-parametric test (á=0.05). The results showed that liquid dilution and the increase in mold temperature did not significantly influence the levels of internal fit of the cast titanium crowns. The lowest means (+/-SD) of internal misfit were obtained for the 430 degrees C/100%: (7.25 mm(2) +/-1.59) and 600 degrees C/100% (8.8 mm(2) +/-2.25) groups, which presented statistically similar levels of internal misfit. PMID:19089139

  14. 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

  15. Cast Metals Coalition Technology Transfer and Program Management Final Report

    SciTech Connect

    Gwyn, Mike

    2009-03-31

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

  16. Application of the ToxMiner Database: Network Analysis of Linkage between ToxCast Phase I Chemicals and Thyroid Related Disease Outcomes

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

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

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

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

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

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

  20. Hickey, W8206, all casts Hickey, W8206, all casts, page 1

    E-print Network

    Hickey, Barbara

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

  1. 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.

  2. Computer cast blast modelling

    Microsoft Academic Search

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

    1994-01-01

    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

  3. Effects of chromium and nitrogen content on the microstructures and mechanical properties of as-cast Co-Cr-Mo alloys for dental applications.

    PubMed

    Yoda, Keita; Suyalatu; Takaichi, Atsushi; Nomura, Naoyuki; Tsutsumi, Yusuke; Doi, Hisashi; Kurosu, Shingo; Chiba, Akihiko; Igarashi, Yoshimasa; Hanawa, Takao

    2012-07-01

    The microstructure and mechanical properties of as-cast Co-(20-33)Cr-5Mo-N alloys were investigated to develop ductile Co-Cr-Mo alloys without Ni addition for dental applications that satisfy the requirements of the type 5 criteria in ISO 22674. The effects of the Cr and N contents on the microstructure and mechanical properties are discussed. The microstructures were evaluated using scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), and electron back-scattered diffraction pattern analysis. The mechanical properties were evaluated using tensile testing. The proof strength and elongation of N-containing 33Cr satisfied the type 5 criteria in ISO 22674. ?-phase with striations was formed in the N-free (20-29)Cr alloys, while there was slight formation of ?-phase in the N-containing (20-29)Cr alloys, which disappeared in N-containing 33Cr. The lattice parameter of the ?-phase increased with increasing Cr content (i.e. N content) in the N-containing alloys, although the lattice parameter remained almost the same in the N-free alloys because of the small atomic radius difference between Co and Cr. Compositional analyses by EDS and XRD revealed that in the N-containing alloys Cr and Mo were concentrated in the cell boundary, which became enriched in N, stabilizing the ?-phase. The mechanical properties of the N-free alloys were independent of the Cr content and showed low strength and limited elongation. Strain-induced martensite was formed in all the N-free alloys after tensile testing. On the other hand, the proof strength, ultimate tensile strength, and elongation of the N-containing alloys increased with increasing Cr content (i.e. N content). Since formation of ?-phase after tensile testing was confirmed in the N-containing alloys the deformation mechanism may change from strain-induced martensite transformation to another form, such as twinning or dislocation slip, as the N content increases. Thus the N-containing 33Cr alloy with large elongation is promising for use in dentures with adjustable clasps through one piece casting. PMID:22430232

  4. Using cold-crucible melting for titanium precision castings

    NASA Astrophysics Data System (ADS)

    Broihanne, Georges; Bannister, John

    2000-05-01

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

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

    NASA Technical Reports Server (NTRS)

    Cooper, K. G.; Wells, D.

    2000-01-01

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

  6. Development of casting investment preventing blackening of noble metal alloys part 1. Application of developed investment for Ag-Pd-Cu-Au alloy.

    PubMed

    Kakuta, Kiyoshi; Nakai, Akira; Goto, Shin-ichi; Wakamatsu, Yasushi; Yara, Atushi; Miyagawa, Yukio; Ogura, Hideo

    2003-03-01

    The objective of this study is to develop a casting investment that prevents the blackening of the cast surface of noble metal alloys. The experimental investments were prepared using a gypsum-bonded investment in which the metallic powders such as boron (B), silicon (Si), aluminum (Al) and titanium (Ti) were added as oxidizing agents. An Ag-Pd-Cu-Au alloy was cast into the mold made of the prepared investment. The effect of the addition of each metal powder was evaluated from the color difference between the as-cast surface and the polished surface of the cast specimen. The color of the as-cast surface approached that of the polished surface with increasing B and Al content. A lower mean value in the color difference was obtained at 0.25-1.00 mass% B content. B and Al are useful as an additive in a gypsum-bonded investment to prevent the blackening of an Ag-Pd-Cu-Au alloy. The effects of Si and Ti powder addition could not be found. PMID:12790300

  7. Numerical Optimization of the Method of Cooling of a Massive Casting of Ductile Cast-Iron

    NASA Astrophysics Data System (ADS)

    Dobrovska, Jana; Kavicka, Frantisek; Stransky, Karel; Sekanina, Bohumil; Stetina, Josef

    2010-06-01

    The numerical models of the temperature field of solidifying castings, according to various authors, have been observing two main goals—directed solidification as the basic assumption for the healthiness of a casting and the optimization of the technology while maintaining the optimal product properties. The achievement of these goals is conditioned by the ability to analyze and, successively, to control the effect of the deciding factors, which either characterize the process or accompany it. An original application of ANSYS simulated the forming of the temperature field of a massive casting from ductile cast-iron during the application various methods of its cooling using steel chills. The numerical model managed to optimize more than one method of cooling but, in addition to that, provided serious results for the successive model of structural and chemical heterogeneity, and so it also contributes to influencing the pouring structure. The file containing the acquired results from both models, as well as from their organic unification, brings new and, simultaneously, remarkable findings of causal relationships between the structural and chemical heterogeneity (i.e. between the sizes of the spheroids of graphite, the cells, density of the spheroids of graphite, etc.) and the local solidification time in any point of the casting. The determined relations therefore enable the prediction of the face density of the spheroids of graphite in dependence on the local solidification time. The calculated temperature field of a two-ton 500×500×1000 mm casting of ductile cast-iron with various methods of cooling has successfully been compared with temperatures obtained experimentally. The casting was cast in sand mould. The calculated model of the kinetics of the temperature field of the casting was verified during casting with temperature measurements in selected points. This has created a tool for the optimization of the structure with an even distribution of the spheroids of graphite in such a way so as to minimize the occurrence of degenerated shapes of graphite, which happens to be one of the conditions for achieving good mechanical properties of castings of ductile cast-iron.

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

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

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

  9. Impact of Simulation Technology on Die and Stamping Business

    NASA Astrophysics Data System (ADS)

    Stevens, Mark W.

    2005-08-01

    Over the last ten years, we have seen an explosion in the use of simulation-based techniques to improve the engineering, construction, and operation of GM production tools. The impact has been as profound as the overall switch to CAD/CAM from the old manual design and construction methods. The changeover to N/C machining from duplicating milling machines brought advances in accuracy and speed to our construction activity. It also brought significant reductions in fitting sculptured surfaces. Changing over to CAD design brought similar advances in accuracy, and today's use of solid modeling has enhanced that accuracy gain while finally leading to the reduction in lead time and cost through the development of parametric techniques. Elimination of paper drawings for die design, along with the process of blueprinting and distribution, provided the savings required to install high capacity computer servers, high-speed data transmission lines and integrated networks. These historic changes in the application of CAE technology in manufacturing engineering paved the way for the implementation of simulation to all aspects of our business. The benefits are being realized now, and the future holds even greater promise as the simulation techniques mature and expand. Every new line of dies is verified prior to casting for interference free operation. Sheet metal forming simulation validates the material flow, eliminating the high costs of physical experimentation dependent on trial and error methods of the past. Integrated forming simulation and die structural analysis and optimization has led to a reduction in die size and weight on the order of 30% or more. The latest techniques in factory simulation enable analysis of automated press lines, including all stamping operations with corresponding automation. This leads to manufacturing lines capable of running at higher levels of throughput, with actual results providing the capability of two or more additional strokes per minute. As we spread these simulation techniques to the balance of our business, from blank de-stacking to the racking of parts, we anticipate continued reduction in lead-time and engineering expense while improving quality and start-up execution. The author will provide an overview of technology and business evolution of the math-based process that brought an historical transition and revitalization to the die and stamping industry in the past decade. Finally, the author will give an outlook for future business needs and technology development directions.

  10. Die betroffenen Religionsgemeinschaften

    Microsoft Academic Search

    Lisa-Maria Bleiler

    \\u000a Um dem zur Entscheidung berufenen Arzt einen Eindruck davon zu vermitteln, weshalb sich der betreffende Patient gegen eine\\u000a bestimmte medizinische Maßnahme entscheidet, sollen im Folgenden drei der Gemeinschaften dargestellt werden, die medizinischen\\u000a Maßnahmen - mehr oder weniger - skeptisch gegenüber stehen: Die Zeugen Jehovas, der Evangelische Brüderverein und die Christian\\u000a Science (Christliche Wissenschaft). Den größten Teil der Darstellung wird die

  11. Casting in Sport

    PubMed Central

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

    1994-01-01

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

  12. Die Coin Experiment

    NSDL National Science Digital Library

    Kyle Siegrist

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

  13. Applying MHD technology to the continuous casting of steel slab

    NASA Astrophysics Data System (ADS)

    Takeuchi, Eiichi

    1995-05-01

    The application of magnetohydrodynamics (MHD) in the continuous casting process started with the electromagnetic stirring of the stand pool with a traveling magnetic field. It has now advanced to the electromagnetic stirring of molten steel in the mold and the control of molten steel flow by an in-mold direct current magnetic field brake. These applied MHD techniques are designed to further improve the continuous casting process capability. They improve the surface quality of cast steel by homogenizing the meniscus temperature, stabilizing initial solidification, and cleaning the surface layer. They also improve the internal quality of cast steel by preventing inclusions from penetrating deep into the pool and promoting the flotation of argon bubbles. Applied MHD technology is still advancing in scope and methods in addition to the improvement of conventional continuously cast slab qualities. The continuous casting of bimetallic slab by suppressing mixing in the pool is one example of this progress.

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

    PubMed

    Krewerth, D; Weidner, A; Biermann, H

    2013-12-01

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

  15. The application of floating dies for high speed growth of CsI single crystals by edge-defined film-fed growth (EFG)

    NASA Astrophysics Data System (ADS)

    Guguschev, Christo; Calvert, George; Podowitz, Stephen; Vailionis, Arturas; Yeckel, Andrew; Feigelson, Robert S.

    2014-10-01

    Floating graphite and fused silica dies were used to grow both undoped and Na doped CsI crystals by the edge-defined film-fed growth (EFG) method. Both die materials yielded high quality CsI crystals at high growth rates. Under the conditions employed in these growth experiments, a pull rate of up to 45 mm/h was possible using a 15 mm diameter graphite die. Growth procedures were developed to enhance crystal quality through iterative die design in combination with numerical modeling. The formation of cylindrical voids (bubble tracks) was investigated and methods were developed for their suppression.

  16. Learning and Removing Cast Shadows through a Multidistribution Approach

    Microsoft Academic Search

    Nicolas Martel-brisson; André Zaccarin

    2007-01-01

    Moving cast shadows are a major concern for foreground detection algorithms. The processing of foreground images in surveillance applications typically requires that such shadows be identified and removed from the detected foreground. This paper presents a novel pixel-based statistical approach to model moving cast shadows of nonuniform and varying intensity. This approach uses the Gaussian mixture model (GMM) learning ability

  17. Moving Cast Shadow Detection from a Gaussian Mixture Shadow Model

    Microsoft Academic Search

    Nicolas Martel-brisson; André Zaccarin

    2005-01-01

    Moving cast shadows are a major concern for foreground detection algorithms. Processing of foreground images in surveillance applications typically requires that such shadows have been identified and removed from the detected foreground. This paper presents a novel pixel-based statistical approach to model moving cast shadows of non-uniform and varying intensity. This approach uses the Gaussian mixture model (GMM) learning ability

  18. Neutron radiography inspection of investment castings.

    PubMed

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

    2004-10-01

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

  19. Development of casting investment preventing blackening of noble metal alloys Part 2. Application of developed investment for type 4 gold alloy.

    PubMed

    Nakai, Akira; Kakuta, Kiyoshi; Goto, Shin-ichi; Kato, Katuma; Yara, Atushi; Ogura, Hideo

    2003-09-01

    The objective of this study was to evaluate the efficacy of the developed investment for the prevention of blackening of a cast Type 4 gold and to analyze the oxides on its surface in relation to the blackening of the alloy. The experimental investments were prepared using a gypsum-bonded investment in which boron (B) or aluminum (Al) was added as a reducing agent. A Type 4 gold alloy was cast into the mold made of the prepared investment. The effect of the additives was evaluated from the color difference (deltaE*) between the as-cast surface and the polished surface of the cast specimen. B and Al were effective to prevent the blackening of a Type 4 gold alloy and the color of the as-cast surface approached that of the polished surface with increasing B and Al content. The prevention of the blackening of the gold alloy can be achieved by restraining the formation of CuO. PMID:14620998

  20. 75 FR 20387 - Contech Castings, LLC, Including Workers Whose Unemployment Insurance (UI) Wages Are Reported...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ...Administration [TA-W-72,649] Contech Castings, LLC, Including Workers Whose Unemployment...2010, applicable to workers of Contech Castings, LLC, including on-site leased workers...June 2009 and a new company, Contech Casting LLC was formed. Some workers...

  1. Cast aluminum in the vehicle structure taking the example of a city car study

    Microsoft Academic Search

    Hoehl

    1989-01-01

    The analysis of the lightweight design potential of different materials for car body application shows that cast aluminum is suitable for the load bearing structure of the passenger compartment. Design freedom, component integration, tooling costs and recycling possibilities are arguments in favour of the casting material. In order to get practical findings about possibilities and limits of aluminum castings in

  2. 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.

  3. Cast shadow segmentation using invariant color features

    Microsoft Academic Search

    Elena Salvador; Andrea Cavallaro; Touradj Ebrahimi

    2004-01-01

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

  4. Nonstandard technique for the manufacture of specimens for mechanical testing of aluminum cast alloys

    Microsoft Academic Search

    S. V. Savchenko; A. V. Koltyguin

    2007-01-01

    To carry out testing of mechanical properties of cast aluminum alloys, the description of a nonstandard technique for preparation\\u000a of cast samples is presented. Recently, cast samples have found increasing application in machine building. However, by their\\u000a mechanical properties, they do not correspond to samples turned from a cast metal of the same alloy. Moreover, their characteristics\\u000a are strongly affected

  5. Centrifugal precision cast TiAl turbocharger wheel using ceramic mold

    Microsoft Academic Search

    Wang Shouren; Guo Peiquan; Yang Liying

    2008-01-01

    It is the potential candidate for gamma TiAl-based alloys that would replace Ni-based superalloys, which are being used in fabrication of the turbocharger wheel currently. Cast Ti–47Al–2Cr–2Nb alloys due to their specific performance requirement are now on the verge of a commercial application. A novel precision casting technique, which combines the ceramic mold casting with centrifugal casting, was described in

  6. Extrusion die and method

    DOEpatents

    Lipp, G. Daniel (Painted Post, NY)

    1994-04-26

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

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  9. Tox21 and ToxCast Chemical Landscapes: Laying the Foundation for 21st Century Toxicology - Application of the Strategy to Chemical Testing

    EPA Science Inventory

    The U.S. Environmental Protection Agency?s ToxCast project and the related, multi-Agency Tox21 project are employing high-throughput technologies to screen hundreds to thousands of chemicals in hundreds of assays, probing a wide diversity of biological targets, pathways and mecha...

  10. Accuracy of one-piece castings, preceramic and postceramic soldering.

    PubMed

    Ziebert, G J; Hurtado, A; Glapa, C; Schiffleger, B E

    1986-03-01

    An investigation was conducted to evaluate the relative accuracy of one-piece castings of FPDs of three, four, and five units with those assembled by preceramic soldering and postceramic soldering. The preceramic soldered FPDs were subjected to six simulated porcelain firing cycles to assure a homogeneous sample. A total of 15 FPDs, five of each length, were evaluated for each test condition. A three-piece aluminum mold with stainless steel dies, which allowed for varying the length of the prosthesis, was used to fabricate the FPDs in 52% gold-palladium alloy. Marginal discrepancies of the castings on the dies were compared for the three test techniques. The mesiodistal length of the FPDs that were pre- and postsoldered were also measured at the occlusal and at the gingival margins and compared with the restorations before soldering. PMID:2870184

  11. Hickey, C8206_all casts Hickey, C8206_all casts, page 1

    E-print Network

    Hickey, Barbara

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

  12. Über die Wirkung von Adrenochrom und Histamin auf die Blutungszeit

    Microsoft Academic Search

    G. Kuschinsky; U. Hille; H. Schimassek

    1952-01-01

    Zusammenfassung Adrenochrom (ACHR) und das Semicarbazon des Adrenochrom = Adrenoxyl verkürzen die Blutungszeit beim Kaninchen. Die Wirkung läßt sich durch Antihistaminica aufheben bzw. verhindern. Auch die Wirkung von Histamin, das in analoger Weise wie ACHR die Blutungszeit verkürzt, läßt sich durch vorherige Gabe eines Antihistaminicum verhindern. Die bereits eingetretene Wirkung von Histamin läßt sich durch Antihistaminiea nicht mehr aufheben.

  13. Probability characterization of tensile strength of an aluminum casting

    Microsoft Academic Search

    X. Teng; H. Mae; Y. Bai

    2010-01-01

    The paper statistically studies fracture properties of an aluminum low-pressure die casting component on basis of 32 tensile tests on round bar specimens. It reveals that the probability distribution of both ultimate tensile strength and fracture strain can be described using either the Weibull or the Gaussian function. Goodness-of-fit tests based on the Anderson–Darling statistic fail to reject either of

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

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

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

  15. 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.

  16. ELID grinding characteristics of large stamping die for Wolter mirror.

    PubMed

    Yin, Shaohui; Ohmori, Hitoshi; Liu, Qing; Morita, Shinnya; Chen, Fengjun; Asami, Muneaki; Fan, Yufeng

    2009-01-01

    An ultra-precision ELID grinding of large stamping dies of Wolter mirror for X-ray telescope was presented in this paper. The large stamping dies (S55C) with confocal paraboloid and hyperboloid was ground by ELID arc-enveloped grinding. In this ELID grinding system, cast iron fiber bonded (CIFB) diamond wheels were controlled by 3-dimentional ways to scan the work-piece and generate required surfaces. Its grinding characteristics such as attainable form accuracy, surface roughness were investigated. Furthermore, some measures to improve form accuracy were discussed and verified such as truing, compensating, and on-machine measuring. PMID:19893217

  17. Die Gemeinschaftsdiagnose der Wirtschaftsforschungsinstitute

    Microsoft Academic Search

    Wolfgang Nierhaus

    2002-01-01

    Zweimal in jedem Jahr – im Frühjahr und im Herbst – erstellen die sechs führenden Wirtschaftsforschungsinstitute in der Bundesrepublik Deutschland im Auftrag des Bundesministeriums für Finanzen ein Konjunkturgutachten über »die Lage der Weltwirtschaft und der deutschen Wirtschaft«. Was sich hinter der »Gemeinschaftsdiagnose« verbirgt, wird in diesem Beitrag erläutert.

  18. Shame, Death, and Dying

    Microsoft Academic Search

    Ramón Martínez de Pisón Liébanas

    2002-01-01

    This paper deals with the influence of shame on the way in which Western society, particularly North America, is coping with death and dying. From being a familiar event, death and dying have become a shameful aspect of life. Thus, this paper provides some understanding of this important transformation, and it challenges some of our present attitudes regarding death and

  19. Villafranca Die Kabinete und die Revolutionen.

    E-print Network

    Prodinger, Helmut

    . »Geht fort, Weib, Oes gehört nit zu uns und Oes seid so schwarz vor Sünd' und Schand', daß die Tyroler, dös Oes ihm an'than, daß Oes a Weib seid und a Gräfin dazu!« »Ich bereue, ich bereue Alles ­ aber habt

  20. Die Darwinsche Theorie und die Eukaryoten

    E-print Network

    Ulmschneider, Peter

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

  1. Casting Of Multilayer Ceramic Tapes

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr.

    1991-01-01

    Procedure for casting thin, multilayer ceramic membranes, commonly called tapes, involves centrifugal casting at accelerations of 1,800 to 2,000 times normal gravitational acceleration. Layers of tape cast one at a time on top of any previous layer or layers. Each layer cast from slurry of ground ceramic suspended in mixture of solvents, binders, and other components. Used in capacitors, fuel cells, and electrolytic separation of oxygen from air.

  2. Evaluation of an improved centrifugal casting machine.

    PubMed

    Donovan, T E; White, L E

    1985-05-01

    A Type III gold alloy, a silver-palladium alloy, and a base metal alloy were cast in two different centrifugal casting machines. With the number of complete cast mesh squares as an indicator of castability, the Airspin casting machine produced superior castings with all three alloys. The base metal alloy produced the greatest number of complete squares with both casting machines. PMID:3889295

  3. The fractography of casting alloys

    Microsoft Academic Search

    G POWELL

    1994-01-01

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

  4. Ohno continuous casting

    Microsoft Academic Search

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

    1995-01-01

    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

  5. Casting and Angling.

    ERIC Educational Resources Information Center

    Little, Mildred J.; Bunting, Camille

    The self-contained packet contains background information, lesson plans, 15 transparency and student handout masters, drills and games, 2 objective examinations, and references for teaching a 15-day unit on casting and angling to junior high and senior high school students, either as part of a regular physical education program or as a club…

  6. 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…

  7. A comparative assessment of crystallite size and lattice strain in differently cast A356 aluminium alloy

    NASA Astrophysics Data System (ADS)

    Mishra, S. K.; Roy, H.; Lohar, A. K.; Samanta, S. K.; Tiwari, S.; Dutta, K.

    2015-02-01

    In this investigation, A356 aluminium alloy has been prepared by different routes viz. gravity casting, rheo pressure die casting (RPDC) and RPDC with T6 heat treatment. X-ray diffraction studies of these samples have been done in the scanning range of 20 – 90°. X-ray peak broadening analysis has been used to estimate the crystallite size and lattice stain, in all the samples. The sample prepared by RPDC with T6 treatment has comparatively smaller crystallite size and lesser lattice strain than gravity cast and RPDC samples.

  8. Fabrication of highly dielectric nano-BaTiO3\\/epoxy-resin composite plate having trenches by mold casting and its application to capacitive energy harvesting

    Microsoft Academic Search

    M. Suzuki; N. Matsushita; T. Hirata; R. Yoneya; J. Onishi; T. Wada; T. Takahashi; T. Nishida; Y. Yoshikawa; S. Aoyagi

    2011-01-01

    We propose a fabrication method of dielectric plate having trenches, in which a composite material of nano-BaTiO3 particles and epoxy-resin is casted into a mold of patterned thick photosensitive dry film. The features are, 1) the relative dielectric constant ? r is a dozen, which is no less than those of other polymer-based ferroelectric such as poly-vinylidene-difluoride (PVDF), 2) fabrication

  9. 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 POP–fibreglass 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

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

    SciTech Connect

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

    2009-09-15

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

  15. 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.

  16. EFFECT OF CAST RECTIFIERS ON THE MARGINAL FIT OF UCLA ABUTMENTS

    PubMed Central

    Jaime, Ana Paula Gumieiro; de Vasconcellos, Diego Klee; Mesquita, Alfredo Mikail Melo; Kimpara, Estevão Tomomitsu; Bottino, Marco Antonio

    2007-01-01

    Objectives: This study assessed the effect of cast rectifiers on the marginal misfit of cast UCLA abutments compared to premachined UCLA abutments. The influence of casting and porcelain baking on the marginal misfit of these components was also investigated. Methods: Two groups were analyzed: test group – 10 cast UCLA abutments, finished with cast rectifier and submitted to ceramic application; control group – 10 premachined UCLA abutments, cast with noble metal alloy and submitted to ceramic application. Vertical misfit measurements were performed under light microscopy. In the test group, measurements were performed before and after the use of cast rectifiers, and after ceramic application. In the control group, measurements were performed before and after casting, and after ceramic application. Data were submitted to statistical analysis by ANOVA and Tukey's test (?= 5%). Results: The use of cast rectifiers significantly reduced the marginal misfit of cast UCLA abutments (from 25.68?m to 14.83?m; p<0.05). After ceramic application, the rectified cylinders presented misfit values (16.18?m) similar to those of premachined components (14.3 ?m). Casting of the premachined UCLA abutments altered the marginal misfit of these components (from 9.63 ?m to 14.6 ?m; p<0.05). There were no significant changes after porcelain baking, in both groups. Conclusion: The use of cast rectifiers reduced the vertical misfit of cast UCLA abutments. Even with carefully performed laboratory steps, changes at the implant interface of premachined UCLA abutments occurred. Ceramic application did not alter the marginal misfit values of UCLA abutments. PMID:19089125

  17. Über die Alkaptonurie

    Microsoft Academic Search

    Kurt Schreier; Hans Plückthun

    1952-01-01

    Es wird der normale und pathologische Stoffwechsel der beiden Aminosäuren Phenylalanin und Tyrosin erörtert, wobei auf die angeborenen Stoffwechselstörungen (Albinismus, Tyrosinosis und Oligophrenia phenylpyruvica neben der Alkaptonurie) kurz eingegangen wird.

  18. Coin Die Experiment

    NSDL National Science Digital Library

    Kyle Siegrist

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

  19. Demokrit und die Quantenmechanik

    NASA Astrophysics Data System (ADS)

    Wahsner, Renate

    Es wird gezeigt, daß der antike Atomismus ein auch für die moderne Physik fundamentales Denkprinzip begründete, ein Prinzip, das es in seiner Newtonschen Modifizierung ermöglicht, die Bewegung und das Kontinuum physikalisch zu fassen.Translated AbstractDemocrit and Quantum MechanicsIt is shown that the antique atomisms founded a thought principle which has also a fundamental meaning for modern physics, a principle which in its Newtonian version makes it possible to grasp motion and continuum physically.

  20. Die Effektivität der Hypnose

    Microsoft Academic Search

    W. Bongartz; E. Flammer; R. Schwonke

    2002-01-01

    Zusammenfassung  \\u000a Von 193 Untersuchungen zur Bestimmung der Wirksamkeit von Hypnose, die bis Ende 1998 verffentlicht wurden, konnten 43 randomisierte,\\u000a klinische Studien, in denen eine ausschlielich mit Hypnose behandelte Patientengruppe mit einer unbehandelten (bzw. mit medizinischer\\u000a Standardversorgung behandelten) Gruppe verglichen wurde, in eine Meta-Analyse integriert werden. Fr die hypnotische Behandlung\\u000a von ICD-10 kodierbaren Strungen wurde bei einem durchschnittlichen Behandlungszeitraum von 5,1

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

    PubMed

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

    2014-02-01

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

  2. AIS/DOE Technology Roadmap Program: Strip Casting: Anticipating New Routes To Steel Sheet

    SciTech Connect

    Prof. Alan W. Camb; Prof. Anthony Rollett

    2001-08-31

    To determine the potential for strip casting in the steel industry and to develop the fundamental knowledge necessary to allow the role of strip casting in the modern steel industry to be understood. Based upon a study of carbon steel strip castings that were either produced for the program at British Steel or were received from a pre-commercial production machine, the following conclusions were made. Strip casting of carbon steels is technically feasible for sheet material from slightly less than 1 mm thick to 3 mm thick, and, assuming that it is economically viable, it will be first applied in carbon steel markets that do not require stringent surface quality or extensive forming. The potential of strip casting as a casting process to be developed for steel castings is very high as the cast strip has some very novel characteristics. Direct cast carbon strip has better surface quality, shape and profile than any other casting process currently available. The more rapidly solidified structure of direct cast strip tends to be strong with low ductility; however, with adequate thermal treatment, it is possible to develop a variety of properties from the same grade. The process is more amenable at this time to production tonnages per year of the order of 500,000 tons and as such will first find niche type applications. This technology is an additional technology for steel production and will be in addition to, rather than a replacement for, current casting machines.

  3. Die Europäische Union, die Europäische Gemeinschaft und ihre Rechtsordnung, die Europäische Lebensmittelkontrolle

    NASA Astrophysics Data System (ADS)

    Gallhoff, Gudrun; Rimkus, Gerhard G.

    Die Europäische Union (EU) ist ein Zusammenschluss von siebenundzwanzig unabhängigen Staaten, um deren wirtschaftliche, politische und soziale Zusammenarbeit zu verstärken. Seit 1. Mai 2007 hat sie die folgenden Mitglieder: Österreich, Belgien, Bulgarien, Dänemark, Finnland, Frankreich, Deutschland, Griechenland, Irland, Italien, Luxemburg, die Niederlande, Portugal, Spanien, Schweden, das Vereinigte Königreich von Großbritannien und Nordirland, Zypern, die Tschechische Republik, Estland, Ungarn, Lettland, Litauen, Malta, Polen, Rumänien, die Slowakei und Slowenien [1]. (Hinweis: Die Republik Zypern hat juristisch Souveränität über die ganze Insel, da die Türkische Republik Nordzypern international nicht anerkannt wird.)

  4. [Casting faults and structural studies on bonded alloys comparing centrifugal castings and vacuum pressure castings].

    PubMed

    Fuchs, P; Küfmann, W

    1978-07-01

    The casting processes in use today such as centrifugal casting and vacuum pressure casting were compared with one another. An effort was made to answer the question whether the occurrence of shrink cavities and the mean diameter of the grain of the alloy is dependent on the method of casting. 80 crowns were made by both processes from the baked alloys Degudent Universal, Degudent N and the trial alloy 4437 of the firm Degusa. Slice sections were examined for macro and micro-porosity and the structural appearance was evaluated by linear analysis. Statistical analysis showed that casting faults and casting structure is independent of the method used and their causes must be found in the conditions of casting and the composition of the alloy. PMID:352670

  5. Casting larger polycrystalline silicon ingots

    SciTech Connect

    Wohlgemuth, J.; Tomlinson, T.; Cliber, J.; Shea, S.; Narayanan, M.

    1995-08-01

    Solarex has developed and patented a directional solidification casting process specifically designed for photovoltaics. In this process, silicon feedstock is melted in a ceramic crucible and solidified into a large grained semicrystalline silicon ingot. In-house manufacture of low cost, high purity ceramics is a key to the low cost fabrication of Solarex polycrystalline wafers. The casting process is performed in Solarex designed casting stations. The casting operation is computer controlled. There are no moving parts (except for the loading and unloading) so the growth process proceeds with virtually no operator intervention Today Solarex casting stations are used to produce ingots from which 4 bricks, each 11.4 cm by 11.4 cm in cross section, are cut. The stations themselves are physically capable of holding larger ingots, that would yield either: 4 bricks, 15 cm by 15 an; or 9 bricks, 11.4 cm by 11.4 an in cross-section. One of the tasks in the Solarex Cast Polycrystalline Silicon PVMaT Program is to design and modify one of the castings stations to cast these larger ingots. If successful, this effort will increase the production capacity of Solarex`s casting stations by 73% and reduce the labor content for casting by an equivalent percentage.

  6. AsCast Acicular Ductile Aluminum Cast Iron

    Microsoft Academic Search

    SM Mostafavi Kashani; SMA Boutorabi

    2009-01-01

    The effects of nickel (2.2%) and molybdenum (0.6%) additions on the kinetics, microstructure, and mechanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic

  7. Advanced Line Die Forming Simulation Technology and Its Impact on Stamping Automotive Body Panels

    NASA Astrophysics Data System (ADS)

    Zhang, Jimmy; Wang, Chuantao; Xu, Siguang; Joshi, Ramesh; Goan, Norman

    2005-08-01

    Line die forming simulation and validation create tremendous business values for automotive die developments and production stamping while they pose a great technological challenge to stamping CAE community. GM Manufacturing Engineering Die Center has developed an integrated line die analysis technology to validate die lines as a productionized business process. In this process, a finished stamping body panel can be streamline analyzed with required time, accuracy, and quality. This paper presents critical issues in line die analysis, discusses technical challenges in production applications and software development, and finally demonstrates the impact of line die forming simulation and validations on automotive body styling and tooling developments.

  8. Development of an Optimization Methodology for the Aluminum Alloy Wheel Casting Process

    NASA Astrophysics Data System (ADS)

    Duan, Jianglan; Reilly, Carl; Maijer, Daan M.; Cockcroft, Steve L.; Phillion, Andre B.

    2015-04-01

    An optimization methodology has been developed for the aluminum alloy wheel casting process. The methodology is focused on improving the timing of cooling processes in a die to achieve improved casting quality. This methodology utilizes (1) a casting process model, which was developed within the commercial finite element package, ABAQUS™—ABAQUS is a trademark of Dassault Systèms; (2) a Python-based results extraction procedure; and (3) a numerical optimization module from the open-source Python library, Scipy. To achieve optimal casting quality, a set of constraints have been defined to ensure directional solidification, and an objective function, based on the solidification cooling rates, has been defined to either maximize, or target a specific, cooling rate. The methodology has been applied to a series of casting and die geometries with different cooling system configurations, including a 2-D axisymmetric wheel and die assembly generated from a full-scale prototype wheel. The results show that, with properly defined constraint and objective functions, solidification conditions can be improved and optimal cooling conditions can be achieved leading to process productivity and product quality improvements.

  9. 75 FR 69470 - JL French Automotive Castings, LLC, Including On-Site Leased Workers From Labor Ready and Seek...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ...Administration [TA-W-70,143] JL French Automotive Castings, LLC, Including On-Site...applicable to workers of JL French Automotive Castings LLC, including on-site leased...Sheboygan, Wisconsin location of JL French Automotive Castings LLC. The Department has...

  10. 78 FR 74163 - Johnstown Specialty Castings Inc., a Subsidiary of WHEMCO, Including On-Site Leased Workers From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ...TA-W-82,671] Johnstown Specialty Castings Inc., a Subsidiary of WHEMCO, Including...applicable to workers of Johnstown Specialty Castings, Inc., a subsidiary of WHEMCO, Johnstown...Pennsylvania location of Johnstown Specialty Castings, Inc., a subsidiary of WHEMCO....

  11. Development of lead-free copper alloy graphite castings. Annual report for the period January through December 1996

    Microsoft Academic Search

    Rohatgi

    1997-01-01

    Centrifugal casting of Copper alloys containing graphite particles established the feasibility of making hollow cylindrical castings. In theses castings, the graphite particles are segregated to the inner periphery making them well suited for bearing applications because of the lubricity of the graphite particles. The recovery of graphite is found to be around 90%. Chemical analysis shows that the average concentration

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

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  13. LOST FOAM CASTING OF MAGNESIUM ALLOYS

    SciTech Connect

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

    2007-01-01

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

  14. High-Speed Cutting of Cast Iron and Alloy Steels - State of Research

    Microsoft Academic Search

    Taylan Altan; Peter Fallböhmer; Ciro A. Rodríguez; Tugrul Özel

    Summary This paper gives a brief overview of HSC technology and presents current progress in high performance machining of cast iron and alloy steels used in die and mold manufacturing. This work covers: a) theoretical and experimental studies of tool failure and tool life in high- speed milling of hard materials, b) optimization of CNC programs by adjusting spindle RPM

  15. Cast dielectric composite linear accelerator

    DOEpatents

    Sanders, David M. (Livermore, CA); Sampayan, Stephen (Manteca, CA); Slenes, Kirk (Albuquerque, NM); Stoller, H. M. (Albuquerque, NM)

    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.

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

  1. First Results of Energy Saving at Process Redesign of Die Forging Al-Alloys

    NASA Astrophysics Data System (ADS)

    Pepelnjak, Tomaž; Kuzman, Karl; Kokol, Anton

    2011-05-01

    The contribution deals with eco-friendly solutions for shortened production chains of forging light alloys. During the die forging operations a remarkable amount of material goes into the flash and later on into chips during finish machining. These low value side products are rich with embedded energy therefore recycling or reprocessing could be very energy saving procedure. In cooperation with a die forging company a shortened reprocessing cycle has been studied starting from re-melting the forging flash and without additional heating to cast preforms for subsequent die forging. As such preforms have not as good formability characteristics as those done from extruded billets the isothermal forging process has been adopted. First results showed that without cracks and other defects the formability is sufficient for a broad spectrum of forgings. To improve the formability a homogenization process of cast preforms has been implemented. As the process started immediately after casting, amount of additional energy for heating was minimized. To reduce voids forging process was redesigned in a way to assure greater hydrostatic pressures in parts during forging. First results were promising therefore research is going towards improving processes without adding significantly more energy as it is needed for casting with homogenization and die forging.

  2. Study on the Low-looped Ability of Forward and Reverse Looping Methods of Gold Wire Ball Bonding for Stacked Die Package Application

    Microsoft Academic Search

    Xiu-Lan Cheng; Yu-Cai Huang

    2006-01-01

    The packaging technology is driving to lower loop height level with the developments of multiple level stacked die packages and multi-tiered IC packages. It is very important to find moderate low-looped method to achieve perfect bondability and low-looped ability. The effects of looping methods on the bondability and low-looped ability were studied and analyzed. The study results shows that the

  3. Cast duplex stainless steel

    SciTech Connect

    Bond, A.P.; Grobner, P.J.; Poznansky, A.

    1985-02-19

    A casting alloy is provided containing about 0.02% to 0.05% carbon, about 23% to about 25% chromium, about 8% to 12% nickel, about 5% to 7% molybdenum, about 0.4% to 0.8% manganese, about 0.1% to 0.3% silicon, about 0.1% to 0.4% nitrogen, and the balance essentially iron, the alloy having a duplex austenite-ferrite grain structure, and being resistant to the corrosive effects of acids, chloride solutions and seawater.

  4. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Noncritical castings. For...

  5. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Noncritical castings. For...

  6. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Noncritical castings. For...

  7. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Non-critical castings. For...

  8. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Non-critical castings. For...

  9. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Non-critical castings. For...

  10. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Noncritical castings. For...

  11. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Non-critical castings. For...

  12. 14 CFR 25.621 - Casting factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Noncritical castings. For...

  13. 14 CFR 23.621 - Casting factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...apply to any structural castings except castings that are pressure tested as parts of hydraulic or other fluid systems...and fuel and oil tank supports and attachments, and cabin pressure valves. (d) Non-critical castings. For...

  14. 21 CFR 888.5940 - Cast component.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...component is a device intended for medical purposes to protect or support a cast. This generic type of device includes the cast heel, toe cap, cast support, and walking iron. (b) Classification. Class I (general controls). The device is...

  15. 14 CFR 27.621 - Casting factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  16. 14 CFR 27.621 - Casting factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  17. 14 CFR 29.621 - Casting factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  18. 14 CFR 27.621 - Casting factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  19. 14 CFR 29.621 - Casting factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  20. 14 CFR 27.621 - Casting factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  1. 14 CFR 27.621 - Casting factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  2. 14 CFR 29.621 - Casting factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  3. 14 CFR 29.621 - Casting factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  4. 14 CFR 29.621 - Casting factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...and (d) of this section apply to structural castings except castings that are pressure tested as parts of hydraulic or other fluid... (b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and...

  5. Stress Corrosion Cracking Behavior of Cast Stainless Steels

    SciTech Connect

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

    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.

  6. Fit of implant-supported fixed prostheses fabricated on master casts made from a dental stone and a dental plaster

    Microsoft Academic Search

    Michael Wise

    2001-01-01

    Statement of Problem. The impression and cast on which an implant-supported fixed prosthesis is fabricated must accurately reproduce the intraoral relations. Purpose. The fit of fixed prostheses fabricated on master casts poured in a conventional die stone and in an ultra-low-expansion plaster was investigated in vitro. Material and Methods. An impression was made of patient replicas with inter-implant abutment distances

  7. Care of the Dying: A Swedish Perspective

    ERIC Educational Resources Information Center

    Feigenberg, Loma; Fulton, Robert

    1977-01-01

    This article illustrates various aspects of terminal care, and shows that rules and norms for such care do not exist today. The authors advocate the formulation of an aim for humane treatment of dying patients, and its application in a manner appropriate to Swedish medical concepts and Swedish conditions. (Author)

  8. Effects of Multi-electromagnetic Field on the Solidification Structure of IN100 Superalloy Castings

    NASA Astrophysics Data System (ADS)

    Jin, Wenzhong; Li, Sufang; Li, Tingju; Yin, Guomao

    2015-05-01

    IN100 superalloy castings were vacuum cast with the application of multi-electromagnetic field. The effect of multiple-electromagnetic field on the solidification structure of IN100 superalloy castings has been studied. The results show that with the application of the multiple-electromagnetic field composed of the main frequency rotary electromagnetic field with 60A current and the steady direct current electromagnetic field with 290A current, the shrinkage porosity of IN100 superalloy castings is greatly improved and the fine equiaxed grain fraction of IN100 superalloy castings is increased to 100%. Moreover, the action mechanism of multiple-electromagnetic field is discussed to explain its effect on improving the solidification structure of IN100 superalloy castings.

  9. Dying Piñon Pine

    USGS Multimedia Gallery

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

  10. Archimedes, und die gestorten

    E-print Network

    van Straten, Duco

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

  11. Die Natur der Bacteriocine

    Microsoft Academic Search

    H. Brandis

    1975-01-01

    The bacteriocins comprise a large, heterogeneous group of bactericidal substances produced by bacteria from widely differing species. The best known bacteriocins are the colieins. Some aspects of research on colicins are discussed especially their chemical nature and mode of action, and their genetic determinants. Bacteriocine stellen eine besondere Gruppe yon antibiotisch wirkenden Substanzen dar, die yon Bakterien gebildet werden, Proteinnatur

  12. Poetry and the Dying.

    ERIC Educational Resources Information Center

    Kramer, Aaron

    1992-01-01

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

  13. Dying with dignity.

    PubMed

    Abiven, M

    1991-01-01

    People facing death because of incurable illness are likely to suffer intense physical and mental distress. The provision of help and support for them can be seen as a medical discipline in its own right, demanding special training and attitudes. Each country needs to work out the best ways of looking after dying people in accordance with its culture and resources. PMID:1726501

  14. Dying with dignity.

    PubMed

    Abiven, M

    1993-03-01

    People facing death because of incurable illness are likely to suffer intense physical and mental distress. The provision of help and support for them can be seen as a medical discipline in its own right, demanding special training and attitudes. Each country needs to work out the best ways of looking after dying people in accordance with its culture and resources. PMID:7682898

  15. HERAUSFORDERUNGEN FR DIE INFORMATIONSGESELLSCHAFT?

    E-print Network

    Lutterbeck, Bernd

    . Vannevar Bush hat in seiner Vision die Innovation vorweggenommen, mit der Tim Berners Lee Jahrzehnte später in Stärken. Tim Berners-Lee hat empirisch eingelöst, was Vannevar Bush noch überwiegend als moralische nicht bekannt ist. (So auch der Ansatz von Benussi (2005)) Auch Tim Berners Lee mit seiner genialen

  16. 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.

  17. Volatile species retention during metallic fuel casting

    NASA Astrophysics Data System (ADS)

    Fielding, Randall S.; Porter, Douglas L.

    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, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  18. 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)

  19. Biotransformation and ToxCast?

    EPA Science Inventory

    A major focus in toxicology research is the development of in vitro methods to predict in vivo chemical toxicity. Within the EPA ToxCast program, a broad range of in vitro biochemical and cellular assays have been deployed to profile the biological activity of 320 ToxCast Phase I...

  20. 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…

  1. SLIP CASTING OF MAGNESIATITANIA BODIES

    Microsoft Academic Search

    Rosenfels

    1961-01-01

    Titania is known to increase the rate of diffusion and sintering in ; pressed magnesia-titania bodies. To meet a need for dense ceramic containers ; which would hold a molten chloride eutectic, methods were developed for slip ; casting and sintering fused magnesia containing 10 wt% titania. The procedures ; were based on the Los Alamos method of slip casting

  2. Low Background Micromegas in CAST

    E-print Network

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

    2015-03-17

    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/cm$^2$/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/cm$^2$/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.

  3. Low Background Micromegas in CAST

    E-print Network

    Garza, J G; 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

    2015-01-01

    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/cm$^2$/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/cm$^2$/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 ...

  4. Die lebensrettende Bluttransfusion ohne die Einwilligung des heilungsfähigen Patienten

    Microsoft Academic Search

    Petra Baltz

    \\u000a Das Landgericht München I und das Oberlandesgericht München haben - soweit ersichtlich - erstmalig in Deutschland richterlich\\u000a darüber befunden, ob die Vornahme einer erfolgreichen, lebensrettenden Behandlung einen Schmerzensgeldanspruch begründen kann,\\u000a wenn der Patient die Einwilligung in die rettende ärztliche Maßnahme verweigert hat. Eine Zeugin Jehovas klagte auf Schmerzensgeld\\u000a wegen einer bei ihr durchgeführten Bluttransfusion, in die sie aus religiösen Gründen

  5. Cracking control in DC casting of high?strength aluminum alloys

    Microsoft Academic Search

    Bruce Kang

    1999-01-01

    This paper summarizes research efforts at WVU, conducted to comprehensively understand the fundamental mechanism of solidification cracking of high?strength aluminum alloys for aerospace plate applications. Three important technical approaches were adapted: 1. in?situ thermal couples drop measurement of DC casting; 2. characterization of thermo?mechanical properties of cast ingots, correlated with the cast structure; 3. numerical modeling of ingot thermal\\/stress history.

  6. Laser-Ultrasonic Inspection of MG/AL Castings

    NASA Astrophysics Data System (ADS)

    Blouin, Alain; Lévesque, Daniel; Monchalin, Jean-Pierre; Baril, Eric; Fischersworring-Bunk, Andreas

    2005-04-01

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

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

    E-print Network

    Hickey, Barbara

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

  8. Die Systemarchitektur von Windows 7

    Microsoft Academic Search

    Martin Grotegut

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

  9. Die pharmakologische Wirkung des Ephedrins

    Microsoft Academic Search

    H. Kreitmair

    1927-01-01

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

  10. Der Islam und die Geschlechterfrage

    E-print Network

    Steinhoff, Heinz-Jürgen

    Der Islam und die Geschlechterfrage ­ theologische, gesellschaftliche, historische und praktische ausloten. Dazu gehört die Analyse der Wurzeln des Diskurses um ,,die Frau im Islam" aus einer and the Transmission of Religious Knowledge in Islam Prof. Dr. Asma Sayeed, University of California 10. Dezember

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

    PubMed

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

    2013-12-01

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

  12. Die Geschichte des Wargaming

    Microsoft Academic Search

    Daniel F. Oriesek; Jan Oliver Schwarz

    Wargaming wurde schon vor langer Zeit entwickelt und eingesetzt, und es ist vermutlich so alt wie der Krieg selbst (Perla\\u000a 1990). Seinen Ursprung hat es wohl im militärischen Bedürfnis, Befehlshaber der Armee und ihre Offiziere besser auf unvorhergesehene\\u000a Entwicklungen auf dem Schlachtfeld vorzubereiten. Wer besser versteht, welche möglichen feindlichen Reaktionen die eigene\\u000a Handlungsweise hervorrufen kann und wie diesen am besten

  13. Einführung in die Laborpraxis

    NASA Astrophysics Data System (ADS)

    Wir leben in einer von Naturwissenschaft und Technik bestimmten Welt. Gerade in Deutschland, das arm an natürlichem Reichtum wie Bodenschätzen ist, hängt der Wohlstand von technischen Errungenschaften und wissenschaftlichen Erkenntnissen ab. Diese gewinnt man hauptsächlich in Labors. Hier wurden und werden die Ideen zahlreicher Wissenschaftler, von Chemikern, Physikern, Genetikern, Medizinern, Biologen, Umwelttechnikern und Ingenieuren umgesetzt, erarbeitet, in ihrer Richtigkeit bestätigt oder verworfen und weiter entwickelt.

  14. Einführung in die Hörgerätetechnik

    NASA Astrophysics Data System (ADS)

    Karamuk, Erdal; Korl, Sascha

    Sechzehn Prozent aller erwachsenen Europäer leiden an so starken Hörminderungen, dass sie ihren Alltag beeinträchtigen. In Europa haben rund 71 Millionen Erwachsene im Alter von 18 bis 80 Jahren eine Hörminderung von mehr als 25 dB, ein Wert, der von der Weltgesundheitsorganisation, WHO, als hörgeschädigt definiert wird. Allein in der EU gibt es über 55 Millionen hörgeschädigte Menschen, davon über 10 Millionen in Deutschland. Die sozialen und volkswirtschaftlichen Kosten der Schwerhörigkeit sind beträchtlich [1].

  15. 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

  16. Strip casting with fluxing agent applied to casting roll

    DOEpatents

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

    1997-07-29

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

  17. Strip casting with fluxing agent applied to casting roll

    DOEpatents

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

    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.

  18. 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.

  19. Strip casting apparatus and method

    DOEpatents

    Williams, Robert S. (Plum, PA); Baker, Donald F. (Hempfield, PA)

    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.

  20. Pressure Rig for Repetitive Casting

    NASA Technical Reports Server (NTRS)

    Vasquez, P.; Hutto, W. R.

    1986-01-01

    Equipment life increased by improved insulation. New design cuts time of preparation for casting from several days to about 1 hour. Savings due to elimination of lengthy heating and drying operations associated with preparation of ceramic mold. Quality of casting improved because moisture in cavity eliminated by use of insulating material, and more uniform pressure applied to process. Commercial blanket insulator protects components from heat, increasing life of pressure rig and enabling repeated use. Improved heat protection allows casting of brass and other alloys with higher melting temperatures in pressure rig.

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

    E-print Network

    Hickey, Barbara

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

  2. Die drool and polymer degradation

    NASA Astrophysics Data System (ADS)

    Hoy, Geoffrey Stephen; Giacomin, Alan Jeffrey; Gilbert, Peter Hunter

    2015-04-01

    Die drool is an operational problem associated with polymer extrusion. Extrudate collects outside of the die, necessitating periodic disruptions for cleaning. There exists some debate as to the mechanism that produces die drool: stress induced fractionation or thermal degradation. This paper examines the latter. In cohesive failure, a slip discontinuity develops in the velocity profile, where heat is generated by friction. This slip heating can contribute to resin degradation, resulting in lower molecular weight fragments in the die drool. This paper examines the kinetics of this degradation, its influence on die drool rates, and on the resulting polymer concentration profiles in the drool layer and in the bulk.

  3. Einführung in die Technische Chemie

    NASA Astrophysics Data System (ADS)

    Behr, Arno; Agar, David W.; Jörissen, Jakob

    Die "Technische Chemie" ist ein Lehrfach an Universitäten und Hochschulen. Nach dem die Studierenden der Chemie in den ersten Semestern ihres Studiums ausrei chen de theoretische Kenntnisse in Allgemeiner, Anorganischer, Organischer und Physikalischer Chemie erlangt haben, soll die Technische Chemie einen Blick auf die praktische Anwendung dieser Naturwissenschaft in unserer Wirtschaft lenken. Es gibt keine "biologische Industrie", "physikalische Industrie" oder "mathematische Industrie", wohl aber seit über 150 Jahren eine "chemische Industrie", die in dieser lan gen Zeit zahlreiche chemische Prozesse entwickelt und dazu vielfältige Methoden erarbeitet hat. Das Lehrfach Technische Chemie gibt einen Überblick über diese Pro zesse und Methoden und erleichtert dadurch den Schritt von der Universität zur be ruflichen Praxis.

  4. Pre-Cast Gel Electrophoresis Guide

    E-print Network

    Kirschner, Marc W.

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

  5. Planarization of a CMOS die for an integrated metal MEMS Hocheol Lee*, Michele H. Miller+

    E-print Network

    for metal MEMS, the polymer benzocyclobutene (BCB), which has been used for multichip module applicationsPlanarization of a CMOS die for an integrated metal MEMS Hocheol Lee*, Michele H. Miller+ , Thomas a flat CMOS die surface for the integration of a MEMS metal mirror array. The CMOS die for our device

  6. 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 [Korea Atomic Energy Research Institute, Daedeok-daro 989-111, Yuseong-gu, Daejeon (Korea, Republic of)

    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.

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

    SciTech Connect

    Fasoyinu, Yemi [CanmetMATERIALS] [CanmetMATERIALS

    2014-03-31

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

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

    SciTech Connect

    MINWALL HJ

    2011-04-08

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

  9. Effect of key alloying elements on the feeding characteristics of aluminum–silicon casting alloys

    Microsoft Academic Search

    Manas Dash; Makhlouf Makhlouf

    2001-01-01

    The most common and serious defect in aluminum castings is porosity, which is a result of two phenomena, insufficient feeding and\\/or hydrogen precipitation during solidification. These defects cause costly scrap loss and limit the use of castings in critical, high-strength applications. In this paper, the effect of alloying elements Si, Fe, Mg, Mn, Cu, Sr, and Ti as well as

  10. Is it possible to decrease skin temperature with ice packs under casts and bandages?

    Microsoft Academic Search

    Guvenir Okcu; H. S. Yercan

    2006-01-01

    Introduction  There is a general belief that the presence of a cast or a bandage eliminates the lowering effects of skin temperature when local cold therapy applied on the surface of the cast or bandage. The purpose of this study is to determine the magnitude of temperature changes at the skin of the ankle after the application of frozen ice packs

  11. Casting a Polyhedron with Directional Uncertainty Hee-kap Ahn Otfried Cheong Rene van Oostrum

    E-print Network

    Utrecht, Universiteit

    Casting a Polyhedron with Directional Uncertainty£ Hee-kap Ahn££ Otfried Cheong££ Ren´e van Oostrum is opened after the material has solidified. As in all applications of robotics, we have to deal with imperfect control of the casting machinery. In this paper, we consider directional uncertainty: given a 3

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

    Microsoft Academic Search

    Mohammad Vaezi; Davood Safaeian; Mohsen Shakeri

    2011-01-01

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

  13. Die Gestalt analytischer, Liouvillescher Flächen im Großen

    Microsoft Academic Search

    Helmut Viesel

    1966-01-01

    bringen l~iBt. Bekannte Liouvillesche Fliichen sind die Rotationsfliichen und die Fl~ichen zweiten Grades. Die Besonderheit dieses Bogenelementes ist, daB man die Differentialgleichung der geodiitischen Linien integrieren kann. JACOBI [5] gelang dies beim Ellipsoid, indem er die Schnittlinien mit den konfokalen Hyperboloiden als Parameterlinien benutzte. LIOUVILLE [6] verallgemeinerte dieses Ergebnis auf die Fliichenstiicke mit obigem Bogenelement. Durch die Kenntnis der geodiitischen

  14. Effects of molten aluminum on H13 dies and coatings

    Microsoft Academic Search

    M. Yu; R. Shivpuri; R. A. Rapp

    1995-01-01

    The effects of molten aluminum casting alloy A390 on a commercially heat treated H13 die steel and two wear-resistant coatings,\\u000a Cr23C6 and TiN, were investigated by an accelerated corrosion test. The H13 steel suffered severe corrosion due to the rapid formation\\u000a of intermetallic compounds. The formation of multilayer intermetallic compounds and the simultaneous dissociation of the intermetallic\\u000a compound ?6 (Al4FeSi)

  15. CASTING ALUMINUM-LITHIUM ALLOYS IN OPEN ATMOSPHERE

    Microsoft Academic Search

    S. Seshan; T. S. Srivatsan

    1990-01-01

    The increasing need for lightweight and cost-effective materials for structural applications has resulted in significant improvements and development of new aluminum alloys for structural applications. Lithium addition to aluminum has the potential for providing a class of high strength alloys with exceptional properties suitable for weight-critical and stiffness-critical applications. Casting of aluminum-lithium alloys presents a variety of problems and high-quality

  16. Die Bedeutung von Business Wargaming für die strategische Planung

    Microsoft Academic Search

    Daniel F. Oriesek; Jan Oliver Schwarz

    Dieses Zitat nach dem berühmten Zukunfts- und Trendforscher Alvin Toffler (2000) greift einige interessante Aspekte der strategischen\\u000a Planung in der heutigen Zeit auf. Die erste Hälfte des Zitats gibt die verbreitete Annahme wieder, dass strategische Planung\\u000a ein langer und unflexibler Prozess ist, der einem sich schnell ändernden Umfeld nicht gerecht werden kann. Im zweiten Teil\\u000a legt Toffler dar, dass die

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

    SciTech Connect

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

    2002-10-15

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

  18. Bioreactor-free tissue engineering: directed tissue assembly by centrifugal casting.

    PubMed

    Mironov, Vladimir; Kasyanov, Vladimir; Markwald, Roger R; Prestwich, Glenn D

    2008-02-01

    Casting is a process by which a material is introduced into a mold while it is liquid, allowed to solidify in a predefined shape inside the mold, and then removed to give a fabricated object, part or casing. Centrifugal casting could be defined as a process of molding using centrifugal forces. Although the centrifugal casting technology has a long history in metal manufacturing and in the plastics industry, only recently has this technology attracted the attention of tissue engineers. Initially, centrifugation was used to optimize cell seeding on a solid scaffold. More recently, centrifugal casting has been used to create tubular scaffolds and both tubular and flat multilayered, living tissue constructs. These newer applications were enabled by a new class of biocompatible in situ crosslinkable hydrogels that mimic the extracellular matrix. Herein the authors summarize the state of the art of centrifugal casting technology in tissue engineering, they outline associated technological challenges, and they discuss the potential future for clinical applications. PMID:18194071

  19. A Membrane Process for Recycling Die Lube from Wastewater Solutions

    SciTech Connect

    Eric S. Peterson; Jessica Trudeau; Bill Cleary; Michael Hackett; William A. Greene

    2003-04-01

    An active-surface membrane technology was used to separate a die lube manufacturing wastewater stream consisting of various oils, hydrocarbons, heavy metals, and silicones. The ultrafiltration membranes reduced organics from initial oil and grease contents by 20–25X, carbon oxygen demand (COD) by 1.5 to 2X, and total organic carbon (TOC) by 0.6, while the biological oxygen demand (BOD) remained constant. The active-surface membranes were not fouled as badly as non-active-surface systems and the active-surface membrane flux levels were consistently higher and more stable than those of the non-active-surface membranes tested. Field testing demonstrated that the rotary microfilter can concentrate the die lube, i.e. remove the glycerin component, and produce a die lube suitable for recycling. The recycling system operated for six weeks with only seven cleaning cycles and no mechanical or electrical failures. Test data and quality records indicate that the die casting scrap was reduced from 8.4 to 7.8%. There is no doubt that this test yielded tremendous results. This separation process presents significant opportunities that can be evaluated further.

  20. A Membrane Process for Recycling Die Lube from Wastewater Solutions

    SciTech Connect

    Peterson, E.S.; Trudeau, J.; Cleary, B.; Hackett, M.; Greene, W.A.

    2003-04-30

    An active-surface membrane technology was used to separate a die lube manufacturing wastewater stream consisting of various oils, hydrocarbons, heavy metals, and silicones. The ultrafiltration membranes reduced organics from initial oil and grease contents by 20?25X, carbon oxygen demand (COD) by 1.5 to 2X, and total organic carbon (TOC) by 0.6, while the biological oxygen demand (BOD) remained constant. The active-surface membranes were not fouled as badly as non-active-surface systems and the active-surface membrane flux levels were consistently higher and more stable than those of the non-active-surface membranes tested. Field testing demonstrated that the rotary microfilter can concentrate the die lube, i.e. remove the glycerin component, and produce a die lube suitable for recycling. The recycling system operated for six weeks with only seven cleaning cycles and no mechanical or electrical failures. Test data and quality records indicate that the die casting scrap was reduced from 8.4 to 7.8%. There is no doubt that this test yielded tremendous results. This separation process presents significant opportunities that can be evaluated further.

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

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

    E-print Network

    Hickey, Barbara

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

  4. Laser Hardening of Austempered Ductile Cast Iron (ADI)

    Microsoft Academic Search

    Susil K. Putatunda; Leslie Bartosiewicz; Robert J. Hull; Michael Lander

    1997-01-01

    Austempered ductile cast iron (ADI) has emerged as a major engineering material in recent years. In addition to high strength and relatively light weight (compared to steel), it has high ductility, good wear resistance and good damping capacity. It has many potential applications such as automotive components (e.g. crank shafts and gear boxes) as well as aircraft components (landing gears).In

  5. Pressure Gelation Process - Recent Developments in Epoxy Resin Casting Processes

    Microsoft Academic Search

    G. Buchi; R. Flynn

    1975-01-01

    Because of their good thermal, electrical and mechanical characteristics, coupled with the fact that on curing they evolve no volatile by-products and undergo only a small volume shrinkage, epoxy resins have found considerable application in the manufacture of castings for the high voltage electrical industry. This trend has been particularly evident in Europe where since the mid-1950s electrical equipment manufacturers

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

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

  7. 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.

  8. Warum Normen für die Instandhaltung?

    NASA Astrophysics Data System (ADS)

    Tschuschke, Werner E.

    Viele kennen Normen wie Konstruktionsnormen, in denen z. B. der Außendurchmesser, die Steigung, der Flankenwinkel und andere Maße eines Gewindes festgelegt sind. Es gibt Prüfnormen aber auch Normen eines Managementsystems wie des Qualitätsmanagements in der DIN-EN-ISO-9000-Familie. Aber warum Normen für die Instandhaltung? Begonnen hat es mit der DIN 31051, die 1985 veröffentlicht wurde. Es war die erste Instandhaltungsnorm weltweit und sie wurde von der Schweiz und Österreich übernommen. In ihr sind Begriffe der Instandhaltung, Grundlagen zum Abnutzungsprozess und Aktivitäten der Instandhaltung beschrieben. Es wurde der Begriff Instandsetzung statt Reparatur publiziert: Nicht mehr Flickschustern sondern einen funktionsfähigen Anlagenzustand möglichst erhalten.

  9. Tape-cast sensors and method of making

    DOEpatents

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

    2009-08-18

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

  10. PostCast Server Free Edition 2.6

    NSDL National Science Digital Library

    Some users may find the need to send a significant number of emails at a time, and the free edition version of PostCast Server may be just the program to help accomplish this. This application allows users to deliver up to 50 messages at a time, and also increases the privacy of outgoing emails as well. Also, this same program may be used to send out electronic newsletters and other such notifications. This version of PostCast Server is compatible with all operating systems running Windows 95 and higher.

  11. Casting Castings: A Classroom Hands-on Activity

    NSDL National Science Digital Library

    Johnson, Craig

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

  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. 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.

  14. The dying thoracic patient.

    PubMed

    Krishna, G; Raffin, T A

    1998-08-01

    Health care providers should understand that the practice of good medicine includes not only diagnosing and curing diseases, but also effectively communicating with patients and families and helping terminally ill patients die a peaceful and dignified death. Patients in America come from varied backgrounds, and it is important for physicians to consider cultural and religious issues. Physicians should combine their clinical judgment with objective outcome data to provide optimal care for patients. Informed consent should be obtained from patients after offering a detailed plan of care that would include appropriate interventions and the consequences of no intervention. The physician should then assist the patient in making a decision that would provide the best possible future for that individual. The four fundamental principles of biomedical ethics, namely beneficence, nonmaleficence, autonomy, and justice, should be considered when analyzing an ethical problem. Voluntary active euthanasia, which means performing a deliberate act (e.g., administering a lethal injection) to end a patient's life, should not be performed by a physician. Withholding and withdrawing basic and advanced life support constitutes passive euthanasia. Good communication with patients early in the clinical course whenever possible results in an ethically correct decision. A nonconfrontational, sympathetic, and compassionate approach to family members and legal surrogates facing the immediate death of their loved ones leads to the best possible outcome. It is the duty of the physician to assure the patient and the family that he or she will not abandon the patient. Effective communication is the key to solving almost all ethical dilemmas when caring for the dying thoracic patient. PMID:9742345

  15. Modeling of Bolt Joint Behavior of Cast Aluminum Alloy (A380-T5) by Coupling Creep and Plasticity in Finite Element Analysis

    Microsoft Academic Search

    Cherng-Chi Chang; Q. G. Wang

    2007-01-01

    Aluminum casting alloys exhibit creep behavior when the materials are exposed to high temperature and load. In this article,\\u000a the stress- and temperature-dependent creep behavior of a die casting A380-T5 aluminum alloy was simulated using a classical\\u000a constitutive model. The bolt-load retention behavior of the material was analyzed in a head bolt joint in an aluminum engine\\u000a under thermal cycle

  16. Blasting casting to raise productivity

    SciTech Connect

    Pilshaw, S.R.

    1987-07-01

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

  17. CAST results and Axion review

    E-print Network

    T. Geralis; for the CAST collaboration

    2009-05-26

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

  18. Study on Macro and Micromodeling of the Solidification Process of Aluminum Shape Casting

    Microsoft Academic Search

    Baicheng Liu; Shoumei Xiong; Qingyan Xu

    2007-01-01

    Numerical methods to improve the computational efficiency and to extend the computational scale of the mold filling and solidification\\u000a of the aluminum die casting process were studied. For molding filling simulation, the parallel computation method was studied,\\u000a while for solidification simulation, an implicit finite difference scheme and a transient surface layer concept were studied.\\u000a In addition, the modified cellular automaton

  19. 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

  20. 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