Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅰ

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2010-02-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Colour Metallography of Cast Iron - Chapter 4: Vermicular Graphite Cast Iron (Ⅱ

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2011-05-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Elimination of Hot Tears in Steel Castings by Means of Solidification Pattern Optimization

Science.gov (United States)

Kotas, Petr; Tutum, Cem Celal; Thorborg, Jesper; Hattel, Jesper Henri

2012-06-01

A methodology of how to exploit the Niyama criterion for the elimination of various defects such as centerline porosity, macrosegregation, and hot tearing in steel castings is presented. The tendency of forming centerline porosity is governed by the temperature distribution close to the end of the solidification interval, specifically by thermal gradients and cooling rates. The physics behind macrosegregation and hot tears indicate that these two defects also are dependent heavily on thermal gradients and pressure drop in the mushy zone. The objective of this work is to show that by optimizing the solidification pattern, i.e., establishing directional and progressive solidification with the help of the Niyama criterion, macrosegregation and hot tearing issues can be both minimized or eliminated entirely. An original casting layout was simulated using a transient three-dimensional (3-D) thermal fluid model incorporated in a commercial simulation software package to determine potential flaws and inadequacies. Based on the initial casting process assessment, multiobjective optimization of the solidification pattern of the considered steel part followed. That is, the multiobjective optimization problem of choosing the proper riser and chill designs has been investigated using genetic algorithms while simultaneously considering their impact on centerline porosity, the macrosegregation pattern, and primarily on hot tear formation.

Colour Metallography of Cast Iron

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2009-05-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron.Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron , uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditionalmaterials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Temperature measurement during solidification of thin wall ductile cast iron. Part 2: Numerical simulations

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Tiedje, Niels Skat

2008-01-01

Temperature measurements in castings are carried out with thermocouples (TC’s), which are inserted in the melt. The TC influence solidification of the casting, especially in thin wall castings where the heat content of the melt is small compared to the cooling power of the TC. A numerical analysi...

Elimination of Hot Tears in Steel Castings by Means of Solidification Pattern Optimization

DEFF Research Database (Denmark)

Kotas, Petr; Tutum, Cem Celal; Thorborg, Jesper

2012-01-01

A methodology of how to exploit the Niyama criterion for the elimination of various defects such as centerline porosity, macrosegregation, and hot tearing in steel castings is presented. The tendency of forming centerline porosity is governed by the temperature distribution close to the end...... of the solidification interval, specifically by thermal gradients and cooling rates. The physics behind macrosegregation and hot tears indicate that these two defects also are dependent heavily on thermal gradients and pressure drop in the mushy zone. The objective of this work is to show that by optimizing...... the solidification pattern, i.e., establishing directional and progressive solidification with the help of the Niyama criterion, macrosegregation and hot tearing issues can be both minimized or eliminated entirely. An original casting layout was simulated using a transient three-dimensional (3-D) thermal fluid model...

Al-Si-Re Alloys Cast by the Rapid Solidification Process / Stopy Al-Si-Re Odlewane Metodą Rapid Solidification

Directory of Open Access Journals (Sweden)

Szymanek M.

2015-12-01

Full Text Available The aim of the studies described in this article was to present the effect of rare earth elements on aluminium alloys produced by an unconventional casting technique. The article gives characteristics of the thin strip of Al-Si-RE alloy produced by Rapid Solidification (RS. The effect of rare earth elements on structure refinement, i.e. on the size of near-eutectic crystallites in an aluminium-silicon alloy, was discussed. To determine the size of crystallites, the Scherrer X-ray diffraction method was used. The results presented capture relationships showing the effect of variable casting parameters and chemical composition on microstructure of the examined alloys. Rapid Solidification applied to Al-Si alloys with the addition of mischmetal (Ce, La, Ne, Pr refines their structure.

Numerical modelling of solidification of thin walled hypereutectic ductile cast iron

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Hattel, Jesper; Tiedje, Niels

2006-01-01

Numerical simulation of solidification of ductile cast iron is normally based on a model where graphite nodules are surrounded by an austenite shell. The two phases are then growing as two concentric spheres governed by diffusion of carbon through the austenite shell. Experiments have however shown...... simulation of thin-walled ductile iron castings. Simulations have been performed with a 1-D numerical solidi¬fication model that includes the precipitation of non-eutectic austenite during the eutectic stage. Results from the simulations have been compared with experimental castings with wall thick...

Autonomous Optimization of a Solidification Pattern and Its Effect on Porosity and Segregation in Steel Castings

DEFF Research Database (Denmark)

Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

2011-01-01

The present paper considers optimization of a solidification pattern of a gravity sand-cast steel part. That is, the choice of proper riser and chill designs has been investigated using genetic algorithms while simultaneously considering their impact on centerline porosity and macrosegregation...... distribution. This was accomplished by coupling a casting simulation software package with an optimization module. The casting process of the original casting design was simulated using a transient 3D thermal model incorporated in a commercial simulation software package to determine potential flaws...... and inadequacies. After this initial assessment, a new geometrical model was suggested with the redesigned gating system and rearranged chills to obtain better filling and solidification patterns. Based on the improved model, relevant optimization targets and constraints were defined. One multi...

Colour Metallography of Cast Iron - Chapter 1: Introduction (Ⅰ

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2009-02-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Solidification, processing and properties of ductile cast iron

DEFF Research Database (Denmark)

Tiedje, Niels Skat

2010-01-01

Ductile cast iron has been an important engineering material in the past 50 years. In that time, it has evolved from a complicated material that required the foundry metallurgist's highest skill and strict process control to being a commonly used material that can easily be produced with modern...... of the latest years of research indicate that ductile cast iron in the future will become a highly engineered material in which strict control of a range of alloy elements combined with intelligent design and highly advanced processing allows us to target properties to specific applications to a much higher...... degree than we have seen previously. It is the aim of the present paper to present ductile iron as a modern engineering material and present the many different possibilities that the material hides. Focus will be on the latest research in solidification and melt treatment. But for completeness...

Colour Metallography of Cast Iron - Chapter 2: Grey Iron (Ⅱ

Directory of Open Access Journals (Sweden)

Zhou Jiyang

2009-08-01

Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

Numerical Simulation of Steady State Conduction Heat Transfer During the Solidification of Aluminum Casting in Green Sand Mould

Directory of Open Access Journals (Sweden)

Victor ANJO

2012-08-01

Full Text Available The solidification of molten metal during the casting process involves heat transfer from the molten metal to the mould, then to the atmosphere. The mechanical properties and grain size of metals are determined by the heat transfer process during solidification. The aim of this study is to numerically stimulate the steady conduction heat transfer during the solidification of aluminum in green sand mould using finite difference analysis 2D. The properties of materials used are industrial AI 50/60 AFS green sand mould, pure aluminum and MATLAB 7.0.1. for the numerical simulation. The method includes; the finite difference analysis of the heat conduction equation in steady (Laplace’s and transient states and using MATLAB to numerically stimulate the thermal flow and cooling curve. The results obtained are: the steady state thermal flow in 2D and transient state cooling curve of casting. The results obtain were consider relevant in the control of the grain size and mechanical properties of the casting.

Thermodynamic Analysis of Cast Irons Solidification With Various Types of Graphite

Directory of Open Access Journals (Sweden)

Elbel T.

2012-12-01

Full Text Available The contribution summarises the results of oxygen activity determinations, which were measured and registered continuously in castings from cast irons with various types of graphite. The results were used to find the relationship between two variables: natural logarithm of oxygen activities and reverse value of thermodynamic temperature 1 /T. Obtained regression lines were used to calculate oxygen activity at different temperatures, to calculate Gibbs free energy ΔG at the different temperatures and to calculate the single ΔG value for significant temperature of the graphite solidification. The results were processed by a statistical analysis of data files for the different types of graphite with flake, vermicular and spheroidal graphite. Each material has its proper typical oxygen activities range and individual temperature function of Gibbs free energy for analysing and governing casting quality.

Simulation of continuous cast steel product solidification

Directory of Open Access Journals (Sweden)

Ardelean, E.

2007-06-01

Full Text Available Primary cooling – inside the tundish – has a great impact over the thickness of the solidified steel crust. If on exiting the tundish the crust is too thin, it can punch and break, as a result of the ferrostatic pressure exerted from the inside by the liquid steel as well as because of the weight of the molten steel. The parameters that influence the amount of dissipated heat depend on the cooling water flow of the tundish, on the pressure and temperature of the cooling water but also on the overheating of the continuously cast steel. The secondary cooling takes place at the exit of the semi-finished product from the tundish, when the solidification is supposed to take place all along the cross section of the strand. In order to achieve it, in addition to a correctly managed primary cooling, it is necessary to obtain the proper correlation of the factors that influence the secondary cooling as well: the water flow rate long the three zones of the installation and its pressure in the secondary circuit. All these have in view a proper solidification length; an intense cooling can generate cracks due to the thermal stress, while a too slow cooling can generate a partial solidification of the strand up to the cropping machine area. The paper presents a mathematical simulation of the continuously cast steel solidification.

El enfriamiento primario del cristalizador tiene una gran importancia sobre el espesor de la costra de acero solidificado. Si al salir del cristalizador, esta costra es demasiado sutil, bajo la acción de la presión ferro estática ejercitada por el acero líquido del interior y gracias el peso propio del hilo, ésta, puede perforar resultando su rompimiento. Los parámetros que influenyen sobre la cantidad de calor cedida dependen del agua de enfriamiento del catalizador, de la presión y de la temperatura de agua de enfriamiento, pero también del sobrecalentamiento del acero fundido continuamente. A la salida del

Casting Technology.

Science.gov (United States)

Wright, Michael D.; And Others

1992-01-01

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

Validated thermodynamic prediction of AlP and eutectic (Si) solidification sequence in Al-Si cast alloys

International Nuclear Information System (INIS)

Liang, S M; Schmid-Fetzer, R

2016-01-01

The eutectic microstructure in hypoeutectic Al-Si cast alloys is strongly influenced by AlP particles which are potent nuclei for the eutectic (Si) phase. The solidification sequence of AlP and (Si) phases is, thus, crucial for the nucleation of eutectic silicon with marked impact on its morphology. This study presents this interdependence between Si- and P-compositions, relevant for Al-Si cast alloys, on the solidification sequence of AlP and (Si). These data are predicted from a series of thermodynamic calculations. The predictions are based on a self-consistent thermodynamic description of the Al-Si-P ternary alloy system developed recently. They are validated by independent experimental studies on microstructure and undercooling in hypoeutectic Al-Si alloys. A constrained Scheil solidification simulation technique is applied to predict the undercooling under clean heterogeneous nucleation conditions, validated by dedicated experimental observations on entrained droplets. These specific undercooling values may be very large and their quantitative dependence on Si and P content of the Al alloy is presented. (paper)

On the Effect of Pouring Temperature on Spheroidal Graphite Cast Iron Solidification

Directory of Open Access Journals (Sweden)

Alex Escobar

2015-04-01

Full Text Available This work is focused on the effect of pouring temperature on the thermal-microstructural response of an eutectic spheroidal graphite cast iron (SGCI. To this end, experiments as well as numerical simulations were carried out. Solidification tests in a wedge-like part were cast at two different pouring temperatures. Five specific locations exhibiting distinct cooling rates along the sample were chosen for temperature measurements and metallographic analysis to obtain the number and size of graphite nodules at the end of the process. The numerical simulations were performed using a multinodular-based model. Reasonably good numerical-experimental agreements were obtained for both the cooling curves and the graphite nodule counts.

Premature melt solidification during mold filling and its influence on the as-cast structure

Science.gov (United States)

Wu, M.; Ahmadein, M.; Ludwig, A.

2018-03-01

Premature melt solidification is the solidification of a melt during mold filling. In this study, a numerical model is used to analyze the influence of the pouring process on the premature solidification. The numerical model considers three phases, namely, air, melt, and equiaxed crystals. The crystals are assumed to have originated from the heterogeneous nucleation in the undercooled melt resulting from the first contact of the melt with the cold mold during pouring. The transport of the crystals by the melt flow, in accordance with the socalled "big bang" theory, is considered. The crystals are assumed globular in morphology and capable of growing according to the local constitutional undercooling. These crystals can also be remelted by mixing with the superheated melt. As the modeling results, the evolutionary trends of the number density of the crystals and the volume fraction of the solid crystals in the melt during pouring are presented. The calculated number density of the crystals and the volume fraction of the solid crystals in the melt at the end of pouring are used as the initial conditions for the subsequent solidification simulation of the evolution of the as-cast structure. A five-phase volume-average model for mixed columnar-equiaxed solidification is used for the solidification simulation. An improved agreement between the simulation and experimental results is achieved by considering the effect of premature melt solidification during mold filling. Finally, the influences of pouring parameters, namely, pouring temperature, initial mold temperature, and pouring rate, on the premature melt solidification are discussed.

Relationships Between Solidification Parameters in A319 Aluminum Alloy

Science.gov (United States)

Vandersluis, E.; Ravindran, C.

2018-03-01

The design of high-performance materials depends on a comprehensive understanding of the alloy-specific relationships between solidification and properties. However, the inconsistent use of a particular solidification parameter for presenting materials characterization in the literature impedes inter-study comparability and the interpretation of findings. Therefore, there is a need for accurate expressions relating the solidification parameters for each alloy. In this study, A319 aluminum alloy castings were produced in a permanent mold with various preheating temperatures in order to control metal cooling. Analysis of the cooling curve for each casting enabled the identification of its liquidus, Al-Si eutectic, and solidus temperatures and times. These values led to the calculation of the primary solidification rate, total solidification rate, primary solidification time, and local solidification time for each casting, which were related to each other as well as to the average casting SDAS and material hardness. Expressions for each of their correlations have been presented with high coefficients of determination, which will aid in microstructural prediction and casting design.

Temperature measurement during solidification of thin wall ductile cast iron. Part 1: Theory and experiment

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Tiedje, Niels Skat

2008-01-01

cooing curves in thin wall ductile iron castings. The experiments show how TC’s of different design interact with the melt and how TC design and surface quality affect the results of the data acquisition. It is discussed which precautions should be taken to ensure reliable acquisition of cooling curves....... Measurement error depending on TC design and cooling conditions is shown. A method is presented that allows acquisition of cooling curves in thin walled ductile iron castings down to thickness of at least 2.8 mm. The obtained cooling curves can be used to compare nucleation and growth during solidification...

Numerical modeling of coupled heat transfer and phase transformation for solidification of the gray cast iron

DEFF Research Database (Denmark)

Jabbari, Masoud; Hosseinzadeh, Azin

2013-01-01

In the present study the numerical model in 2D is used to study the solidification bahavior of the gray cast iron. The conventional heat transfer is coupled with the proposed micro-model to predict the amount of different phases, i.e. total austenite (c) phase, graphite (G) and cementite (C...

Influence of Secondary Cooling Mode on Solidification Structure and Macro-segregation Behavior for High-carbon Continuous Casting Bloom

Science.gov (United States)

Dou, Kun; Yang, Zhenguo; Liu, Qing; Huang, Yunhua; Dong, Hongbiao

2017-07-01

A cellular automaton-finite element coupling model for high-carbon continuously cast bloom of GCr15 steel is established to simulate the solidification structure and to investigate the influence of different secondary cooling modes on characteristic parameters such as equiaxed crystal ratio, grain size and secondary dendrite arm spacing, in which the effect of phase transformation and electromagnetic stirring is taken into consideration. On this basis, evolution of carbon macro-segregation for GCr15 steel bloom is researched correspondingly via industrial tests. Based on above analysis, the relationship among secondary cooling modes, characteristic parameters for solidification structure as well as carbon macro-segregation is illustrated to obtain optimum secondary cooling strategy and alleviate carbon macro-segregation degree for GCr15 steel bloom in continuous casting process. The evaluating method for element macro-segregation is applicable in various steel types.

Polymer Solidification Technology - Technical Issues and Challenges

International Nuclear Information System (INIS)

Jensen, Charles; Kim, Juyoul

2010-01-01

Many factors come into play, most of which are discovered and resolved only during full-scale solidification testing of each of the media commonly used in nuclear power plants. Each waste stream is unique, and must be addressed accordingly. This testing process is so difficult that Diversified's Vinyl Ester Styrene and Advanced Polymer Solidification are the only two approved processes in the United States today. This paper summarizes a few of the key obstacles that must be overcome to achieve a reliable, repeatable process for producing an approved Stable Class B and C waste form. Before other solidification and encapsulation technologies can be considered compliant with the requirements of a Stable waste form, the tests, calculations and reporting discussed above must be conducted for both the waste form and solidification process used to produce the waste form. Diversified's VERI TM and APS TM processes have gained acceptance in the UK. These processes have also been approved and gained acceptance in the U. S. because we have consistently overcome technical hurdles to produce a complaint product. Diversified Technologies processes are protected intellectual property. In specific instances, we have patents pending on key parts of our process technology

Analysis and calculation of macrosegregation in a casting ingot. MPS solidification model. Volume 1: Formulation and analysis

Science.gov (United States)

Maples, A. L.; Poirier, D. R.

1980-01-01

The physical and numerical formulation of a model for the horizontal solidification of a binary alloy is described. It can be applied in an ingot. The major purpose of the model is to calculate macrosegregation in a casting ingot which results from flow of interdendritic liquid during solidification. The flow, driven by solidification contractions and by gravity acting on density gradients in the interdendritic liquid, was modeled as flow through a porous medium. The symbols used are defined. The physical formulation of the problem leading to a set of equations which can be used to obtain: (1) the pressure field; (2) the velocity field: (3) mass flow and (4) solute flow in the solid plus liquid zone during solidification is presented. With these established, the model calculates macrosegregation after solidification is complete. The numerical techniques used to obtain solution on a computational grid are presented. Results, evaluation of the results, and recommendations for future development of the model are given. The macrosegregation and flow field predictions for tin-lead, aluminum-copper, and tin-bismuth alloys are included as well as comparisons of some of the predictions with published predictions or with empirical data.

Solidification microstructure development

Indian Academy of Sciences (India)

Unknown

A majority of manufacturing processes involve melting and solidification of metals and ... In such a case (for example, chill casting), the solidification thickness (S) is ... (5). Here, LX is the system length scale in one dimension and DS is the solute diffusivity in solid. Thermal and solutal diffusivities are finite and usually very ...

A coupled model on fluid flow, heat transfer and solidification in continuous casting mold

Directory of Open Access Journals (Sweden)

Xu-bin Zhang

2017-11-01

Full Text Available Fluid flow, heat transfer and solidification of steel in the mold are so complex but crucial, determining the surface quality of the continuous casting slab. In the current study, a 2D numerical model was established by Fluent software to simulate the fluid flow, heat transfer and solidification of the steel in the mold. The VOF model and k-ε model were applied to simulate the flow field of the three phases (steel, slag and air, and solidification model was used to simulate the solidification process. The phenomena at the meniscus were also explored through interfacial tension between the liquid steel and slag as well as the mold oscillation. The model included a 20 mm thick mold to clarify the heat transfer and the temperature distribution of the mold. The simulation results show that the liquid steel flows as upper backflow and lower backflow in the mold, and that a small circulation forms at the meniscus. The liquid slag flows away from the corner at the meniscus or infiltrates into the gap between the mold and the shell with the mold oscillating at the negative strip stage or at the positive strip stage. The simulated pitch and the depth of oscillation marks approximate to the theoretical pitch and measured depth on the slab.

Development of heat pipe technology for permanent mold casting of magnesium alloys

International Nuclear Information System (INIS)

Elalem, K.; Mucciardi, F.; Gruzleski, J.E.; Carbonneau, Y.

2002-01-01

One of the key techniques for producing sound permanent mold castings is to use controlled mold cooling such as air cooling, water cooling and heat pipe cooling. Air-cooling has limited applications in permanent mold casting due to its low cooling capability and high cost. Water-cooling is widely used in permanent mold casting, but has some disadvantages such as safety issues and the facilities required. The early applications of heat pipes in permanent mold casting have shown tremendous results due to their high cooling rates, low cost and safety. In this work, a permanent mold for magnesium casting has been designed with the intention of producing shrinkage defects in the castings. Novel heat pipes that can generate high cooling rates have been constructed and used to direct the solidification in order to reduce the shrinkage. In this paper, the design of the mold and that of the heat pipes are presented. The results of some of the computer simulations that were conducted to determine casting conditions along with the potential of using heat pipes to direct the solidification are also presented. Moreover, a preliminary evaluation of the performance of heat pipes in the permanent mold casting of magnesium will also be discussed. (author)

Fundamental Metallurgy of Solidification

DEFF Research Database (Denmark)

Tiedje, Niels

2004-01-01

The text takes the reader through some fundamental aspects of solidification, with focus on understanding the basic physics that govern solidification in casting and welding. It is described how the first solid is formed and which factors affect nucleation. It is described how crystals grow from...

Finite volume modeling of the solidification of an axial steel cast impeller

Directory of Open Access Journals (Sweden)

M. Copur

2014-04-01

Full Text Available In the foundry industry, obtaining the solidification contours in cast geometries are extremely important to know the last location(s to solidify in order to define the correct feeding path and the number of risers. This paper presents three-dimensional simulation of transient conduction heat transfer within an axial impeller, made of AISI 1016 steel, poured and solidified in chemically bonded mold and core medium, by using FVM technique and ANSYS CFX. Specific heat, density and thermal conductivity of AISI 1016 steel, mold and Core materials are considered as functions of temperatures. In this transient thermal analysis, the convection heat transfer phenomenon is also considered at the outer surfaces of the mold. In order to shorten the run-time, the nonlinear transient analysis has been made for 600/3600 segment of the impeller, core and mold. The solidification contours of the impeller as well as isothermal lines in core and mold have been obtained in 3-D. The cooling curves of diff erent points are also shown in the result section.

''New ' technology of solidification of liquid radioactive waste'

International Nuclear Information System (INIS)

Sytyl, V.A.; Svistova, L.M.; Spiridonova, V.P.

1998-01-01

It is generally accepted that the best method of processing of radioactive waste is its solidification and then storage. At present time, three methods of solidification of radioactive waste are widely used in the world: cementation, bituminous grouting and vitrification. But they do not solve the problem of ecologically processing of waste because of different disadvantages. General disadvantages are: low state of filling, difficulties in solidification of the crystalline hydrated forms of radioactive waste; particular sphere of application and economical difficulties while processing the great volume of waste. In connection with it the urgent necessity is emerging: to develop less expensive and ecologically more reliable technology of solidification of radioactive waste. A new method of solidification is presented with its technical schema. (N.C.)

Solidification of Hypereutectic Thin Wall Ductile Cast Iron

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Tiedje, Niels Skat

2006-01-01

solidification. The first stage, which was relatively short, had none or very little recalescence. Further under cooling, followed by reheating during recalescence, was necessary to initiate the second part of the eutectic solidification. Both the secondary under cooling and recalescence was larger in the 3 mm...... a higher Si content in the ferrite around the larger nodules compared to the ferrite around the rest of the nodules. This indicates that solidification took place along the following path: The solidification starts with nucleation and growth of primary graphite nodules. This probably starts during...

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

Science.gov (United States)

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

2012-07-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Fluid mechanics of directional solidification at reduced gravity

Science.gov (United States)

Chen, C. F.

1992-01-01

The primary objective of the proposed research is to provide additional groundbased support for the flight experiment 'Casting and Solidification Technology' (CAST). This experiment is to be performed in the International Microgravity Laboratory-1 (IML-1) scheduled to be flown on a space shuttle mission scheduled for 1992. In particular, we will provide data on the convective motion and freckle formation during directional solidification of NH4Cl from its aqueous solution at simulated parameter ranges equivalent to reducing the gravity from the sea-level value down to 0.1 g or lower. The secondary objectives of the proposed research are to examine the stability phenomena associated with the onset of freckles and the mechanisms for their subsequent growth and decline (to eventual demise of some) by state-of-the-art imaging techniques and to formulate mathematical models for the prediction of the observed phenomena.

A Review of Permanent Magnet Stirring During Metal Solidification

Science.gov (United States)

Zeng, Jie; Chen, Weiqing; Yang, Yindong; Mclean, Alexander

2017-12-01

Rather than using conventional electromagnetic stirring (EMS) with three-phase alternating current, permanent magnet stirring (PMS), based on the use of sintered NdFeB material which has excellent magnetic characteristics, can be employed to generate a magnetic field for the stirring of liquid metal during solidification. Recent experience with steel casting indicates that PMS requires less than 20 pct of the total energy compared with EMS. Despite the excellent magnetic density properties and low power consumption, this relatively new technology has received comparatively little attention by the metal casting community. This paper reviews simulation modeling, experimental studies, and industrial trials of PMS conducted during recent years. With the development of magnetic simulation software, the magnetic field and associated flow patterns generated by PMS have been evaluated. Based on the results obtained from laboratory experiments, the effects of PMS on metal solidification structures and typical defects such as surface pinholes and center cavities are summarized. The significance of findings obtained from trials of PMS within the metals processing sector, including the continuous casting of steel, are discussed with the aim of providing an overview of the relevant parameters that are of importance for further development and industrial application of this innovative technology.

Development of casting technology and localization for a medical radioisotope transport cask

International Nuclear Information System (INIS)

Lee, Y. S.; Kim, H. S.; Jang, S. J.; Seo, K. S.; Kim, C. G.

2003-01-01

In order to localize the shielding casks for shipping medical isotopes, this research was carried out. The various casting factors such as the diameter of shielding casting, the temperature of melt and the temperature gradient of a mold were determined with the calculation results of solidification analysis computer code. Through the experiment, the manufacturing method of Ti core was developed to have no defects causing casting failure. As a results of casting experiment, depleted uranium shielding castings were successfully cast without any defect. Also as the results of the radiation shielding capability test, it was good enough to satisfied the standards of transport regulations

FY 1999 report on the results of the research and development project for new industry creating type industrial science and technology. Innovated casting simulation technology; 1999 nendo kakushinteki chuzo simulation gijutsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Described herein are the results of the FY1999 research and development project, implemented for development of the casting process simulation technologies, with the objectives to improve productivity, reduce cost, reduce the development periods, and so on for casting. For development of the mold filling and solidification process simulation programs, the fundamental algorithm and basic designs of the three-dimensional programs are developed, and the two-dimensional programs are made on a trial basis. For the analysis of the two-dimensional mold filling models, it is found that gas entrapment may occur even in the case of sand mold casting with low permeability. For development of the solidification structure and defect formation simulation programs, the basic investigations are done for the fundamental algorithms to simulate the solidification structures and porosity defects, and for the mechanisms involved in formation of these defects. These efforts lead to adoption of the CA method, and development of the algorithms for reducing CPU time and computational memory requirements by the active block method. For development of the related measurement techniques, the construction plans and specifications of an electromagnetic levitation furnace are investigated for the underground microgravity test center. (NEDO)

Casting technology for manufacturing metal rods from simulated metallic spent fuels

Science.gov (United States)

Leeand, Y. S.; Lee, D. B.; Kim, C. K.; Shin, Y. J.; Lee, J. H.

2000-09-01

A uranium metal rod 13.5 mm in diameter and 1,150 mm long was produced from simulated metallic spent fuels with advanced casting equipment using the directional-solidification method. A vacuum casting furnace equipped with a four-zone heater to prevent surface oxidation and the formation of surface shrinkage holes was designed. By controlling the axial temperature gradient of the casting furnace, deformation by the surface shrinkage phenomena was diminished, and a sound rod was manufactured. The cooling behavior of the molten uranium was analyzed using the computer software package MAGMAsoft.

Simulation of the as-cast structure of Al-4.0wt.%Cu ingots with a 5-phase mixed columnar-equiaxed solidification model

International Nuclear Information System (INIS)

Wu, M; Ahmadein, M; Kharicha, A; Ludwig, A; Li, J H; Schumacher, P

2012-01-01

Empirical knowledge about the formation of the as-cast structure, mostly obtained before 1980s, has revealed two critical issues: one is the origin of the equiaxed crystals; one is the competing growth of the columnar and equiaxed structures, and the columnar-to-equiaxed transition (CET). Unfortunately, the application of empirical knowledge to predict and control the as-cast structure was very limited, as the flow and crystal transport were not considered. Therefore, a 5-phase mixed columnar-equiaxed solidification model was recently proposed by the current authors based on modeling the multiphase transport phenomena. The motivation of the recent work is to determine and evaluate the necessary modeling parameters, and to validate the mixed columnar-equiaxed solidification model by comparison with laboratory castings. In this regard an experimental method was recommended for in-situ determination of the nucleation parameters. Additionally, some classical experiments of the Al-Cu ingots were conducted and the as-cast structural information including distinct columnar and equiaxed zones, macrosegregation, and grain size distribution were analysed. The final simulation results exhibited good agreement with experiments in the case of high pouring temperature, whereas disagreement in the case of low pouring temperature. The reasons for the disagreement are discussed.

Simulation of the as-cast structure of Al-4.0wt.%Cu ingots with a 5-phase mixed columnar-equiaxed solidification model

Science.gov (United States)

Wu, M.; Ahmadein, M.; Kharicha, A.; Ludwig, A.; Li, J. H.; Schumacher, P.

2012-07-01

Empirical knowledge about the formation of the as-cast structure, mostly obtained before 1980s, has revealed two critical issues: one is the origin of the equiaxed crystals; one is the competing growth of the columnar and equiaxed structures, and the columnar-to-equiaxed transition (CET). Unfortunately, the application of empirical knowledge to predict and control the as-cast structure was very limited, as the flow and crystal transport were not considered. Therefore, a 5-phase mixed columnar-equiaxed solidification model was recently proposed by the current authors based on modeling the multiphase transport phenomena. The motivation of the recent work is to determine and evaluate the necessary modeling parameters, and to validate the mixed columnar-equiaxed solidification model by comparison with laboratory castings. In this regard an experimental method was recommended for in-situ determination of the nucleation parameters. Additionally, some classical experiments of the Al-Cu ingots were conducted and the as-cast structural information including distinct columnar and equiaxed zones, macrosegregation, and grain size distribution were analysed. The final simulation results exhibited good agreement with experiments in the case of high pouring temperature, whereas disagreement in the case of low pouring temperature. The reasons for the disagreement are discussed.

PREFACE: Third International Conference on Advances in Solidification Processes (ICASP - 3)

Science.gov (United States)

Zimmermann, Gerhard; Ratke, Lorenz

2012-01-01

The 3rd International Conference on Advances in Solidification Processes was held in the Rolduc Abbey in the Netherlands a few kilometres away from Aachen. Around 200 scientists from 24 countries come in for the four day meeting. They found a stimulating but also relaxing environment and atmosphere, with beautiful weather and the medieval abbey inviting for walks, discussions, sitting outside and drinking a beer or wine. The contributions given at the conference reflected recent advances in various topics of solidification processes, ranging from fundamental aspects to applied casting technologies. In 20 oral sessions and a large poster session innovative results of segregation phenomena, microstructure evolution, nucleation and growth, phase formation, polyphase solidification, rapid solidification and welding, casting technology, thermophysics of molten alloys, solidification with forced melt flow and growth of single crystals and superalloys together with innovative diagnostic techniques were presented. Thereby, findings from experiments as well as from numerical modeling on different lengths scales were jointly discussed and contribute to new insight in solidification behaviour. The papers presented in this open access proceedings cover about half the oral and poster presentations given. They were carefully reviewed as in classical peer reviewed journals by two independent referees and most of them were revised and thus improved according to the reviewers comments. We think that this collection of papers presented at ICASP-3 gives an impression of the excellent contributions made. The papers embrace both the basic and applied aspects of solidification. We especially wish to express our appreciation for the team around Georg Schmitz and Margret Nienhaus organising this event and giving us their valued advice and support at every stage in preparing the conference. We also thank Lokasenna Lektorat for taking the task of checking all language-associated issues and

Direct Cast U-6Nb – 2017 Progress on Cylindrical Castings

Energy Technology Data Exchange (ETDEWEB)

Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-10-04

This report describes work to further develop a sound technical basis and best practices for mold design and process parameters for the Direct Casting of U-6wt%Nb components. One major challenge to the production of U-6Nb components is the propensity for niobium segregation during casting and solidification. This is especially true for cylindrical castings where the vertical side walls allow flotation of Nb resulting in severe inverse macrosegregation. In this work, a small (120 mm diameter by 180 mm tall) and large cylinder (250 mm diameter by 310 mm tall) are examined with a focus on reducing, or eliminating, niobium segregation. It is demonstrated that counter gravity casting (top-to-bottom solidification) can be used to minimize segregation in the small cylinder. Attempts to counter gravity cast the large cylinder were unsuccessful, in large part due to size limitations of the current furnace. A path forward for casting of the large cylinders is discussed.

TECHNOLOGICAL PARAMETERS OF SLUGS CASTING OF GREY CAST IRON BY FROSTING

Directory of Open Access Journals (Sweden)

E. I. Marukovich

2009-01-01

Full Text Available The relation of geometrical parametres of casting with technological ones is shown. The monogram for definition of basic technological parametres of obtaining of castings by the method of continuously-cyclic iterative casting by freezing-up is presented.

Clean Cast Steel Technology - Machinability and Technology Transfer

Energy Technology Data Exchange (ETDEWEB)

C. E. Bates; J. A. Griffin

2000-05-01

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

The effects of casting speed on steel continuous casting process

Energy Technology Data Exchange (ETDEWEB)

Sadat, Mohammad; Honarvar Gheysari, Ali; Sadat, Saeid [Islamic Azad University, Department of Mechanics, Mashhad Branch, Mashhad (Iran, Islamic Republic of)

2011-12-15

A three dimensional simulation of molten steel flow, heat transfer and solidification in mold and ''secondary cooling zone'' of Continuous Casting machine was performed with consideration of standard k-{epsilon} model. For this purpose, computational fluid dynamics software, FLUENT was utilized. From the simulation standpoint, the main distinction between this work and preceding ones is that, the phase change process (solidification) and flow (turbulent in mold section and laminar in secondary cooling zone) have been coupled and solved jointly instead of dividing it into ''transient heat conduction'' and ''steady fluid flow'' that can lead to more realistic simulation. Determining the appropriate boundary conditions in secondary cooling zone is very complicated because of various forms of heat transfer involved, including natural and forced convection and simultaneous radiation heat transfer. The main objective of this work is to have better understanding of heat transfer and solidification in the continuous casting process. Also, effects of casting speed on heat flux and shell thickness and role of radiation in total heat transfer is discussed. (orig.)

Experimental Observation and Analytical Modeling of Melting and Solidification during Aluminum Alloy Repair by Turbulence Flow Casting

Directory of Open Access Journals (Sweden)

Muki Satya Permana

2015-10-01

Full Text Available This paper presents an overview on the state of the art of applicable casting technology for applications in the field of repairing aluminum alloy components. Repair process on the Al alloy sample using similar metal has been carried out to investigate the micro-structural effect. Joining occurs as a result of convection heat transfer of molten flow into the sand mold which melts the existing base metal inside the mold and subsequent solidification. The analytical model has been developed to describe aluminum alloy component repair by turbulence flow casting. The model is designed based on heat transfer principle that can handle the phenomena of heat flow. The experimental result and analytical model analyses pointed out that joint quality are greatly affected by parameters of preheating temperature and duration of molten metal flow in the mold. To obtain a desired metallurgical sound at the joint, the optimum temperature and time were adjusted in order to obtain a similarity of microstructure between filler and base metal. This model is aimed to predict the use of the process parameter ranges in order to have the optimum parameters when it is applied to the experiment. The fixed parameters are flow rate, sand ratio, and pouring temperature. The process parameters are preheating temperature and pouring time. It is concluded that analytical modeling has good agreement with the experimental result.

Experimental Observation and Analytical Modeling of Melting and Solidification during Aluminum Alloy Repair by Turbulence Flow Casting

Directory of Open Access Journals (Sweden)

Muki Satya Permana

2017-03-01

Full Text Available This paper presents an overview on the state of the art of applicable casting technology for applications in the field of repairing Aluminium Alloy components. Repair process on the Aluminium sample using similar metal has been carried out to investigate the micro-structural effect. Joining occurs as a result of convection heat transfer of molten flow into the sand mold which melts the existing base metal inside the mold and subsequent solidification. The analytical model has been developed to describe aluminium component repair by Turbulence Flow Casting. The model built is based on heat transfer principle that can handle the phenomena of heat flow. The experimental result and analytical model analyses pointed out that joint quality are greatly affected by parameters of preheating temperature and duration of molten metal flow in the mold. To obtain a desired metallurgical sound at the joint, the optimum temperature and time were adjusted in order to obtain a similarity of microstructure between filler and base metal. This model is aimed to predict the use of the process parameter ranges in order to have the optimum parameters when it is applied to the experiment. The fixed parameters are flow rate, sand ratio, and pouring temperature. The process parameters are preheating temperature and pouring time. It is concluded that anaytical modeling has good agreement with the experimental result

Simulation of mould filling process for composite skeleton castings

OpenAIRE

M. Dziuba; M. Cholewa

2008-01-01

In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of skeleton casting and mould filling process. The aim of conducted simulations was the choice of thermal and geometrical parameters for the needs of designed calculations of the skeleton castings and the estimation of the guidelines for the technology of manufacturing. The subject of numerical simulation was the analysis of ability of filling the channels of c...

Effect of thermophysical property and coating thickness on microstructure and characteristics of a casting

Directory of Open Access Journals (Sweden)

Ai-chao Cheng

2017-01-01

Full Text Available A new improved investment casting technology (IC has been presented and compared with the existing IC technology such as lost foam casting (LFC. The effect of thermophysical property and coating thickness on casting solidification temperature field, microstructure and hardness has been investigated. The results show that the solidification rate decreases inversely with the coating thickness when the coating contains silica sol, zircon powder, mullite powder and defoaming agent. In contrast, the solid cooling rate increases as the coating thickness increases. However, the solidification rate and solid cooling rate of the casting produced by the existing IC and the improved IC are very similar when the coating thickness is 5 mm, so the microstructure and hardness of a container corner fitting produced by the improved IC and the existing IC are similar. The linear regression equation for the grain size (d and cooling rate (v of the castings is d= –0.41v+206.1. The linear regression equation for the content of pearlite (w and solid cooling rate (t is w=1.79t + 6.71. The new improved IC can greatly simplify the process and decrease the cost of production compared with the existing IC. Contrasting with LFC, container corner fittings produced by the new improved IC have fewer defects and better properties. It was also found that the desired microstructure and properties can be obtained by changing the thermophysical property and thickness of the coating.

Mathematics simulation and experiments of continuous casting with strip feeding in mold

Directory of Open Access Journals (Sweden)

M. G. Shen

2017-01-01

Full Text Available Steel strip feeding technology can reduce the degree of superheat of the molten steel, change the solidification order of the molten steel; raise the equiaxed crystal rate of the slab and improve the continuous casting quality. The paper establishes the mathematical model of heat transfer and temperature field of casting billet of steel strip feeding in continuous casting mold. Results show that if Plate Billet is 1 000 mm × 220 mm and the steel strip is 100 mm × 3 mm, feeding position of parallel is 250 mm from the narrow side. When the feeding speed is 3,6 m/min, the superheat degree can be reduced by 5 °C, and the solidification length can be reduced by 2,9 m. When the feeding speed is 6 m/min, the superheat degree can be reduced by about 9 °C, and the solidification length can be reduced by 3,7 m. The results of the test in a steel plant are in good agreement with the experimental results.

Solidification, growth mechanisms, and associated properties of Al-Si and magnesium lightweight casting alloys

Energy Technology Data Exchange (ETDEWEB)

Hosch, Timothy [Iowa State Univ., Ames, IA (United States)

2010-01-01

Continually rising energy prices have inspired increased interest in weight reduction in the automotive and aerospace industries, opening the door for the widespread use and development of lightweight structural materials. Chief among these materials are cast Al-Si and magnesium-based alloys. Utilization of Al-Si alloys depends on obtaining a modified fibrous microstructure in lieu of the intrinsic flake structure, a process which is incompletely understood. The local solidification conditions, mechanisms, and tensile properties associated with the flake to fiber growth mode transition in Al-Si eutectic alloys are investigated here using bridgman type gradient-zone directional solidification. Resulting microstructures are examined through quantitative image analysis of two-dimensional sections and observation of deep-etched sections showing three-dimensional microstructural features. The transition was found to occur in two stages: an initial stage dominated by in-plane plate breakup and rod formation within the plane of the plate, and a second stage where the onset of out-of-plane silicon rod growth leads to the formation of an irregular fibrous structure. Several microstructural parameters were investigated in an attempt to quantify this transition, and it was found that the particle aspect ratio is effective in objectively identifying the onset and completion velocity of the flake to fiber transition. The appearance of intricate out-of-plane silicon instability formations was investigated by adapting a perturbed-interface stability analysis to the Al-Si system. Measurements of silicon equilibrium shape particles provided an estimate of the anisotropy of the solid Si/liquid Al-Si system and incorporation of this silicon anisotropy into the model was found to improve prediction of the instability length scale. Magnesium alloys share many of the benefits of Al-Si alloys, with the added benefit of a 1/3 lower density and increased machinability. Magnesium castings

FY 1999 report on the results of the research and development project for new industry creating type industrial science and technology. Innovated casting simulation technology (Development project for commercialization of technologies related to rational use of energy); 1999 nendo kakushinteki chuzo simulation gijutsu seika hokokusho. Energy shiyo gorika kankei gijutsu jitsuyoka kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Described herein are the results of the FY1999 research and development project, implemented for development of the casting process simulation technologies, with the objectives to improve efficiency and energy-saving for the various industrial areas, e.g., industrial machines, aircraft, automobiles and vehicles, and power generation plants. For development of the mold filling and solidification process simulation programs, the efforts are directed to development of the fundamental algorithms for simulation of unidirectional solidification casting used for, e.g., turbine blades, and also to the basic works for validation of the programs. For development of the solidification structures and defect formation simulation programs, the fundamental works are done for simulation of solidification structures and channel-type segregation, which are the main problems for columnar blades, to predict the defects formed in, e.g., turbines. For development of the related measurement techniques, investigations are made for evaluation of the levitation characteristics of nickel alloys by the electromagnetically levitated droplet method and problems involved therein, prior to the tests in the the underground microgravity test center. (NEDO)

Development of high-level waste solidification technology 1

Energy Technology Data Exchange (ETDEWEB)

Kim, Joon Hyung; Kim, Hwan Young; Kim, In Tae [and others

1999-02-01

Spent nuclear fuel contains useful nuclides as valuable resource materials for energy, heat and catalyst. High-level wastes (HLW) are expected to be generated from the R and D activities and reuse processes. It is necessary to develop vitrification or advanced solidification technologies for the safe long-term management of high level wastes. As a first step to establish HLW vitrification technology, characterization of HLWs that would arise at KAERI site, glass melting experiments with a lab-scale high frequency induction melter, and fabrication and property evaluation of base-glass made of used HEPA filter media and additives were performed. Basic study on the fabrication and characterization of candidate ceramic waste form (Synroc) was also carried out. These HLW solidification technologies would be directly useful for carrying out the R and Ds on the nuclear fuel cycle and waste management. (author). 70 refs., 29 tabs., 35 figs.

Current high-level waste solidification technology

International Nuclear Information System (INIS)

Bonner, W.F.; Ross, W.A.

1976-01-01

Technology has been developed in the U.S. and abroad for solidification of high-level waste from nuclear power production. Several processes have been demonstrated with actual radioactive waste and are now being prepared for use in the commercial nuclear industry. Conversion of the waste to a glass form is favored because of its high degree of nondispersibility and safety

SPRAY CASTING

OpenAIRE

SALAMCI, Elmas

2010-01-01

ABSTRACT This paper is designed to provide a basic review of spray casting. A brief overview of the historical development of spray  casting and the description of plant and equipment have been given. Following metallurgical characteristics of spray formed alloys, process parameters and solidification mechanism of spray deposition have been discussed in detail. Finally, microstructure and mechanical properties of the selected spray cast Al-Zn-Mg-Cu alloys have been presented and comp...

Segregation in cast products

Indian Academy of Sciences (India)

Unknown

The agreement with experimental data is mostly qualitative. The paper also ... For example, a high degree of positive segregation in the central region .... solute in a cast product, important ones being: size of casting, rate of solidification, mode.

Numerical modelling of thin-walled hypereutectic ductile cast iron parts

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Hattel, Jesper Henri; Tiedje, Niels Skat

2006-01-01

Solidification of hypereutectic thin-walled ductile cast iron has been modelled in one dimension taking into account the precipitation of off-eutectic austenite dendrites during solidification. The simulations have been compared with casting experiments on plate geometries with plate thicknesses...

Evolution of Fe based intermetallic phases in Al–Si hypoeutectic casting alloys: Influence of the Si and Fe concentrations, and solidification rate

International Nuclear Information System (INIS)

Gorny, Anton; Manickaraj, Jeyakumar; Cai, Zhonghou; Shankar, Sumanth

2013-01-01

Highlights: •Anomalous evolution of Fe based intermetallic phases in Al–Si–Fe alloys. •XRF coupled with nano-diffraction to confirm the nano-size Fe intermetallic phases. •Crystallography of the θ-Al 13 Fe 4 , τ 5 -Al 8 Fe 2 Si and τ 6 -Al 9 Fe 2 Si 2 phases. •Peritectic reactions involving the Fe intermetallic phases in Al–Si–Fe alloys. -- Abstract: Al–Si–Fe hypoeutectic cast alloy system is very complex and reported to produce numerous Fe based intermetallic phases in conjunction with Al and Si. This publication will address the anomalies of phase evolution in the Al–Si–Fe hypoeutectic casting alloy system; the anomaly lies in the peculiarities in the evolution and nature of the intermetallic phases when compared to the thermodynamic phase diagram predictions and past publications of the same. The influence of the following parameters, in various combinations, on the evolution and nature of the intermetallic phases were analyzed and reported: concentration of Si between 2 and 12.6 wt%, Fe between 0.05 and 0.5 wt% and solidification rates of 0.1, 1, 5 and 50 K s −1 . Two intermetallic phases are observed to evolve in these alloys under these solidification conditions: the τ 5 -Al 8 SiFe 2 and τ 6 -Al 9 Fe 2 Si 2 . The τ 5 -Al 8 SiFe 2 phase evolves at all levels of the parameters during solidification and subsequently transforms into the τ 6 -Al 9 Fe 2 Si 2 through a peritectic reaction when promoted by certain combinations of solidification parameters such as higher Fe level, lower Si level and slower solidification rates. Further, it is also hypothesized from experimental evidences that the θ-Al 13 Fe 4 binary phase precludes the evolution of the τ 5 during solidification and subsequently transforms into the τ 6 phase during solidification. These observations are anomalous to the publications as prior art and simulation predictions of thermodynamic phase diagrams of these alloys, wherein, only one intermetallic phases in the �

Macrosegregation Resulting from Directional Solidification Through an Abrupt Change in Cross-Sections

Science.gov (United States)

Lauer, M.; Poirier, D. R.; Ghods, M.; Tewari, S. N.; Grugel, R. N.

2017-01-01

Simulations of the directional solidification of two hypoeutectic alloys (Al-7Si alloy and Al-19Cu) and resulting macrosegregation patterns are presented. The casting geometries include abrupt changes in cross-section from a larger width of 9.5 mm to a narrower 3.2 mm width then through an expansion back to a width of 9.5 mm. The alloys were chosen as model alloys because they have similar solidification shrinkages, but the effect of Cu on changing the density of the liquid alloy is about an order of magnitude greater than that of Si. The simulations compare well with experimental castings that were directionally solidified in a graphite mold in a Bridgman furnace. In addition to the simulations of the directional solidification in graphite molds, some simulations were effected for solidification in an alumina mold. This study showed that the mold must be included in numerical simulations of directional solidification because of its effect on the temperature field and solidification. For the model alloys used for the study, the simulations clearly show the interaction of the convection field with the solidifying alloys to produce a macrosegregation pattern known as "steepling" in sections with a uniform width. Details of the complex convection- and segregation-patterns at both the contraction and expansion of the cross-sectional area are revealed by the computer simulations. The convection and solidification through the expansions suggest a possible mechanism for the formation of stray grains. The computer simulations and the experimental castings have been part of on-going ground-based research with the goal of providing necessary background for eventual experiments aboard the ISS. For casting practitioners, the results of the simulations demonstrate that computer simulations should be applied to reveal interactions between alloy solidification properties, solidification conditions, and mold geometries on macrosegregation. The simulations also presents the

Secondary Waste Simulant Development for Cast Stone Formulation Testing

Energy Technology Data Exchange (ETDEWEB)

Russell, Renee L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rinehart, Donald E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Swanberg, David J. [Washington River Protection Solutions, Richland, WA (United States); Mahoney, J. [Washington River Protection Solutions, Richland, WA (United States)

2015-04-01

Washington River Protection Solutions, LLC (WRPS) funded Pacific Northwest National Laboratory (PNNL) to conduct a waste form testing program to implement aspects of the Secondary Liquid Waste Treatment Cast Stone Technology Development Plan (Ashley 2012) and the Hanford Site Secondary Waste Roadmap (PNNL 2009) related to the development and qualification of Cast Stone as a potential waste form for the solidification of aqueous wastes from the Hanford Site after the aqueous wastes are treated at the Effluent Treatment Facility (ETF). The current baseline is that the resultant Cast Stone (or grout) solid waste forms would be disposed at the Integrated Disposal Facility (IDF). Data and results of this testing program will be used in the upcoming performance assessment of the IDF and in the design and operation of a solidification treatment unit planned to be added to the ETF. The purpose of the work described in this report is to 1) develop simulants for the waste streams that are currently being fed and future WTP secondary waste streams also to be fed into the ETF and 2) prepare simulants to use for preparation of grout or Cast Stone solid waste forms for testing.

Centrifugal casting of ZA8 zinc alloy and composite A356/silicon carbide: Study and modeling of phases' and particles' segregation

Science.gov (United States)

Balout, Bahaa

Centrifugation is a casting technology that allows the production of cylindrical and graduated parts with different mechanical properties through the section. The need for materials with good quality and specific mechanical properties has been driven this technology in order to produce different types of materials such as zinc alloys and graduated metal matrix composites reinforced by hard and wear resistant particles. The goal of this research project is to study and model the eutectic macrosegregation, the solidification speed, and the speeds of solidification fronts during centrifugal casting of ZA8 zinc-aluminum alloy in order to improve the part quality and increase its strength and field reliability. Moreover, the segregation of the particles during centrifugal casting of an aluminum matrix composite reinforced by silicon carbide particles (A356/SiC) is also studied to improve and control the graduation of the parts. The cooling rate, the speed, acceleration/deceleration, displacement, and segregation of the particles across the section will be modeled by discretization of Stokes' law in time in order to take into consideration the change in the centrifugal radius and melt viscosity during cooling process. This study will allow the control of the graduation degree of particles across the section in order to improve the properties and wear resistance of the composite. This composite can be used in systems where friction is critical and load is high (reinforcements of parts for the cylinders of pneumatic systems). The results show that the maximum macrosegregation zone of the eutectic across the casting section corresponds to the last point of solidification. The eutectic macrosegregation produced during centrifugal casting of thin walled part is a normal segregation which varies depending on the solidification speed and the ratio between the speeds of solidification fronts. On the other hand, it was found that the position and volume fraction of the particles

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

Energy Technology Data Exchange (ETDEWEB)

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.

Temperature and Pressure Evolution during Al Alloy Solidification at Different Squeeze Pressures

International Nuclear Information System (INIS)

Li, Junwen; Zhao, Haidong; Chen, Zhenming

2015-01-01

Squeeze casting is an advanced and near net-shape casting process, in which external high pressure is applied to solidifying castings. The castings are characterized with fine grains and good mechanical properties. In this study, a series of experiments were carried out to measure the temperature and pressure histories in cavity of Al-Si-Mg direct squeeze castings with different applied solidification pressures of 0.1, 50, 75, and 100 MPa. The evolution of the measured temperatures and pressures was compared and discussed. The effect of pressure change on formation of shrinkage defects was analyzed. Further the friction between the castings and dies during solidification was calculated. It is shown that the applied squeeze pressure has significant influence on the friction at die and casting interfaces, which affects the pressure evolution and transmission. The results could provide some benchmark data for future thermal-mechanics coupled modeling of squeeze castings. (paper)

Development of casting technology for manufacturing metal rods with simulated metallic spent fuels

International Nuclear Information System (INIS)

Lee, D. B.; Lee, Y. S.; Woo, Y. M.; Jang, S. J.; Kim, J. D; Kim, C. K.; Shin, Y. J.; Lee, J. H.

1999-01-01

The advanced casting equipment based on the directional solidification method was developed for manufacturing the uranium metal rod having 13.5 mm diameter and 1,200 mm length. In order to prevent surface-shrunk holes revealed easily in course of casting the small diameter and long rods, the vacuum casting furnace has the four pre-heaters equipped with temperature controller. On the other hand, the computer simulation to estimate the defective location and to analyze the solidus behavior of molten uranium in the mold were also performed by using MAGMA Code. As a result of the experimental and theoretical study, the sound rod has successfully been manufactured

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

Science.gov (United States)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-04-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

Science.gov (United States)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-06-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

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

Science.gov (United States)

Wang, Qiangqiang; Zhang, Lifeng

2016-06-01

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

Fluid flow and heat transfer modeling for castings

International Nuclear Information System (INIS)

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

1986-01-01

Casting is fundamental to manufacturing of many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of the modeling work has been in the area of heat transfer and solidification. Very little work has been done in modeling fluid flow of the liquid melt. This paper presents a model of fluid flow coupled with heat transfer of a liquid melt for casting processes. The model to be described in this paper is an extension of the COMMIX code and is capable of handling castings with any shape, size, and material. A feature of this model is the ability to track the liquid/gas interface and liquid/solid interface. The flow of liquid melt through the sprue and runners and into the mold cavity is calculated as well as three-dimensional temperature and velocity distributions of the liquid melt throughout the casting process. 14 refs., 13 figs

Stochastic simulation of grain growth during continuous casting

International Nuclear Information System (INIS)

Ramirez, A.; Carrillo, F.; Gonzalez, J.L.; Lopez, S.

2006-01-01

The evolution of microstructure is a very important topic in material science engineering because the solidification conditions of steel billets during continuous casting process affect directly the properties of the final products. In this paper a mathematical model is described in order to simulate the dendritic growth using data of real casting operations; here a combination of deterministic and stochastic methods was used as a function of the solidification time of every node in order to create a reconstruction about the morphology of cast structures

Stochastic simulation of grain growth during continuous casting

Energy Technology Data Exchange (ETDEWEB)

Ramirez, A. [Department of Aerounatical Engineering, S.E.P.I., E.S.I.M.E., IPN, Instituto Politecnico Nacional (Unidad Profesional Ticoman), Av. Ticoman 600, Col. Ticoman, C.P.07340 (Mexico)]. E-mail: adalop123@mailbanamex.com; Carrillo, F. [Department of Processing Materials, CICATA-IPN Unidad Altamira Tamps (Mexico); Gonzalez, J.L. [Department of Metallurgy and Materials Engineering, E.S.I.Q.I.E.-IPN (Mexico); Lopez, S. [Department of Molecular Engineering of I.M.P., AP 14-805 (Mexico)

2006-04-15

The evolution of microstructure is a very important topic in material science engineering because the solidification conditions of steel billets during continuous casting process affect directly the properties of the final products. In this paper a mathematical model is described in order to simulate the dendritic growth using data of real casting operations; here a combination of deterministic and stochastic methods was used as a function of the solidification time of every node in order to create a reconstruction about the morphology of cast structures.

Evolution of Fe based intermetallic phases in Al–Si hypoeutectic casting alloys: Influence of the Si and Fe concentrations, and solidification rate

Energy Technology Data Exchange (ETDEWEB)

Gorny, Anton; Manickaraj, Jeyakumar [Light Metal Casting Research Centre (LMCRC), Department of Mechanical Engineering, McMaster University, 1280 Main Street W, Hamilton, ON, Canada L8S 4L7 (Canada); Cai, Zhonghou [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Shankar, Sumanth, E-mail: shankar@mcmaster.ca [Light Metal Casting Research Centre (LMCRC), Department of Mechanical Engineering, McMaster University, 1280 Main Street W, Hamilton, ON, Canada L8S 4L7 (Canada)

2013-11-15

Highlights: •Anomalous evolution of Fe based intermetallic phases in Al–Si–Fe alloys. •XRF coupled with nano-diffraction to confirm the nano-size Fe intermetallic phases. •Crystallography of the θ-Al{sub 13}Fe{sub 4}, τ{sub 5}-Al{sub 8}Fe{sub 2}Si and τ{sub 6}-Al{sub 9}Fe{sub 2}Si{sub 2} phases. •Peritectic reactions involving the Fe intermetallic phases in Al–Si–Fe alloys. -- Abstract: Al–Si–Fe hypoeutectic cast alloy system is very complex and reported to produce numerous Fe based intermetallic phases in conjunction with Al and Si. This publication will address the anomalies of phase evolution in the Al–Si–Fe hypoeutectic casting alloy system; the anomaly lies in the peculiarities in the evolution and nature of the intermetallic phases when compared to the thermodynamic phase diagram predictions and past publications of the same. The influence of the following parameters, in various combinations, on the evolution and nature of the intermetallic phases were analyzed and reported: concentration of Si between 2 and 12.6 wt%, Fe between 0.05 and 0.5 wt% and solidification rates of 0.1, 1, 5 and 50 K s{sup −1}. Two intermetallic phases are observed to evolve in these alloys under these solidification conditions: the τ{sub 5}-Al{sub 8}SiFe{sub 2} and τ{sub 6}-Al{sub 9}Fe{sub 2}Si{sub 2}. The τ{sub 5}-Al{sub 8}SiFe{sub 2} phase evolves at all levels of the parameters during solidification and subsequently transforms into the τ{sub 6}-Al{sub 9}Fe{sub 2}Si{sub 2} through a peritectic reaction when promoted by certain combinations of solidification parameters such as higher Fe level, lower Si level and slower solidification rates. Further, it is also hypothesized from experimental evidences that the θ-Al{sub 13}Fe{sub 4} binary phase precludes the evolution of the τ{sub 5} during solidification and subsequently transforms into the τ{sub 6} phase during solidification. These observations are anomalous to the publications as prior art and

The Effect of Water Mist Cooling of Casting Die on the Solidification, Microstructure and Properties of AlSi20 Alloy

Directory of Open Access Journals (Sweden)

Władysiak R.

2017-03-01

Full Text Available Unmodified AlSi20 alloy were casted at the research station, allowing for sequential multipoint cooling using a dedicated computer- controlled program. This method allows for the formation of the microstructure of hypereutectic AlSi20 alloy and also increases hardness. Primary silicon dendrites were found in the microstructure of cooled samples. Based on these dendrites, the formation of primary silicon particles is explained. Cooling of casting die with a water mist stream causes changes in solidification, which leads to expansion of the boundary layer with columnar crystals and shrinkage of the core zone with equiaxed crystals. It also causes more regular hardness distribution around pre-eutectic Si crystals, which can lead to tensile strength and machinability improvement.

Cast iron - a predictable material

Directory of Open Access Journals (Sweden)

Jorg C. Sturm

2011-02-01

Full Text Available High strength compacted graphite iron (CGI or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven

Finite-element solidification modelling of metals and binary alloys

International Nuclear Information System (INIS)

Mathew, P.M.

1986-12-01

In the Canadian Nuclear Fuel Waste Management Program, cast metals and alloys are being evaluated for their ability to support a metallic fuel waste container shell under disposal vault conditions and to determine their performance as an additional barrier to radionuclide release. These materials would be cast to fill residual free space inside the container and allowed to solidify without major voids. To model their solidification characteristics following casting, a finite-element model, FAXMOD-3, was adopted. Input parameters were modified to account for the latent heat of fusion of the metals and alloys considered. This report describes the development of the solidification model and its theoretical verification. To model the solidification of pure metals and alloys that melt at a distinct temperature, the latent heat of fusion was incorporated as a double-ramp function in the specific heat-temperature relationship, within an interval of +- 1 K around the solidification temperature. Comparison of calculated results for lead, tin and lead-tin eutectic melts, unidirectionally cooled with and without superheat, showed good agreement with an alternative technique called the integral profile method. To model the solidification of alloys that melt over a temperature interval, the fraction of solid in the solid-liquid region, as calculated from the Scheil equation, was used to determine the fraction of latent heat to be liberated over a temperature interval within the solid-liquid zone. Comparison of calculated results for unidirectionally cooled aluminum-4 wt.% copper melt, with and without superheat, showed good agreement with alternative finite-difference techniques

design, construction and performance evaluation of multiple casting

African Journals Online (AJOL)

eobe

time taken for solidification, plays an important role in the casting. There should not ... Keywords: Design, Construction, Multiple casting machine, Compo Casting operation. 1. Introduction .... metal and pathway channel pipe with heater is used.

Titanium Aluminide Casting Technology Development

Science.gov (United States)

Bünck, Matthias; Stoyanov, Todor; Schievenbusch, Jan; Michels, Heiner; Gußfeld, Alexander

2017-12-01

Titanium aluminide alloys have been successfully introduced into civil aircraft engine technology in recent years, and a significant order volume increase is expected in the near future. Due to its beneficial buy-to-fly ratio, investment casting bears the highest potential for cost reduction of all competing production technologies for TiAl-LPTB. However, highest mechanical properties can be achieved by TiAl forging. In view of this, Access e.V. has developed technologies for the production of TiAl investment cast parts and TiAl die cast billets for forging purposes. While these parts meet the highest requirements, establishing series production and further optimizing resource and economic efficiency are present challenges. In order to meet these goals, Access has recently been certified according to aircraft standards, aiming at qualifying parts for production on technology readiness level 6. The present work gives an overview of the phases of development and certification.

Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking

Energy Technology Data Exchange (ETDEWEB)

Das, S.K.; Ningileri, S.; Long, Z.; Saito, K.; Khraisheh, M.; Hassan, M.H.; Kuwana, K.; Han, Q.; Viswanathan, S.; Sabau, A.S.; Clark, J.; Hyrn, J. (ANL)

2006-08-15

Approximately 68% of the aluminum produced in the United States is first cast into ingots prior to further processing into sheet, plate, extrusions, or foil. The direct chill (DC) semi-continuous casting process has been the mainstay of the aluminum industry for the production of ingots due largely to its robust nature and relative simplicity. Though the basic process of DC casting is in principle straightforward, the interaction of process parameters with heat extraction, microstructural evolution, and development of solidification stresses is too complex to analyze by intuition or practical experience. One issue in DC casting is the formation of stress cracks [1-15]. In particular, the move toward larger ingot cross-sections, the use of higher casting speeds, and an ever-increasing array of mold technologies have increased industry efficiencies but have made it more difficult to predict the occurrence of stress crack defects. The Aluminum Industry Technology Roadmap [16] has recognized the challenges inherent in the DC casting process and the control of stress cracks and selected the development of 'fundamental information on solidification of alloys to predict microstructure, surface properties, and stresses and strains' as a high-priority research need, and the 'lack of understanding of mechanisms of cracking as a function of alloy' and 'insufficient understanding of the aluminum solidification process', which is 'difficult to model', as technology barriers in aluminum casting processes. The goal of this Aluminum Industry of the Future (IOF) project was to assist the aluminum industry in reducing the incidence of stress cracks from the current level of 5% to 2%. Decreasing stress crack incidence is important for improving product quality and consistency as well as for saving resources and energy, since considerable amounts of cast metal could be saved by eliminating ingot cracking, by reducing the scalping thickness of

A Comparative study of solidification of Al-Cu alloy under flow of cylindrical radial heat and the unidirectional vertically

Directory of Open Access Journals (Sweden)

Jean Robert P. Rodrigues

2014-09-01

Full Text Available In spite of technological importance of solidification of metallic alloys under radial heat flow, relatively few studies have been carried out in this area. In this work the solidification of Al 4.5 wt% Cu cylinders against a steel massive mold is analyzed and compared with unidirectional solidification against a cooled mold. Initially temperature variations at different positions in the casting and in the mold were measured during solidification using a data acquisition system. These temperature variations were introduced in a numerical method in order to determine the variation of heat transfer coefficient at metal/mold interface by inverse method. The primary and secondary dendrite arm spacing variations were measured through optical microscopy. Comparisons carried out between experimental and numerical data showed that the numerical method describes well the solidification processes under radial heat flux.

NUMERICAL MODELING OF HARDENING OF UNINTERRUPTEDLY-CASTED BRONZE CASTING

Directory of Open Access Journals (Sweden)

E. I. Marukovich

2009-01-01

Full Text Available The three-dimensional numerical model for calculation of thermal fields during solidification of continuously casted bronze casting is developed. Coefficients of heat transfer on borders of calculation areas on the basis of the solution of inverse heat transfer conduction problem are determined. The analysis of thermal fields, depending on loop variables of drawing and the sizes of not cooled zone of crystallizer is curried out.

Nucleation and solidification of thin walled ductile iron - Experiments and numerical simulation

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Tiedje, Niels Skat

2005-01-01

Investigation of solidification of thin walled ductile cast iron has been performed based on experiments and numerical simulation. The experiments were based on temperature and microstructure examination. Results of the experiments have been compared with a 1-D numerical solidification model...

Constrained/unconstrained solidification within the massive cast steel/iron ingots

Directory of Open Access Journals (Sweden)

W. S. Wołczyński

2010-04-01

Full Text Available Some properties of the ingot and especially of the steel forging ingots depend on the ratio of a columnar structure area to an equiaxed structure area created during solidification. The C-E transition is fundamental phenomenon that can be applied to characterize massive cast steel ingots produced by the casting house. The mentioned ratio is created spontaneously due to the rate of heat transfer towards the ceramic mould and then to the environment. The ceramic mould operates as an isolator. So that the thickness of the mould together with a growing solid fraction control the heat transfer and finally the ratio of the columnar structure area to the equiaxed structure area. At first the increase of heat accumulation within the ceramic mould is observed. Next the stationary state for heat transfer is created and finally a gentle abatement of the mould temperature associated with the heat output to the environment is expected. The steep thermal gradients correspond to the increase of heat accumulation in the ceramic mould. The steep thermal gradients are required to promote the columnar structure formation. The full heat accumulation in the mould corresponds well with the C-E transformation while the appearance of the moderate thermal gradients is referred to the gentle temperature abatement within the ceramic mould. The equiaxed structure is expected within this period of heat transfer behavior. The steep thermal gradients involve the activity of viscosity gradient in the liquid. As the result a sedimentary cones are formed at the bottom of the ingot. The C-E transformation is associated with competition between columnar and equaixed structure formation. At the end of competition a fully equiaxed structure is formed. The viscosity gradient is replaced by the thermophoresis which is the driving force for the deposition of some equiaxed grain layers onto the surface of C+E zone. The convection together with the gravity allow the layers to be uniform

The mechanical properties of the polycrystalline investment casting superalloy IN738LC

International Nuclear Information System (INIS)

Im, H.J.; Banerji, A.

1995-01-01

The mechanical properties of the polycrystaline investment casting superalloys, IN738LC in the present case, require an optimization of the microstructure. This is generally achieved by suitable founding measures as well as through the subsequent heat-treatment. Thereby, however, it is necessary to control the casting and solidification parameters. In the present study, additional measures have been adopted to inoculate the melt with a suitable chemical additive with the aim of obtaining a uniformly distributed fine equiaxial cast microstructure throughout the test-specimen. The addition of a suitable refiner substance increases the nucleation sites within the melt, which results into a fine equiaxial solidification. This imparts better casting properties thereby improving most of the mechanical properties significantly. The present report deals with refinement of cast microstructure through melt-treatment with chemical additions under varying casting and solidification parameters, wherein the grain size and dendrite arm spacing (DAS) have been quantified. (orig.) [de

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

Science.gov (United States)

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

2014-07-01

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

SILICATE TECHNOLOGY CORPORATION'S SOLIDIFICATION/ STABILIZATION TECHNOLOGY FOR ORGANIC AND INORGANIC CONTAMINANTS IN SOILS - APPLICATIONS ANALYSIS REPORT

Science.gov (United States)

This Applications Analysis Report evaluates the solidification/stabilization treatment process of Silicate Technology Corporation (STC) for the on-site treatment of hazardous waste. The STC immobilization technology utilizes a proprietary product (FMS Silicate) to chemically stab...

Analysis of nucleation modelling in ductile cast iron

DEFF Research Database (Denmark)

Moumeni, Elham; Tutum, Cem Celal; Tiedje, Niels Skat

2012-01-01

Heterogeneous nucleation of nodular graphite at inclusions in ductile iron during eutectic solidification has been investigated. The experimental part of this work deals with casting of ductile iron samples with two different inoculants in four different thicknesses. Chemical analysis, metallogra......Heterogeneous nucleation of nodular graphite at inclusions in ductile iron during eutectic solidification has been investigated. The experimental part of this work deals with casting of ductile iron samples with two different inoculants in four different thicknesses. Chemical analysis...

FY 1997 report on the study on solidification process of high-temperature melt of heat resistant metals; 1997 nendo chosa hokokusho (tainetsu kinzoku koon yueki no gyoko katei no kenkyu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

Study was made on a solidification process of metal melt under micro-gravity condition in an underground non-gravity experiment center, considering that improvement of the heat resistance of turbine blades for jet engines and power generation gas turbines contributes to prevention of global warming through improvement of thermal engine efficiencies and consumption reduction of precious fossil fuel. Study was made on a simulation program and precise measurement of thermal properties for precision casting of heat-resistant alloy members. Study was also made on Al and Zn alloys and their welding for production and evaluation technologies of new metal textures by supercooling solidification. Some issues for strongly desired improvement of a simulation program for precision casting were clarified. In addition, since thermal property data of practical heat-resistant polyalloy members are poor, data and measurement method for precision casting were clarified. It was also suggested that basic elucidation of the solidification process under micro- gravity condition is possible. 34 refs., 41 figs., 5 tabs.

Advancement of Solidification Processing Technology Through Real Time X-Ray Transmission Microscopy: Sample Preparation

Science.gov (United States)

Stefanescu, D. M.; Curreri, P. A.

1996-01-01

Two types of samples were prepared for the real time X-ray transmission microscopy (XTM) characterization. In the first series directional solidification experiments were carried out to evaluate the critical velocity of engulfment of zirconia particles in the Al and Al-Ni eutectic matrix under ground (l-g) conditions. The particle distribution in the samples was recorded on video before and after the samples were directionally solidified. In the second series samples of the above two type of composites were prepared for directional solidification runs to be carried out on the Advanced Gradient Heating Facility (AGHF) aboard the space shuttle during the LMS mission in June 1996. X-ray microscopy proved to be an invaluable tool for characterizing the particle distribution in the metal matrix samples. This kind of analysis helped in determining accurately the critical velocity of engulfment of ceramic particles by the melt interface in the opaque metal matrix composites. The quality of the cast samples with respect to porosity and instrumented thermocouple sheath breakage or shift could be easily viewed and thus helped in selecting samples for the space shuttle experiments. Summarizing the merits of this technique it can be stated that this technique enabled the use of cast metal matrix composite samples since the particle location was known prior to the experiment.

Analysis of weld solidification cracking in cast nickel aluminide alloys

International Nuclear Information System (INIS)

Santella, M.L.; Feng, Z.

1995-01-01

A study of the response of several nickel aluminide alloys to SigmaJig testing was done to examine their weld solidification cracking behavior and the effect of Zr concentration. The alloys were based on the Ni-8Al-7.7Cr-1.5Mo-0.003B wt% composition and contained Zr concentrations of 3, 4.5, and 6 wt%. Vacuum induction melted ingots with a diameter of 2.7 in and weight about 18 lb were made of each alloy, and were used to make 2 x 2 x 0.030 in specimens for the Sigmajig test. The gas tungsten arc welds were made at travel speeds of 10, 20, and 30 ipm with heat inputs of 2--2.5 kJ/in. When an arc was established before traveling onto the test specimen centerline cracking was always observed. This problem was overcome by initiating the arc directly on the specimens. Using this approach, the 3 wt% Zr alloy withstood an applied stress of 24 ksi without cracking at a welding speed of 10 ipm. This alloy cracked at 4 ksi applied at 20 ipm, and with no applied load at 30 ipm. Only limited testing was done on the remaining alloys, but the results indicate that resistance to solidification cracking increases with Zr concentration. Zirconium has limited solid solubility and segregates strongly to interdendritic regions during solidification where it forms a Ni solid solution-Ni 5 Zr eutectic. The volume fraction of the eutectic increases with Zr concentration. The solidification cracking behavior of these alloys is consistent with phenomenological theory, and is discussed in this context. The results from SigmaJig testing are analyzed using finite element modeling of the development of mechanical strains during solidification of welds. Experimental data from the test substantially agree with recent analysis results

Clean Cast Steel Technology, Phase IV

Energy Technology Data Exchange (ETDEWEB)

Charles E. Bates

2003-02-24

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

Application of digital pattern-less molding technology to produce art casting

Directory of Open Access Journals (Sweden)

Chen Li1

2014-11-01

Full Text Available Compared with the conventional casting process, digital pattern-less casting technology has many advantages such as good machining accuracy, a short processing cycle, and low production cost. It is a new rapid manufacturing technology for castings, integrated with CAD/CAM, casting, CNC machining and many other advanced technologies. With this digital casting technology, no pattern is needed for making molds; it is precise, flexible, and green. Usually, art castings have complex structures and are made in small batches or even made in a single-piece, especially for large-sized art castings. So it has the shortcomings of high cost, low efficiency and long time for making a pattern to produce art castings with the conventional casting processes. However, the digital pattern-less casting technology can be applied to fabricate art castings, since it can greatly shorten the manufacturing cycle and lower the production cost, thus having a very good prospect. In this study, based on the digital pattern-less casting technology, a plaque casting with artistic Chinese characters (a Chinese poem was designed and manufactured, and the production process was demonstrated in detail.

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

International Nuclear Information System (INIS)

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 R 2 factor of 0.99 was obtained.

[Recent advance in solidification/stabilization technology for the remediation of heavy metals-contaminated soil].

Science.gov (United States)

Hao, Han-zhou; Chen, Tong-bin; Jin, Meng-gui; Lei, Mei; Liu, Cheng-wu; Zu, Wen-pu; Huang, Li-mi

2011-03-01

Remediation of heavy metals-contaminated soil is still a difficulty and a hotspot of international research projects. At present, the technologies commonly adopted for the remediation of contaminated sites mainly include excavation, solidification/stabilization (S/S), soil washing, soil vapor extraction (SVE), thermal treatment, and bioremediation. Based on the S/S technical guidelines of Unite State Environmental Protection Agency (EPA) and United Kingdom Environment Agency (EA) and the domestic and foreign patents, this paper introduced the concepts of S/S and its development status at home and abroad, and discussed its future development directions. Solidification refers to a process that binds contaminated media with a reagent, changing the media's physical properties via increasing its compressive strength, decreasing its permeability, and encapsulating the contaminants to form a solid material. Stabilization refers to the process that involves a chemical reaction which reduces the leachability of a waste, chemically immobilizes the waste and reduces its solubility, making the waste become less harmful or less mobile. S/S technology includes cement solidification, lime pozzolanic solidification, plastic materials stabilization, vitrification, and regent-based stabilization. Stabilization (or immobilization) treatment processes convert contaminants to less mobile forms through chemical or thermal interactions. In stabilization technology, the aim of adding agents is to change the soil physical and chemical properties through pH control technology, redox potential technology, precipitation techniques, adsorption technology, and ion-exchange technology that change the existing forms of heavy metals in soil, and thus, reduce the heavy metals bioavailability and mobility. This review also discussed the S/S evaluation methods, highlighted the need to enhance S/S technology in the molecular bonding, soil polymers, and formulation of China's S/S technical guidelines.

Development of sodium disposal technology. Experiment of sodium compound solidification process

International Nuclear Information System (INIS)

Matsumoto, Toshiyuki; Ohura, Masato; Yatoh, Yasuo

2007-07-01

A large amount of sodium containing radioactive waste will come up at the time of final shutdown/decommission of FBR plant. The radioactive waste is managed as solid state material in a closed can in Japan. As for the sodium, there is no established method to convert the radioactive sodium to solid waste. Further, the sodium is highly reactive. Thus, it is recommended to convert the sodium to a stable substance before the solidification process. One of the stabilizing methods is conversion of sodium into sodium hydroxide solution. These stabilization and solidification processes should be safe, economical, and efficient. In order to develop such sodium disposal technology, nonradioactive sodium was used and a basic experiment was performed. Waste-fluid Slag Solidification method was employed as the solidification process of sodium hydroxide solution. Experimental parameters were mixing ratio of the sodium hydroxide and the slag solidification material, temperature and concentration of the sodium hydroxide. The best parameters were obtained to achieve the maximum filling ratio of the sodium hydroxide under a condition of enough high compressive strength of the solidified waste. In a beaker level test, the solidified waste was kept in a long term and it was shown that there was no change of appearance, density, and also the compressive strength was kept at a target value. In a real scale test, homogeneous profiles of the density and the compressive strength were obtained. The compressive strength was higher than the target value. It was shown that the Waste-fluid Slag Solidification method can be applied to the solidification process of the sodium hydroxide solution, which was produced by the stabilization process. (author)

TECHNOLOGY EVALUATION REPORT: SILICATE TECHNOLOGY CORPORATION - SOLIDIFICATION/STABILIZATION OF PCP AND INORGANIC CONTAMINANTS IN SOILS - SELMA, CA

Science.gov (United States)

This Technolgy Evaluation Report evaluates the solidification/stabilization process of Silicate Technology Corporation (STC) for the on-site treatment of contaminated soil The STC immobilization technology uses a proprietary product (FMS Silicate) to chemically stabilize and ...

Casting fine grained, fully dense, strong inorganic materials

Science.gov (United States)

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

2015-11-24

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

Investigation of Dendrite Coarsening in Complex Shaped Lamellar Graphite Iron Castings

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Péter Svidró

2017-07-01

Full Text Available Shrinkage porosity and metal expansion penetration are two casting defects that appear frequently during the production of complex-shaped lamellar graphite iron components. These casting defects are formed during the solidification and usually form in the part of the casting which solidifies last. The position of the area that solidifies last is dependent on the thermal conditions. Test castings with thermal conditions like those existing in a complex-shaped casting were successfully applied to provoke a shrinkage porosity defect and a metal expansion penetration defect. The investigation of the primary dendrite morphology in the defected positions indicates a maximum intradendritic space, where the shrinkage porosity and metal expansion penetration defects appear. Moving away from the defect formation area, the intradendritic space decreases. A comparison of the intradendritic space with the simulated local solidification times indicates a strong relationship, which can be explained by the dynamic coarsening process. More specifically, long local solidification times facilitates the formation of a locally coarsened austenite morphology. This, in turn, enables the formation of a shrinkage porosity or a metal expansion penetration.

Manufacturing technology of high-quality pressure castings

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S. Pietrowski

2011-10-01

Full Text Available The paper presents manufacturing technology of pressure castings made of Al-Si alloy without porosity or with low microporosity of castings. It has been shown that the greatest impact on the porosity of the castings and the concentration of hydrogen has had the charge to the melting furnace. Liquidation or occurrence of a small microporosity of castings provides refining with solid refiners, nitrogen and modification of liquid alloy after various operations of preparing process. The liquid alloy stored in holding furnace should be refined once every 2 h with nitrogen. Authors developed a computer program of Al-Si alloys inspection with using of TDA method. The developed technology was verified under production conditions.

Research and Development of the Solidification of Slab Ingots from Special Tool Steels

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Tkadlečková M.

2017-09-01

Full Text Available The paper describes the research and development of casting and solidification of slab ingots from special tool steels by means of numerical modelling using the finite element method. The pre-processing, processing and post-processing phases of numerical modelling are outlined. Also, problems with determining the thermophysical properties of materials and heat transfer between the individual parts of the casting system are discussed. Based on the type of grade of tool steel, the risk of final porosity is predicted. The results allowed to improve the production technology of slab ingots, and also to verify the ratio, the chamfer and the external/ internal shape of the wall of the new designed slab ingots.

Control of segregation in squeeze cast Al-4.5Cu binary alloy

Energy Technology Data Exchange (ETDEWEB)

Durrant, G. [Oxford Univ. (United Kingdom). Dept. of Materials; Gallerneault, M. [Alcan International Ltd., Kingston, ON (Canada); Cantor, B. [Oxford Univ. (United Kingdom). Dept. of Materials

1997-10-01

The high pressure applied in squeeze casting allows Al alloys of wrought composition to be cast to near net-shape, although their long freezing range leads to the segregation of alloying elements. In this paper we present results on the squeeze casting and gravity casting of a model Al-4.5 wt%Cu alloy. Squeeze cast Al-4.5Cu has a normal segregation pattern with eutectic macrosegregates towards the centre of the billet, whereas gravity cast material has a typical inverse segregation pattern. Normal segregation in squeeze cast Al-4.5Cu is due to large temperature gradients during solidification. Segregation can be minimized by releasing the applied pressure during solidification to allow backflow of the interdendritic fluid, or by the addition of grain refiner to remove the large columnar dendritic growth structure. (orig.)

Undercooling and nodule count in thin walled ductile iron castings

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Tiedje, Niels Skat

2007-01-01

Casting experiments have been performed with eutectic and hypereutectic castings with plate thicknesses from 2 to 8 mm involving both temperature measurements during solidification and microstructural examination afterwards. The nodule count was the same for the eutectic and hypereutectic casting...

Reengineering of Permanent Mould Casting with Lean Manufacturing Methods

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R. Władysiak

2007-07-01

Full Text Available At the work were introduced main areas of production system project of casts produced in permanent moulds, that constitutes reengineering of conventional production system according to Lean Manufacturing (LM methods. New resolution of cooling of dies with water mist was shown to casting of car wheels made from aluminium alloys in low pressure casting process. It was implemented as a part of goal-oriented project in R.H. Alurad Sp.z o.o. in Gorzyce. Its using intensifies solidification and self-cooling of casts shortening the time of casting cycle by the 30%. It was described reorganizing casting stations into multi-machines cells production and the process of their fast tool’s exchange with applying the SMED method. A project of the system was described controlling the production of the foundry with the computer aided light Kanban system. A visualization of the process was shown the production of casts with use the value stream mapping method. They proved that applying casting new method in the technology and LM methods allowed to eliminate down-times, to reduce the level of stocks, to increase the productivity and the flow of the castings production.

Developing technological process of obtaining giality casts

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A. Issagulov

2014-10-01

Full Text Available The article considers the process of manufacturing castings using sand-resin forms and alloying furnace. Were the optimal technological parameters of manufacturing shell molds for the manufacture of castings of heating equipment. Using the same upon receipt of castings by casting in shell molds furnace alloying and deoxidation of the metal will provide consumers with quality products and have a positive impact on the economy in general engineering.

Low-level radwaste solidification

International Nuclear Information System (INIS)

Naughton, M.D.; Miller, C.C.; Nelson, R.A.; Tucker, R.F.

1983-01-01

This paper reports on a study of ''Advanced Low-Level Radioactive Waste Treatment Systems'' conducted under an EPRI contract. The object of the study is to identify advanced lowlevel radwaste treatment systems that are commercially available or are expected to be in the near future. The current state-ofthe-art in radwaste solidification technology is presented. Related processing technologies, such as the compaction of dry active waste (DAW), containers available for radwaste disposal, and the regulatory aspects of radwaste transportation and solidification, are described. The chemical and physical properties of the currently acceptable solidification agents, as identified in the Barnwell radwaste burial site license, are examined. The solidification agents investigated are hydraulic cements, thermoplastic polymers, and thermosetting polymers. It is concluded that solidification processes are complex and depend not only on the chemical and physical properties of the binder material and the waste, but also on how these materials are mixed

Theoretic and Experimental Studies on the Casting of Large Die-Type Parts Made of Lamellar Graphite Grey Pig Irons by Using the Technology of Polystyrene Moulds Casting from Two Sprue Cups

Directory of Open Access Journals (Sweden)

Constantin Marta

2012-01-01

Full Text Available This paper presents a comparative analysis between the practical results of pig iron die-type part casting and the results reached by simulation. The insert was made of polystyrene, and the casting was downward vertical. As after the part casting and heat treatment cracks were observed in the part, it became necessary to locate and identify these fissures and to establish some measures for eliminating the casting defects and for locating them. The research method was the comparisons of defects identified through verifications, measurements, and metallographic analyses applied to the cast part with the results of some criteria specific to simulation after simulating the casting process. In order to verify the compatibility between reality and simulation, we then simulated the part casting respecting the real conditions in which it was cast. By visualising certain sections of the cast part during solidification, relevant details occur about the possible evolution of defects. The simulation software was AnyCasting, the measurements were done through nondestructive methods.

Simulation of mould filling process for composite skeleton castings

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M. Dziuba

2008-04-01

Full Text Available In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of skeleton casting and mould filling process. The aim of conducted simulations was the choice of thermal and geometrical parameters for the needs of designed calculations of the skeleton castings and the estimation of the guidelines for the technology of manufacturing. The subject of numerical simulation was the analysis of ability of filling the channels of core by liquid metal at estability technological parameters.. Below the assumptions and results of the initial simulated calculations are presented. The total number of the nodes in the casting was 1920 and of the connectors was 5280 what gave filling of 100% for the nodes and 99,56% for the connectors in the results of the simulation. Together it resulted as 99,78 % of filling the volume of the casting. The nodes and connectors were filled up to the 30 level of the casting in the simulation. The all connectors were filled up to the 25 level of the casting in the simulation. Starting from the 25 level individual connectors at the side surface of the casting weren’t filled up. The connectors weren’t supplied by multi-level getting system. The differences of filling the levels are little (maximally 5 per cent.

Effect of Microstructures on Working Properties of Nickel-Manganese-Copper Cast Iron

Directory of Open Access Journals (Sweden)

Daniel Medyński

2018-05-01

Full Text Available In the paper, the effects, on basic usable properties (abrasive wear and corrosion resistance, of solidification (acc. to the stable and non-stable equilibrium system and transformations occurring in the matrix during the cooling of castings of Ni-Mn-Cu cast iron were determined. Abrasive wear resistance was mainly determined by the types and arrangements of high-carbon phases (indicated by eutectic saturation degree, and the kinds of matrices (indicated by the nickel equivalent value, calculated from chemical composition. The highest abrasive wear resistance was found for white cast iron, with the highest degree of austenite to martensite transformation occurring in its matrix. Irrespective of solidification, a decrease of the equivalent value below a limit value resulted in increased austenite transformation, and thus, to a significant rise in hardness and abrasive wear resistance for the castings. At the same time, corrosion resistance of the alloy was slightly reduced. The examinations showed that corrosion resistance of Ni-Mn-Cu cast iron is, too a much lesser degree, decided by the means of solidification of the castings, rather than transformations occurring in the matrix, as controlled by nickel equivalent value (especially elements with high electrochemical potential.

Casting Simulation of an Austrian Bronze Age Sword Hilt

Science.gov (United States)

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

2015-07-01

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

Effect of electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting

Directory of Open Access Journals (Sweden)

ZHOU Shu-cai

2007-08-01

Full Text Available An investigation on the influence of low frequency rotary electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting was experimentally conducted and carried out on an industrial trial basis. The results show that application of appropriate electromagnetic stirring parameters can obviously improve the macrostructure of austenitic stainless steel, in which both columnar and equiaxed grains can be greatly refined and shrinkage porosity or cavity zone along centerline can be remarkably decreased due to eliminating intracrystalline and enlarging equiaxed grains zone. The industrial trials verify that the electromagnetic stirring intensity of austenitic stainless steel should be higher than that of plain carbon steel. Electromagnetic stirring has somewhat affected the macrostructure of austenitic stainless steel even if the magnetic flux density of the electromagnetic stirring reaches 90 mT (amplitude reaches 141 mT in average at frequency f=3-4Hz, which provides a reference for the optimization of design and process parameters when applying the rotary electromagnetic stirrer.

A Stochastic mesoscopic model for predicting the globular grain structure and solute redistribution in cast alloys at low superheat

International Nuclear Information System (INIS)

Nastac, Laurentiu; El Kaddah, Nagy

2012-01-01

It is well known that casting at low superheat has a strong influence on the solidification morphology and macro- and microstructures of the cast alloy. This paper describes a stochastic mesoscopic solidification model for predicting the grain structure and segregation in cast alloy at low superheat. This model was applied to predict the globular solidification morphology and size as well as solute redistribution of Al in cast Mg AZ31B alloy at superheat of 5°C produced by the Magnetic Suspension Melting (MSM) process, which is an integrated containerless induction melting and casting process. The castings produced at this low superheat have fine globular grain structure, with an average grain size of 80 μm, which is about 3 times smaller than that obtained by conventional casting techniques. The stochastic model was found to reasonably predict the observed grain structure and Al microsegregation. This makes the model a useful tool for controlling the structure of cast magnesium alloys.

Matemathical description of solidification cooling curves of pure metals

Directory of Open Access Journals (Sweden)

Arno Müller

1998-10-01

Full Text Available The introduction of an "incubation time" to the Schwarz classical mathematical description of metals solidification, resulted in a new model called Modified Schwarz Model. By doing so it was possible to identify and quantify the "delay time" that separates the two heat waves traveling independently in a casting during the solidification: the Supercooled / Superheated Liquid and the Solid / Liquid. The thermal shock produced in the initial stage of the undercooling generation process, can be used as an important parameter in the forecasting of the solidification's behavior of pure metals and alloys, when changing mold's materials, pouring and ambient temperatures. The hypercooling proneness degree of metals and alloys, can also be calculated.

Wide Strip Casting Technology of Magnesium Alloys

Science.gov (United States)

Park, W.-J.; Kim, J. J.; Kim, I. J.; Choo, D.

Extensive investigations relating to the production of high performance and low cost magnesium sheet by strip casting have been performed for the application to automotive parts and electronic devices. Research on magnesium sheet production technology started in 2004 by Research Institute of Industrial Science and Technology (RIST) with support of Pohang Iron and Steel Company (POSCO). POSCO has completed the world's first plant to manufacture magnesium coil. Another big project in order to develop wide strip casting technology for the automotive applications of magnesium sheets was started in succession.

Micrograph evidence of meniscus solidification and sub-surface microstructure evolution in continuous-cast ultralow-carbon steels

International Nuclear Information System (INIS)

Sengupta, J.; Shin, H.-J.; Thomas, B.G.; Kim, S.-H.

2006-01-01

Hooks and other sub-surface features in continuous-cast ultralow-carbon steel samples were examined using optical microscopy, electron backscattering diffraction, energy dispersive X-ray spectroscopy, and electron probe microanalysis techniques. Special etching reagents revealed dendrites growing from both sides of the line of hook origin. This line was found to represent the frozen meniscus and persisted into the final microstructure, as revealed by grain orientation measurements. A broken hook tip was observed in one micrograph, which explains the characteristic truncated shape of most hooks. Mold powder was found entrapped along the frozen meniscus. These results provide evidence of both solidification and subsequent overflow of the liquid steel meniscus. Thus, the instantaneous meniscus shape governs the shape and microstructure of the final hook, and the extent of the liquid steel overflow determines the shape of oscillation marks. This mechanism has important implications for the entrapment of inclusions and other surface defects

Gating system optimization of low pressure casting A356 aluminum alloy intake manifold based on numerical simulation

Directory of Open Access Journals (Sweden)

Jiang Wenming

2014-03-01

Full Text Available To eliminate the shrinkage porosity in low pressure casting of an A356 aluminum alloy intake manifold casting, numerical simulation on filling and solidification processes of the casting was carried out using the ProCAST software. The gating system of the casting is optimized according to the simulation results. Results show that when the gating system consists of only one sprue, the filling of the molten metal is not stable; and the casting does not follow the sequence solidification, and many shrinkage porosities are observed through the casting. After the gating system is improved by adding one runner and two in-gates, the filling time is prolonged from 4.0 s to 4.5 s, the filling of molten metal becomes stable, but this casting does not follow the sequence solidification either. Some shrinkage porosity is also observed in the hot spots of the casting. When the gating system was further improved by adding risers and chill to the hot spots of the casting, the shrinkage porosity defects were eliminated completely. Finally, by using the optimized gating system the A356 aluminum alloy intake manifold casting with integrated shape and smooth surface as well as dense microstructure was successfully produced.

An Electron Microscopy Study of Graphite Growth in Nodular Cast Irons

Science.gov (United States)

Laffont, L.; Jday, R.; Lacaze, J.

2018-04-01

Growth of graphite during solidification and high-temperature solid-state transformation has been investigated in samples cut out from a thin-wall casting which solidified partly in the stable (iron-graphite) and partly in the metastable (iron-cementite) systems. Transmission electron microscopy has been used to characterize graphite nodules in as-cast state and in samples having been fully graphitized at various temperatures in the austenite field. Nodules in the as-cast material show a twofold structure characterized by an inner zone where graphite is disoriented and an outer zone where it is well crystallized. In heat-treated samples, graphite nodules consist of well-crystallized sectors radiating from the nucleus. These observations suggest that the disoriented zone appears because of mechanical deformation when the liquid contracts during its solidification in the metastable system. During heat-treatment, the graphite in this zone recrystallizes. In turn, it can be concluded that nodular graphite growth mechanism is the same during solidification and solid-state transformation.

Solidification processing of intermetallic Nb-Al alloys

Science.gov (United States)

Smith, Preston P.; Oliver, Ben F.; Noebe, Ronald D.

1992-01-01

Several Nb-Al alloys, including single-phase NbAl3 and the eutectic of Nb2Al and NbAl3, were prepared either by nonconsumable arc melting in Ar or by zone processing in He following initial induction melting and rod casting, and the effect of the solidification route on the microstructure and room-temperature mechanical properties of these alloys was investigated. Automated control procedures and melt conditions for directional solidification of NbAl3 and the Nb2Al/Nb3Al eutectic were developed; high purity and stoichiometry were obtained. The effects of ternary additions of Ti and Ni are described.

Determining casting defects in near-net shape casting aluminum parts by computed tomography

Science.gov (United States)

Li, Jiehua; Oberdorfer, Bernd; Habe, Daniel; Schumacher, Peter

2018-03-01

Three types of near-net shape casting aluminum parts were investigated by computed tomography to determine casting defects and evaluate quality. The first, second, and third parts were produced by low-pressure die casting (Al-12Si-0.8Cu-0.5Fe-0.9Mg-0.7Ni-0.2Zn alloy), die casting (A356, Al-7Si-0.3Mg), and semi-solid casting (A356, Al-7Si-0.3Mg), respectively. Unlike die casting (second part), low-pressure die casting (first part) significantly reduced the formation of casting defects (i.e., porosity) due to its smooth filling and solidification under pressure. No significant casting defect was observed in the third part, and this absence of defects indicates that semi-solid casting could produce high-quality near-net shape casting aluminum parts. Moreover, casting defects were mostly distributed along the eutectic grain boundaries. This finding reveals that refinement of eutectic grains is necessary to optimize the distribution of casting defects and reduce their size. This investigation demonstrated that computed tomography is an efficient method to determine casting defects in near-net shape casting aluminum parts.

Microstructural evolution in Mg-Zn alloys during solidification: An experimental and simulation study

Science.gov (United States)

Paliwal, Manas; Jung, In-Ho

2014-05-01

A comprehensive microstructural evolution of Mg-1.5, 4.0 and 5.5 wt% Zn alloys with respect to the solidification parameters such as thermal gradient (G), solidification velocity (V), cooling rate (GV) and solute (Zn) content were investigated in the present study. Solidification techniques such as directional solidification and wedge casting were employed in order to obtain cooling rates between 0.05 and 250 K/s. Microstructural features such as secondary dendrite arm spacing (SDAS), primary dendrite arm spacing (PDAS), microsegregration along the secondary dendrites and secondary phase fractions were experimentally determined. A solidification model that incorporates solute back diffusion, secondary arm coarsening, dendrite tip undercooling and dynamically linked with accurate thermodynamic databases is used to explain the experimental results.

Chemical casting of high-Tc superconducting BiSCCO

International Nuclear Information System (INIS)

Toth, L.E.; Das, B.N.; Rayne, R.J.; Bender, B.A.; Lechter, W.L.; Hoff, H.A.; Osofsky, M.S.; Soulen, R.J. Jr.

1989-01-01

BiSCCO has been successfully cast into a number of useful shapes. This casting process differs significantly from traditional casting in that the process includes a change in the oxygen content of the melt. A heat treatment is required to restore the original chemistry, properly form the BiSCCO crystal structure and develop the superconducting properties. This paper emphasizes the microstructures of as-cast and heat treated BiSCCO. Casting causes considerable grain alignment of the BiSCCO platelets. The platelets align preferentially along the thermal gradients which exist during the solidification process

Modeling of TiAl Alloy Grating by Investment Casting

OpenAIRE

Yi Jia; Shulong Xiao; Jing Tian; Lijuan Xu; Yuyong Chen

2015-01-01

The investment casting of TiAl alloys has become the most promising cost-effective technique for manufacturing TiAl components. This study aimed to investigate a series of problems associated with the investment casting of TiAl alloys. The mold filling and solidification of this casting model were numerically simulated using ProCAST. Shrinkage porosity was quantitatively predicted by a built-in feeding criterion. The results obtained from the numerical simulations were compared with experimen...

A new casting defect healing technology

Energy Technology Data Exchange (ETDEWEB)

Hodge, E.S.; Reddoch, T.W. [ForMat Industries, Inc., Knoxville, TN (United States); Viswanathan, S. [Oak Ridge National Lab., TN (United States)

1997-01-01

A new technology is presented for healing of defects in 356 aluminium alloys that provides economic upgrading of these cast alloys. It uses pneumatic isostatic forging (PIF) to produce high quality Al alloys products with enhanced mechanical properties uniform throughout the part, allowing higher design allowables and increased usage of Al alloy castings. The fundamental mechanism underlying PIF is a single mode plastic deformation process that uses isostatic application of pressures for 10-30 seconds at temperature. The process can be integrated in-line with other production operations, i.e., using the latent heat from the previous casting step. Results of applying the PIF process indicate lower cost and significant improvement in mechanical properties that rival and often exceed corresponding properties of other technologies like hot isostatic pressing and related processes. This process offers many advantages that are described in this paper in addition to presenting case histories of property enhancement by PIF and the mechanism responsible for property enhancement.

Validation Studies of Temperature Distribution and Mould Filling Process for Composite Skeleton Castings

Directory of Open Access Journals (Sweden)

M. Cholewa

2007-07-01

Full Text Available In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of composite skeleton casting and mould filling process (Fig. 4, 5, 6. The basic subject of the computer simulation was the analysis of ability of metal to fill the channels creating the skeleton shape and prepared in form of a core. Analysis of filling for each consecutive levels of the skeleton casting was conducted for simulation results and real casting. The skeleton casting was manufactured according to proposed technology (Fig. 5. Number of fully filled nodes in simulation was higher than obtained in experimental studies. It was observed in the experiment, that metal during pouring did not flow through the whole channel section, what enabled possibilities of reducing the channel section and pointed out the necessity of local pressure increase.

Section thickness-dependent tensile properties of squeeze cast magnesium alloy AM60

Directory of Open Access Journals (Sweden)

Xuezhi Zhang

2012-05-01

Full Text Available The development of alternative casting processes is essential for the high demand of light weight magnesium components to be used in the automotive industry, which often contain different section thicknesses. Squeeze casting with its inherent advantages has been approved for the capability of minimizing the gas porosity in magnesium alloys. For advanced engineering design of light magnesium automotive applications, it is critical to understand the effect of section thickness on mechanical properties of squeeze cast magnesium alloys. In this study, magnesium alloy AM60 with different section thicknesses of 6, 10 and 20 mm squeeze cast under an applied pressure of 30 MPa was investigated. The prepared squeeze cast AM60 specimens were tensile tested at room termperature. The results indicate that the mechanical properties including yield strength (YS, ultimate tensile strength (UTS and elongation (A decrease with an increase in section thickness of squeeze cast AM60. The microstructure analysis shows that the improvement in the tensile behavior of squeeze cast AM60 is primarily attributed to the low-gas porosity level and fine grain strucuture which result from the variation of cooling rate of different section thickness. The numerical simulation (Magmasoft? was employed to determine the solidification rates of each step, and the simulated results show that the solidification rate of the alloy decreases with an increase in the section thickness. The computed solidification rates support the experimental observation on grain structural development.

The deformation of wax patterns and castings in investment casting technology

Directory of Open Access Journals (Sweden)

A. Herman

2012-01-01

Full Text Available The dimensional accuracy of the final casting of Inconel alloy 738 LC is affected by many aspects. One of them is the choice of method and time of cooling wax model for precision investment casting. The main objective was to study the initial deformation of the complex shape of the casting of the rotor blades. Various approaches have been tested for cooling wax pattern. When wax models are cooling on the air, without clamping in jig for cooling, deviations from the ideal shape of the casting are very noticeable (up to 8 mm and most are in extreme positions of the model. When blade is cooled in fixing jig in water environment, the resulting deviations compared with cooling in air are significantly larger, sometimes up to 10 mm. This itself does not mean that the final shape of the casting is dimensionally more accurate with usage of wax models, which have deviations from the ideal position smaller. Another deformation occurs when shell mould is produced around wax pattern and furthermore deformations emerge while casting of blade is cooling. This paper demonstrates first steps in describing complex process of deformations of Inconel alloy blades produced with investment casting technology by comparing results from thermal imagery, simulations in foundry simulation software ProCAST 2010 and measurements from CNC scanning system Carl Zeiss MC 850. Conclusions are so far not groundbreaking, but it seems deformations of wax pattern and deformations of castings do in some cases cancel each other by having opposite directions. Describing entirely whole process of deformations will help increase precision of blade castings so that models at the beginning and blades in the end are the same.

Heat and fluid flow during rapid solidification of non-equilibrium materials

International Nuclear Information System (INIS)

Negli, S.C.; Eddingfield, D.L.; Brower, W.E. Jr.

1990-01-01

Rapid solidification technology (RST) is an advanced solidification process which is being utilized to produce non-equilibrium structures with properties not previously available with conventionally cast materials. An iron based alloy rapidly quenched to form a metallic glass is being installed on a large scale in electric power transformers where it cuts heat losses dramatically. The formation of a non-equilibrium structure usually requires a cooling rate of at least a million degrees per second. Achieving this high a cooling rate depends not only on the heat transfer conditions during the quenching process, but also on the fluid flow conditions in the molten metal before and during solidification. This paper presents a model of both heat and fluid flow during RST by the hammer and anvil method. The symmetry of two sided cooling permits analysis which is still applicable to the one sided cooling that occurs during melt spinning, the prevalent method of RST. The heat flow is modeled as one dimensional, normal to the quench surface. Previous models have shown the heat flow in the plane of the quench surface not to be significant. The fluid flow portion of the model utilizes the squeeze film solution for flow between two parallel flat plates. The model predicts the effects of superheat of the melt and of the quench hammer speed upon cooling rate during the formation of nonequilibrium phases. An unexpected result is that increased superheat results in much higher cooling rates, due to fluid flow before a potential transformation would take place; this enhanced liquid metal flow results in a thinner section casting which in turn has a dominant effect on the cooling rate. The model also predicts an expanded regime of Newtonian (interface controlled) cooling by about a factor of ten as compared to previous model of RST

Influence of silicon content and heat treatment on wear resistance of white chromium cast irons under high speed solidification conditions; Influencia del contenido de silicio y el tratamiento termico en la resistencia al desgaste de fundiciones blancas al cromo en condiciones de rapida solidificacion

Energy Technology Data Exchange (ETDEWEB)

Goyo, L.; Varela, A.; Verhaege, M.; Garcia, A.; Mier, J.; Moors, M.

2012-11-01

The influence of silicon content and heat treatment on microstructure, abrasive and dry friction wear resistance of a 3 % C, 12 % Cr cast iron, under fast solidification conditions is studied. The fast solidification condition diminishes the carbide volume and the silicon content increases their dispersion and finesses. All matrixes obtained were perlitics, whit different finesses. No intermediate transformation products were noticed. Hardness had little variation. Austenization treatment show little effectivity, with tendency to increase wear in reference to as cast and maintenance treatments. Behavior under dry friction and abrasive wear were similar under test conditions applied whit more influence of carbide morphology in the abrasive wear conditions. (Author) 32 refs.

Solidification Technologies for Radioactive and Chemical Liquid Waste Treatment - Final CRADA Report

International Nuclear Information System (INIS)

Castiglioni, Andrew J.; Gelis, Artem V.

2016-01-01

This project, organized under DOE/NNSA's Global Initiatives for Proliferation Prevention program, joined Russian and DOE scientists in developing more effective solidification and storage technologies for liquid radioactive waste. Several patent applications were filed by the Russian scientists (Russia only) and in 2012, the technology developed was approved by Russia's Federal State Unitary Enterprise RADON for application throughout Russia in cleaning up and disposing of radioactive waste.

Polymer solidification national program

International Nuclear Information System (INIS)

Kalb, P.D.; Colombo, P.

1993-04-01

Brookhaven National Laboratory (BNL) has developed several new and innovative polymer processes for the solidification of low-level radioactive, hazardous and mixed wastes streams. Polyethylene and modified sulfur cement solidification technologies have undergone steady, gradual development at BNL over the past nine years. During this time they have progressed through each of the stages necessary for logical technology maturation: from process conception, parameter optimization, waste form testing, evaluation of long-term durability, economic analysis, and scale-up feasibility. This technology development represents a significant investment which can potentially provide DOE with both short- and long-term savings

Fracture Mechanisms in Steel Castings

Directory of Open Access Journals (Sweden)

Stradomski Z.

2013-09-01

Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

Cellular automaton modelling of ductile iron microstructure in the thin wall casting

International Nuclear Information System (INIS)

Burbelko, A A; Gurgul, D; Kapturkiewicz, W; Górny, M

2012-01-01

The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD) calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the ductile iron solidification in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration.

Effect of electromagnetic vibration on the microstructure of direct chill cast Al-Zn-Mg-Cu alloy

International Nuclear Information System (INIS)

Zuo, Y; Fu, X; Zhu, Q; Li, L; Wang, P; Cui, J

2016-01-01

An electromagnetic vibration was achieved by the combined application of an alternating magnetic field and a stationary magnetic field during direct chill (DC) casting process. The ingots with 200 mm in diameter were prepared under the influence of electromagnetic vibration. The effect of electromagnetic vibration on the microstructure of an Al-Zn-Mg-Cu alloy was studied. The results showed that electromagnetic vibration has a significant effect on the solidification behaviour, under the influence of electromagnetic vibration during DC casting process, the microstructure is significantly refined and the uniformity of microstructure is evidently improved. This paper introduces the DC casting technology with the application of electromagnetic vibration, presents these results and gives corresponding discussions. (paper)

Crystallization characteristics of cast aluminum alloys during a unidirectional solidification process

Energy Technology Data Exchange (ETDEWEB)

Okayasu, Mitsuhiro, E-mail: mitsuhiro.okayasu@utoronto.ca; Takeuchi, Shuhei

2015-05-01

The crystal orientation characteristics of cast Al–Si, Al–Cu and Al–Mg alloys produced by a unidirectional solidification process are examined. Two distinct crystal orientation patterns are observed: uniform and random formation. A uniform crystal orientation is created by columnar growth of α-Al dendrites in the alloys with low proportions of alloying element, e.g., the Al–Si alloy (with Si <12.6%) and the Al–Cu and Al–Mg alloys (with Cu and Mg <2%). A uniformly organized crystal orientation with [100] direction is created by columnar growth of α-Al dendrites. With increasing proportion of alloying element (>2% Cu or Mg), the uniform crystal orientations collapse in the Al–Cu and Al–Mg alloys, owing to interruption of the columnar α-Al dendrite growth as a result of different dynamics of the alloying atoms and the creation of a core for the eutectic phases. For the hypo-eutectic Al–Si alloys, a uniform crystal orientation is obtained. In contrast, a random orientation can be detected in the hyper-eutectic Al–Si alloy (15% Si), which results from interruption of the growth of the α-Al dendrites due to precipitation of primary Si particles. There is no clear effect of crystal formation on ultimate tensile strength (UTS), whereas crystal orientation does influence the material ductility, with the alloys with a uniform crystal orientation being elongated beyond their UTS points and with necking occurring in the test specimens. In contrast, the alloys with a nonuniform crystal orientation are not elongated beyond their UTS points.

Crystallization characteristics of cast aluminum alloys during a unidirectional solidification process

International Nuclear Information System (INIS)

Okayasu, Mitsuhiro; Takeuchi, Shuhei

2015-01-01

The crystal orientation characteristics of cast Al–Si, Al–Cu and Al–Mg alloys produced by a unidirectional solidification process are examined. Two distinct crystal orientation patterns are observed: uniform and random formation. A uniform crystal orientation is created by columnar growth of α-Al dendrites in the alloys with low proportions of alloying element, e.g., the Al–Si alloy (with Si <12.6%) and the Al–Cu and Al–Mg alloys (with Cu and Mg <2%). A uniformly organized crystal orientation with [100] direction is created by columnar growth of α-Al dendrites. With increasing proportion of alloying element (>2% Cu or Mg), the uniform crystal orientations collapse in the Al–Cu and Al–Mg alloys, owing to interruption of the columnar α-Al dendrite growth as a result of different dynamics of the alloying atoms and the creation of a core for the eutectic phases. For the hypo-eutectic Al–Si alloys, a uniform crystal orientation is obtained. In contrast, a random orientation can be detected in the hyper-eutectic Al–Si alloy (15% Si), which results from interruption of the growth of the α-Al dendrites due to precipitation of primary Si particles. There is no clear effect of crystal formation on ultimate tensile strength (UTS), whereas crystal orientation does influence the material ductility, with the alloys with a uniform crystal orientation being elongated beyond their UTS points and with necking occurring in the test specimens. In contrast, the alloys with a nonuniform crystal orientation are not elongated beyond their UTS points

EVALUATION OF SOLIDIFICATION/STABILIZATION AS A BEST DEMONSTRATED AVAILABLE TECHNOLOGY FOR CONTAMINATED SOILS

Science.gov (United States)

This project involved the evaluation of solidification/stabilization technology as a BDAT for contaminated soil. Three binding agents were used on four different synthetically contaminated soils. Performance evaluation data included unconfined compressive strength (UCS) and the T...

Advances in Solidification Processing

Directory of Open Access Journals (Sweden)

Hugo F. Lopez

2015-08-01

Full Text Available Melt solidification is the shortest and most viable route to obtain components, starting from the design to the finished products. Hence, a sound knowledge of the solidification of metallic materials is essential for the development of advanced structural metallic components that drive modern technological societies. As a result, there have been innumerable efforts and full conferences dedicated to this important subject [1–6]. In addition, there are various scientific journals fully devoted to investigating the various aspects which give rise to various solidification microstructures [7–9]. [...

Mechanical Properties of Al-Si-Mg Alloy Castings as a Function of Structure Refinement and Porosity Fraction

Directory of Open Access Journals (Sweden)

Hajkowski M.

2012-12-01

Full Text Available During design of the casting products technology, an important issue is a possibility of prediction of mechanical properties resulting from the course of the casting solidification process. Frequently there is a need for relations describing mechanical properties of silumin alloys as a function of phase refinement in a structure and a porosity fraction, and relations describing phase refinement in the structure and the porosity fraction as a function of solidification conditions. The study was conducted on castings of a 22 mm thick plate, made of EN AC-AlSi7Mg0,3 alloy in moulds: of quartz sand, of quartz sand with chill and in permanent moulds. On the basis of cooling curves, values of cooling rate in various casting parts were calculated. The paper also presents results of examination of distance between arms in dendrites of a solid solution α (DASL, precipitations length of silicon in an eutectic (DlSi and gas-shrinkage porosity (Por as a function of cooling rate. Statistical relations of DASL, DlSi, Por as a function of cooling rate and statistical multiparameter dependencies describing mechanical properties (tensile strength, yield strength, elongation of alloy as a function of DASL, DlSi and Por are also presented in the paper.

Additional grain refinement in recrystallization controlled rolling of Ti-microalloyed steels processed by near-net-shape casting technology

International Nuclear Information System (INIS)

Arribas, M.; Lopez, B.; Rodriguez-Ibabe, J.M.

2008-01-01

This paper analyzes the recrystallization kinetics in Ti-microalloyed steels processed using 'beam blank' casting technology. The faster solidification rates associated with this technology brings a finer precipitation of TiN particles which are very effective in controlling austenite grain growth during hot working. Furthermore, these small precipitates have been shown to delay static and dynamic recrystallization. The finer the precipitates the higher the delay in recrystallization. Nevertheless, beyond particle size and distribution, the level of delay is very dependent on microstructure (above all austenite grain size) and deformation conditions (strain and temperature). This paper studies the effects of this recrystallization delay on the microstructure evolution during hot rolling. Special attention was paid to the study of the occurrence of partial recrystallization during the final stages of rolling, which could lead to the presence of mixed microstructures before transformation. The possibility of achieving an additional austenite grain size refinement prior to transformation was evaluated

A Casting Yield Optimization Case Study: Forging Ram

DEFF Research Database (Denmark)

Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

2010-01-01

This work summarizes the findings of multi-objective optimization of a gravity sand-cast steel part for which an increase of the casting yield via riser optimization was considered. This was accomplished by coupling a casting simulation software package with an optimization module. The benefits...... of this approach, recently adopted in foundry industry world wide and based on fully automated computer optimization, were demonstrated. First, analyses of filling and solidification of the original casting design were conducted in the standard simulation environment to determine potential flaws and inadequacies...

Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

Energy Technology Data Exchange (ETDEWEB)

Thangirala, Mani

2015-09-30

The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynes 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which

Centrifugal Casting Features/Metallurgical Characterization of Aluminum Alloys

International Nuclear Information System (INIS)

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

2008-01-01

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

Aeronautical Cast Ti Alloy and Forming Technology Development

OpenAIRE

ZHANG Meijuan; NAN Hai; JU Zhongqiang; GAO Fuhui; QIE Xiwang; ZHU Langping

2016-01-01

The application and feature of Ti alloy and TiAl alloy for aviation at home and abroad were briefly introduced. According to the patent application status in Ti alloy field, the development of Ti alloy casting technology was analyzed in the recent thirty years, especially the transformation in aviation. Along with the development of aeronautional manufacturing technology and demand of high performance aircraft, Ti alloy casting is changing towards to be large, integral and complicated, and th...

Relationship Between Solidification Microstructure and Hot Cracking Susceptibility for Continuous Casting of Low-Carbon and High-Strength Low-Alloyed Steels: A Phase-Field Study

Science.gov (United States)

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

2013-08-01

Hot cracking is one of the major defects in continuous casting of steels, frequently limiting the productivity. To understand the factors leading to this defect, microstructure formation is simulated for a low-carbon and two high-strength low-alloyed steels. 2D simulation of the initial stage of solidification is performed in a moving slice of the slab using proprietary multiphase-field software and taking into account all elements which are expected to have a relevant effect on the mechanical properties and structure formation during solidification. To account for the correct thermodynamic and kinetic properties of the multicomponent alloy grades, the simulation software is online coupled to commercial thermodynamic and mobility databases. A moving-frame boundary condition allows traveling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. From the simulation results, significant microstructure differences between the steel grades are quantitatively evaluated and correlated with their hot cracking behavior according to the Rappaz-Drezet-Gremaud (RDG) hot cracking criterion. The possible role of the microalloying elements in hot cracking, in particular of traces of Ti, is analyzed. With the assumption that TiN precipitates trigger coalescence of the primary dendrites, quantitative evaluation of the critical strain rates leads to a full agreement with the observed hot cracking behavior.

Investigation of solidification behavior of the Sn-rich ternary Sn–Bi–Zn alloys

Directory of Open Access Journals (Sweden)

S Mladenović

2017-03-01

Full Text Available Solidification properties and microstructure of six as-cast Sn–Bi–Zn alloys with 80 at.% of Sn and variable contents of Bi and Zn were experimentally investigated using the scanning electron microscopy (SEM with energy-dispersive X-ray spectroscopy (EDS and differential scanning calorimetry (DSC. The experimentally obtained results were compared with predicted phase equilibria according to the calculation of phase diagram (CALPHAD method and by the Scheil solidification simulation.

Technology for producing synthetic cast iron for nuclear power station parts

International Nuclear Information System (INIS)

Blozhko, N.K.; Kurochkin, V.S.; Narkevich, E.A.; Nikitin, L.A.; Petrov, L.A.

1984-01-01

A technology was developed and implemented for producing grades SCh-30 through SCh-40 synthetic cast iron in industrial-frequency induction melting furnaces. Alternative innoculations with ferrosilicon and silicocalcium and alloying with chrome and nickel were studied. The mechanical properties and structure of cast irons produced by various technological methods were studied. The research showed that the sector's plants, equipped with industrial-frequency induction furnaces, can produce high-quality synthetic cast irons containing flake graphite for nuclear-power-station casting, without the use of expensive innoculants. Careful observance of the melting and innoculating technologies makes it possible to produce SCh 40 cast iron, without cementite inclusions, by innoculating with FS 75 ferrosilicon in the amount of 0.7% of the total melt weight. Using an innoculant mixture of 0.2% FS 75 and 0.5% SK 30 and low alloying with nickel and chromium, the cast-iron strength can be increased to 440-450 MPa, although the danger of cementite inclusions increase

Casting and stress-strain simulations of a cast ductile iron component using microstructure based mechanical behavior

International Nuclear Information System (INIS)

Olofsson, Jakob; Svensson, Ingvar L

2012-01-01

The industrial demand for increased component performance with concurrent reductions in component weight, development times and verifications using physical prototypes drives the need to use the full potential of casting and Finite Element Method (FEM) simulations to correctly predict the mechanical behavior of cast components in service. The mechanical behavior of the component is determined by the casting process, and factors as component geometry and casting process parameters are known to affect solidification and microstructure formation throughout the component and cause local variations in mechanical behavior as well as residual stresses. Though residual stresses are known to be an important factor in the mechanical behavior of the component, the importance of local mechanical behavior is not well established and the material is typically considered homogeneous throughout the component. This paper deals with the influence of solidification and solid state transformation on microstructure formation and the effect of local microstructure variations on the mechanical behavior of the cast component in service. The current work aims to investigate the coupling between simulation of solidification, microstructure and local variations in mechanical behavior and stress-strain simulation. This is done by performing several simulations of a ductile iron component using a recently developed simulation strategy, a closed chain of simulations for cast components, able to predict and describe the local variations in not only elastic but also plastic behavior throughout the component by using microstructural parameters determined by simulations of microstructural evolution in the component during the casting process. In addition the residual stresses are considered. The results show that the FEM simulation results are significantly affected by including microstructure based mechanical behavior. When the applied load is low and the component is subjected to stress levels

Recent Advances in Study of Solid-Liquid Interfaces and Solidification of Metals

Directory of Open Access Journals (Sweden)

Mohsen Asle Zaeem

2018-02-01

Full Text Available Solidification occurs in several material processing methods, such as in casting, welding, and laser additive manufacturing of metals, and it controls the nano- and microstructures, as well as the overall properties of the products[...

Prediction of as-cast grain size of inoculated aluminum alloys melt solidified under non-isothermal conditions

International Nuclear Information System (INIS)

Du, Qiang; Li, Yanjun

2015-01-01

In this paper, a multi-scale as-cast grain size prediction model is proposed to predict as-cast grain size of inoculated aluminum alloys melt solidified under non-isothermal condition, i.e., the existence of temperature gradient. Given melt composition, inoculation and heat extraction boundary conditions, the model is able to predict maximum nucleation undercooling, cooling curve, primary phase solidification path and final as-cast grain size of binary alloys. The proposed model has been applied to two Al-Mg alloys, and comparison with laboratory and industrial solidification experimental results have been carried out. The preliminary conclusion is that the proposed model is a promising suitable microscopic model used within the multi-scale casting simulation modelling framework. (paper)

Effect of Solidification Behavior on Microstructures and Mechanical Properties of Ni-Cr-Fe Superalloy Investment Casting

Science.gov (United States)

Kang, Maodong; Wang, Jun; Gao, Haiyan; Han, Yanfeng; Wang, Guoxiang; He, Shuxian

2017-01-01

The effect of solidification behavior on the microstructures and mechanical properties of Ni-Cr-Fe superalloy investment casting is given. Metallographic and image analysis have been used to quantitatively examine the microstructures’ evolution. For the parts with the thickness of 3 mm and 24 mm, the volume fraction and maximum equivalent radius of the Laves phase increases from 0.3% to 1.2%, from 11.7 μm to 23.4 μm, respectively. Meanwhile, the volume fraction and maximum equivalent radius of carbides increase from 0.3% to 0.5%, from 8.1 μm to 9.9 μm, respectively. In addition, the volume fraction of microporosity increases from 0.3% to 2.7%. As a result, the ultimate tensile strength is reduced from 1125.5 MPa to 820.9 MPa, the elongation from 13.3% to 7.7%, and the quality index from 1294.2 MPa to 954.0 MPa, respectively. A typical brittle fracture is observed on the tensile fracture. As the cooling rate decreases, the microstructures become coarser. PMID:28772611

Undercooling, nodule count and carbides in thin walled ductile cast iron

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Tiedje, Niels Skat

2008-01-01

Ductile cast iron has been cast in plate thicknesses between 2 to 8 mm. The temperature has been measured during the solidification and the graphite nodule count and size distribution together with the type and amount of carbides have been analysed afterwards. Low nodule count gives higher...

New insight on glass-forming ability and designing Cu-based bulk metallic glasses: The solidification range perspective

International Nuclear Information System (INIS)

Wu, Jili; Pan, Ye; Li, Xingzhou; Wang, Xianfei

2014-01-01

Highlights: • The equation, T rg = T g /T l , was rotationally modified to T rg = κ(T m /T l ) + C/T l . • The newly generalized equation suggests a way for describing glass-forming ability. • Several new Cu-based bulk metallic glasses were discovered by solidification range. - Abstract: In this paper, a new equation was rationally generalized from the reduced glass transition temperature. This equation indicates that solidification range can be used for describing glass-forming ability, which can be calculated with the aid of computational thermodynamic approach. Based on this scenario, several new Cu-based bulk metallic glasses in the ternary Cu–Zr–Ti alloy system were discovered. The as-cast samples were characterized by X-ray diffraction and transmission electronic microscopy. The results indicate that as-cast samples have monolithic amorphous nature. Thermal analysis validates that the smaller solidification range is closely related to the higher glass-forming ability, which is contributed to the effect of solidification time on the formation of bulk metallic glasses. This work also suggests that solidus can influence glass formation

Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts

International Nuclear Information System (INIS)

Sonne, M R; Hattel, J H; Frandsen, J O

2015-01-01

In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than for the chill casting, resulting in a very course microstructure. From the simulations the nodule count is found to be 17 nodules per mm 2 and 159 nodules per mm 2 for the sand and chill casting, respectively, in the critical region of the main bearing seat. This is verified from nodule counts performed on the real cast main shafts. Residual stress evaluations show an overall increase of the maximum principal stress field for the chill casting, which is expected. However, the stresses are found to be in compression on the surface of the chill cast main shaft, which is unforeseen. (paper)

Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts

DEFF Research Database (Denmark)

Sonne, Mads Rostgaard; Frandsen, J. O.; Hattel, Jesper Henri

2015-01-01

In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than...... for the chill casting, resulting in a very course microstructure.From the simulations the nodule count is found to be 17 nodules per mm2 and 159 nodules permm2 for the sand and chill casting, respectively, in the critical region of the main bearing seat.This is verified from nodule counts performed on the real...... cast main shafts. Residual stressevaluations show an overall increase of the maximum principal stress field for the chill casting,which is expected. However, the stresses are found to be in compression on the surface of thechill cast main shaft, which is unforeseen....

Characteristics of Cement Solidification of Metal Hydroxide Waste

Directory of Open Access Journals (Sweden)

Dae-Seo Koo

2017-02-01

Full Text Available To perform the permanent disposal of metal hydroxide waste from electro-kinetic decontamination, it is necessary to secure the technology for its solidification. The integrity tests on the fabricated solidification should also meet the criteria of the Korea Radioactive Waste Agency. We carried out the solidification of metal hydroxide waste using cement solidification. The integrity tests such as the compressive strength, immersion, leach, and irradiation tests on the fabricated cement solidifications were performed. It was also confirmed that these requirements of the criteria of Korea Radioactive Waste Agency on these cement solidifications were met. The microstructures of all the cement solidifications were analyzed and discussed.

Characteristics of cement solidification of metal hydroxide waste

Energy Technology Data Exchange (ETDEWEB)

Koo, Dae Seo; Sung, Hyun Hee; Kim, Seung Soo; Kim, Gye Nam; Choi, Jong Won [Dept. of Decontemination Decommission Technology Development, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-02-15

To perform the permanent disposal of metal hydroxide waste from electro-kinetic decontamination, it is necessary to secure the technology for its solidification. The integrity tests on the fabricated solidification should also meet the criteria of the Korea Radioactive Waste Agency. We carried out the solidification of metal hydroxide waste using cement solidification. The integrity tests such as the compressive strength, immersion, leach, and irradiation tests on the fabricated cement solidifications were performed. It was also confirmed that these requirements of the criteria of Korea Radioactive Waste Agency on these cement solidifications were met. The microstructures of all the cement solidifications were analyzed and discussed.

Application of a novel cellular automaton porosity prediction model to aluminium castings

International Nuclear Information System (INIS)

Atwood, R.C.; Chirazi, A.; Lee, P.D.

2002-01-01

A multiscale model was developed to predict the formation of porosity within a solidifying aluminium-silicon alloy. The diffusion of silicon and dissolved gas was simulated on a microscopic scale combined with cellular automaton models of gas porosity formation within the growing three-dimensional solidification microstructure. However, due to high computational cost, the modelled volume is limited to the millimetre range. This renders the application of direct modelling of complex shape castings unfeasible. Combining the microstructural modelling with a statistical response-surface prediction method allows application of the microstructural model results to industrial scale casts by incorporating them in commercial solidification software. (author)

Microstructure and Corrosion Resistance Property of a Zn-AI-Mg Alloy with Different Solidification Processes

Directory of Open Access Journals (Sweden)

Jiang Guang-rui

2017-01-01

Full Text Available Zn-Al-Mg alloy coating attracted much attention due to its high corrosion resistance properties, especially high anti-corrosion performance at the cut edge. As the Zn-Al-Mg alloy coating was usually produced by hot-dip galvanizing method, solidification process was considered to influence its microstructure and corrosion properties. In this work, a Zn-Al-Mg cast alloy was melted and cooled to room temperature with different solidification processes, including water quench, air cooling and furnace cooling. Microstructure of the alloy with different solidification processes was characterized by scanning electron microscopy (SEM. Result shows that the microstructure of the Zn-Al-Mg alloy are strongly influenced by solidification process. With increasing solidification rate, more Al is remained in the primary crystal. Electrochemical analysis indicates that with lowering solidification rate, the corrosion current density of the Zn-Al-Mg alloy decreases, which means higher corrosion resistance.

Refining processes in the copper casting technology

OpenAIRE

Rzadkosz, S.; Kranc, M.; Garbacz-Klempka, A.; Kozana, J.; Piękoś, M.

2015-01-01

The paper presents the analysis of technology of copper and alloyed copper destined for power engineering casts. The casts quality was assessed based on microstructure, chemical content analysis and strength properties tests. Characteristic deoxidising (Logas, Cup) and modifying (ODM2, Kupmod2) formulas were used for the copper where high electrical conductivity was required. Chosen examples of alloyed copper with varied Cr and Zr content were studied, and the optimal heat treatment parameter...

Numerical and experimental investigation of the melt casting of explosives

Energy Technology Data Exchange (ETDEWEB)

Sun, Dawei; Garimella, Suresh V. [School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907-2088 (United States); Singh, Sanjeev; Naik, Neelam [US Army Armaments Research, Development and Engineering Center, Picatinny Arsenal, NJ 07806 (United States)

2005-10-01

Melt casting of energetic materials is investigated, and a numerical model is formulated for the analysis of the coupled fluid flow, heat transfer, and stress fields involved in this phase-change process. The numerical model is based on a conservative multi block control volume method. The SIMPLE algorithm is employed along with an enthalpy method approach to model the solidification process. Results from the model are verified against analytical solutions, experimental results, and published numerical results for simplified cases. In the melt casting of RDX-binder mixtures, the very high viscosity of the melt limits the influence of melt convection. The impacts of different cooling conditions on the velocity, temperature and stress distributions, as well as on the solidification time, are discussed. The present model can be used to improve the quality of cast explosives, by optimizing and controlling the processing conditions. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

The solidification behavior of dilute aluminium-scandium alloys

International Nuclear Information System (INIS)

Norman, A.F.; Prangnell, P.B.; McEwen, R.S.

1998-01-01

The solidification behavior of dilute Sc containing Al alloys has been investigated. In binary Al-Sc alloys, Sc additions greater than the eutectic composition (0.55 wt%) were found to produce a remarkable refinement in the grain size of aluminum castings, of two orders of magnitude, due to the formation of the primary Al 3 Sc intermetallic phase during solidification. The refinement in grain size only occurred in hypereutectic compositions and was shown to be far greater than can be achieved by conventional Al grain refiners. Grain refinement by the addition of Sc is accompanied by a change in growth morphology from dendritic, in the large unrefined grains, to fine spherical grains with a divorced eutectic appearing on the grain boundaries in the refined castings. Similar levels of refinement were observed in Al-Sc-Zr and Al-Cu-Sc alloys. In the latter, a change in the segregation behavior of Cu was observed, from a strongly interdendritic segregation pattern to a more homogeneous distribution. The supersaturated Al-Sc solid solution can decompose via a discontinuous precipitation reaction to form coherent rod-like precipitates of the L1 2 Al 3 Sc phase

Data Package for Secondary Waste Form Down-Selection-Cast Stone

International Nuclear Information System (INIS)

Serne, R. Jeffrey; Westsik, Joseph H.

2011-01-01

Available literature on Cast Stone and Saltstone was reviewed with an emphasis on determining how Cast Stone and related grout waste forms performed in relationship to various criteria that will be used to decide whether a specific type of waste form meets acceptance criteria for disposal in the Integrated Disposal Facility (IDF) at Hanford. After the critical review of the Cast Stone/Saltstone literature, we conclude that Cast Stone is a good candidate waste form for further consideration. Cast stone meets the target IDF acceptance criteria for compressive strength, no free liquids, TCLP leachate are below the UTS permissible concentrations and leach rates for Na and Tc-99 are suiteably low. The cost of starting ingredients and equipment necessary to generate Cast Stone waste forms with secondary waste streams are low and the Cast Stone dry blend formulation can be tailored to accommodate variations in liquid waste stream compositions. The database for Cast Stone short-term performance is quite extensive compared to the other three candidate waste solidification processes. The solidification of liquid wastes in Cast Stone is a mature process in comparison to the other three candidates. Successful production of Cast Stone or Saltstone has been demonstrated from lab-scale monoliths with volumes of cm3 through m3 sized blocks to 210-liter sized drums all the way to the large pours into vaults at Savannah River. To date over 9 million gallons of low activity liquid waste has been solidified and disposed in concrete vaults at Savannah River.

Data Package for Secondary Waste Form Down-Selection—Cast Stone

Energy Technology Data Exchange (ETDEWEB)

Serne, R. Jeffrey; Westsik, Joseph H.

2011-09-05

Available literature on Cast Stone and Saltstone was reviewed with an emphasis on determining how Cast Stone and related grout waste forms performed in relationship to various criteria that will be used to decide whether a specific type of waste form meets acceptance criteria for disposal in the Integrated Disposal Facility (IDF) at Hanford. After the critical review of the Cast Stone/Saltstone literature, we conclude that Cast Stone is a good candidate waste form for further consideration. Cast stone meets the target IDF acceptance criteria for compressive strength, no free liquids, TCLP leachate are below the UTS permissible concentrations and leach rates for Na and Tc-99 are suiteably low. The cost of starting ingredients and equipment necessary to generate Cast Stone waste forms with secondary waste streams are low and the Cast Stone dry blend formulation can be tailored to accommodate variations in liquid waste stream compositions. The database for Cast Stone short-term performance is quite extensive compared to the other three candidate waste solidification processes. The solidification of liquid wastes in Cast Stone is a mature process in comparison to the other three candidates. Successful production of Cast Stone or Saltstone has been demonstrated from lab-scale monoliths with volumes of cm3 through m3 sized blocks to 210-liter sized drums all the way to the large pours into vaults at Savannah River. To date over 9 million gallons of low activity liquid waste has been solidified and disposed in concrete vaults at Savannah River.

Novel casting processes for single-crystal turbine blades of superalloys

Science.gov (United States)

Ma, Dexin

2018-03-01

This paper presents a brief review of the current casting techniques for single-crystal (SC) blades, as well as an analysis of the solidification process in complex turbine blades. A series of novel casting methods based on the Bridgman process were presented to illustrate the development in the production of SC blades from superalloys. The grain continuator and the heat conductor techniques were developed to remove geometry-related grain defects. In these techniques, the heat barrier that hinders lateral SC growth from the blade airfoil into the extremities of the platform is minimized. The parallel heating and cooling system was developed to achieve symmetric thermal conditions for SC solidification in blade clusters, thus considerably decreasing the negative shadow effect and its related defects in the current Bridgman process. The dipping and heaving technique, in which thinshell molds are utilized, was developed to enable the establishment of a high temperature gradient for SC growth and the freckle-free solidification of superalloy castings. Moreover, by applying the targeted cooling and heating technique, a novel concept for the three-dimensional and precise control of SC growth, a proper thermal arrangement may be dynamically established for the microscopic control of SC growth in the critical areas of large industrial gas turbine blades.

Additive Manufacturing and Casting Technology Comparison: Mechanical Properties, Productivity and Cost Benchmark

Science.gov (United States)

Vevers, A.; Kromanis, A.; Gerins, E.; Ozolins, J.

2018-04-01

The casting technology is one of the oldest production technologies in the world but in the recent years metal additive manufacturing also known as metal 3D printing has been evolving with huge steps. Both technologies have capabilities to produce parts with internal holes and at first glance surface roughness is similar for both technologies, which means that for precise dimensions parts have to be machined in places where precise fit is necessary. Benchmark tests have been made to find out if parts which are produced with metal additive manufacturing can be used to replace parts which are produced with casting technology. Most of the comparative tests have been made with GJS-400-15 grade which is one of the most popular cast iron grades. To compare mechanical properties samples have been produced using additive manufacturing and tested for tensile strength, hardness, surface roughness and microstructure and then the results have been compared with the samples produced with casting technology. In addition, both technologies have been compared in terms of the production time and production costs to see if additive manufacturing is competitive with the casting technology. The original paper has been written in the Latvian language as part of the Master Thesis within the framework of the production technology study programme at Riga Technical University.

Quality evaluation of cast Al-SiCp composites

International Nuclear Information System (INIS)

Adalarasu, S.; Mahadevan, S.; Satyanarayana, K.G.; Pai, B.C.; Pillai, R.M.

1996-01-01

This paper presents a methodology for using x-ray radiography and ultrasonic for testing the soundness and distribution of dispersoids and identifying the casting defects in a cast aluminium cast alloy matrix SiCp composites. The ultrasonic inspection could detect in 6061-SiCp cast composites 1) the presence of low levels of locked in stresses and 2) existence of local imperfection due to the combined effects of the local solidification condition and the presence of the dispersoids which were not possible through x-ray radiography. This clearly suggests that ultrasonic test can be used as a powerful NDE tool for screening the composite ingots. (author)

Wafer level hermetic packaging based on Cu-Sn isothermal solidification technology

International Nuclear Information System (INIS)

Cao Yuhan; Luo Le

2009-01-01

A novel wafer level bonding method based on Cu-Sn isothermal solidification technology is established. A multi-layer sealing ring and the bonding processing are designed, and the amount of solder and the bonding parameters are optimized based on both theoretical and experimental results. Verification shows that oxidation of the solder layer, voids and the scalloped-edge appearance of the Cu 6 Sn 5 phase are successfully avoided. An average shear strength of 19.5 MPa and an excellent leak rate of around 1.9 x 10 -9 atm cc/s are possible, meeting the demands of MIL-STD-883E. (semiconductor technology)

The role and impact of 3D printing technologies in casting

Directory of Open Access Journals (Sweden)

Jin-wu Kang

2017-05-01

Full Text Available 3D printing is such a magical technology that it extends into almost every sector relating to manufacturing, not to mention casting production. In this paper, the past, present and future of 3D printing in the foundry sector are profoundly reviewed. 3D printing has the potential to supplement or partially replace the casting method. Today, some castings can be directly printed by metal powders, for example, titanium alloys, nickel alloys and steel parts. Meanwhile, 3D printing has found an unique position in other casting aspects as well, such as printing the wax pattern, ceramic shell, sand core, sand mould, etc. Most importantly, 3D printing is not just a manufacturing method, it will also revolutionize the design of products, assemblies and parts, such as castings, patterns, cores, moulds and shells in casting production. The solid structure of castings and moulds will be redesigned in future into truss or spatially open and skeleton structures. This kind of revolution is just sprouting, but it will bring unimaginable impact on manufacturing including casting production. Nobody doubts the potential of 3D printing technologies in manufacturing, but they do have limitations and drawbacks.

Fluid flow solidification simulation of molten alloys

International Nuclear Information System (INIS)

Kaschnitz, E.

1997-01-01

In an effort to minimize costs and to obtain optimum designs, computer simulation of shape casting processes is more and more used as a development tool. Accurate predictions are possible by means of three dimensional fluid flow and solidification modelling. The bases of the model are the transient laminar Navier-Stokes-equations for a Newtonian fluid including the tracking of the free surface. They are describing the melt flow pattern during the mold filling sequence. Simultaneously, the temperature development in the alloy and mold is calculated using Fourier's heat transfer equation. At OEGI, a commercial software package (MAGMAsoft) with a finite difference equation solver is used for improvement of casting processes. Different examples of industrial applications will be shown. (author)

Kinetics modeling of delta-ferrite formation and retainment during casting of supermartensitic stainless steel

DEFF Research Database (Denmark)

Nießen, Frank; Tiedje, Niels Skat; Hald, John

2017-01-01

The kinetics model for multi-component diffusion DICTRA was applied to analyze the formation and retainment of δ-ferrite during solidification and cooling of GX4-CrNiMo-16-5-1 cast supermartensitic stainless steel. The obtained results were compared with results from the Schaeffler diagram......, equilibrium calculations and the Scheil model in Thermo-Calc, and validated by using microscopy and energy dispersive X-ray spectroscopy for chemical analysis on a cast ingot. The kinetics model showed that micro-segregation from solidification homogenizes within 2–3 s (70 °C) of cooling, and that retained δ...

Microstructural characterization of second phase regions in cast stainless steels

International Nuclear Information System (INIS)

Hoelzer, D.; Kenik, E.A.; Rowcliffe, A.F.; Busby, J.; Vitek, J.M.

2007-01-01

Full text of publication follows: Cast austenitic stainless steels offer the possibility of directly producing large and/or relatively complex structures, such as the first wall shield modules or the divertor cassette for the International Tokamak Experimental Reactor (ITER). Unfortunately, one of the inherent problems associated with casting stainless steel, especially large castings, is the formation of coarse dendrites with possibly inhomogeneously distributed second phases separated by up to several hundred microns in the microstructure. These microstructural features result from temperature and composition gradients that develop during solidification and subsequent cooling. However, detailed characterization of the second phase regions in the cast microstructures can be quite challenging to techniques such as transmission electron microscopy (TEM), which is useful for phase identification. furthermore, the information about the phases that may be present in the cast microstructures, both equilibrium and nonequilibrium, is important as input as well as for confirming predictions made by computational thermodynamics and solidification modeling. In this study, the investigation of second phase regions that formed in a large cast of a 316 stainless steel (equivalent to CF3M) will be presented and compared to simulations of the phases predicted by computational thermodynamic modeling of the solidification process. The preliminary TEM investigation of the cast microstructure was performed with specimens that were prepared by jet-polishing of 3 mm diameter discs. Although this approach allowed for the identification of the sigma and chi phases, which was consistent with the simulations, it was not suitable for detailed analysis of the second phase regions since these specimens often contained only grains of the gamma austenite phase. A better approach for preparing TEM specimens consisted of strategically lifting small sections of material from second phase regions

Thermodynamic modeling of mineralogical phases formed by continuous casting powders

International Nuclear Information System (INIS)

Romo-Castaneda, Julio; Cruz-Ramirez, Alejandro; Romero-Serrano, Antonio; Vargas-Ramirez, Marissa; Hallen-Lopez, Manuel

2011-01-01

A great amount of mineralogical phases were predicted and represented in stability phase diagrams, which were obtained by the use of the thermodynamic software FACTSage considering both the chemical composition and the melting temperature of the mould flux. Melting-solidification tests on commercial mould flux glasses for thin slab casting of steel revealed the existence of cuspidine (Ca 4 Si 2 O 7 F 2 ) as the main mineralogical phase formed during the flux solidification by X-ray powder diffraction (XRD). This phase directly influences the heat transfer phenomena from the strand to the mould and it is obtained with higher fluorite content (22% CaF 2 ). Cuspidine is desirable only in fluxes to produce medium carbon (included peritectic grade) steels, because it reduces the heat flux from the strand to the mould, thus controlling the shrinkage rate during the flux solidification. The experimental results are in agreement with those obtained by the thermodynamic software. The stability phase diagrams could be used as an important tool in the flux design for continuous casting process.

Thermodynamic modeling of mineralogical phases formed by continuous casting powders

Energy Technology Data Exchange (ETDEWEB)

Romo-Castaneda, Julio [Metallurgy and Materials Department, Instituto Politecnico Nacional-ESIQIE, Apdo. P. 118-431, 07051 Mexico D.F. (Mexico); Cruz-Ramirez, Alejandro, E-mail: alcruzr@ipn.mx [Metallurgy and Materials Department, Instituto Politecnico Nacional-ESIQIE, Apdo. P. 118-431, 07051 Mexico D.F. (Mexico); Romero-Serrano, Antonio; Vargas-Ramirez, Marissa; Hallen-Lopez, Manuel [Metallurgy and Materials Department, Instituto Politecnico Nacional-ESIQIE, Apdo. P. 118-431, 07051 Mexico D.F. (Mexico)

2011-01-10

A great amount of mineralogical phases were predicted and represented in stability phase diagrams, which were obtained by the use of the thermodynamic software FACTSage considering both the chemical composition and the melting temperature of the mould flux. Melting-solidification tests on commercial mould flux glasses for thin slab casting of steel revealed the existence of cuspidine (Ca{sub 4}Si{sub 2}O{sub 7}F{sub 2}) as the main mineralogical phase formed during the flux solidification by X-ray powder diffraction (XRD). This phase directly influences the heat transfer phenomena from the strand to the mould and it is obtained with higher fluorite content (22% CaF{sub 2}). Cuspidine is desirable only in fluxes to produce medium carbon (included peritectic grade) steels, because it reduces the heat flux from the strand to the mould, thus controlling the shrinkage rate during the flux solidification. The experimental results are in agreement with those obtained by the thermodynamic software. The stability phase diagrams could be used as an important tool in the flux design for continuous casting process.

Variations of Microsegregation and Second Phase Fraction of Binary Mg-Al Alloys with Solidification Parameters

Science.gov (United States)

Paliwal, Manas; Kang, Dae Hoon; Essadiqi, Elhachmi; Jung, In-Ho

2014-07-01

A systematic experimental investigation on microsegregation and second phase fraction of Mg-Al binary alloys (3, 6, and 9 wt pct Al) has been carried out over a wide range of cooling rates (0.05 to 700 K/s) by employing various casting techniques. In order to explain the experimental results, a solidification model that takes into account dendrite tip undercooling, eutectic undercooling, solute back diffusion, and secondary dendrite arm coarsening was also developed in dynamic linkage with an accurate thermodynamic database. From the experimental data and solidification model, it was found that the second phase fraction in the solidified microstructure is not determined only by cooling rate but varied independently with thermal gradient and solidification velocity. Lastly, the second phase fraction maps for Mg-Al alloys were calculated from the solidification model.

On the role of solidification modelling in Integrated Computational Materials Engineering “ICME”

International Nuclear Information System (INIS)

Schmitz, G J; Böttger, B; Apel, M

2016-01-01

Solidification during casting processes marks the starting point of the history of almost any component or product. Integrated Computational Materials Engineering (ICME) [1-4] recognizes the importance of further tracking the history of microstructure evolution along the subsequent process chain. Solidification during joining processes in general happens quite late during production, where the parts to be joined already have experienced a number of processing steps which affected their microstructure. Reliable modelling of melting and dissolution of these microstructures represents a key issue before eventually modelling ‘re’-solidification e.g. during welding or soldering. Some instructive examples of microstructure evolution during a joining process obtained on the basis of synthetic and simulated initial microstructures of an Al-Cu binary model system are discussed. (paper)

Technological control of slip casting by the method of PMR

International Nuclear Information System (INIS)

Rozental', O.M.; Toropov, Yu.S.; Sobolev, A.S.; Pliner, S.Yu.; Demina, T.E.; Permikina, I.M.

1980-01-01

The method of proton magnetic resonance (PMR) is suggested for operational chemico-technological control of slip casting made of oxides of metals in the technology of technical ceramics. PMR spectra of finely dispersed slip casting made of aluminium and zirconium oxides (0.9 mol. of the ZrO 2 shake + 0.1 V 2 O 3 ) are analysed. It is shown that the quality of slip casting out of aqueous suspensions of aluminium and zirconium oxides is abruptly reduced if dP/dW (P - parameter of the PMR line shape, W - humidity) decrease. It is established that slip casting made of zirconium oxide should not be kept in the air more than 5 days, and that of aluminium oxide, more than 3 days at room temperature and should not be exposed to high (> 105 deg C) temperatures. The quality of slip casting is reduced in the regime of too energetic electrosedimentation the optimum regime of electrosedimentation is approximately 5/3 under the conditions of the above experiment

Fibreglass Total Contact Casting, Removable Cast Walkers, and Irremovable Cast Walkers to Treat Diabetic Neuropathic Foot Ulcers: A Health Technology Assessment

Science.gov (United States)

Costa, Vania; Tu, Hong Anh; Wells, David; Weir, Mark; Holubowich, Corinne; Walter, Melissa

2017-01-01

Background Diabetic neuropathic foot ulcers are a risk factor for lower leg amputation. Many experts recommend offloading with fibreglass total contact casting, removable cast walkers, and irremovable cast walkers as a way to treat these ulcers. Methods We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences for offloading devices. We performed a systematic literature search on August 17, 2016, to identify randomized controlled trials that compared fibreglass total contact casting, removable cast walkers, and irremovable cast walkers with other treatments (offloading or non-offloading) in patients with diabetic neuropathic foot ulcers. We developed a decision-analytic model to assess the cost-effectiveness of fibreglass total contact casting, removable cast walkers, and irremovable cast walkers, and we conducted a 5-year budget impact analysis. Finally, we interviewed people with diabetes who had lived experience with foot ulcers, asking them about the different offloading devices and the factors that influenced their treatment choices. Results We identified 13 randomized controlled trials. The evidence suggests that total contact casting, removable cast walkers, and irremovable cast walkers are beneficial in the treatment of neuropathic, noninfected foot ulcers in patients with diabetes but without severe peripheral arterial disease. Compared to removable cast walkers, ulcer healing was improved with total contact casting (moderate quality evidence; risk difference 0.17 [95% confidence interval 0.00–0.33]) and irremovable cast walkers (low quality evidence; risk difference 0.21 [95% confidence interval 0.01–0.40]). We found no difference in ulcer healing between total contact casting and irremovable cast walkers (low quality evidence; risk difference 0.02 [95% confidence interval −0.11–0.14]). The economic analysis showed that total contact casting and irremovable

Modelling the solidification of ductile cast iron parts with varying wall thicknesses

DEFF Research Database (Denmark)

Bjerre, Mathias Karsten; Tiedje, Niels Skat; Thorborg, Jesper

2015-01-01

] with a 2D FE solution of the heat conduction equation is developed in an in-house code and model parameters are calibrated using experimental data from representative castings made of ductile cast iron. The main focus is on the influence of casting thickness and resulting local cooling conditions...

Direct chill casting of aluminium alloys under electromagnetic interaction by permanent magnet assembly

Science.gov (United States)

Bojarevičs, Andris; Kaldre, Imants; Milgrāvis, Mikus; Beinerts, Toms

2018-05-01

Direct chill casting is one of the methods used in industry to obtain good microstructure and properties of aluminium alloys. Nevertheless, for some alloys grain structure is not optimal. In this study, we offer the use of electromagnetic interaction to modify melt convection near the solidification interface. Solidification under various electromagnetic interactions has been widely studied, but usually at low solidification velocity and high thermal gradient. This type of interaction may succeed fragmentation of dendrite arms and transport of solidification nuclei thus leading to improved material structure and properties. Realization of experimental small-scale crystallizer and electromagnetic system has been described in this article.

Liquid-liquid phase separation and solidification behavior of Al55Bi36Cu9 monotectic alloy with different cooling rates

Science.gov (United States)

Bo, Lin; Li, Shanshan; Wang, Lin; Wu, Di; Zuo, Min; Zhao, Degang

2018-03-01

The cooling rate has a significant effect on the solidification behavior and microstructure of monotectic alloy. In this study, different cooling rate was designed through casting in the copper mold with different bore diameters. The effects of different cooling rate on the solidification behavior of Al55Bi36Cu9 (at.%) immiscible alloy have been investigated. The liquid-liquid phase separation of Al55Bi36Cu9 immiscible alloy melt was investigated by resistivity test. The solidification microstructure and phase analysis of Al55Bi36Cu9 immiscible alloy were performed by the SEM and XRD, respectively. The results showed that the liquid-liquid phase separation occurred in the solidification of Al55Bi36Cu9 monotectic melt from 917 °C to 653 °C. The monotectic temperature, liquid phase separation temperature and immiscibility zone of Al55Bi36Cu9 monotectic alloy was lower than those of Al-Bi binary monotectic alloy. The solidification morphology of Al55Bi36Cu9 monotectic alloy was very sensitive to the cooling rate. The Al/Bi core-shell structure formed when Al55Bi36Cu9 melt was cast in the copper mold with a 8 mm bore diameter.

Simulation of Stress Distribution in a Thick- Walled Bushing Produced by Die-Casting

Directory of Open Access Journals (Sweden)

Pisarek B.P.

2017-12-01

Full Text Available Metallographic investigations and a computer simulation of stresses in a gravity die-casting bushing were performed. Simulation of the casting process, solidification of the thick-walled bushing and calculations of the stress was performed using MAGMA5.3 software. The size variability of phases κII affecting the formation of phase stresses σf, depending on the location of the metallographic test area, was identified. The distribution of thermal σt and shrinkage stresses σs, depending on the location of the control point SC in the bushing's volume, was estimated. Probably the nature of these stresses will change slightly even after machining. This can cause variations in operating characteristics (friction coefficient, wear. Due to the strong inhomogeneity of the stress distribution in the bushing's casting, it is necessary to perform further tests of the possibility to conduct thermal treatment guaranteeing homogenization of the internal stresses in the casting, as well as to introduce changes in the bushing' s construction and the casting technology. The paper presents the continuation of the results of research aimed at identifying the causes of defects in the thick-walled bushing, die-casting made of CuAl10Fe5Ni5Cr aluminium bronze.

Modelling of Eutectic Saturation Influence on Microstructure in Thin Wall Ductile Iron Casting Using Cellular Automata

Directory of Open Access Journals (Sweden)

Burbelko A.A.

2012-12-01

Full Text Available The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the ductile iron solidification in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration. Calculation of eutectic saturation influence (Sc = 0.9 - 1.1 on microstructure (austenite and graphite fraction, density of austenite and graphite grains and temperature curves in 2 mm wall ductile iron casting has been done.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Cast Stone Technology For The Treatment And Immobilization Of Low-Activity Waste

International Nuclear Information System (INIS)

Minwall, H.J.

2011-01-01

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.

Simulation and Experimental Study on the Steady Conduction Solution for Continuous Rheo-Casting for A356 Alloy

Energy Technology Data Exchange (ETDEWEB)

Duc, Do Minh; Hai, Nguyen Hong; Quang, Pham [Hanoi University of Science and Technology (HUST), Hanoi (Viet Nam)

2017-03-15

Computational fluid dynamic modeling of a continuous rheo-casting technology was conducted, consistent with the manufacturing of 3 {sup mm-thin} plates made of aluminum alloy A356. The A numerical simulation on of the stabilizing time of the material crystallization was carried out using the ANSYS FLUENT code. Solidification and melting models were simulated with heat transfer and solid-liquid phase transformation involving the latent heat of crystallization were simulated. The calculated temperature distribution and the evolution of cooling rate through the material were examined and used to clarify their influence on microstructure, and further investigated with hardness testing. The thickness of the mushy zone was determined for the steady conduction solution of the continuous rheo-casting process.

Fatigue and Fracture Resistance of Heavy-Section Ferritic Ductile Cast Iron

Directory of Open Access Journals (Sweden)

Matteo Benedetti

2017-03-01

Full Text Available In this paper, we explore the effect of a long solidification time (12 h on the mechanical properties of an EN-GJS-400-type ferritic ductile cast iron (DCI. For this purpose, static tensile, rotating bending fatigue, fatigue crack growth and fracture toughness tests are carried out on specimens extracted from the same casting. The obtained results are compared with those of similar materials published in the technical literature. Moreover, the discussion is complemented with metallurgical and fractographic analyses. It has been found that the long solidification time, representative of conditions arising in heavy-section castings, leads to an overgrowth of the graphite nodules and a partial degeneration into chunky graphite. With respect to minimum values prescribed for thick-walled (t > 60 mm EN-GJS-400-15, the reduction in tensile strength and total elongation is equal to 20% and 75%, respectively. The rotating bending fatigue limit is reduced by 30% with respect to the standard EN-1563, reporting the results of fatigue tests employing laboratory samples extracted from thin-walled castings. Conversely, the resistance to fatigue crack growth is even superior and the fracture toughness comparable to that of conventional DCI.

Numerical Simulation of Cast Distortion in Gas Turbine Engine Components

International Nuclear Information System (INIS)

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

2015-01-01

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

Cloud-Based Speech Technology for Assistive Technology Applications (CloudCAST).

Science.gov (United States)

Cunningham, Stuart; Green, Phil; Christensen, Heidi; Atria, José Joaquín; Coy, André; Malavasi, Massimiliano; Desideri, Lorenzo; Rudzicz, Frank

2017-01-01

The CloudCAST platform provides a series of speech recognition services that can be integrated into assistive technology applications. The platform and the services provided by the public API are described. Several exemplar applications have been developed to demonstrate the platform to potential developers and users.

Solidification of Magnesium (AM50A) / vol%. SiCp composite

International Nuclear Information System (INIS)

Zhang, X; Hu, H

2012-01-01

Magnesium matrix composite is one of the advanced lightweight materials with high potential to be used in automotive and aircraft industries due to its low density and high specific mechanical properties. The magnesium composites can be fabricated by adding the reinforcements of fibers or/and particles. In the previous literature, extensive studies have been performed on the development of matrix grain structure of aluminum-based metal matrix composites. However, there is limited information available on the development of grain structure during the solidification of particulate-reinforced magnesium. In this work, a 5 vol.% SiC p particulate-reinforced magnesium (AM50A) matrix composite (AM50A/SiC p ) was prepared by stir casting. The solidification behavior of the cast AM50A/SiC p composite was investigated by computer-based thermal analysis. Optical and scanning electron microscopies (SEM) were employed to examine the occurrence of nucleation and grain refinement involved. The results indicate that the addition of SiC p particulates leads to a finer grain structure in the composite compared with the matrix alloy. The refinement of grain structure should be attributed to both the heterogeneous nucleation and the restricted primary crystal growth.

Direct Metal Laser Sintering: A Digitised Metal Casting Technology

OpenAIRE

Venkatesh, K. Vijay; Nandini, V. Vidyashree

2013-01-01

Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

Direct metal laser sintering: a digitised metal casting technology.

Science.gov (United States)

Venkatesh, K Vijay; Nandini, V Vidyashree

2013-12-01

Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

Solidification structure and abrasion resistance of high chromium white irons

Science.gov (United States)

Doğan, Ö. N.; Hawk, J. A.; Laird, G.

1997-06-01

Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.

A comparative study of ternary Al-Sn-Cu immiscible alloys prepared by conventional casting and casting under high-intensity ultrasonic irradiation

Energy Technology Data Exchange (ETDEWEB)

Kotadia, H.R., E-mail: hiren.kotadia@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Das, A. [Materials Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Doernberg, E.; Schmid-Fetzer, R. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

2011-12-15

Highlights: Black-Right-Pointing-Pointer Systematic investigation on the solidification microstructure of ternary Al-Sn-Cu immiscible system aided by computational thermodynamics calculations. Black-Right-Pointing-Pointer Comparative study of conventional casting and casting under high-intensity ultrasonic irradiation. Black-Right-Pointing-Pointer Demonstrated the high effectiveness of ultrasound exposure during solidification. Black-Right-Pointing-Pointer Effect of cavitation on nucleation and the relative effects of cavitation and acoustic streaming on the dispersion of Sn-rich liquid phases have been explained from the experimental observation. Cavitation was found to promote fragmentation and dispersion of Sn-rich liquid leading to homogeneous dispersion of refined Sn phase. Microstructural modification was found to be contributed by cavitation and associated shockwave generation while bulk fluid flow under acoustic streaming was found to be less effective on the microstructure evolution. Black-Right-Pointing-Pointer Globular and highly refined {alpha}-Al formed near the radiator through enhanced heterogeneous nucleation in contrast to dendritic {alpha}-Al observed in conventional solidification. - Abstract: A comparative study on the microstructure of four ternary Al-Sn-Cu immiscible alloys, guided by the recent thermodynamic assessment of the system, was carried out with specific focus on the soft Sn particulate distribution in hard Al-rich matrix in the presence and absence of ultrasonic irradiation during solidification. The results clearly demonstrate high effectiveness of ultrasonication in promoting significantly refined and homogeneously dispersed microstructure, probably aided by enhanced nucleation and droplet fragmentation under cavitation. While conventional solidification produced highly segregated Sn phase at the centre and bottom of Sn-rich alloy ingots, ultrasonic treatment produced effective dispersion irrespective of the alloy constitution in

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

International Nuclear Information System (INIS)

Chuan Huat Ng; Grote, Karl-Heinrich; Baehr, Ruediger

2007-01-01

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

Investigation of the effects of cooling rate on the microstructure of investment cast biomedical grade Co alloys

International Nuclear Information System (INIS)

Kaiser, R; Browne, D J; Williamson, K

2012-01-01

The objective of this work is to determine the microstructural characteristics of investment cast cobalt alloy as the cross-sectional area is varied, thus changing the local effective cooling rates and solidification times. The extent of published work on the as-cast properties of cobalt alloys is minimal. The primary aim of this work is therefore to extend knowledge of the behaviour of such alloys as they solidify, which will influence the design of new products as well as the industrial optimisation of the casting process. Wedge-shaped parts were cast from a biomedical grade cobalt alloy employing the method of lost wax investment casting. Analytical techniques such as optical microscopy, image analysis and microhardness testing were used to characterise the as-cast parts. Parameters studied include variations in grain structure, nature of the columnar and equiaxed zones and the spread of porosity (both shrinkage and gas). Changes in microstructure were compared to microhardness values obtained. The solidification profile of the alloy through the prototype cast component was investigated based on measurement of the dendrite arm spacings. A discussion on the physical phenomena controlling the microstructural variations is presented.

Rapidly cast crystalline thin sheet materials

International Nuclear Information System (INIS)

Warlimont, H.; Emmerich, K.

1986-01-01

The current state and progress of casting thin sheet and ribbons directly from the melt are reviewed. First, the solidification phenomena pertinent to the process are outlined. Subsequently, Fe-Si,l Fe-Si-Al, Fe-Nd-B, Ag-Cu-Ti, alloy steels, Ni superalloys and Si are treated as examples. Finally, the information available on process development is critically assessed

Mathematical Modelling of the Thermical Regime in the Continous Casting Process

Directory of Open Access Journals (Sweden)

Monika Erika POPA

2005-10-01

Full Text Available Continuous casting is one of the prominent methods of production of casts. Effective design and operation of continuous casting machines needs complete analysis of the continuous casting process. In this paper the basic principles of continuous casting and its heat transfer analysis using the finite element method are presented. In the analysis phase change is assumed to take place at constant temperature. A front tracking algorithm has been developed to predict the position of the solidification front at each step. Finally, examples that are solved by the proposed algorithm are discussed. The results show that there is a good agreement between the method developed in this work and other previously reported works.

Melting, solidification, remelting, and separation of glass and metal

International Nuclear Information System (INIS)

Ebadian, M.A.; Xin, R.C.; Liu, Y.Z.

1998-01-01

Several high-temperature vitrification technologies have been developed for the treatment of a wide range of mixed waste types in both the low-level waste and transuranic (TRU) mixed waste categories currently in storage at DOE sites throughout the nation. The products of these processes are an oxide slag phase and a reduced metal phase. The metal phase has the potential to be recycled within the DOE Complex. Enhanced slag/metal separation methods are needed to support these processes. This research project involves an experimental investigation of the melting, solidification, remelting, and separation of glass and metal and the development of an efficient separation technology. The ultimate goal of this project is to find an efficient way to separate the slag phase from the metal phase in the molten state. This two-year project commenced in October 1995 (FY96). In the first fiscal year, the following tasks were accomplished: (1) A literature review and an assessment of the baseline glass and metal separation technologies were performed. The results indicated that the baseline technology yields a high percentage of glass in the metal phase, requiring further separation. (2) The main melting and solidification system setup was established. A number of melting and solidification tests were conducted. (3) Temperature distribution, solidification patterns, and flow field in the molten metal pool were simulated numerically for the solidification processes of molten aluminum and iron steel. (4) Initial designs of the laboratory-scale DCS and CS technologies were also completed. The principal demonstration separation units were constructed. (5) An application for a patent for an innovative liquid-liquid separation technology was submitted and is pending

Modeling of TiAl Alloy Grating by Investment Casting

Directory of Open Access Journals (Sweden)

Yi Jia

2015-12-01

Full Text Available The investment casting of TiAl alloys has become the most promising cost-effective technique for manufacturing TiAl components. This study aimed to investigate a series of problems associated with the investment casting of TiAl alloys. The mold filling and solidification of this casting model were numerically simulated using ProCAST. Shrinkage porosity was quantitatively predicted by a built-in feeding criterion. The results obtained from the numerical simulations were compared with experiments, which were carried out on Vacuum Skull Furnace using an investment block mold. The investment casting of TiAl grating was conducted for verifying the correctness and feasibility of the proposed method. The tensile test results indicated that, at room temperature, the tensile strength and elongation were approximately 675 MPa and 1.7%, respectively. The microstructure and mechanical property of the investment cast TiAl alloy were discussed.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Simulation and Experimental Study on the Steady Conduction Solution for Continuous Rheo-Casting for A356 Alloy

International Nuclear Information System (INIS)

Duc, Do Minh; Hai, Nguyen Hong; Quang, Pham

2017-01-01

Computational fluid dynamic modeling of a continuous rheo-casting technology was conducted, consistent with the manufacturing of 3 "m"m"-"t"h"i"n plates made of aluminum alloy A356. The A numerical simulation on of the stabilizing time of the material crystallization was carried out using the ANSYS FLUENT code. Solidification and melting models were simulated with heat transfer and solid-liquid phase transformation involving the latent heat of crystallization were simulated. The calculated temperature distribution and the evolution of cooling rate through the material were examined and used to clarify their influence on microstructure, and further investigated with hardness testing. The thickness of the mushy zone was determined for the steady conduction solution of the continuous rheo-casting process.

The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification

Directory of Open Access Journals (Sweden)

Szymaneka M.

2014-06-01

Full Text Available In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion.

Development of Thin Section Zinc Die Casting Technology

Energy Technology Data Exchange (ETDEWEB)

Goodwin, Frank [International Lead Zinc Research Org., Inc., Durham, NC (United States)

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.

OVERVIEW OF THE HISTORY, PRESENT STATUS, AND FUTURE DIRECTION OF SOLIDIFICATION/STABILIZATION TECHNOLOGIES FOR HAZARDOUS WASTE TREATMENT

Science.gov (United States)

Solidification/stabilization (S/S) technology processes are currently being utilized in the United States to treat inorganic and organic hazardous waste and radioactive waste. These wastes are generated from operating industry or have resulted from the uncontrolled management of ...

Microstructure analysis of AISI 304 stainless steel produced by twin-roll thin strip casting process

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

The microstructure of AISI 304 austenite stainless steel fabricated by the thin strip casting process were investigated using optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD).The microstructures of the casting strips show a duplex structure consisting of delta ferrite and austenite. The volume fraction of the delta ferrite is about 9.74vol% at the center and 6.77vol% at the surface of the casting thin strip, in vermicular and band shapes. On account of rapid cooling and solidification in the continuous casting process, many kinds of inclusions and precipitates have been found. Most of the inclusions and precipitates are spherical complex compounds consisting of oxides, such as, SiO2, MnO, Al2O3,Cr2O3,and FeO or their multiplicity oxides of MnO·Al2O3,2FeO·SiO2, and 2MnO·SiO2. Many defects including dislocations and stacking faults have also formed during the rapid cooling and solidification process, which is helpful to improve the mechanical properties of the casting strips.

On the relation between primary and eutectic solidification structures in gray iron

International Nuclear Information System (INIS)

Elmquist, L; Sonawane, P A

2012-01-01

The solidification of hypoeutectic gray cast iron starts with the nucleation of primary austenite crystals. Before graphite is nucleated, and the eutectic structure is formed, these crystals start to grow as columnar or equiaxed dendrites. However, very little is known about these dendrites, and especially how they influence the subsequent eutectic structure. Besides, it has previously been shown that the primary solidification structure influences the formation of defects. Shrinkage porosity was found between the dendrites, in the grain boundaries, and the formation of the primary solidification structure was found to influence problems related to metal expansion penetration. Therefore a better understanding about the formation of this structure is of importance. In this work, different inoculants and their influence on the formation of the micro- and macrostructures has been investigated. The inoculants considered are commercially used inoculants, i.e. inoculants used in the foundries, as well as different iron powders. The addition of iron powder is used to promote the primary solidification structure. It is shown that the nucleation of the dendrites is influenced by the amount of iron powder. Secondary dendrite arm spacing is a quantitative measurement in the microstructure related to these dendrites, which in turn depends on the solidification time. Eutectic cell size, on the other hand, is found to depend on secondary dendrite arm spacing. It is shown how the addition of inoculants influences both primary and eutectic solidification structures, and how they are related to each other.

Effect of Y additions on the solidification behavior of a copper mold cast CuZrAl alloy with high oxygen content

International Nuclear Information System (INIS)

Coury, F.G.; Batalha, W.; Botta, W.J.; Bolfarini, C.; Kiminami, C.S.

2014-01-01

Bulk glassy samples of the CuAlZr system were produced by copper mold casting in the form of wedges with different amounts of yttrium (0 , 0.3 and 2 at%) , the processing conditions led to high oxygen contents on the samples (1000ppm). A reportedly good glass-former composition was chosen as the base alloy, it’s nominal composition is Cu47Zr45Al8. This study aimed to understand the influence of oxygen and yttrium in the solidification of these alloys. The samples were analyzed by scanning and transmission electron microscopy, differential scanning calorimetry and X-Ray diffraction. The sequence of formation of crystalline phases in these alloys was determined as a function of the different cooling rates inherent in the process. It was observed that the formation of CuZr2 phase was inhibited in samples with Y allowing the production of a fully glassy 8mm. (author)

The Effect of Applied Pressure During Feeding of Critical Cast Aluminum Alloy Components With Particular Reference to Fatigue Resistance

Energy Technology Data Exchange (ETDEWEB)

J.T. Berry; R. Luck; B. Zhang; R.P. Taylor

2003-06-30

the medium to long freezing range alloys of aluminum such as A356, A357, A206, 319 for example are known to exhibit dispersed porosity, which is recognized as a factor affecting ductility, fracture toughness, and fatigue resistance of light alloy castings. The local thermal environment, for example, temperature gradient and freezing from velocity, affect the mode of solidification which, along with alloy composition, heat treatment, oxide film occlusion, hydrogen content, and the extent to which the alloy contracts on solidification, combine to exert strong effects on the porosity formation in such alloys. In addition to such factors, the availability of liquid metal and its ability to flow through the partially solidified casting, which will be affect by the pressure in the liquid metal, must also be considered. The supply of molten metal will thus be controlled by the volume of the riser available for feeding the particular casting location, its solidification time, and its location together with any external pressure that might be applied at the riser.

Kinetics of steel heavy ingot formation in dies of semicontinuous-casting machines

International Nuclear Information System (INIS)

Tsukerman, V.Ya.; Marchenko, I.K.

1986-01-01

Formation kinetics of round section ingot of up to 0.67 m in diameter was analyzed in dies of semicontinuous-casting machines on casting of the most usable assortment steels: medium-carbon low-alloyed and chromium-nickel stainless steels. It is established that solidification coefficient decreases in direct proportion to ingot diameter. Value of different-thickness ingot skin at die outlet is in direct proportion to a casted steel overheating temperature, ingot diameter and inversely proportional to the number and diameter of holes in a ladder nozzle and square root of ingot drawing rate

Use of a general-purpose heat-transfer code for casting simulation

International Nuclear Information System (INIS)

Erickson, W.C.

1975-07-01

The practical use of numerical techniques in simulating casting solidification dictate that a general purpose heat transfer code be used and that results be obtained in an easy-to-analyze format. Color film plotting routines were developed for use with NASA's CINDA-3G heat transfer code; the combination of which meet the above criteria. The subroutine LQSLTR written for SINDA, the successor to CINDA-3G, was verified by comparing calculated results obtained using LQSLTR with those obtained using the specific heat method for handling the heat of fusion. Excellent agreement existed when similar data was used. When the more restrictive requirement of a 1 0 F melting range was used, comparable results were obtained. Uranium and lead rod castings were cast in instrumented graphite molds and the solidification sequence simulated using CINDA-3G. Discrepancies attributed to initial assumptions of instantaneous mold filling, uniform melt temperature, and intimate metal/mold contact were encountered. Further calculations using a model incorporating a gap between the mold and casting showed that the intimate contact assumption could not be used; a three-dimensional model also showed that the thermocouple assemblies used with the platinum--platinum-10 percent rhodium were a significant perturbation to the system. An L-shaped steel casting was simulated and the results compared to those reported in the literature. The experimental data for this casting were reproduced within the accuracy permitted by the thermal conductivity of the sand, thus demonstrating that agreement can be obtained when the mold material does not act as a chill. (U.S.)

Development of High-Performance Cast Crankshafts. Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Bauer, Mark E [General Motors, Detroit, MI (United States)

2017-03-31

The objective of this project was to develop technologies that would enable the production of cast crankshafts that can replace high performance forged steel crankshafts. To achieve this, the Ultimate Tensile Strength (UTS) of the new material needs to be 850 MPa with a desired minimum Yield Strength (YS; 0.2% offset) of 615 MPa and at least 10% elongation. Perhaps more challenging, the cast material needs to be able to achieve sufficient local fatigue properties to satisfy the durability requirements in today’s high performance gasoline and diesel engine applications. The project team focused on the development of cast steel alloys for application in crankshafts to take advantage of the higher stiffness over other potential material choices. The material and process developed should be able to produce high-performance crankshafts at no more than 110% of the cost of current production cast units, perhaps the most difficult objective to achieve. To minimize costs, the primary alloy design strategy was to design compositions that can achieve the required properties with minimal alloying and post-casting heat treatments. An Integrated Computational Materials Engineering (ICME) based approach was utilized, rather than relying only on traditional trial-and-error methods, which has been proven to accelerate alloy development time. Prototype melt chemistries designed using ICME were cast as test specimens and characterized iteratively to develop an alloy design within a stage-gate process. Standard characterization and material testing was done to validate the alloy performance against design targets and provide feedback to material design and manufacturing process models. Finally, the project called for Caterpillar and General Motors (GM) to develop optimized crankshaft designs using the final material and manufacturing processing path developed. A multi-disciplinary effort was to integrate finite element analyses by engine designers and geometry-specific casting

Effect of vibration frequency on microstructure and performance of high chromium cast iron prepared by lost foam casting

Directory of Open Access Journals (Sweden)

Wen-qi Zou

2016-07-01

Full Text Available In the present research, high chromium cast irons (HCCIs were prepared using the lost foam casting (LFC process. To improve the wear resistance of the high chromium cast irons (HCCIs, mechanical vibration was employed during the solidification of the HCCIs. The effects of vibration frequency on the microstructure and performance of the HCCIs under as-cast, as-quenched and as-tempered conditions were investigated. The results indicated that the microstructures of the LFC-produced HCCIs were refined due to the introduction of mechanical vibration, and the hardness was improved compared to that of the alloy without vibration. However, only a slight improvement in hardness was found in spite of the increase of vibration frequency. In contrast, the impact toughness of the as-tempered HCCIs increased with an increase in the vibration frequency. In addition, the wear resistance of the HCCIs was improved as a result of the introduction of vibration and increased with an increase in the vibration frequency.

Review of production status of heavy steel castings and key technologies for their manufacture in China

Directory of Open Access Journals (Sweden)

Liu Baicheng

2008-02-01

Full Text Available This paper expatiates on domestic status of heavy steel casting production, with a special focus on hydraulic turbine castings for Three Gorges Project. In China, there is magnificent demand for heavy castings with the rapid growth of the national economy in recent years and the expected high growth in the coming 10 to 20 years. Some heavy and large castings such as mill housing and hydraulic turbine runner crown, blade and band for Three Gorges Project have been successfully made. However, the domestic production capability is still far from meeting the gigantic requirements. The domestic capability still lags behind the world class level, and a lot of heavy castings still depend on import. The paper also gives a particular introduction of the key technologies in the manufacturing of heavy steel castings like metal melting, foundry technology, heat treatment technology and numerical simulation technique, etc. In addition, several case studies on the application of numerical simulation in the production of heavy steel castings are presented.

Effect of Feeder Configuration on the Microstructure of Ductile Cast Iron

DEFF Research Database (Denmark)

Vedel-Smith, Nikolaj Kjelgaard; Tiedje, Niels Skat

2014-01-01

influence the soundness of different sections of the castings. Moreover, the microstructural changes due to variations in thermal gradients are classified, and the variations in the mushy zone described. The paper discusses how solidification and segregation influence porosity and microstructure of ductile...

Phase-field modelling of as-cast microstructure evolution in nickel-based superalloys

International Nuclear Information System (INIS)

Warnken, N.; Ma, D.; Drevermann, A.; Reed, R.C.; Fries, S.G.; Steinbach, I.

2009-01-01

A modelling approach is presented for the prediction of microstructure evolution during directional solidification of nickel-based superalloys. A phase-field model is coupled to CALPHAD thermodynamic and kinetic (diffusion) databases, so that a multicomponent alloy representative of those used in industrial practice can be handled. Dendritic growth and the formation of interdendritic phases in an isothermal (2-D) cross-section are simulated for a range of solidification parameters. The sensitivity of the model to changes in the solidification input parameters is investigated. It is demonstrated that the predicted patterns of microsegregation obtained from the simulations compare well to the experimental ones; moreover, an experimentally observed change in the solidification sequence is correctly predicted. The extension of the model to 3-D simulations is demonstrated. Simulations of the homogenization of the as-cast structure during heat treatment are presented.

Phase-field modelling of as-cast microstructure evolution in nickel-based superalloys

Energy Technology Data Exchange (ETDEWEB)

Warnken, N., E-mail: n.warnken@bham.ac.uk [University of Birmingham, Department of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom); Ma, D. [Foundry Institute of the RWTH-Aachen, Intzestr. 5, 52072 Aachen (Germany); Drevermann, A. [ACCESS e.V., Intzestr. 5, 52072 Aachen (Germany); Reed, R.C. [University of Birmingham, Department of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom); Fries, S.G. [SGF Consultancy, 52064 Aachen (Germany)] [ICAMS, Ruhr University Bochum, Stiepeler Strasse 129, D-44780 Bochum (Germany); Steinbach, I. [ICAMS, Ruhr University Bochum, Stiepeler Strasse 129, D-44780 Bochum (Germany)

2009-11-15

A modelling approach is presented for the prediction of microstructure evolution during directional solidification of nickel-based superalloys. A phase-field model is coupled to CALPHAD thermodynamic and kinetic (diffusion) databases, so that a multicomponent alloy representative of those used in industrial practice can be handled. Dendritic growth and the formation of interdendritic phases in an isothermal (2-D) cross-section are simulated for a range of solidification parameters. The sensitivity of the model to changes in the solidification input parameters is investigated. It is demonstrated that the predicted patterns of microsegregation obtained from the simulations compare well to the experimental ones; moreover, an experimentally observed change in the solidification sequence is correctly predicted. The extension of the model to 3-D simulations is demonstrated. Simulations of the homogenization of the as-cast structure during heat treatment are presented.

Cast Metals Coalition Technology Transfer and Program Management Final Report

Energy Technology Data Exchange (ETDEWEB)

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

A scaling analysis of alloy solidification in presence of electromagnetic stirring

International Nuclear Information System (INIS)

Kumar, Arvind; Dutta, Pradip

2006-01-01

Application of electromagnetic stirring (EMS) during continuous casting shears off the dendrites from the solidification front to produce billets with a non-dendritic microstructure. In the present study, a systematic approach to the scaling analysis of momentum, energy and species conservation equations pertaining to the case of the solidification of a binary alloy in the presence of EMS is outlined. With suitable choices of non-dimensionalizing parameters, the governing equations coupled with appropriate boundary conditions are first scaled, and then the relative significance of various terms appearing in them are analysed. In the physical domain two regions are identified, one where the electromagnetic forces play a dominant role in the momentum equations, and the other where the inertia and viscous effects play major roles. Using the scaling predictions, the influence of various processing parameters on the system variables can be utilized for the selection of appropriate electromagnetic forces to shear off the dendrites from the solidification area. For the sake of assessment of the scaling analysis, the predictions are validated against corresponding computational results

Technological Aspects of Low-Alloyed Cast Steel Massive Casting Manufacturing

Directory of Open Access Journals (Sweden)

Szajnara J.

2013-12-01

Full Text Available In the paper authors have undertaken the attempt of explaining the causes of cracks net occurrence on a massive 3-ton cast steel casting with complex geometry. Material used for casting manufacturing was the low-alloyed cast steel with increased wear resistance modified with vanadium and titanium. The studies included the primary and secondary crystallization analysis with use of TDA and the qualitative and quantitative analysis of non-metallic inclusions.

Validation of stress prediction during solidification of cast components

CSIR Research Space (South Africa)

Paine, AP

2007-07-01

Full Text Available to solidify and undergoes changes in phases where different material laws are valid. In the fluid state the metal is almost stress free but as the part starts to solidify and shrink, stresses are induced in the casting due to constraints from the mould. Some...

Microstructural investigation of D2 tool steel during rapid solidification

Science.gov (United States)

Delshad Khatibi, Pooya

Solidification is considered as a key processing step in developing the microstructure of most metallic materials. It is, therefore, important that the solidification process can be designed and controlled in such a way so as to obtain the desirable properties in the final product. Rapid solidification refers to the system's high undercooling and high cooling rate, which can yield a microstructure with unique chemical composition and mechanical properties. An area of interest in rapid solidification application is high-chromium, high-carbon tool steels which experience considerable segregation of alloying elements during their solidification in a casting process. In this dissertation, the effect of rapid solidification (undercooling and cooling rate) of D2 tool steel on the microstructure and carbide precipitation during annealing was explored. A methodology is described to estimate the eutectic and primary phase undercooling of solidifying droplets. The estimate of primary phase undercooling was confirmed using an online measurement device that measured the radiation energy of the droplets. The results showed that with increasing primary phase and eutectic undercooling and higher cooling rate, the amount of supersaturation of alloying element in metastable retained austenite phase also increases. In the case of powders, the optimum hardness after heat treatment is achieved at different temperatures for constant periods of time. Higher supersaturation of austenite results in obtaining secondary hardness at higher annealing temperature. D2 steel ingots generated using spray deposition have high eutectic undercooling and, as a result, high supersaturation of alloying elements. This can yield near net shape D2 tool steel components with good mechanical properties (specifically hardness). The data developed in this work would assist in better understanding and development of near net shape D2 steel spray deposit products with good mechanical properties.

Evaluation of microstructure of A356 aluminum alloy casting ...

Indian Academy of Sciences (India)

The objective of this investigation was to evaluate the effect of vibrations (during solidification) on the metallurgical properties of A356 aluminum casting. Mechanical vibrations were applied to A356 aluminum alloy through set up. A356 melt has been subjected to mechanical vibration with the frequency range from 0 to 400 ...

Interplay among solidification, microstructure, residual strain and hot tearing in B206 aluminum alloy

Energy Technology Data Exchange (ETDEWEB)

D’Elia, F., E-mail: f.delia10@gmail.com [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. East, Toronto, Ontario, Canada M5B 2K3 (Canada); Ravindran, C. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. East, Toronto, Ontario, Canada M5B 2K3 (Canada); Sediako, D. [Canadian Neutron Beam Centre, Chalk River Laboratories, Chalk River, Ontario, Canada K0J 1J0 (Canada)

2015-01-29

Hot tearing is a complex phenomenon attributed to alloy solidification, microstructure and stress/strain development within a casting. In this research, the conditions associated with the formation of hot tears in B206 aluminum alloy were investigated. Neutron diffraction strain mapping was carried out on three B206 castings with varying levels of titanium (i.e. unrefined, 0.02 and 0.05 wt%). Titanium additions effectively reduced grain size and transformed grain morphology from coarse dendrites to fine globular grains. Further, thermal analysis suggested that grain refinement delayed the onset of dendrite coherency in B206 and therefore enhanced the duration of bulk liquid metal feeding for the refined casting conditions. As a result, the interactive effects of such factors resulted in a more uniform distribution of strain, and subsequent higher resistance to hot tearing for the grain refined castings.

Continuation of Crosscutting Technology Development at Cast

Energy Technology Data Exchange (ETDEWEB)

Yoon, Roe-Hoan

2012-03-31

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

Sharing casting technological data on web site

Directory of Open Access Journals (Sweden)

Li Hailan

2008-11-01

Full Text Available Based on database and asp.net technologies, a web platform of scientific data in the casting technology fi eld has been developed. This paper presents the relevant data system structure, the approaches to the data collection, the applying methods and policy in data sharing, and depicts the collected and shared data recently fi nished. Statistics showed that there are about 20,000 visitors in China every day visiting the related data through the web, proving that many engineers or other relevant persons are interested in the data.

Effect and kinetic mechanism of ultrasonic vibration on solidification of 7050 aluminum alloy

Directory of Open Access Journals (Sweden)

Ripeng Jiang

2014-07-01

Full Text Available The work described in this paper dealt with the effect of ultrasonic vibration on the solidification of 7050 aluminum alloy. Two experiments were carried out through introducing ultrasound into the semi-continuous direct-chill (DC casting of aluminum alloy and into alloy solidifying in a crucible, respectively. Results show that ultrasonic vibration can refine grains in the whole cross-section of a billet in the first experiment and is able to increase the cooling rate within the temperature range from 625 °C to 590 °C in the other one. The mechanism of particle resonance caused by ultrasonic vibration was illustrated on the basis of theoretical analysis of the kinetics and energy conversion during the solidification. It is demonstrated that the kinetic energy of resonant particles are mainly from the latent heat energy of solidification, which can shorten the cooling time, inhibit the crystal growth and then lead to the grain refinement.

Effect of modification melt treatment on casting/chill interfacial heat transfer and electrical conductivity of Al-13% Si alloy

International Nuclear Information System (INIS)

Narayan Prabhu, K.; Ravishankar, B.N.

2003-01-01

For successful modelling of the solidification process, a reliable heat transfer boundary condition data is required. These boundary conditions are significantly influenced by the casting and mould parameters. In the present work, the effect of sodium modification melt treatment on casting/chill interfacial heat transfer during upward solidification of an Al-13% Si alloy against metallic chills is investigated using thermal analysis and inverse modelling techniques. In the presence of chills, modification melt treatment resulted in an increase in the cooling rate of the solidifying casting near the casting/chill interfacial region. The corresponding interfacial heat flux transients and electrical conductivities are also found to be higher. This is attributed to (i) improvement in the casting/chill interfacial thermal contact condition brought about by the decrease in the surface tension of the liquid metal on addition of sodium and (ii) increase in the electronic heat conduction in the initial solidified shell due to change in the morphology of silicon from a acicular type to a fine fibrous structure and increase in the ratio of the modification rating to the secondary dendrite arm spacing

Effect of steady and time-harmonic magnetic fields on macrosegragation in alloy solidification

Energy Technology Data Exchange (ETDEWEB)

Incropera, F.P.; Prescott, P.J. [Purdue Univ., West Lafayette, IN (United States)

1995-12-31

Buoyancy-induced convection during the solidification of alloys can contribute significantly to the redistribution of alloy constituents, thereby creating large composition gradients in the final ingot. Termed macrosegregation, the condition diminishes the quality of the casting and, in the extreme, may require that the casting be remelted. The deleterious effects of buoyancy-driven flows may be suppressed through application of an external magnetic field, and in this study the effects of both steady and time-harmonic fields have been considered. For a steady magnetic field, extremely large field strengths would be required to effectively dampen convection patterns that contribute to macrosegregation. However, by reducing spatial variations in temperature and composition, turbulent mixing induced by a time-harmonic field reduces the number and severity of segregates in the final casting.

Making Artificial Heart Components – Selected Aspects Of Casting Technology

Directory of Open Access Journals (Sweden)

Sobczak J.J.

2015-09-01

Full Text Available This study shown possibilities of Rapid Prototyping techniques (RP and metal casting simulation software (MCSS, including non inertial reference systems. RP and MCSS have been used in order to design and produce essential elements for artificial heart. Additionally it has been shown possibilities of Fused Deposition Modeling (FDM technique and DodJet technology using prototyped elements of rotodynamic pump. MAGMASOFT® software allowed to verify the cast kit heart valves model. Optical scanner Atos III enabled size verification of experimental elements supplied by rapid prototyping together with metal casting elements. Due to the selection of ceramic materials and assessment of molten metal – ceramic reactivity at high temperatures together with pattern materials selection model it was possible to design, manufacture a ceramic mould for titanium based alloys. The casting structure modification has been carried out by means of high isostatic pressure technique (HIP. The quality assessment of the casting materials has been performed using X-ray fluorescence (XRF, ARL 4460 Optical Emission Spectrometer, metallographic techniques and X-ray computed tomography.

Development of a manufacturing technology of compacted graphite iron castings from a cupola furnace

Directory of Open Access Journals (Sweden)

O. Bouska

2012-01-01

Full Text Available Compacted graphite iron, also known as vermicular cast iron or semiductile cast iron is a modern material, the production of which is increasing globaly. Recently this material has been very often used in automotive industry. This paper reviews some findigs gained during the development of the manufacturing technology of compacted graphite iron under the conditions in Slévárna Heunisch Brno, Ltd. The new technology assumes usage of cupola furnace for melting and is beeing developed for production of castings weighing up to 300 kilograms poured into bentonite sand moulds.

Measurement of casting parameters in ZnAlCu3 molds created by additive technology

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S. Medić

2016-10-01

Full Text Available This paper examines the parameters of casting ZnAl4Cu3 alloy (volume, castability, density and occupancy of the mold in mold made additive technology. Molds made by additive technology are: cheaper in production of a small number of castings, geometrically more accurate and faster made. From obtained results of this paper it is clearly seen that printed mold must be protected with thermal coating because liquid adhesive of powder otherwise evaporates during casting and creates additional moisture in the mold, as it was noted.

PECULIARITIES OF THE TECHNOLOGY OF CONTINUOUS CASTING OF SLUGS OF MACHINE- AND MACHINE-TOOL-BUILDING

OpenAIRE

E. B. Demchenko; E. I. Marukovich

2006-01-01

The peculiarities of technology of continuous casting of ingots of machine- and machine tool building are shown. At development of technology it is necessary to subject the nomenclature of ingots to analysis in order to reveal expediency of their production by means of continuous casting.

Sixty Years of Casting Research

Science.gov (United States)

Campbell, John

2015-11-01

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

Development of industry processes simulators. Part III (Continuous casting)

International Nuclear Information System (INIS)

Ramirez, A.; Morales, R.; Morales, A. J.; Ramos, A.; Solorio, G.

2006-01-01

This work written for illustrating the use of Monte Carlo methods and generating of random number in combination with the information of the simulation system of thermal behaviour described previously in order to reproduce in a computer the solidification process of the steel and simulate the formation of strictures of casting step by step. (Author). 12 refs

Thermodynamic analysis of as-cast and heat-treated microstructures of Mg-Ce-Nd alloys

International Nuclear Information System (INIS)

Groebner, Joachim; Kozlov, Artem; Schmid-Fetzer, Rainer; Easton, Mark A.; Zhu Suming; Gibson, Mark A.; Nie, Jian-Feng

2011-01-01

Alloys based on Mg-rare earth (RE) systems are of increasing technical interest in automotive powertrain applications due to their superior elevated temperature creep resistance. However, there is a deficiency in the literature of phase diagrams of multi-component RE systems that could assist alloy development and composition refinement for enhanced property optimization. The phase relationships in the Mg-rich corner of the Mg-Ce-Nd system have been investigated through the evaluation of selected compositions in the as-cast and heat-treated condition. Consistent thermodynamic CALPHAD-type assessments have also been generated for the Mg-Ce-Nd system. It is shown that this system reveals a significant degree of metastability under technologically significant solidification conditions (i.e. permanent-mould or high-pressure die casting). This is simulated in thermodynamic calculations by suppression of the RE 5 Mg 41 phase and reasonable agreement is found with the as-cast microstructures. After heat treatment these microstructures transform, depending on the alloy composition, into phase assemblies consistent with the calculated stable equilibrium phase diagram. It is the elucidation of such metastable phase formation and the subsequent transformation from the as-cast to the heat-treated state that is a particular strength of the thermodynamic approach and which makes it a powerful tool for alloy development.

Thermodynamic analysis of as-cast and heat-treated microstructures of Mg-Ce-Nd alloys

Energy Technology Data Exchange (ETDEWEB)

Groebner, Joachim; Kozlov, Artem [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, Rainer, E-mail: schmid-fetzer@tu-clausthal.de [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Easton, Mark A.; Zhu Suming [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); Gibson, Mark A. [CAST CRC, CSIRO Process Science and Engineering, Clayton, Victoria 3169 (Australia); Nie, Jian-Feng [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia)

2011-01-15

Alloys based on Mg-rare earth (RE) systems are of increasing technical interest in automotive powertrain applications due to their superior elevated temperature creep resistance. However, there is a deficiency in the literature of phase diagrams of multi-component RE systems that could assist alloy development and composition refinement for enhanced property optimization. The phase relationships in the Mg-rich corner of the Mg-Ce-Nd system have been investigated through the evaluation of selected compositions in the as-cast and heat-treated condition. Consistent thermodynamic CALPHAD-type assessments have also been generated for the Mg-Ce-Nd system. It is shown that this system reveals a significant degree of metastability under technologically significant solidification conditions (i.e. permanent-mould or high-pressure die casting). This is simulated in thermodynamic calculations by suppression of the RE{sub 5}Mg{sub 41} phase and reasonable agreement is found with the as-cast microstructures. After heat treatment these microstructures transform, depending on the alloy composition, into phase assemblies consistent with the calculated stable equilibrium phase diagram. It is the elucidation of such metastable phase formation and the subsequent transformation from the as-cast to the heat-treated state that is a particular strength of the thermodynamic approach and which makes it a powerful tool for alloy development.

Increased corrosion resistance of the AZ80 magnesium alloy by rapid solidification.

Science.gov (United States)

Aghion, E; Jan, L; Meshi, L; Goldman, J

2015-11-01

Magnesium (Mg) and Mg-alloys are being considered as implantable biometals. Despite their excellent biocompatibility and good mechanical properties, their rapid corrosion is a major impediment precluding their widespread acceptance as implantable biomaterials. Here, we investigate the potential for rapid solidification to increase the corrosion resistance of Mg alloys. To this end, the effect of rapid solidification on the environmental and stress corrosion behavior of the AZ80 Mg alloy vs. its conventionally cast counterpart was evaluated in simulated physiological electrolytes. The microstructural characteristics were examined by optical microscopy, SEM, TEM, and X-ray diffraction analysis. The corrosion behavior was evaluated by immersion, salt spraying, and potentiodynamic polarization. Stress corrosion resistance was assessed by Slow Strain Rate Testing. The results indicate that the corrosion resistance of rapidly solidified ribbons is significantly improved relative to the conventional cast alloy due to the increased Al content dissolved in the α-Mg matrix and the correspondingly reduced presence of the β-phase (Mg17 Al12 ). Unfortunately, extrusion consolidated solidified ribbons exhibited a substantial reduction in the environmental performance and stress corrosion resistance. This was mainly attributed to the detrimental effect of the extrusion process, which enriched the iron impurities and increased the internal stresses by imposing a higher dislocation density. In terms of immersion tests, the average corrosion rate of the rapidly solidified ribbons was <0.4 mm/year compared with ∼2 mm/year for the conventionally cast alloy and 26 mm/year for the rapidly solidified extruded ribbons. © 2014 Wiley Periodicals, Inc.

Solidification microstructures and solid-state parallels: Recent developments, future directions

Energy Technology Data Exchange (ETDEWEB)

Asta, M. [Department of Chemical Engineering and Materials Science, University of California at Davis, Davis, CA 95616 (United States); Beckermann, C. [Department of Mechanical and Industrial Engineering, University of Iowa, Iowa City, IA 52242 (United States); Karma, A. [Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA 02115 (United States); Kurz, W. [Institute of Materials, Ecole Polytechnique Federale de Lausanne (EPFL), 1015 Lausanne (Switzerland)], E-mail: wilfried.kurz@epfl.ch; Napolitano, R. [Department of Materials Science and Engineering, Iowa State University, and Ames Laboratory USDOE, Ames, IA 50011 (United States); Plapp, M. [Physique de la Matiere Condensee, Ecole Polytechnique, CNRS, 91128 Palaiseau (France); Purdy, G. [Department of Materials Science and Engineering, McMaster University, Hamilton, Ont., L8S 4L7 (Canada); Rappaz, M. [Institute of Materials, Ecole Polytechnique Federale de Lausanne (EPFL), 1015 Lausanne (Switzerland); Trivedi, R. [Department of Materials Science and Engineering, Iowa State University, and Ames Laboratory USDOE, Ames, IA 50011 (United States)

2009-02-15

Rapid advances in atomistic and phase-field modeling techniques as well as new experiments have led to major progress in solidification science during the first years of this century. Here we review the most important findings in this technologically important area that impact our quantitative understanding of: (i) key anisotropic properties of the solid-liquid interface that govern solidification pattern evolution, including the solid-liquid interface free energy and the kinetic coefficient; (ii) dendritic solidification at small and large growth rates, with particular emphasis on orientation selection; (iii) regular and irregular eutectic and peritectic microstructures; (iv) effects of convection on microstructure formation; (v) solidification at a high volume fraction of solid and the related formation of pores and hot cracks; and (vi) solid-state transformations as far as they relate to solidification models and techniques. In light of this progress, critical issues that point to directions for future research in both solidification and solid-state transformations are identified.

Study on interfacial heat transfer coefficient at metal/die interface during high pressure die casting process of AZ91D alloy

Directory of Open Access Journals (Sweden)

GUO Zhi-peng

2007-02-01

Full Text Available The high pressure die casting (HPDC process is one of the fastest growing and most efficient methods for the production of complex shape castings of magnesium and aluminum alloys in today’s manufacturing industry.In this study, a high pressure die casting experiment using AZ91D magnesium alloy was conducted, and the temperature profiles inside the die were Measured. By using a computer program based on solving the inverse heat problem, the metal/die interfacial heat transfer coefficient (IHTC was calculated and studied. The results show that the IHTC between the metal and die increases right after the liquid metal is brought into the cavity by the plunger,and decreases as the solidification process of the liquid metal proceeds until the liquid metal is completely solidified,when the IHTC tends to be stable. The interfacial heat transfer coefficient shows different characteristics under different casting wall thicknesses and varies with the change of solidification behavior.

Numerical study of crucial parameters in tilt casting for titanium aluminides

Directory of Open Access Journals (Sweden)

Hong Wang

2011-08-01

Full Text Available Numerical modeling of the tilt casting process for TiAl alloys was investigated to achieve a tranquil mould filling and TiAl castings free of defects. Titanium alloys are very reactive in molten state, so they are widely melted in cold crucible, e.g. the Induction Skull Melting (ISM furnace. Then the crucible holding the molten metal together with the mould is rotated to transfer the metal into the mould — ISM+ tilt casting. This paper emphasizes the effect of crucial parameters on mould filling and solidification of the castings during tilt casting. All crucial parameters, such as rotation rate, rotation profile, venting, initial mould temperature, casting orientation, feeder design, change of radius in 'T' junction and mould insulation have been discussed using numerical modeling data. Simulations were performed using a 3D CFD code PHYSICA implemented with front tracking, heat transfer algorithms and a turbulence model (which accounts for an advancing solid front.

TECHNOLOGICAL PROCESSES OF PRODUCTION OF THE MASS FUNCTION CAST BARS

Directory of Open Access Journals (Sweden)

A. N. Krutilin

2012-01-01

Full Text Available A number of scientifically grounded technical decisions, the whole set of which has enabled to create technological processes of production of high-quality cast bars of mass appointment is offered.

Microstructure, texture and magnetic properties of strip-cast 1.3% Si non-oriented electrical steels

Energy Technology Data Exchange (ETDEWEB)

Zhang Yuanxiang, E-mail: yunboxu@126.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China); Xu Yunbo; Liu Haitao; Li Chenggang; Cao Guangming; Liu Zhenyu; Wang Guodong [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China)

2012-10-15

In this work, the evolution of microstructure, texture and magnetic properties of non-oriented 1.3% silicon steel processed using the twin-roll strip casting was investigated, especially under different solidification structures. A number of microstructures about the as-cast strips show that the initial solidification structure of casting a strip can be controlled by the melt superheats. The microstructures with the average grain size of {approx}100-400 {mu}m can be obtained in strips when the melt superheats are from 20 to 60 Degree-Sign C. A nearly random, diffuse, homogeneous texture under a low melt superheat, but comparatively developed {l_brace}100{r_brace} oriented grains are formed under a high melt superheat through the cast strip thickness. The relatively low core loss and high magnetic induction can be obtained in the cold rolled and annealed sheets when increasing the initial grain size of cast-strip. The textures in annealed sheets with coarse initial grain size are characterized by the relatively strong Goss component and {l_brace}001{r_brace} fiber but weak {gamma}-fiber component, which lead to the high permeability. - Highlights: Black-Right-Pointing-Pointer The superheat has an evident effect on the grain size and orientation of strip. Black-Right-Pointing-Pointer Developed Cube and Goss textures were formed in the annealed sheet. Black-Right-Pointing-Pointer High magnetic properties were obtained in the twin-rolled strip casting process.

Integrated Modeling of Process, Structures and Performance in Cast Parts

DEFF Research Database (Denmark)

Kotas, Petr

This thesis deals with numerical simulations of gravity sand casting processes for the production of large steel parts. The entire manufacturing process is numerically modeled and evaluated, taking into consideration mould filling, solidification, solid state cooling and the subsequent stress build...... and to defects occurrence. In other words, it is desired to eliminate all of the potential casting defects and at the same time to maximize the casting yield. The numerical optimization algorithm then takes these objectives and searches for a set of the investigated process, design or material parameters e.......g. chill design, riser design, gating system design, etc., which would satisfy these objectives the most. The first step in the numerical casting process simulation is to analyze mould filling where the emphasis is put on the gating system design. There are still a lot of foundry specialists who ignore...

Precipitation hardening of cast Zr-containing A356 aluminium alloy

International Nuclear Information System (INIS)

Baradarani, B.; Raiszadeh, R.

2011-01-01

The effect of small additions of zirconium on the hardness, grain size, precipitate type and size of cast A356 aluminium alloy was investigated. The cast alloys were solution treated and then artificially aged for different periods of time. Hardness tests and scanning electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) studies were carried out on the as-cast, as-solutionised and age-hardened specimens. Incoherent, coarse Al 3 Zr particles formed in the microstructure during the solidification of the alloy and caused grain refinement in the as-cast structure. These particles dissolved and reprecipitated as smaller-size particles during the solution treatment, causing the hardness of the alloy to remain constant at high temperatures for long periods of time due to the slow diffusion of Zr in the α-Al.

A Real Time Investigation of Morphological Evolution During Solidification of Different Alloy Systems

Science.gov (United States)

Sen, S.; Kaukler, W. F.; Curreri, P. A.

1999-01-01

Solidification phenomenon which occur at the solid/liquid (s/I) interface play a major role in the determination of structure and hence the technologically important properties of a casting. However, metals being opaque, conclusions related to several important phenomenon such as boundary layer thickness, morphological evolution, and eutectic and cell spacing are deduced from quenching experiments and subsequent post solidification metallographic analysis. Consequently, limited information is obtained about the dynamics of the process. This paper will discuss the recent efforts at the Space Science Laboratory, NASA Marshall Space Flight Center, to view and quantify in-situ and in real time the dynamics of the solidification process and to measure interfacial undercooling. First, a high resolution x-ray transmission microscope (XTM) has been developed to monitor fundamental interfacial phenomena during directional solidification of metals and alloys. The XTM operates in the range of 10-100 KeV and through projection is capable of achieving magnification of up to 16OX. Secondly, an innovative collapsible furnace has been designed to quantify interfacial undercooling by measuring the temperature of a moving s/I interface in reference to a fixed s/l interface. This measurement technique is non-intrusive in nature and is based on the Seebeck principle. In this paper real time results obtained to characterize the dynamics of irregular eutectic spacing will be presented. As an example fiber to lamella or plate transition in the Al-Al2Au eutectic system will be discussed. Further, a resolution limit of 25 micron has permitted viewing in real time morphological instability and cellular growth in Al-Au and Al-Ag systems. Simultaneously, a systematic investigation has been carried out to measure interfacial undercooling for Pb-1 wt.% Sn at and near the marginal stability regime. In conjunction with the XTM observations this study attempts to validate existing relationships

Analysis and calculation of macrosegregation in a casting ingot, exhibits C and E

Science.gov (United States)

Poirier, D. R.; Maples, A. L.

1984-01-01

A computer model which describes the solidification of a binary metal alloy in an insulated rectangular mold with a temperature gradient is presented. A numerical technique, applicable to a broad class of moving boundary problems, was implemented therein. The solidification model described is used to calculate the macrosegregation within the solidified casting by coupling the equations for liquid flow in the solid/liquid or mushy zone with the energy equation for heat flow throughout the ingot and thermal convection in the bulk liquid portion. The rate of development of the solid can be automatically calculated by the model. Numerical analysis of such solidification parameters as enthalpy and boundary layer flow is displayed. On-line user interface and software documentation are presented.

Solidification of eutectic system alloys in space (M-19)

Science.gov (United States)

Ohno, Atsumi

1993-01-01

It is well known that in the liquid state eutectic alloys are theoretically homogeneous under 1 g conditions. However, the homogeneous solidified structure of this alloy is not obtained because thermal convection and non-equilibrium solidification occur. The present investigators have clarified the solidification mechanisms of the eutectic system alloys under 1 g conditions by using the in situ observation method; in particular, the primary crystals of the eutectic system alloys never nucleated in the liquid, but instead did so on the mold wall, and the crystals separated from the mold wall by fluid motion caused by thermal convection. They also found that the equiaxed eutectic grains (eutectic cells) are formed on the primary crystals. In this case, the leading phase of the eutectic must agree with the phase of the primary crystals. In space, no thermal convection occurs so that primary crystals should not move from the mold wall and should not appear inside the solidified structure. Therefore no equiaxed eutectic grains will be formed under microgravity conditions. Past space experiments concerning eutectic alloys were classified into two types of experiments: one with respect to the solidification mechanisms of the eutectic alloys and the other to the unidirectional solidification of this alloy. The former type of experiment has the problem that the solidified structures between microgravity and 1 g conditions show little difference. This is why the flight samples were prepared by the ordinary cast techniques on Earth. Therefore it is impossible to ascertain whether or not the nucleation and growth of primary crystals in the melt occur and if primary crystals influence the formation of the equiaxed eutectic grains. In this experiment, hypo- and hyper-eutectic aluminum copper alloys which are near eutectic point are used. The chemical compositions of the samples are Al-32.4mass%Cu (Hypo-eutectic) and Al-33.5mass%Cu (hyper-eutectic). Long rods for the samples are

Modeling of high temperature- and diffusion-controlled die soldering in aluminum high pressure die casting

DEFF Research Database (Denmark)

Domkin, Konstantin; Hattel, Jesper Henri; Thorborg, Jesper

2009-01-01

of the die lifetime based on a quantitative analysis of die soldering in the framework of the numerical simulations of the die-casting process. Full 3D simulations of the process, including the filling. solidification, and the die cooling, are carried out using the casting simulation software MAGMAsoft....... The resulting transient temperature fields on the die surface and in the casting are then post-processed to estimate the die soldering. The present work deals only with the metallurgical/chemical kind of soldering which occurs at high temperatures and involves formation and growth of intermetallic layers...

Solidification of oils and organic liquids

International Nuclear Information System (INIS)

Clark, D.E.; Colombo, P.; Neilson, R.M. Jr.

1982-07-01

The suitability of selected solidification media for application in the disposal of low-level oil and other organic liquid wastes has been investigated. In the past, these low-level wastes (LLWs) have commonly been immobilized by sorption onto solid absorbents such as vermiculite or diatomaceous earth. Evolving regulations regarding the disposal of these materials encourage solidification. Solidification media which were studied include Portland type I cement; vermiculite plus Portland type I cement; Nuclear Technology Corporation's Nutek 380-cement process; emulsifier, Portland type I cement-sodium silicate; Delaware Custom Materiel's cement process; and the US Gypsum Company's Envirostone process. Waste forms have been evaluated as to their ability to reliably produce free standing monolithic solids which are homogeneous (macroscopically), contain < 1% free standing liquids by volume and pass a water immersion test. Solidified waste form specimens were also subjected to vibratory shock testing and flame testing. Simulated oil wastes can be solidified to acceptable solid specimens having volumetric waste loadings of less than 40 volume-%. However, simulated organic liquid wastes could not be solidified into acceptable waste forms above a volumetric loading factor of about 10 volume-% using the solidification agents studied

Evaluation of thermophysical properties of Al–Sn–Si alloys based on computational thermodynamics and validation by numerical and experimental simulation of solidification

International Nuclear Information System (INIS)

Bertelli, Felipe; Cheung, Noé; Ferreira, Ivaldo L.; Garcia, Amauri

2016-01-01

Highlights: • A numerical routine coupled to a computational thermodynamics software is proposed to calculate thermophysical properties. • The approach encompasses numerical and experimental simulation of solidification. • Al–Sn–Si alloys thermophysical properties are validated by experimental/numerical cooling rate results. - Abstract: Modelling of manufacturing processes of multicomponent Al-based alloys products, such as casting, requires thermophysical properties that are rarely found in the literature. It is extremely important to use reliable values of such properties, as they can influence critically on simulated output results. In the present study, a numerical routine is developed and connected in real runtime execution to a computational thermodynamic software with a view to permitting thermophysical properties such as: latent heats; specific heats; temperatures and heats of transformation; phase fractions and composition and density of Al–Sn–Si alloys as a function of temperature, to be determined. A numerical solidification model is used to run solidification simulations of ternary Al-based alloys using the appropriate calculated thermophysical properties. Directional solidification experiments are carried out with two Al–Sn–Si alloys compositions to provide experimental cooling rates profiles along the length of the castings, which are compared with numerical simulations in order to validate the calculated thermophysical data. For both cases a good agreement can be observed, indicating the relevance of applicability of the proposed approach.

Inoculation Effects of Cast Iron

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E. Fraś

2012-12-01

Full Text Available The paper presents a solidification sequence of graphite eutectic cells of A and D types, as well as globular and cementite eutectics. The morphology of eutectic cells in cast iron, the equations for their growth and the distances between the graphite precipitations in A and D eutectic types were analyzed. It is observed a critical eutectic growth rate at which one type of eutectic transformed into another. A mathematical formula was derived that combined the maximum degree of undercooling, the cooling rate of cast iron, eutectic cell count and the eutectic growth rate. One type of eutectic structure turned smoothly into the other at a particular transition rate, transformation temperature and transformational eutectic cell count. Inoculation of cast iron increased the number of eutectic cells with flake graphite and the graphite nodule count in ductile iron, while reducing the undercooling. An increase in intensity of inoculation caused a smooth transition from a cementite eutectic structure to a mixture of cementite and D type eutectic structure, then to a mixture of D and A types of eutectics up to the presence of only the A type of eutectic structure. Moreover, the mechanism of inoculation of cast iron was studied.

Simulation of ingot casting processes at Deutsche Edelstahlwerke GmbH®

International Nuclear Information System (INIS)

Hartmann, L; Ernst, C; Klung, J-S

2012-01-01

To enhance the quality of tool steels it is necessary to analyse all stages of the production process. During the ingot- or continuous casting processes and the following solidification, material and geometry depending reactions cause defects such as macro segregations or porosities. In former times the trial and error approach, together with the experience and creativity of the steelworks engineers was used to improve the as-cast quality, with a high amount of test procedures and a high demand of research time and costs. Further development in software and algorithms has allowed modern simulation techniques to find their way into industrial steel production and casting-simulations are widely used to achieve an accurate prediction of the ingot quality. To improve the as-cast quality, several ingot casting processes of tool steels were studied at the R and D department of Deutsche Edelstahlwerke GmbH by using the numerical casting simulation software MAGMASOFT ® . In this paper some results extracted from the simulation software are shown and compared to experimental investigations.

Medical implants by using RP and investment casting technologies

Directory of Open Access Journals (Sweden)

Milan Horacek

2011-02-01

Full Text Available The paper deals with the production technology of knee joint replacement by using rapid prototyping technology. The aim of the work is to outline the manufacturing technology intended for prototype production with the use of rapid prototyping and investment casting technology for use in orthopaedics and the surgery of knee joint replacement. The research results should make an effective contribution in the attempts to minimize the invasive surgical procedure, shorten the production of knee joint replacement as well as reduce the cost. At present, the research is focused on the preparation of STL data from CT (Computed Tomography and verification of the production technology of prototypes made using available RP technology and its evaluation.

CENTER FOR ADVANCED SEPARATION TECHNOLOGY (CAST) PROGRAM

Energy Technology Data Exchange (ETDEWEB)

Yoon, Roe-Hoan; Hull, Christopher

2014-09-30

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

A reliable and consistent production technology for high volume compacted graphite iron castings

Directory of Open Access Journals (Sweden)

Liu Jincheng

2014-07-01

Full Text Available The demands for improved engine performance, fuel economy, durability, and lower emissions provide a continual challenge for engine designers. The use of Compacted Graphite Iron (CGI has been established for successful high volume series production in the passenger vehicle, commercial vehicle and industrial power sectors over the last decade. The increased demand for CGI engine components provides new opportunities for the cast iron foundry industry to establish efficient and robust CGI volume production processes, in China and globally. The production window range for stable CGI is narrow and constantly moving. Therefore, any one step single addition of magnesium alloy and the inoculant cannot ensure a reliable and consistent production process for complicated CGI engine castings. The present paper introduces the SinterCast thermal analysis process control system that provides for the consistent production of CGI with low nodularity and reduced porosity, without risking the formation of flake graphite. The technology is currently being used in high volume Chinese foundry production. The Chinese foundry industry can develop complicated high demand CGI engine castings with the proper process control technology.

Three-Dimensional Numerical Modeling of Macrosegregation in Continuously Cast Billets

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Qipeng Dong

2017-06-01

Full Text Available Macrosegregation, serving as a major defect in billets, can severely degrade material homogeneity. Better understanding of the physical characteristics of macrosegregation through numerical simulation could significantly contribute to the segregation control. The main purpose of this study was to predict macrosegregation in continuously cast billets with a newly developed three-dimensional macrosegregation model. The fluid flow, solidification, and solute transport in the entire billet region were solved and analyzed. Flow patterns, revealing a typical melt recirculation at the upper region of mold and thermosolutal convection at the secondary cooling zone, significantly affect the solidification and solute distribution. The solute redistribution occurring with thermosolutal convection at the solidification front contributes significantly to continued macrosegregation as solidification proceeds. The results of this study show that the equilibrium partition coefficient is mostly responsible for the magnitude of macrosegregation, while comparison between solute P and S indicated that diffusion coefficients also have some amount of influence. Typical macrosegregation patterns containing a positively segregated peak at the centerline and negatively segregated minima at either side were obtained via the proposed three-dimensional macrosegregation model, which validated by the measured surface temperatures and segregation degree.

Influence of Cooling Conditions on a Slab’s Chill Zone Formation During Continuous Casting of Steel

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Drożdż P.

2017-06-01

Full Text Available The cooling conditions of a slab during continuous casting of steel have an impact on the crystalline structure formation. Numerical methods allow real processes to be modelled. Professional computer programs are available on the market, so the results of their simulations allow us to understand the processes that occur during the casting and solidification of the slab. The study attempts to evaluate the impact of the intensity of the secondary cooling on the chilled zone size. The calculations show the differences in the structure of a slab cast with various speeds while maintaining industrial cooling parameters during operation of a continuous casting machine.

Multiscale modelling of solidification microstructures, including microsegregation and microporosity, in an Al-Si-Cu alloy

International Nuclear Information System (INIS)

Lee, P.D.; Chirazi, A.; Atwood, R.C.; Wang, W.

2004-01-01

Phase transition phenomena in metallic alloys involve complex physical processes occurring over a wide range of temporal, spatial and energy scales. Multiscale modelling is a powerful methodology for understanding these complex systems. In this paper, a multiscale model of grain and pore formation is presented during solidification. At the microscale, a combined stochastic-deterministic approach based on the cellular automata method is used to solve multicomponent diffusion in a three-phase system (liquid, solid and gas), simulating the nucleation and growth of both grains and pores. The impingement of the growing pores upon the developing solid is also solved to predict the tortuous shape of the porosity, a critical factor for fatigue properties. The micromodel is coupled with a finite element method (FEM) solution of the macroscale heat transfer and fluid flow in industrial castings through the temperature and pressure fields. The result model was used to investigate the influence of local solidification time, hydrogen content, local metallostatic pressure and alloy composition upon the predicted grain structure and pore morphology. Comparison of the model predictions to both laboratory and industrial scale castings are presented

A Novel Approach for Evaluating the Contraction of Hypo-Peritectic Steels during Initial Solidification by Surface Roughness

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Junli Guo

2018-04-01

Full Text Available The contraction of peritectic steels in the initial solidification has an important influence on the formation of surface defects of continuously cast slabs. In order to understand the contraction behavior of the initial solidification of steels in the mold, the solidification process and surface roughness in a commercial hypo-peritectic and several non-peritectic steels were investigated using Confocal Scanning Laser Microscope (CSLM. The massive transformation of delta-Fe (δ to austenite (γ was documented in the hypo-peritectic steel, which caused surface wrinkles and greatly increases the surface roughness of samples in the experiments. Surface roughness (Ra(δ→γ was calculated to evaluate the contraction level of the hypo-peritectic steel due to δ–γ transformation. The result shows that the surface roughness method can facilitate the estimation of the contraction level of peritectic transformation over a wide range of cooling rates.

Solidification microstructures in a short fiber reinforced alloy composite containing different fiber fractions

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JING Qing-xiu

2006-02-01

Full Text Available The solidification microstructures and micro-segregation of a fiber reinforced Al-9 Cu alloy, containing different volume fractions of Al2O3 short fibers about 6 μm diameter and made by squeeze casting have been studied. The results indicate that as volume fraction of fiber Vf increases, the size of final grains becomes finer in the matrix. If λf /λ＞1, the fibers have almost no influence on the solidification behavior of the matrix, so the final grains grow coarse, where λf is the average inter-fiber spacing and λ is the secondary dendrite arm spacing. While if λf /λ＜1, the growth of crystals in the matrix is affected significantly by the fibers and the grain size is reduced to the value of the inter-fiber spacing. The fibers influence the average length of a solidification volume element L of the matrix and also influence the solidification time θt of the matrix. As a result of fibers influencing L and θt, the micro-segregation in the matrix is improved when the composite contains more fibers, although the level of the improvement is slight. The Clyne-Kurz model can be used to semi-quantitatively analyze the relationship between Vf and the volume fraction fe of the micro-segregation eutectic structure.

Effects of heat pipe cooling on permanent mold castings of aluminum alloys

International Nuclear Information System (INIS)

Zhang, C.; Mucciardi, F.; Gruzleski, J.E.

2002-01-01

The temperature distribution within molds is a critical parameter in determining the ultimate casting quality in permanent mold casting processes, so there is a considerable incentive to develop a more effective method of mold cooling. Based on this consideration, a novel, effective and controllable heat pipe has been successfully developed and used as a new method of permanent mold cooling. Symmetric step casting of A356 alloy have been produced in an experimental permanent mold made of H13 tool steel, which is cooled by such heat pipes. The experimental results show that heat pipes can provide extremely high cooling rates in permanent mold castings of aluminum. The dendrite arm spacing of A356 alloy is refined considerably, and porosity and shrinkage of the castings are redistributed by the heat pipe cooling. Moreover, the heat pipe can be used to determine the time when the air gap forms at the interface between the mold and the casting. The effect of heat pipe cooling on solidification time of castings of A356 alloy with different coating types is also discussed in this paper. (author)

The effect of major alloying elements on the size of the secondary dendrite arm spacing in the as-cast Al-Si-Cu alloys

Directory of Open Access Journals (Sweden)

M. B. Djurdjevič

2012-01-01

Full Text Available A comprehensive understanding of melt quality is of paramount importance for the control and prediction of actual casting characteristics. Among many phenomenons that occur during the solidification of castings, there are four that control structure and consequently mechanical properties: chemical composition, liquid metal treatment, cooling rate and temperature gradient. The cooling rate and alloy composition are among them most important. This paper investigates the effect of some major alloying elements (silicon and copper of Al-Si-Cu alloys on the size of the secondary dendrite arm spacing. It has been shown that both alloying elements have reasonable influence on the refinement of this solidification parameter.

Clean Metal Casting

Energy Technology Data Exchange (ETDEWEB)

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.

Solidification of highly active liquid waste

International Nuclear Information System (INIS)

Morris, J.B.

1985-03-01

This document contains the annual progress reports on the following subjects: Joule ceramic melter; microwave vitrification; glass technology; identification, evaluation and review of potential alternative solidification processes; rotary kiln calcination; alternative glass feedstocks; volatile ruthenium trapping by solid adsorbents; irrigated baffle column dust scrubber. (author)

Use of SEM and EDS analysis in the investigation of Al-Si-Cu piston alloy cast porosity

Directory of Open Access Journals (Sweden)

D. Kakaš

2009-07-01

Full Text Available Porosity formation was detected in the casting thinnest section in the proximity of the as cast surface and near the wall centerline. In order to investigate the cause of the porosity formation light microscopy was used to define as cast structure. After initial findings SEM and EDS analyses were performed. Based on the results it is possible to define cause of the observed porosity. A number of pores originates from the mould filling stage and entrainment of the oxide films, while others appear due to insufficient feeding during solidification.

Residual Stresses in DC cast Aluminum Billet: Neutron Diffraction Measurements and Thermomechanical Modeling

International Nuclear Information System (INIS)

Drezet, J.-M.; Evans, A.; Pirling, T.

2011-01-01

Thermally-induced residual stresses, generated during the industrial Direct Chill casting process of aluminum alloys, can cause both significant safety concerns as well as the formation of defects during down-stream processing. Although these thermally induced strains can be partially relieved by permanent deformation, cracks will be generated either during solidification (hot tears) or post-solidification cooling (cold cracks) when stresses exceed the deformation limit of the alloy. Furthermore, the thermally induced strains result in the presence of large internal stresses within the billet before further processing steps. Although numerical models have been previously developed to compute these residual stresses, most of the computations have been validated only against measured surface distortions. In the present work, the variation in residual elastic strains and stresses in the steady state regime of casting has been measured as a function of radial position using neutron diffraction in an AA6063 grain-refined cylindrical billet. These measurements have been carried out on the same billet section at Poldi at PSI-Villigen and at Salsa at ILL-Grenoble and compare favorably. The results are used to validate a thermo-mechanical finite element casting model and to assess the level of stored elastic energy within the billet.

Measurement and simulation of deformation and stresses in steel casting

Science.gov (United States)

Galles, D.; Monroe, C. A.; Beckermann, C.

2012-07-01

Experiments are conducted to measure displacements and forces during casting of a steel bar in a sand mold. In some experiments the bar is allowed to contract freely, while in others the bar is manually strained using embedded rods connected to a frame. Solidification and cooling of the experimental castings are simulated using a commercial code, and good agreement between measured and predicted temperatures is obtained. The deformations and stresses in the experiments are simulated using an elasto-viscoplastic finite-element model. The high temperature mechanical properties are estimated from data available in the literature. The mush is modeled using porous metal plasticity theory, where the coherency and coalescence solid fraction are taken into account. Good agreement is obtained between measured and predicted displacements and forces. The results shed considerable light on the modeling of stresses in steel casting and help in developing more accurate models for predicting hot tears and casting distortions.

Measurement and simulation of deformation and stresses in steel casting

International Nuclear Information System (INIS)

Galles, D; Beckermann, C; Monroe, C A

2012-01-01

Experiments are conducted to measure displacements and forces during casting of a steel bar in a sand mold. In some experiments the bar is allowed to contract freely, while in others the bar is manually strained using embedded rods connected to a frame. Solidification and cooling of the experimental castings are simulated using a commercial code, and good agreement between measured and predicted temperatures is obtained. The deformations and stresses in the experiments are simulated using an elasto-viscoplastic finite-element model. The high temperature mechanical properties are estimated from data available in the literature. The mush is modeled using porous metal plasticity theory, where the coherency and coalescence solid fraction are taken into account. Good agreement is obtained between measured and predicted displacements and forces. The results shed considerable light on the modeling of stresses in steel casting and help in developing more accurate models for predicting hot tears and casting distortions.

In-situ surface hardening of cast iron by surface layer metallurgy

International Nuclear Information System (INIS)

Fischer, Sebastian F.; Muschna, Stefan; Bührig-Polaczek, Andreas; Bünck, Matthias

2014-01-01

Abrasive wear is a serious problem in many cast iron castings used in industry. To minimize failure and repair of these components, different strategies exist to improve their surface microhardness thus enhancing their wear resistance. However, most of these methods lead to very brittle and/or expensive castings. In the current work a new method for surface hardening is presented which utilizes surface layer metallurgy to generate in-situ a boron-enriched white cast iron surface layer with a high microhardness on a gray cast iron casting. To do this, sand molds are coated with a ferroboron suspension and cast with a cast iron melt. After solidification, a 100–900 µm thick layer of boron-enriched ledeburite is formed on the surface of the casting which produces an increase in the average microhardness from 284 HV 0.1 ±52 HV 0.1 to 505 HV 0.1 ±87 HV 0.1 . Analyses of the samples' core reveal a typical cast iron microstructure which leads to the conclusion that the coating mainly affects the castings' surface. By varying the grain size of the ferroboron powder in the coatings, it is shown that a powder size ≤100 µm is most suitable to create a boron-enriched ledeburite surface layer possessing high hardness values

Cement solidification of spent ion exchange resins produced by the nuclear industry

International Nuclear Information System (INIS)

Jaouen, C.; Vigreux, B.

1988-01-01

Cement solidification technology has been applied to spent ion exchange resins for many years in countries throughout the world (at reactors, research centers and spent fuel reprocessing plants). Changing specifications for storage of radioactive waste have, however, confronted the operators of such facilities with a number of problems. Problems related both to the cement solidification process (water/cement/resin interactions and chemical interactions) and to its utilization (mixing, process control, variable feed composition, etc.) have often led waste producers to prefer other, polymer-based processes, which are very expensive and virtually incompatible with water. This paper discusses research on cement solidification of ion exchange resins since 1983 and the development of application technologies adapted to nuclear service conditions and stringent finished product quality requirements

The Influence of Cr on the Solidification Behavior of Polycrystalline γ(Ni)/ γ'(Ni3Al)- δ(Ni3Nb) Eutectic Ni-Base Superalloys

Science.gov (United States)

Xie, Mengtao; Helmink, Randolph; Tin, Sammy

2012-04-01

In the current investigation, the effect of Cr on the solidification characteristics and as-cast microstructure of pseudobinary γ- δ eutectic alloys based on a near-eutectic composition (Ni-5.5Al-13.5Nb at. pct) was investigated. It was found that Cr additions promote the formation of a higher volume fraction of γ- δ eutectic microstructure in the interdendritic region. Increasing levels of Cr also triggered morphological changes in the γ- δ eutectic and the formation of γ- γ'- δ ternary eutectic during the last stage of solidification. A detailed characterization of the as-cast alloys also revealed that Cr additions suppressed the liquidus, solidus, and γ' precipitation temperature of these γ/ γ'- δ eutectic alloys. A comparison of the experimental results with thermodynamic calculations using the CompuTherm Pandat database (CompuTherm LLC, Madison, WI) showed qualitative agreement.

Microstructures and creep properties of Mg–4Al–(1–4) La alloys produced by different casting techniques

International Nuclear Information System (INIS)

Bai Jing; Sun Yangshan; Xue Feng; Qiang Jing

2012-01-01

The microstructures, mechanical properties and creep resistance of Mg–4Al–(1–4) La alloys produced by permanent mold casting and high pressure die casting (HPDC) were investigated. In addition to solute atoms in α-Mg matrix, Al element may exist in the form of three different intermetallic phases in the present alloys depending on the experimental conditions. In both casting states, the increase of La addition results in a rise in the volume fraction of Al 11 La 3 eutectic, and simultaneously Mg 17 Al 12 phase, including divorced eutectic in as-cast state and discontinuous precipitation after creep, is suppressed until completely disappears. This leads to a gradual increase in creep resistance. The formation of more Mg 17 Al 12 phase in HPDC alloys is considered a major factor in causing their worse creep properties by comparison with that of the permanent mold casting alloys when La content is in a lower level below 2 wt.%. By contrast, the HPDC alloys show better creep resistance with La content added above 2 wt.% owing to the formation of denser network distribution of Al 11 La 3 phase along grain/dendrite boundaries as a result of more rapid solidification rate and higher solidification pressure. For the alloys studied, grain/dendrite boundary sliding is suggested to be a possible controlling mechanism responsible for creep deformation at elevated temperatures.

High-Throughput Study of Diffusion and Phase Transformation Kinetics of Magnesium-Based Systems for Automotive Cast Magnesium Alloys

Energy Technology Data Exchange (ETDEWEB)

Luo, Alan A [The Ohio State Univ., Columbus, OH (United States); Zhao, Ji-Cheng [The Ohio State Univ., Columbus, OH (United States); Riggi, Adrienne [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Joost, William [US Dept. of Energy, Washington, DC (United States)

2017-10-02

The objective of the proposed study is to establish a scientific foundation on kinetic modeling of diffusion, phase precipitation, and casting/solidification, in order to accelerate the design and optimization of cast magnesium (Mg) alloys for weight reduction of U.S. automotive fleet. The team has performed the following tasks: 1) study diffusion kinetics of various Mg-containing binary systems using high-throughput diffusion multiples to establish reliable diffusivity and mobility databases for the Mg-aluminum (Al)-zinc (Zn)-tin (Sn)-calcium (Ca)-strontium (Sr)-manganese (Mn) systems; 2) study the precipitation kinetics (nucleation, growth and coarsening) using both innovative dual-anneal diffusion multiples and cast model alloys to provide large amounts of kinetic data (including interfacial energy) and microstructure atlases to enable implementation of the Kampmann-Wagner numerical model to simulate phase transformation kinetics of non-spherical/non-cuboidal precipitates in Mg alloys; 3) implement a micromodel to take into account back diffusion in the solid phase in order to predict microstructure and microsegregation in multicomponent Mg alloys during dendritic solidification especially under high pressure die-casting (HPDC) conditions; and, 4) widely disseminate the data, knowledge and information using the Materials Genome Initiative infrastructure (http://www.mgidata.org) as well as publications and digital data sharing to enable researchers to identify new pathways/routes to better cast Mg alloys.

Numerical simulation of low pressure die-casting aluminum wheel

Directory of Open Access Journals (Sweden)

Mi Guofa

2009-02-01

Full Text Available The FDM numerical simulation software, ViewCast system, was employed to simulate the low pressure die casting (LPDC of an aluminum wheel. By analyzing the mold-fi lling and solidifi cation stage of the LPDC process, the distribution of liquid fraction, temperature field and solidification pattern of castings were studied. The potential shrinkage defects were predicted to be formed at the rim/spoke junctions, which is in consistence with the X-ray detection result. The distribution pattern of the defects has also been studied. A solution towards reducing such defects has been presented. The cooling capacity of the mold was improved by installing water pipes both in the side mold and the top mold. Analysis on the shrinkage defects under forced cooling mode proved that adding the cooling system in the mold is an effective method for reduction of shrinkage defects.

Polyethylene solidification of low-level wastes

International Nuclear Information System (INIS)

Kalb, P.D.; Colombo, P.

1985-02-01

This topical report describes the results of an investigation on the solidification of low-level radioactive waste in polyethylene. Waste streams selected for this study included those which result from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Four types of commercially available low-density polyethylenes were employed which encompass a range of processing and property characteristics. Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste and polyethylene type. Property evaluation testing was performed on laboratory-scale specimens to assess the potential behavior of actual waste forms in a disposal environment. Waste form property tests included water immersion, deformation under compressive load, thermal cycling and radionuclide leaching. Recommended waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash, and 30 wt % ion exchange resins, which are based on process control and waste form performance considerations are reported. 37 refs., 33 figs., 22 tabs

In situ Neutron Diffraction during Casting: Determination of Rigidity Point in Grain Refined Al-Cu Alloys.

Science.gov (United States)

Drezet, Jean-Marie; Mireux, Bastien; Szaraz, Zoltan; Pirling, Thilo

2014-02-12

The rigidity temperature of a solidifying alloy is the temperature at which the solid plus liquid phases are sufficiently coalesced to transmit long range tensile strains and stresses. It determines the point at which thermally induced deformations start to generate internal stresses in a casting. As such, it is a key parameter in numerical modelling of solidification processes and in studying casting defects such as solidification cracking. This temperature has been determined in Al-Cu alloys using in situ neutron diffraction during casting in a dog bone shaped mould. In such a setup, the thermal contraction of the solidifying material is constrained and stresses develop at a hot spot that is irradiated by neutrons. Diffraction peaks are recorded every 11 s using a large detector, and their evolution allows for the determination of the rigidity temperatures. We measured rigidity temperatures equal to 557 °C and 548 °C, depending on cooling rate, for a grain refined Al-13 wt% Cu alloy. At high cooling rate, rigidity is reached during the formation of the eutectic phase and the solid phase is not sufficiently coalesced, i.e. , strong enough, to avoid hot tear formation.

In situ Neutron Diffraction during Casting: Determination of Rigidity Point in Grain Refined Al-Cu Alloys

Directory of Open Access Journals (Sweden)

Jean-Marie Drezet

2014-02-01

Full Text Available The rigidity temperature of a solidifying alloy is the temperature at which the solid plus liquid phases are sufficiently coalesced to transmit long range tensile strains and stresses. It determines the point at which thermally induced deformations start to generate internal stresses in a casting. As such, it is a key parameter in numerical modelling of solidification processes and in studying casting defects such as solidification cracking. This temperature has been determined in Al-Cu alloys using in situ neutron diffraction during casting in a dog bone shaped mould. In such a setup, the thermal contraction of the solidifying material is constrained and stresses develop at a hot spot that is irradiated by neutrons. Diffraction peaks are recorded every 11 s using a large detector, and their evolution allows for the determination of the rigidity temperatures. We measured rigidity temperatures equal to 557 °C and 548 °C, depending on cooling rate, for a grain refined Al-13 wt% Cu alloy. At high cooling rate, rigidity is reached during the formation of the eutectic phase and the solid phase is not sufficiently coalesced, i.e., strong enough, to avoid hot tear formation.

Optimization design of a gating system for sand casting aluminium A356 using a Taguchi method and multi-objective culture-based QPSO algorithm

Directory of Open Access Journals (Sweden)

Wen-Jong Chen

2016-04-01

Full Text Available This article combined Taguchi method and analysis of variance with the culture-based quantum-behaved particle swarm optimization to determine the optimal models of gating system for aluminium (Al A356 sand casting part. First, the Taguchi method and analysis of variance were, respectively, applied to establish an L27(38 orthogonal array and determine significant process parameters, including riser diameter, pouring temperature, pouring speed, riser position and gating diameter. Subsequently, a response surface methodology was used to construct a second-order regression model, including filling time, solidification time and oxide ratio. Finally, the culture-based quantum-behaved particle swarm optimization was used to determine the multi-objective Pareto optimal solutions and identify corresponding process conditions. The results showed that the proposed method, compared with initial casting model, enabled reducing the filling time, solidification time and oxide ratio by 68.14%, 50.56% and 20.20%, respectively. A confirmation experiment was verified to be able to effectively reduce the defect of casting and improve the casting quality.

Radioactive gas solidification apparatus

International Nuclear Information System (INIS)

Kobayashi, Yoshihiro; Seki, Eiji; Yabu, Tomohiko; Matsunaga, Hiroyuki.

1990-01-01

Handling of a solidification container from the completion for the solidifying processing to the storage of radioactive gases by a remote control equipment such as a manipulator requires a great cost and is difficult to realize. In a radioactive gas solidification device for injection and solidification in accumulated layers of sputtered metals by glow discharge, radiation shieldings are disposed surrounding the entire container, and cooling water is supplied to a cooling vessel formed between the container and the shielding materials. The shielding materials are divided into upper and lower shielding materials, so that solidification container can be taken out from the shielding materials. As a result, the solidification container after the solidification of radioactive gases can be handled with ease. Further, after-heat can be removed effectively from the ion injection electrode upon solidifying treatment upon storage, to attain a radioactive gas solidifying processing apparatus which is safe, economical and highly reliable. (N.H.)

Stimulating R and D of industrial energy-efficient technology; the effect of government intervention on the development of strip casting technology

International Nuclear Information System (INIS)

Luiten, E.E.M.; Blok, Kornelis

2003-01-01

Strip casting technology in steel-making is known as an innovative energy-efficient technology. Stimulating the development (R and D) of such industrial process technologies is an appealing government intervention strategy for reducing greenhouse gas emissions. In this article, we analyse (a) the R and D trajectory of strip casting technology and (b) the effect of government intervention on the development of this particular energy-efficient technology. For this purpose we made a detailed investigation of the networks within which the technology was developed. The huge capital cost advantages of strip casting technology were already notified back in the 19th century. However, only after 1975 a robust technology network emerged. There is no single, simple determinant explaining the slow emergence of the technology network: the innovative technology had to become a more incremental improvement to the conventional production facilities before R and D was seriously pursued. Once the technology network emerged, it proved to have a strong momentum of itself. Steel firms maintained their confidence in the strategic cost advantages of the technology and persistently invested in up-scaling the technology. The effect of government intervention was minimal, because the technology network had its own strong momentum. All in all, R and D was only loosely influenced by energy-efficiency considerations or by government intervention. The major policy lesson is that information on technology networks and its momentum--in addition to classic information on energy-efficiency improvements and investments costs--is required to improve the effect of government intervention in the field of industrial energy-efficiency R and D and innovation

Microstructure and corrosion properties of as sub-rapid solidification Mg-Zn-Y-Nd alloy in dynamic simulated body fluid for vascular stent application.

Science.gov (United States)

Wang, Jun; Wang, Liguo; Guan, Shaokang; Zhu, Shijie; Ren, Chenxing; Hou, Shusen

2010-07-01

Magnesium alloy stent has been employed in animal and clinical experiment in recent years. It has been verified to be biocompatible and degradable due to corrosion after being implanted into blood vessel. Mg-Y-Gd-Nd alloy is usually used to construct an absorbable magnesium alloy stent. However, the corrosion resistant of as cast Mg-Y-Gd-Nd alloy is poor relatively and the control of corrosion rate is difficult. Aiming at the requirement of endovascular stent in clinic, a new biomedical Mg-Zn-Y-Nd alloy with low Zn and Y content (Zn/Y atom ratio 6) was designed, which exists quasicrystals to improve its corrosion resistance. Additionally, sub-rapid solidification processing was applied for preparation of corrosion-resisting Mg-Zn-Y-Nd and Mg-Y-Gd-Nd alloys. Compared with the as cast sample, the corrosion behavior of alloys in dynamic simulated body fluid (SBF) (the speed of body fluid: 16 ml/800 ml min(-1)) was investigated. The results show that as sub-rapid solidification Mg-Zn-Y-Nd alloy has the better corrosion resistance in dynamic SBF due to grain refinement and fine dispersion distribution of the quasicrystals and intermetallic compounds in alpha-Mg matrix. In the as cast sample, both Mg-Zn-Y-Nd and Mg-Y-Gd-Nd alloys exhibit poor corrosion resistance. Mg-Zn-Y-Nd alloy by sub-rapid solidification processing provides excellent corrosion resistance in dynamic SBF, which open a new window for biomedical materials design, especially for vascular stent application.

Product development within the framework of a National Casting Technology Centre

CSIR Research Space (South Africa)

Du Preez, WB

2006-01-01

Full Text Available The need for a state of the art advanced National Casting Technology Centre (NCTC) has been widely supported throughout industry and recognised as an important facilitator in the growth of the foundry industry. This initiative also aligns itself...

Computation material science of structural-phase transformation in casting aluminium alloys

Science.gov (United States)

Golod, V. M.; Dobosh, L. Yu

2017-04-01

Successive stages of computer simulation the formation of the casting microstructure under non-equilibrium conditions of crystallization of multicomponent aluminum alloys are presented. On the basis of computer thermodynamics and heat transfer during solidification of macroscale shaped castings are specified the boundary conditions of local heat exchange at mesoscale modeling of non-equilibrium formation the solid phase and of the component redistribution between phases during coalescence of secondary dendrite branches. Computer analysis of structural - phase transitions based on the principle of additive physico-chemical effect of the alloy components in the process of diffusional - capillary morphological evolution of the dendrite structure and the o of local dendrite heterogeneity which stochastic nature and extent are revealed under metallographic study and modeling by the Monte Carlo method. The integrated computational materials science tools at researches of alloys are focused and implemented on analysis the multiple-factor system of casting processes and prediction of casting microstructure.

Structure fields in the solidifying cast iron roll

Directory of Open Access Journals (Sweden)

W.S. Wołczyński

2010-01-01

Full Text Available Some properties of the rolls depend on the ratio of columnar structure area to equiaxed structure area created during roll solidification. The transition is fundamental phenomenon that can be apply to characterize massive cast iron rolls produced by the casting house. As the first step of simulation, a temperature field for solidifying cast iron roll was created. The convection in the liquid is not comprised since in the first approximation, the convection does not influence the studied occurrence of the (columnar to equiaxed grains transition in the roll. The obtained temperature field allows to study the dynamics of its behavior observed in the middle of the mould thickness. This midpoint of the mould thickness was treated as an operating point for the transition. A full accumulation of the heat in the mould was postulated for the transition. Thus, a plateau at the curve was observed at the midpoint. The range of the plateau existence corresponded to the incubation period , that appeared before fully equiaxed grains formation. At the second step of simulation, behavior of the thermal gradients field was studied. Three ranges within the filed were visible: EC→EC→EC→EC→(tTECtt↔RERCtt↔a/ for the formation of columnar structure (the C – zone: ( and 0>>T&0>>=−>−=REREttGttG.The columnar structure formation was significantly slowed down during incubation period. It resulted from a competition between columnar growth and equiaxed growth expected at that period of time. The 0≈=−=RERCttGttG relationship was postulated to correspond well with the critical thermal gradient, known in the Hunt’s theory. A simulation was performed for the cast iron rolls solidifying as if in industrial condition. Since the incubation divides the roll into two zones: C and E; (the first with columnar structure and the second with fully equiaxed structure some experiments dealing with solidification were made on semi-industrial scale.

Microwave solidification project overview

Energy Technology Data Exchange (ETDEWEB)

Sprenger, G.

1993-01-01

The Rocky Flats Plant Microwave Solidification Project has application potential to the Mixed Waste Treatment Project and the The Mixed Waste Integrated Program. The technical areas being addressed include (1) waste destruction and stabilization; (2) final waste form; and (3) front-end waste handling and feed preparation. This document covers need for such a program; technology description; significance; regulatory requirements; and accomplishments to date. A list of significant reports published under this project is included.

Microwave solidification project overview

International Nuclear Information System (INIS)

Sprenger, G.

1993-01-01

The Rocky Flats Plant Microwave Solidification Project has application potential to the Mixed Waste Treatment Project and the The Mixed Waste Integrated Program. The technical areas being addressed include (1) waste destruction and stabilization; (2) final waste form; and (3) front-end waste handling and feed preparation. This document covers need for such a program; technology description; significance; regulatory requirements; and accomplishments to date. A list of significant reports published under this project is included

Microstructure of Magnesium alloy AZ91-HP cast in permanent and non-permanent moulds

DEFF Research Database (Denmark)

Tiedje, Niels; Sørensen, Rasmus Kirkegaard; Albachari, Sami

2003-01-01

Casting of different geometries were made with AZ91-HP in different moulding media, so that a range of cooling conditions were obtained. Cooling curves were measured and compared to the microstructures found in the castings. It was shown that segregation in the alloy is highly dependent on cooling...... rate. This leads to precipitation of varying amounts of intermetallic phases. The distribution of phases in the material is controlled both by interdendritic and intergranular segregation, leading to an inhomogeneous microstructure. It is shown that local solidification time, segregation and diffusion...

A computational study of low-head direct chill slab casting of aluminum alloy AA2024

Science.gov (United States)

Hasan, Mainul; Begum, Latifa

2016-04-01

The steady state casting of an industrial-sized AA2024 slab has been modeled for a vertical low-head direct chill caster. The previously verified 3-D CFD code is used to investigate the solidification phenomena of the said long-range alloy by varying the pouring temperature, casting speed and the metal-mold contact heat transfer coefficient from 654 to 702 °C, 60-180 mm/min, and 1.0-4.0 kW/(m2 K), respectively. The important predicted results are presented and thoroughly discussed.

Microwave solidification development for Rocky Flats waste

Energy Technology Data Exchange (ETDEWEB)

Dixon, D.; Erle, R.; Eschen, V. [and others

1994-04-01

The Microwave Engineering Team at the Rocky Flats Plant has developed a production-scale system for the treatment of hazardous, radioactive, and mixed wastes using microwave energy. The system produces a vitreous final form which meets the acceptance criteria for shipment and disposal. The technology also has potential for application on various other waste streams from the public and private sectors. Technology transfer opportunities are being identified and pursued for commercialization of the microwave solidification technology.

Microwave solidification development for Rocky Flats waste

International Nuclear Information System (INIS)

Dixon, D.; Erle, R.; Eschen, V.

1994-04-01

The Microwave Engineering Team at the Rocky Flats Plant has developed a production-scale system for the treatment of hazardous, radioactive, and mixed wastes using microwave energy. The system produces a vitreous final form which meets the acceptance criteria for shipment and disposal. The technology also has potential for application on various other waste streams from the public and private sectors. Technology transfer opportunities are being identified and pursued for commercialization of the microwave solidification technology

Effects of Eutectic Si Particles on Mechanical Properties and Fracture Toughness of Cast A356 Aluminum Alloys

International Nuclear Information System (INIS)

Lee, Kyu Hong; Lee, Sung Hak; Kwon, Yong Nam

2007-01-01

The present study aims at investigating the effects of eutectic Si particles on mechanical properties and fracture toughness of three A356 aluminum alloys. These A356 alloys were fabricated by casting processes such as rheo-casting, squeeze-casting, and casting-forging, and their mechanical properties and fracture toughness were analyzed in relation with microfracture mechanism study. All the cast A356 alloys contained eutectic Si particles mainly segregated along solidification cells, and the distribution of Si particles was modified by squeeze-casting and casting-forging processes. Microfracture observation results showed that eutectic Si particles segregated along cells were cracked first, but that aluminum matrix played a role in blocking crack propagation. Tensile properties and fracture toughness of the squeeze cast and cast-forged alloys having homogeneous distribution of eutectic Si particles were superior to those of the rheo-cast alloy. In particular, the cast-forged alloy had excellent hardness, strength, ductility, and fracture toughness because of the matrix strengthening and homogeneous distribution of eutectic Si particles due to forging process

Feeding and Distribution of Porosity in Cast Al-Si Alloys as Function of Alloy Composition and Modification

DEFF Research Database (Denmark)

Tiedje, Niels Skat; Taylor, John A.; Easton, Mark A.

2012-01-01

Unmodified, Na-modified, and Sr-modified castings of Al-7 pct Si and Al-12.5 pct Si alloys were cast in molds in which it was possible to create different cooling conditions. It is shown how solidification influences the distribution of porosity at the surface and the center of the castings...... of the casting, while Sr-modified castings solidify in a mushy manner that creates a more homogeneous distribution of porosity in the casting. The amount of porosity was highest in the Sr-modified alloys, lower in the Na-modified alloys, and lowest in the unmodified alloys. The size of the porosity-free layer...... as a function of modification and Si content in sand- and chill-cast samples. Eutectic modification, Si content, and cooling conditions have a great impact on the distribution of porosity. Unmodified and Na-modified castings are more easily fed with porosity tending to congregate near the centerline...

Contribute to quantitative identification of casting defects based on computer analysis of X-ray images

Directory of Open Access Journals (Sweden)

Z. Ignaszak

2007-12-01

Full Text Available The forecast of structure and properties of casting is based on results of computer simulation of physical processes which are carried out during the casting processes. For the effective using of simulation system it is necessary to validate mathematica-physical models describing process of casting formation and the creation of local discontinues, witch determinate the casting properties.In the paper the proposition for quantitative validation of VP system using solidification casting defects by information sources of II group (methods of NDT was introduced. It was named the VP/RT validation (virtual prototyping/radiographic testing validation. Nowadays identification of casting defects noticeable on X-ray images bases on comparison of X-ray image of casting with relates to the ASTM. The results of this comparison are often not conclusive because based on operator’s subjective assessment. In the paper the system of quantitative identification of iron casting defects on X-ray images and classification this defects to ASTM class is presented. The methods of pattern recognition and machine learning were applied.

Clean Metal Casting; FINAL

International Nuclear Information System (INIS)

Makhlouf M. Makhlouf; Diran Apelian

2002-01-01

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

Development of vacuum continuous casting technology for uranium

International Nuclear Information System (INIS)

Lee, Y.S.; Kim, C. K.; Kim, K. H.; Lee, D. B.; Kim, J. D.; Jang, S. J.; Ahn, H. S.; Shin, Y. J.

2001-02-01

The spent fuel disposal process of new dry storage concept has been developed in KAERI, in which the uranium metal abstracted by Li-reduction of spent fuel will be formed to long rods and then the rods will be arranged uniformly in canister. The objective of this study is to review the feasibility of applying the continuous casting method to cast a long rod with modifying the vacuum high-frequency induction furnace to vacuum continuous casting system, which was normally used to cast the uranium. The results are as follows. With the nozzle size of 3mm and the withdrawal speed of 3.5 mm/sec, the length of 160mm, diameter of 30 mm continuous casting uranium bar was successfully cast. This result shows there might be a possibility of continuous casting of uranium and helps the design and fabrication of new continuous casting equipment

Applying RP-FDM Technology to Produce Prototype Castings Using the Investment Casting Method

Directory of Open Access Journals (Sweden)

M. Macků

2012-09-01

Full Text Available The research focused on the production of prototype castings, which is mapped out starting from the drawing documentation up to theproduction of the casting itself. The FDM method was applied for the production of the 3D pattern. Its main objective was to find out whatdimensional changes happened during individual production stages, starting from the 3D pattern printing through a silicon mouldproduction, wax patterns casting, making shells, melting out wax from shells and drying, up to the production of the final casting itself.Five measurements of determined dimensions were made during the production, which were processed and evaluated mathematically.A determination of shrinkage and a proposal of measures to maintain the dimensional stability of the final casting so as to meetrequirements specified by a customer were the results.

A new multi-zone model for porosity distribution in Al–Si alloy castings

DEFF Research Database (Denmark)

Tiedje, Niels Skat; Taylor, John A.; Easton, Mark A.

2013-01-01

A new multi-zone model is proposed that explains how porosity forms in various regions of a casting under different conditions and leads to distinct zonal differences in pore shape, size and distribution. This model was developed by considering the effect of cooling rate on solidification......) a central zone where the thermal gradient is low and equiaxed dendritic grains and eutectic cells grow at the centre of the casting and larger, rounded pores tend to form. The paper discusses how Si content, modification type and cooling conditions influence the location and size (i.e. depth) of each...

Inspection method for solidification product of radioactive waste and method of preparing solidification product of radiation waste

International Nuclear Information System (INIS)

Izumida, Tatsuo; Tamada, Shin; Matsuda, Masami; Kamata, Shoji; Kikuchi, Makoto.

1993-01-01

A powerful X-ray generation device using an electron-ray accelerator is used for inspecting presence or absence of inner voids in solidification products of radioactive wastes during or after solidification. By installing the X-ray CT system and the radioactive waste solidifying facility together, CT imaging for solidification products is conducted in a not-yet cured state of solidifying materials during or just after the injection. If a defect that deteriorates the durability of the solidification products should be detected, the solidification products are repaired, for example, by applying vibrations to the not-yet cured solidification products. Thus, since voids or cracks in the radioactive wastes solidification products, which were difficult to be measured so far, can be measured in a short period of time accurately thereby enabling to judge adaptability to the disposal standards, inspection cost for the radioactive waste solidification product can be saved remarkably. Further, the inside of the radioactive waste solidification products can be evaluated correctly and visually, so that safety in the ground disposal storage of the radioactive solidification products can be improved remarkably. (N.H.)

Modeling diffusion-governed solidification of ternary alloys - Part 2: Macroscopic transport phenomena and macrosegregation.

Science.gov (United States)

Wu, M; Li, J; Ludwig, A; Kharicha, A

2014-09-01

Part 1 of this two-part investigation presented a multiphase solidification model incorporating the finite diffusion kinetics and ternary phase diagram with the macroscopic transport phenomena (Wu et al., 2013). In Part 2, the importance of proper treatment of the finite diffusion kinetics in the calculation of macrosegregation is addressed. Calculations for a two-dimensional (2D) square casting (50 × 50 mm 2 ) of Fe-0.45 wt.%C-1.06 wt.%Mn considering thermo-solutal convection and crystal sedimentation are performed. The modeling result indicates that the infinite liquid mixing kinetics as assumed by classical models (e.g., the Gulliver-Scheil or lever rule), which cannot properly consider the solute enrichment of the interdendritic or inter-granular melt at the early stage of solidification, might lead to an erroneous estimation of the macrosegregation. To confirm this statement, further theoretical and experimental evaluations are desired. The pattern and intensity of the flow and crystal sedimentation are dependent on the crystal morphologies (columnar or equiaxed); hence, the potential error of the calculated macrosegregation caused by the assumed growth kinetics depends on the crystal morphology. Finally, an illustrative simulation of an engineering 2.45-ton steel ingot is performed, and the results are compared with experimental results. This example demonstrates the model applicability for engineering castings regarding both the calculation efficiency and functionality.

Radioactive gas solidification treatment device

International Nuclear Information System (INIS)

Igarashi, Ryokichi; Watanabe, Yu; Seki, Eiji.

1992-01-01

In a radioactive gas solidification treatment device by using sputtering, spiral pipelines are disposed with a gap therebetween for cooling an ion injection electrode by passing cooling water during operation of the solidification treatment. During the operation of the solidification treatment, cooling water is passed in the pipelines to cool the ion injection electrode. During storage, a solidification vessel is cooled by natural heat dissipation from an exposed portion at the surface of the solidification vessel. Accordingly, after-heat of radioactive gas solidified in a metal accumulation layer can be removed efficiently, safely and economically to improve the reliability. (N.H.)

Numerical simulation of casting process to assist in defects reduction in complex steel tidal power component

International Nuclear Information System (INIS)

Guo, E J; Zhao, S C; Wang, L P; Wu, T; Xin, B P; Tan, J J; Jia, H L

2016-01-01

In order to reduce defects and improve casting quality, ProCAST software is performed to study the solidification process of discharge bowl. Simulated results of original casting process show that the hot tearing is serious at the intersection of blades and outer or inner rings. The shrinkage porosity appears at the bottom of discharge bowl and the transition area of wall thickness. Based on the formation mechanisms of the defects, the structure of chills attached on the outer surface of discharge bowl casting is optimized. The thickness of chills ranges from 25mm to 35mm. The positions of chills corresponded to the outer surface of the T-shaped parts. Compared to the original casting design (without chills), the hot tearing and shrinkage porosity of the discharge bowl are greatly improved with addition of chills. (paper)

Applying RP-FDM Technology to Produce Prototype Castings Using the Investment Casting Method

Directory of Open Access Journals (Sweden)

Macků M.

2012-09-01

Full Text Available The research focused on the production of prototype castings, which is mapped out starting from the drawing documentation up to the production of the casting itself. The FDM method was applied for the production of the 3D pattern. Its main objective was to find out what dimensional changes happened during individual production stages, starting from the 3D pattern printing through a silicon mould production, wax patterns casting, making shells, melting out wax from shells and drying, up to the production of the final casting itself. Five measurements of determined dimensions were made during the production, which were processed and evaluated mathematically. A determination of shrinkage and a proposal of measures to maintain the dimensional stability of the final casting so as to meet requirements specified by a customer were the results.

Multi-layers castings

Directory of Open Access Journals (Sweden)

J. Szajnar

2010-01-01

Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

Perspectives of single cast nanowires technology

International Nuclear Information System (INIS)

Ioisher, Anatolii; Badinter, Efim; Postolache, Vitalie; Leporda, Nicolae; Tiginyanu, Ion; Monaico, Eduard

2011-01-01

The paper is dedicated to production potential of glass-coated cast nanowire with metal-, semimetal- and semiconductor-based cores by means of Taylor-Ulitovsky method. Criteria of melted core-formative material penetration into a drawing capillary were analyzed. Theoretical preconditions of the reduction of cast microwire diameter up to nano-dimensions of core are reviewed and an improved method of cast nanowire manufacturing is proposed. Correctness of conclusions was experimentally proved and laboratory samples of micro- and nano-wires with core diameter of about 200-300 nanometers were produced, even in case of materials with poor adhesion.

In situ synchrotron x-ray characterization of microstructure formation in solidification processing of Al-based metallic alloys

International Nuclear Information System (INIS)

Billia, Bernard; Nguyen-Thi, Henri; Mangelinck-Noel, Nathalie

2010-01-01

The microstructure formed during the solidification step has a major influence on the properties of materials processed by major techniques (casting, welding ...). In situ and real-time characterization by synchrotron X-ray imaging is the method of choice to unveil the dynamical formation of the solidification microstructure in metallic alloys, and thus provide precise data for the critical validation of the theoretical predictions that is needed for sound advancement of modeling and numerical simulation. After a description of the experimental procedure used at the European Synchrotron Radiation Facility (ESRF), dynamical phenomena in the formation of the grain structure and dendritic or equiaxed solidification microstructure in Al-based alloys are presented. Beyond fluid flow interaction, earth gravity induces stresses, deformation and fragmentation in the dendritic mush. Settling of dendrite arms and equiaxed grains thus occurs, in particular in the columnar to equiaxed transition. Other types of stresses and strains are caused by the mere formation of the solidification microstructure itself. In white-beam X-ray topography, stresses and strains are manifested by specific contrasts and breaking of the Laue images into several pieces. Finally, quantitative analysis of the grey level in radiographs enables the analysis of solute segregation, which noticeably results in solutal poisoning of growth when equiaxed grains are interacting. (author)

The Impact of Ceramic Shell Strength on Hot Tearing during Investment Casting

International Nuclear Information System (INIS)

Norouzi, Saeid; Farhangi, Hassan

2011-01-01

The effect of ceramic shell strength on hot tearing susceptibility during solidification was inspected practicing investment casting of the cobalt-base superalloy samples with the same casting conditions, but different ceramic shell systems. Results showed that the lower the ceramic shell strength upon using polymer additives, the lower the hindered contraction rate, and the lower the hindered contraction rate, the smaller the hot tearing tendency. Optical microscopy and electron microscopy scanning revealed that the hot tear propagated along the last solidified interdendritic phase, and that the hot tear surface had two major modes: 1) the ductile region in the outer layer; and 2) the inner region of liquid embrittlement.

Solidification method of radioactive wastes

Energy Technology Data Exchange (ETDEWEB)

Baba, Tsutomu; Chino, Koichi; Sasahira, Akira; Ikeda, Takashi

1992-07-24

Metal solidification material can completely seal radioactive wastes and it has high sealing effect even if a trace amount of evaporation should be caused. In addition, the solidification operation can be conducted safely by using a metal having a melting point of lower than that of the decomposition temperature of the radioactive wastes. Further, the radioactive wastes having a possibility of evaporation and scattering along with oxidation can be solidified in a stable form by putting the solidification system under an inert gas atmosphere. Then in the present invention, a metal is selected as a solidification material for radioactive wastes, and a metal, for example, lead or tin having a melting point of lower than that of the decomposition temperature of the wastes is used in order to prevent the release of the wastes during the solidification operation. Radioactive wastes which are unstable in air and scatter easily, for example, Ru or the like can be converted into a stable solidification product by conducting the solidification processing under an inert gas atmosphere. (T.M.).

Triple Plate Mold Final Report: Optimization of the Mold Design and Casting Parameters for a Thin U-10mo Fuel Casting

Energy Technology Data Exchange (ETDEWEB)

Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-01-04

This work describes the experiments and modeling that have been performed to improve and try to optimize the simultaneous casting of three plates of U-10wt%Mo in a single coil vacuum induction melting (VIM) furnace. The plates of interest are 280 mm wide by 203 mm tall by 5 mm thick (11" x 8" x 0.2"). The initial mold design and processing parameters were supplied by Y-12. The mold and casting cavity were instrumented with a number of thermocouples, and the casting performed to determine the thermal history of the mold and casting. The resulting cast plates were radiographed and numerous defects identified. Metallography was performed to help identify the nature of the radiographically observed defects. This information was then used to validate a mold filling and solidification model of that casting. Based on the initial casting, good casting design practice, and process simulation of several design alternatives, a revised design was developed with the goal of minimizing casting defects such as porosity. The redesigned mold had a larger hot-top and had its long axis along the horizontal direction. These changes were to try to develop a strong thermal gradient conducive to good feeding and minimization of micro- and macroporosity in the cast plates. An instrumented casting was then performed with the revised mold design and a linear distributor. This design yielded cast plates with significantly less radiographically identified defects. Unfortunately, there was significant variation in plate weight and metal content in their hot-tops. Fluid flow simulations were then performed on this mold/distributor design. This helped identify the issue with this linear distributor design. Additional simulations were then performed on candidate distributor redesigns and a preferred distributor annular design was identified. This improved annular design was used to produce a third instrumented casting with favorable results. These refined designs and their radiographic

Electroerosion formation and technology of cast iron coatings on aluminum alloys

Directory of Open Access Journals (Sweden)

Smolentsev Vladislav P.

2017-01-01

Full Text Available At present in the course of designing basic production parts and industrial equipment designers pay more and more attention to aluminum alloys having a number of properties compared favorably with other materials. In particular, technological aluminum tool electrodes without coating in the presence of products of processing with alkali in the composition of operation environment are being destroyed at the expense of intensified material dissolution. It is shown in the paper that the method offered by the authors and covered by the patents on cast iron coating of products made of aluminum alloys, allows obtaining on a product surface the layers with high adhesion durability ensuring a high protection against destruction in the friction units including operation in hostile environment. Thereupon, aluminum, as compared with iron-based alloys used at manufacturing technological equipment for electrical methods of processing, has a high electrical and thermal conduction, its application will allow achieving considerable energy-saving in the course of parts production. A procedure for the design of a technological process of qualitative cast iron coatings upon aluminum tool electrodes and parts of basic production used in different branches of mechanical engineering is developed.

Resource-saving technology for manufacturing billets for piston’s rings

Directory of Open Access Journals (Sweden)

A. N. Krutilin

2010-10-01

shortcomings, the proposed process is characterized by a significant reduction of laboriousness, improved working conditions, a significant decreasing of molding materials, decreasing of production areas, complete except flasks and ladles. In the Belarusian National Technical University was developed an improved method of casting immersion [2], schematic diagram of the process was shown in Figure 1. Thin ring single mould (5-10 mm, core sand - made, collect by means of a special device to the blocks. Pouring and filling billets are being when preheated moulds immersing in melt metal through one or more gatings, leaving the outer surface of the mould. Filling billet is directly from the molten pool until its complete solidification, after finishing of billet’s crystallization, non - solidified metal from the gatings goes back into the oven. For a long time, based on experimental investigation are identified optimal technological parameters of the process of casting billets of low-alloyed gray and ductile iron.Through the minimum time between the modification and pouring moulds of melt, graphitized items, in ligatures, have the greatest effect. Crystallization of the alloy is mainly running with the formation of austenite-graphite eutectic, which also has a positive effect on reducing marriage to porosity. Due to the active influence on the rate of solidification and cooling at different periods of the formation of the casting, provides technological process provide to obtaining billets without structurally - free carbides with the requisite level of physical and mechanical properties without the using of energy-intensive heat treatment. Optimal thermal conditions for the formation provide uniformity of hardness on the perimeter of billet. Physical-mechanical properties and microstructure satisfy the technical requirements for piston’s rings. Possibility to obtain a single cast billets of ductile iron with hypoeutectic composition, free shrinkage defects. Significantly

Effects of Manganese Content on Solidification Structures, Thermal Properties, and Phase Transformation Characteristics in Fe-Mn-Al-C Steels

Science.gov (United States)

Yang, Jian; Wang, Yu-Nan; Ruan, Xiao-Ming; Wang, Rui-Zhi; Zhu, Kai; Fan, Zheng-Jie; Wang, Ying-Chun; Li, Cheng-Bin; Jiang, Xiao-Fang

2015-04-01

To assist developments of the continuous-casting technology of Fe-Mn-Al-C steels, the solidification structures and the thermal properties of Fe-Mn-Al-C steel ingots with different manganese contents have been investigated and the phase transformation characteristics have been revealed by FactSage (CRCT-ThermFact Inc., Montréal, Canada). The results show that the thermal conductivity of the 0Mn steel is the highest, whereas the thermal conductivity of the 8Mn steel is slightly higher than that of the 17Mn steel. Increasing the manganese content promotes a columnar solidification structure and coarse grains in steel. With the increase of manganese content, the mass fraction of austenite phase is increased. Finally, a single austenite phase is formed in the 17Mn steel. The mean thermal expansion coefficients of the steels are in the range from 1.3 × 10-5 to 2.3 × 10-5 K-1, and these values increase with the increase of manganese content. The ductility of the 17Mn steel and the 8Mn steel are higher than 40 pct in the temperature range from 873 K to 1473 K (600 °C to 1200 °C), and the cracking during the straightening operation should be avoided. However, the ductility of the 0Mn steel is lower than 40 pct at 973 K and 1123 K (700 °C and 850 °C), which indicates that the temperature of the straightening operation during the continuous-casting process should be above 1173 K (900 °C). Manganese has the effect of enlarging the austenite phase region and reducing the δ-ferrite phase region and α-ferrite phase region. At the 2.1 mass pct aluminum level, the precipitate temperature of AlN is high. Thus, the formed AlN is too coarse to deteriorate the hot ductility of steel.

Improving the casting properties of high-strength aluminium alloys:

OpenAIRE

Ekrt, Ondřej; Šerák, Jan; Vojtěch, Dalibor

2004-01-01

Al-Zn-Mg-Cu alloys are examples of high-strength alloys. After age-hardening they often possess tensile strengths of more than 500 MPa. However, their casting properties are relatively poor as a result of solidification intervals that are too wide. Therefore, they often require an extrusion, rolling, or forging treatment, and the production of small series of special parts can, as a consequence, be very expensive. In this study, an improvement in the castability and a reduction of the hot-tea...

Cast irons

CERN Document Server

1996-01-01

Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

Numerical investigation on natural convection and solidification of molten pool with OpenFOAM

International Nuclear Information System (INIS)

Wang Xi; Meng Zhaocan; Cheng Xu

2015-01-01

The in-vessel retention is adopted by the third generation nuclear power technology as an important severe accident mitigation strategy. The integrity of reactor pressure vessel depends on the heat flux distribution of molten pool. In present study, the solidification model in open source CFD software OpenFOAM was applied to simulate solidification and natural convection which was driven by internal heat source or temperature difference. The stratified molten pool heat transfer experiment carried out by Royal Institute of Technology was analyzed in the paper, and the solidified crust, temperature and heat flux distributions were obtained. The simulation results were compared with experimental data. It is shown that this numerical method can be used in the simulation of natural convection and solidification of molten pool, and it will probably be used in the analysis of molten corium behavior in reactor lower head. (authors)

The simulation of magnesium wheel low pressure die casting based on PAM-CASTTM

International Nuclear Information System (INIS)

Peng Yinghong; Wang Yingchun; Li Dayong; Zeng Xiaoqin

2004-01-01

Magnesium is the lightest metal commonly used in engineering, with various excellent characteristics such as high strength and electromagnetic interference shielding capability. Particularly, the usage of magnesium in automotive industry can meet better the need to reduce fuel consumption and CO2 emissions. Nowadays, most current magnesium components in automobiles are made by die casting. In this paper, commercial software for die casting, PAM-CAST TM , was utilized to simulate the low pressure die casting process of magnesium wheel. Through calculating temperature field and velocity field during filling and solidification stages, the evolution of temperature distribution and liquid fraction was analyzed. Then, the potential defects including the gas entrapments in the middle of the spokes, shrinkages between the rim and the spokes were forecasted. The analytical results revealed that the mold geometry and die casting parameters should be improved in order to get the sound magnesium wheel. The reasons leading to these defects were also analyzed and the solutions to eliminate them were put forward. Furthermore, through reducing the pouring velocity, the air gas entrapments and partial shrinkages were eliminated effectively

Peculiarities of the coolant of large ingots in crystallizators of semicontinuous casting machines

International Nuclear Information System (INIS)

Tsukerman, V.Ya.; Marchenko, I.K.; Rimen, V.Kh.

1983-01-01

Peculiarities of heat transfer in crystallizator of semicontinuous blank casting machine were investigated, taking carbon and chromium-nickel steels as an example. The effect of crystallizator cross-section and decrease of the rate of metal casting on ingot cooling was considered at that. It was established that nonuniformity of deformation of ingot skin as well as the state of crystallizator operating walls affect on heat transfer in crystallizator. Crystallizator structure with ribs in upper part and without ribs in lower cone part is optimal. It provides more uniform skin growth in initial period of solidification and compensation of gap, which appears due to shrinkage

On the stable eutectic solidification of iron–carbon–silicon alloys

International Nuclear Information System (INIS)

Stefanescu, Doru M.; Alonso, Gorka; Larrañaga, Pello; Suarez, Ramon

2016-01-01

Extensive effort was expanded to elucidate the growth and morphology of the stable eutectic grains during early solidification of continuous cooled Fe–C–Si alloys. To this purpose, quenching experiments at successive stages during solidification have been carried out on five cast irons with various magnesium and titanium levels designed to produce graphite morphologies ranging from lamellar to mixed compacted–spheroidal. The graphite shape factors were measured on the metallographic samples, and their evolution as a function of the chemical composition and the solid fraction was analyzed. Extensive scanning electron microscopy was carried on to evaluate the change in graphite shape during early solidification, to establish the fraction of solid at which the transition from spheroidal-to-compacted-to-lamellar graphite occurs, and to outline the early morphology of the eutectic grains. It was confirmed that solidification of Mg containing irons started with the development of spheroidal graphite even at Mg levels as low as 0.013 mass%. Then, as solidification proceeds, when some spheroids developed one or more tails (tadpole graphite), the spheroidal-to-compacted graphite transition occurs. The new findings were then integrated in previous knowledge to produce an understanding of the eutectic solidification of these materials. It was concluded that in hypoeutectic lamellar graphite iron austenite/graphite eutectic grains can nucleate at the austenite/liquid interface or in the bulk of the liquid, depending on the sulfur content and on the cooling rate. When graphite nucleation occurs on the primary austenite, several eutectic grains can nucleate and grow on the same dendrite. The primary austenite continues growing as eutectic austenite and therefore the two have the same crystallographic orientation. Thus, a final austenite grain may include several eutectic grains. In eutectic irons the eutectic grains nucleate and grow mostly in the liquid. The eutectic

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

Energy Technology Data Exchange (ETDEWEB)

Fasoyinu, Yemi [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.

Thermosetting polymer for dynamic nuclear polarization: Solidification of an epoxy resin mixture including TEMPO

Energy Technology Data Exchange (ETDEWEB)

Noda, Yohei, E-mail: noda.yohei@jaea.go.jp [Quantum Beam Science Centre, Sector of Nuclear Science Research, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan); Kumada, Takayuki [Quantum Beam Science Centre, Sector of Nuclear Science Research, Kansai Photon Science Institute, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Yamaguchi, Daisuke; Shamoto, Shin-ichi [Quantum Beam Science Centre, Sector of Nuclear Science Research, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan)

2015-03-11

We investigated the dynamic nuclear polarization (DNP) of typical thermosetting polymers (two-component type epoxy resins; Araldite{sup ®} Standard or Araldite{sup ®} Rapid) doped with a (2,2,6,6-tetramethylpiperidine-1-yl)oxy (TEMPO) radical. The doping process was developed by carefully considering the decomposition of TEMPO during the solidification of the epoxy resin. The TEMPO electron spin in each two-component paste decayed slowly, which was favorable for our study. Furthermore, despite the dissolved TEMPO, the mixture of the two-component paste successfully solidified. With the resulting TEMPO-doped epoxy-resin samples, DNP experiments at 1.2 K and 3.35 T indicated a magnitude of a proton-spin polarization up to 39%. This polarization is similar to that (35%) obtained for TEMPO-doped polystyrene (PS), which is often used as a standard sample for DNP. To combine this solidification of TEMPO-including mixture with a resin-casting technique enables a creation of polymeric target materials with a precise and complex structure.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Solidification of high-level radioactive wastes. Final report

International Nuclear Information System (INIS)

1979-06-01

A panel on waste solidification was formed at the request of the Nuclear Regulatory Commission to study the scientific and technological problems associated with the conversion of liquid and semiliquid high-level radioactive wastes into a stable form suitable for transportation and disposition. Conclusions reached and recommendations made are as follows. Many solid forms described in this report could meet standards as stringent as those currently applied to the handling, storage, and transportation of spent fuel assemblies. Solid waste forms should be selected only in the context of the total radioactive waste management system. Many solid forms are likely to be satisfactory for use in an appropriately designed system, The current United States policy of deferring the reprocessing of commercial reactor fuel provides additional time for R and D solidification technology for this class of wastes. Defense wastes which are relatively low in radioactivity and thermal power density can best be solidified by low-temperature processes. For solidification of fresh commercial wastes that are high in specific activity and thermal power density, the Panel recommends that, in addition to glass, the use of fully-crystalline ceramics and metal-matrix forms be actively considered. Preliminary analysis of the characteristics of spent fuel pins indicates that they may be eligible for consideration as a waste form. Because the differences in potential health hazards to the public resulting from the use of various solid form and disposal options are likely to be small, the Panel concludes that cost, reliability, and health hazards to operating personnel will be major considerations in choosing among the options that can meet safety requiremens. The Panel recommends that responsibility for all radioactive waste management operations (including solidification R and D) should be centralized

Improved cement solidification of low and intermediate level radioactive wastes

International Nuclear Information System (INIS)

1993-01-01

Cementation was the first and is still the most widely applied technique for the conditioning of low and intermediate level radioactive wastes. Compared with other solidification techniques, cementation is relatively simple and inexpensive. However, the quality of the final cemented waste forms depends very much on the composition of the waste and the type of cement used. Different kinds of cement are used for different kinds of waste and the compatibility of a specific waste with a specific cement type should always be carefully evaluated. Cementation technology is continuously being developed in order to improve the characteristics of cemented waste in accordance with the increasing requirements for quality of the final solidified waste. Various kinds of additives and chemicals are used to improve the cemented waste forms in order to meet all safety requirements. This report is meant mainly for engineers and designers, to provide an explanation of the chemistry of cementation systems and to facilitate the choice of solidification agents and processing equipment. It reviews recent developments in cementation technology for improving the quality of cemented waste forms and provides a brief description of the various cement solidification processes in use. Refs, figs and tabs

Optimization of die filling in high pressure die cast part using MAGMAsoft®

DEFF Research Database (Denmark)

Kotas, Petr; Hattel, Jesper Henri

2008-01-01

Integrated modeling of an entire casting process has become a tool which favors design and optimization of manufactured parts. The aim of this project was to examine and optimize a high-pressure die cast part and its production process with respect to die filling and issues of residual stresses...... in the process and machine parameters were done and assessed. All simulations revealed that, the main causes of the problems were: a poor geometry of the casting leading to an improper filling pattern, and a massive gating system bringing thermal imbalance into the solidification process. Thus deformations due...... to residual stresses occurred. The numerical results were evaluated and appeared to be in agreement with the results from the actual manufacturing process. Based on these findings, proposals for improvements were given. In order to avoid distortions and cold shuts further geometrical adjustments should...

Solidification as low cost technology prior to land filling of industrial hazardous waste sludge.

Science.gov (United States)

El-Sebaie, O; Ahmed, M; Ramadan, M

2000-01-01

The aim of this study is to stabilize and solidify two different treated industrial hazardous waste sludges, which were selected from factories situated close to Alexandria. They were selected to ensure their safe transportation and landfill disposal by reducing their potential leaching of hazardous elements, which represent significant threat to the environment, especially the quality of underground water. The selected waste sludges have been characterized. Ordinary Portland Cement (OPC), Cement Kiln Dust (CKD) from Alexandria Portland Cement Company, and Calcium Sulphate as a by-product from the dye industry were used as potential solidification additives to treat the selected treated waste sludges from tanning and dyes industry. Waste sludges as well as the solidified wastes have been leach-tested, using the General Acid Neutralization Capacity (GANC) procedure. Concentration of concerning metals in the leachates was determined to assess changes in the mobility of major contaminants. The treated tannery waste sludge has an acid neutralization capacity much higher than that of the treated dyes waste sludge. Experiment results demonstrated the industrial waste sludge solidification mix designs, and presented the reduction of contaminant leaching from two types of waste sludges. The main advantages of solidification are that it is simple and low cost processing which includes readily available low cost solidification additives that will convert industrial hazardous waste sludges into inert materials.

Plastic solidification of radioactive wastes

International Nuclear Information System (INIS)

Moriyama, Noboru

1981-01-01

Over 20 years have elapsed after the start of nuclear power development, and the nuclear power generation in Japan now exceeds the level of 10,000 MW. In order to meet the energy demands, the problem of the treatment and disposal of radioactive wastes produced in nuclear power stations must be solved. The purpose of the plastic solidification of such wastes is to immobilize the contained radionuclides, same as other solidification methods, to provide the first barrier against their move into the environment. The following matters are described: the nuclear power generation in Japan, the radioactive wastes from LWR plants, the position of plastic solidification, the status of plastic solidification in overseas countries and in Japan, the solidification process for radioactive wastes with polyethylene, and the properties of solidified products, and the leachability of radionuclides in asphalt solids. (J.P.N.)

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

Science.gov (United States)

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 α-Al grains surrounded by an Al-Si eutectic aggregate, while primary dendritic α-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.

Solidification Sequence of Spray-Formed Steels

Science.gov (United States)

Zepon, Guilherme; Ellendt, Nils; Uhlenwinkel, Volker; Bolfarini, Claudemiro

2016-02-01

Solidification in spray-forming is still an open discussion in the atomization and deposition area. This paper proposes a solidification model based on the equilibrium solidification path of alloys. The main assumptions of the model are that the deposition zone temperature must be above the alloy's solidus temperature and that the equilibrium liquid fraction at this temperature is reached, which involves partial remelting and/or redissolution of completely solidified droplets. When the deposition zone is cooled, solidification of the remaining liquid takes place under near equilibrium conditions. Scanning electron microscopy (SEM) and optical microscopy (OM) were used to analyze the microstructures of two different spray-formed steel grades: (1) boron modified supermartensitic stainless steel (SMSS) and (2) D2 tool steel. The microstructures were analyzed to determine the sequence of phase formation during solidification. In both cases, the solidification model proposed was validated.

Microstructural evolution and mechanical properties of a novel FeCrNiBSi advanced high-strength steel: Slow, accelerated and fast casting cooling rates

Energy Technology Data Exchange (ETDEWEB)

Askari-Paykani, Mohsen; Shahverdi, Hamid Reza, E-mail: shahverdi@modares.ac.ir; Miresmaeili, Reza

2016-06-21

In the current work, three different solidification routes and a two-step heat treatment process were applied to a novel FeCrNiBSi alloy system to introduce a new candidate for advanced high-strength steels. The evolution of the microstructure after solidification, heat treatment, and tensile deformation was characterized using optical and electron microscopy techniques, as well as hardness and room temperature uniaxial tensile tests. The effects of the different solidification routes and heat treatment parameters on the deformation and fracture mechanisms of this steel are discussed. Grain refinement, precipitation hardening, and solid solution as a result of the fast casting cooling rate led to an increase in strength at improved ductility. This result can be explained partly by the less severe stress/strain partitioning at the matrix grain/M{sub 2}B interfaces and better interface cohesion. Moreover, the stress/strain partitioning characteristics between the matrix grains and M{sub 2}B led to a higher initial strain hardening rate. The fast casting cooling rate further promoted ductile fracture mechanisms, which is a result of increased cleavage fracture stress. The higher casting cooling rate and two-step heat treatment resulted in a strong increase in formability index, from 8 GPa% to 24 GPa%, at which the mechanical properties occupy the TRIP envelope. Heat treatment of the fast-cooling specimens led to a small reduction in yield and tensile strength and 22% total elongation percentage improvement (from 10% to 32%).

Diffusion-controlled growth of hydrogen pores in aluminum-silicon castings: In situ observation and modeling

Energy Technology Data Exchange (ETDEWEB)

Atwood, R.C.; Sridhar, S.; Zhang, W.; Lee, P.D.

2000-01-24

In situ observations were made of the nucleation and growth kinetics of hydrogen porosity during the directional solidification of aluminium-7 wt% silicon (Al7Si) with TiB{sub 2} grain refiner added, using an X-ray temperature gradient stage (XTGS). The effect of altering the solidification velocity on the growth rate and morphology of the porosity formed was characterized by tracking individual pores with digital analysis of the micro-focal video images. It was found that increasing the solidification velocity caused the pore radius to decrease and pore density to increase. Insight gained from the experimental results was used to develop a computational model of the evolution of hydrogen pores during solidification of aluminum-silicon cast alloys. The model solves for the diffusion-limited growth of the pores in spherical coordinates, using a deterministic solution of the grain nucleation and growth as a sub-model to calculate the parameters that depend upon the fraction solid. Sensitivity analysis was carried out to assess the effects of equiaxed grain density, pore density, initial hydrogen content and cooling rate. The model agrees with the experimental results within the resolution limits of the XTGS experiments performed.

The sort of carburization and the quality of obtained cast iron

Directory of Open Access Journals (Sweden)

K. Janerka

2008-12-01

Full Text Available In the production of cast iron, the pig iron’s amount in charge material is more and more often limited, and replaced by steel scrap. That extorts the necessity of know-how the carburization and one is looking for carburizers, which ensure obtaining big carbon increment as quickly as possible with the high repeatability and the ones which ensure getting the adequate quality of cast iron. The object of presented research was definition of the influence of charge materials’ sort on the structure, course of solidification, and the effectiveness of process. The cast iron melts, which are presented below, are made only on the basis of steel scrap with portion of graphitoidal, coke and anthracite carburizers, which were added to the charge in solid. In the article one compared the carburizers in respect of their structure, chemical constitution and the effectiveness obtained during the carburization of liquid metal. The melting of cast iron, based on the special pig iron, was carried out as well. The course of melts, chemical constitution of obtained cast iron and its structure were presented. The comparison between quality distribution and the volume fraction of graphite in classes of size for the individual melts were achieved and the TDA curves were inserted.

INTERRELATION OF RHOMBICITY AND OCCURRENCE OF INTERNAL CRACKS AT CONTINUOUS CASTING OF SORTED SLUG

Directory of Open Access Journals (Sweden)

Ju. A. Samojlovich

2008-01-01

Full Text Available Analysis of deformations and stresses in cross section of sorted uninterruptedly-casted slugs at their solidification and cooling within limits of crystallizer with the aim of determination of possibilities for occurrence of internal cracks of diagonal type is carried out on basis of mathematical modeling, the peculiarities of the slug skin cooling at its shrinkage and separation from crystallizer wall are revealed.

Evaluation of Technetium Getters to Improve the Performance of Cast Stone

International Nuclear Information System (INIS)

Neeway, James J.; Qafoku, Nikolla P.; Serne, R. Jeffrey; Lawter, Amanda R.; Stephenson, John R.; Lukens, Wayne W.; Westsik, Joseph H.

2015-01-01

Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. One of the major radionuclides that Cast Stone has the potential to immobilize is technetium (Tc). The mechanism for immobilization is through the reduction of the highly mobile Tc(VII) species to the less mobile Tc(IV) species by the blast furnace slag (BFS) used in the Cast Stone formulation. Technetium immobilization through this method would be beneficial because Tc is one of the most difficult contaminants to address at the U.S. Department of Energy (DOE) Hanford Site due to its complex chemical behavior in tank waste, limited incorporation in mid- to high-temperature immobilization processes (vitrification, steam reformation, etc.), and high mobility in subsurface environments. In fact, the Tank Closure and Waste Management Environmental Impact Statement for the Hanford Site, Richland, Washington (TC&WM EIS) identifies technetium-99 ( 99 Tc) as one of the radioactive tank waste components contributing the most to the environmental impact associated with the cleanup of the Hanford Site. The TC&WM EIS, along with an earlier supplemental waste-form risk assessment, used a diffusion-limited release model to estimate the release of different contaminants from the WTP process waste forms. In both of these predictive modeling exercises, where effective diffusivities based on grout performance data available at the time, groundwater at the 100-m down-gradient well exceeded the allowable maximum permissible concentrations for 99 Tc. (900 pCi/L). Recent relatively short-term (63 day

Evaluation of Technetium Getters to Improve the Performance of Cast Stone

Energy Technology Data Exchange (ETDEWEB)

Neeway, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lawter, Amanda R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephenson, John R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lukens, Wayne W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-11-01

Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. One of the major radionuclides that Cast Stone has the potential to immobilize is technetium (Tc). The mechanism for immobilization is through the reduction of the highly mobile Tc(VII) species to the less mobile Tc(IV) species by the blast furnace slag (BFS) used in the Cast Stone formulation. Technetium immobilization through this method would be beneficial because Tc is one of the most difficult contaminants to address at the U.S. Department of Energy (DOE) Hanford Site due to its complex chemical behavior in tank waste, limited incorporation in mid- to high-temperature immobilization processes (vitrification, steam reformation, etc.), and high mobility in subsurface environments. In fact, the Tank Closure and Waste Management Environmental Impact Statement for the Hanford Site, Richland, Washington (TC&WM EIS) identifies technetium-99 (⁹⁹Tc) as one of the radioactive tank waste components contributing the most to the environmental impact associated with the cleanup of the Hanford Site. The TC&WM EIS, along with an earlier supplemental waste-form risk assessment, used a diffusion-limited release model to estimate the release of different contaminants from the WTP process waste forms. In both of these predictive modeling exercises, where effective diffusivities based on grout performance data available at the time, groundwater at the 100-m down-gradient well exceeded the allowable maximum permissible concentrations for ⁹⁹Tc. (900 pCi/L). Recent relatively

Influence of non-technical policies on choices of waste solidification technologies

International Nuclear Information System (INIS)

Trubatch, S.L.

1987-01-01

This paper describes and discusses non-technical policy considerations which may improperly influence decisions on the solidification of low-level radioactive wastes (''LLW''). These policy considerations are contained principally in several State and Federal statutes which regulate various aspects of LLW disposal. One policy consideration in particular, the unqualified bias in favor of volume reduction, is shown to present a substantial potential for leading to technically suboptimal decisions on the appropriate processes for solidifying LLW. To avoid the unintended skewing of technical decisions by non-technical policy considerations, certain current policies may need to be revised to ensure that the choices of waste treatment, including decisions on solidification, are based primarily on reasonable assurance of adequate protection of public health and safety. This goal may be realized in part by basing any disposal fee structure on more than just LLW volume to include consideration of the waste's activity and its difficulty of confinement

Next-generation casting technologies and their adaptation and development in Russia: I. at the beginning of a new technological paradigm

Science.gov (United States)

Semenov, A. B.; Gavrilenko, A. E.; Semenov, B. I.

2016-12-01

The up-to-date methods of powder metallurgy and casting technology are considered. They can be used to apply the design and technological solutions that are intended to form parts with the optimum space configuration, to deLcrease the number of assembly elements, and to decrease the number of mechanical and welded joints in units.

Direct strip casting of steel - historical perspective and future direction

International Nuclear Information System (INIS)

Manohar, P.A.; Hunter, A.; Ferry, M.

2000-01-01

The commercialisation of direct strip casting (DSC) of steel represents the realisation of a dream cherished by engineers for over one hundred and fifty years. The story of the global competition for DSC of steel, that has ingredients of romanticism of chasing of a dream, adventure and intrigue, is being played out across continents over dozens of decades with an interplay of setbacks and successes. At this stage, DSC is set to make a profound impact on the steelmaking landscape. This paper reviews the important milestones in this compelling story, presents the current status and then gazes into the crystal ball in an attempt to predict which turn the story may take in the near future. The constraints and critical challenges for the successful commercialisation of DSC are highlighted. Recent results are discussed relating the production process to quality control and properties of unalloyed, low carbon strip-cast steels. future metallurgical challenges include a better understanding of solidification mechanism during high-speed casting and secondary processing variables affecting the final microstructure of austenitic grains

Hot Ductility Behavior of a Peritectic Steel during Continuous Casting

Directory of Open Access Journals (Sweden)

Mustafa Merih Arıkan

2015-06-01

Full Text Available Hot ductility properties of a peritectic steel for welded gas cylinders during continuous casting were studied by performing hot tensile tests at certain temperatures ranging from 1200 to 700 °C for some cooling rates by using Gleeble-3500 thermo-mechanical test and simulation machine in this study. The effects of cooling rate and strain rate on hot ductility were investigated and continuous casting process map (time-temperature-ductility were plotted for this material. Reduction of area (RA decreases and cracking susceptibility increases during cooling from solidification between certain temperatures depending on the cooling rate. Although the temperatures which fracture behavior change upon cooling during continuous casting may vary for different materials, it was found that the type of fracture was ductile at 1100 and 1050 °C; semi-ductile at 1000 °C, and brittle at 800 °C for the steel P245NB. There is a ductility trough between 1000 and 725 °C. The ductility trough gets slightly narrower as the cooling rate decreases.

Solidification paths of multicomponent monotectic aluminum alloys

Energy Technology Data Exchange (ETDEWEB)

Mirkovic, Djordje; Groebner, Joachim [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Street 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, Rainer [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Street 42, D-38678 Clausthal-Zellerfeld (Germany)], E-mail: schmid-fetzer@tu-clausthal.de

2008-10-15

Solidification paths of three ternary monotectic alloy systems, Al-Bi-Zn, Al-Sn-Cu and Al-Bi-Cu, are studied using thermodynamic calculations, both for the pertinent phase diagrams and also for specific details concerning the solidification of selected alloy compositions. The coupled composition variation in two different liquids is quantitatively given. Various ternary monotectic four-phase reactions are encountered during solidification, as opposed to the simple binary monotectic, L' {yields} L'' + solid. These intricacies are reflected in the solidification microstructures, as demonstrated for these three aluminum alloy systems, selected in view of their distinctive features. This examination of solidification paths and microstructure formation may be relevant for advanced solidification processing of multicomponent monotectic alloys.

Graphite nodule count and size distribution in thin-walled ductile cast iron

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Tiedje, Niels Skat

2008-01-01

Graphite nodule count and size distribution have been analysed in thin walled ductile cast iron. The 2D nodule counts have been converted into 3D nodule count by using Finite Difference Method (FDM). Particles having a diameter smaller than 5 µm should be neglected in the nodule count as these ar......Graphite nodule count and size distribution have been analysed in thin walled ductile cast iron. The 2D nodule counts have been converted into 3D nodule count by using Finite Difference Method (FDM). Particles having a diameter smaller than 5 µm should be neglected in the nodule count...... as these are inclusions and micro porosities that do not influence the solidification morphology. If there are many small graphite nodules as in thin walled castings only 3D nodule count calculated by FDM will give reliable results. 2D nodule count and 3D nodule count calculated by simple equations will give too low...

Report of Separate Effects Testing for Modeling of Metallic Fuel Casting Process

Energy Technology Data Exchange (ETDEWEB)

Crapps, Justin M. [Los Alamos National Laboratory; Galloway, Jack D. [Los Alamos National Laboratory; Decroix, David S. [Los Alamos National Laboratory; Korzekwa, David A. [Los Alamos National Laboratory; Aikin, Robert M. Jr. [Los Alamos National Laboratory; Unal, Cetin [Los Alamos National Laboratory; Fielding, R. [Idaho National Laboratory; Kennedy, R [Idaho National Laboratory

2012-06-29

In order to give guidance regarding the best investment of time and effort in experimental determination of parameters defining the casting process, a Flow-3D model of the casting process was used to investigate the most influential parameters regarding void fraction of the solidified rods and solidification speed for fluid flow parameters, liquid heat transfer parameters, and solid heat transfer parameters. Table 1 summarizes the most significant variables for each of the situations studied. A primary, secondary, and tertiary effect is provided for fluid flow parameters (impacts void fraction) and liquid heat transfer parameters (impacts solidification). In Table 1, the wetting angle represents the angle between the liquid and mold surface as pictured in Figure 1. The viscosity is the dynamic viscosity of the liquid and the surface tension is the property of the surface of a liquid that allows it to resist an external force. When only considering solid heat transfer properties, the variations from case to case were very small. Details on this conclusion are provided in the section considering solid heat transfer properties. The primary recommendation of the study is to measure the fluid flow parameters, specifically the wetting angle, surface tension, and dynamic viscosity, in order of importance, as well as the heat transfer parameters latent heat and specific heat of the liquid alloy. The wetting angle and surface tension can be measured simultaneously using the sessile drop method. It is unclear whether there is a temperature dependency in these properties. Thus measurements for all three parameters are requested at 1340, 1420, and 1500 degrees Celsius, which correspond to the minimum, middle, and maximum temperatures of the liquid alloy during the process. In addition, the heat transfer coefficient between the mold and liquid metal, the latent heat of transformation, and the specific heat of the liquid metal all have strong influences on solidification. These

Impact of External Pressure on the Heat Transfer Coefficient during Solidification of Al-A356 Alloy

DEFF Research Database (Denmark)

Jabbari, Masoud; Ilkhchy, A.Fardi; Moumani, E.

In this paper the interfacial heat transfer coefficient (IHTC) is correlated to applied external pressure, in which IHTC at the interface between A356 aluminum alloy and metallic mold during the solidification of the casting under different pressures were obtained using the Inverse Heat Conduction...... Problem (IHCP) method. The method covers the expedient of comparing theoretical and experimental thermal histories. Temperature profiles obtained from thermocouples were used in a finite difference heat flow program to estimate the transient heat transfer coefficients. The new simple formula was presented...

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

Science.gov (United States)

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

Applying a Numerical Model of the Continuous Steel Casting Process to Control the Length of the Liquid Core in the Strand

Directory of Open Access Journals (Sweden)

Miłkowska-Piszczek K.

2015-04-01

Full Text Available This paper presents development and the application of a numerical model of the continuous steel casting process to optimise the strand solidification area. The design of the numerical model of the steel continuous casting process was presented and which was developed based on the actual dimensions of the slab continuous casting machine in ArcelorMittal Poland Unit in Kraków. The S235 steel grade and the cast strand format of 220×1280 mm were selected for the tests. Three strand casting speeds were analysed: 0.6, 0.8 and 1 m min-1. An algorithm was presented, allowing the calculation of the heat transfer coefficient values for the secondary cooling zone. In order to verify the results of numerical simulations, additional temperature measurements of the strand surface within the secondary cooling chamber were made. The ProCAST software was used to construct the numerical model of continuous casting of steel.

Modified sulfur cement solidification of low-level wastes

Energy Technology Data Exchange (ETDEWEB)

1985-10-01

This topical report describes the results of an investigation on the solidification of low-level radioactive wastes in modified sulfur cement. The work was performed as part of the Waste Form Evaluation Program, sponsored by the US Department of Energy's Low-Level Waste Management Program. Modified sulfur cement is a thermoplastic material developed by the US Bureau of Mines. Processing of waste and binder was accomplished by means of both a single-screw extruder and a dual-action mixing vessel. Waste types selected for this study included those resulting from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste type and method of processing. Property evaluation testing was carried out on laboratory scale specimens in order to compare with waste form performance for other potential matrix materials. Waste form property testing included compressive strength, water immersion, thermal cycling and radionuclide leachability. Recommended waste loadings of 40 wt. % sodium sulfate and boric acid salts and 43 wt. % incinerator ash, which are based on processing and performance considerations, are reported. Solidification efficiencies for these waste types represent significant improvements over those of hydraulic cements. Due to poor waste form performance, incorporation of ion exchange resin waste in modified sulfur cement is not recommended.

Modified sulfur cement solidification of low-level wastes

International Nuclear Information System (INIS)

1985-10-01

This topical report describes the results of an investigation on the solidification of low-level radioactive wastes in modified sulfur cement. The work was performed as part of the Waste Form Evaluation Program, sponsored by the US Department of Energy's Low-Level Waste Management Program. Modified sulfur cement is a thermoplastic material developed by the US Bureau of Mines. Processing of waste and binder was accomplished by means of both a single-screw extruder and a dual-action mixing vessel. Waste types selected for this study included those resulting from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste type and method of processing. Property evaluation testing was carried out on laboratory scale specimens in order to compare with waste form performance for other potential matrix materials. Waste form property testing included compressive strength, water immersion, thermal cycling and radionuclide leachability. Recommended waste loadings of 40 wt. % sodium sulfate and boric acid salts and 43 wt. % incinerator ash, which are based on processing and performance considerations, are reported. Solidification efficiencies for these waste types represent significant improvements over those of hydraulic cements. Due to poor waste form performance, incorporation of ion exchange resin waste in modified sulfur cement is not recommended

Advanced Casting Technology

Science.gov (United States)

1982-08-01

Anodic Films for the Protection of Magnesium Alloys". G.R. Kotler, D.L. Hawke and E.N. Agua . Proc. International Magnesium Association, Montreal, May...HCF testing, impellers were bench tested to assess the in situ fatigue capabilities of 250-C28 impeller airfoils. In this testing, the airfoils...64 at 204oC (400oF), 13- T to a> o >-, o r- i—l CD -*—• Cast Wrought TE-2222 Ficure 11. In situ HCF results for Ti-64 Model 250

Crystallography and Morphology of MC Carbides in Niobium-Titanium Modified As-Cast HP Alloys

Science.gov (United States)

Buchanan, Karl G.; Kral, Milo V.; Bishop, Catherine M.

2014-07-01

The microstructures of two as-cast heats of HP alloy stainless steels modified with niobium and titanium were examined with particular attention paid to the interdendritic niobium-titanium-rich carbides formed during solidification of these alloys. Generally, these precipitates obtain a blocky morphology in the as-cast condition. However, the (NbTi)C precipitates may obtain a nodular morphology. To provide further insight to the origin of the two different morphologies obtained by the (NbTi)C precipitates in the HP-NbTi alloy, the microstructure and crystallography of each have been studied in detail using scanning electron microscopy, transmission electron microscopy, various electron diffraction methods (EBSD, SAD, and CBED), and energy-dispersive X-ray spectroscopy.

Influence of the chemical composition on steel casting performance

Directory of Open Access Journals (Sweden)

Roney Eduardo Lino

2017-01-01

Full Text Available Improving the quality of steel and the steelmaking process has been a matter of routine for metallurgical engineers and steelmaking companies in a demanding market for quality products at highly competitive price. The chemical and temperature adjustment are made during the secondary refining process, as well as the inclusion modification required to product quality, and also the demand for castability accuracy. Continuous casting process is the most used solidification casting process, in which the flow of pouring liquid metal through the submerged entry nozzle is assured by the correct temperature and the formation of liquid inclusion in the casting temperature. Thermocalc and CEQCSI were the software used in this work to assess the effect of carbon, silicon and sulphur in the castability window of the aluminium vs calcium phase diagrams. They have proved to be highly suitable and effective and the results showed that the chemical elements used directly affected the position of the castability window of carbon steel. An analysis of a 0.2%C billet sample using Scanning Electron Microscopy showed that there is a great heterogeneity of inclusions in aluminium-killed and calcium-treated steel.

Real-time measurement system for tracking birefringence, weight, thickness, and surface temperature during drying of solution cast coatings and films

Science.gov (United States)

Unsal, E.; Drum, J.; Yucel, O.; Nugay, I. I.; Yalcin, B.; Cakmak, M.

2012-02-01

This paper describes the design and performance of a new instrument to track temporal changes in physical parameters during the drying behavior of solutions, as well as curing of monomers. This real-time instrument follows in-plane and out-of-plane birefringence, weight, thickness, and surface temperature during the course of solidification of coatings and films through solvent evaporation and thermal or photocuring in a controlled atmosphere. It is specifically designed to simulate behavior of polymer solutions inside an industrial size, continuous roll-to-roll solution casting line and other coating operations where resins are subjected to ultraviolet (UV) curing from monomer precursors. Controlled processing parameters include air speed, temperature, initial cast thickness, and solute concentration, while measured parameters are thickness, weight, film temperature, in-plane and out-of-plane birefringence. In this paper, we illustrate the utility of this instrument with solution cast and dried poly (amide-imide)/DMAc (Dimethylacetamide) solution, water based black paint, and organo-modified clay/NMP (N-Methylpyrrolidone) solution. In addition, the physical changes that take place during UV photo polymerization of a monomer are tracked. This instrument is designed to be generic and it can be used for tracking any drying/swelling/solidification systems including paper, foodstuffs such as; grains, milk as well as pharmaceutical thin paste and slurries.

The structure of abrasion-resisting castings made of chromium cast iron

Directory of Open Access Journals (Sweden)

D. Kopyciński

2011-01-01

Full Text Available In this study presents the analyse of chrome iron cast structure (as-cast condition which are used in rugged conditions abrasion-percussive and high temperature. While producing the casts of chrome iron major influence has been preserve the structure of technologi cal process parameters. The addition to Fe-C-Cr alloy Ni, Mo or Cu and then proper heat treatment leads to the improvement of functional and mechanical cast qualities. Then it is possible to develop high mechanical properties which are recommended by PN-EN12513. As can it be seen from the above research silicon is an adverse chemical element in this kind of alloy cast iron. However, the reason of cracksappearing in chrome iron casts are phosphorus eutectic microareas. When the compound of Si and P reach the critical point, described inPN-88/H-83144 outdated standard, the microareas might appear.

Focused Ion Beam Nanotomography of ruthenium-bearing nickel-base superalloys with focus on cast-microstructure and phase stability

International Nuclear Information System (INIS)

Cenanovic, Samir

2012-01-01

The influence of rhenium and ruthenium on the multi component system nickel-base superalloy is manifold and complex. An experimental nickel-base superalloy containing rhenium and ruthenium within defined contents, named Astra, was used to investigate the influences of these two elements on the alloy system. The last stage solidification of nickel-base superalloys after Bridgman casting and the high temperature phase stability of these alloys, could be explored with the aid of focused ion beam nanotomography. FIB-nt therefore was introduced and realized at the chair of General Materials Properties of the University Erlangen-Nuremberg. Cast Astra alloys are like other nickel-base superalloys morphologically very inhomogeneous and affected by segregation. In the interdendritic region different structures with huge γ' precipitates are formed. These inhomogeneities and remaining eutectics degrade the mechanical properties, witch makes an understanding of the subsiding processes at solidification of residual melt important for the casting process and the heat treatment. This is why the last stage solidification in the interdendritic region was analyzed. With the help of focused ion beam nanotomography, three different structures identified from 2-D sections could be assigned to one original 3-D structure. It was pointed out, that only the orientation of the plane of the 2-D cut influences the appearance in the 2-D section. The tomography information was used to explain the development during solidification and to create a model of last stage solidification. The interdendritic region is solidifying under the development of eutectic islands. The structure nucleates eutectically epitaxially at primary dendrite arms, with formation of fine γ/γ' precipitates. During solidification the γ' precipitates coarsen in a rod-like structure, and end up in large γ' precipitates. Simulations and other investigations could approve this model. First three

Solidification and performance of cement doped with phenol

International Nuclear Information System (INIS)

Vipulanandan, C.; Krishnan, S.

1991-01-01

Treating mixed hazardous wastes using the solidification/stabilization technology is becoming a critical element in waste management planning. The effect of phenol, a primary constituent in many hazardous wastes, on the setting and solidification process of Type I Portland cement was evaluated. The leachability of phenol from solidified cement matrix (TCLP test) and changes in mechanical properties were studied after curing times up to 28 days. The changes in cement hydration products due to phenol were studied using the X-ray diffraction (XRD) powder technique. Results show that phenol interferes with initial cement hydration by reducing the formation of calcium hydroxide and also reduces the compressive strength of cement. A simple model has been proposed to quantify the phenol leached from the cement matrix during the leachate test

Influence of trace boron addition on the directional solidification characteristics of Ti-6Al-4V

International Nuclear Information System (INIS)

Srinivasan, Raghavan; Tamirisakandala, Sesh

2010-01-01

Trace boron addition to several titanium alloys results in a reduction in the as-cast grain size by an order of magnitude. TiB needles are observed along the prior beta grain boundaries and not the grain interior in these alloys, indicating that TiB needles are not sites for the heterogeneous nucleation of beta grains. This study seeks to understand the influence of the growth rate R on microstructure evolution and grain refinement in Ti-6Al-4V-0.1B alloy using directional solidification experiments and microstructural characterization.

Secondary Waste Cast Stone Waste Form Qualification Testing Plan

Energy Technology Data Exchange (ETDEWEB)

Westsik, Joseph H.; Serne, R. Jeffrey

2012-09-26

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

The solidification velocity of nickel and titanium alloys

Science.gov (United States)

Altgilbers, Alex Sho

2002-09-01

The solidification velocity of several Ni-Ti, Ni-Sn, Ni-Si, Ti-Al and Ti-Ni alloys were measured as a function of undercooling. From these results, a model for alloy solidification was developed that can be used to predict the solidification velocity as a function of undercooling more accurately. During this investigation a phenomenon was observed in the solidification velocity that is a direct result of the addition of the various alloying elements to nickel and titanium. The additions of the alloying elements resulted in an additional solidification velocity plateau at intermediate undercoolings. Past work has shown a solidification velocity plateau at high undercoolings can be attributed to residual oxygen. It is shown that a logistic growth model is a more accurate model for predicting the solidification of alloys. Additionally, a numerical model is developed from simple description of the effect of solute on the solidification velocity, which utilizes a Boltzmann logistic function to predict the plateaus that occur at intermediate undercoolings.

Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys.

Science.gov (United States)

Hong, Jianping; Ma, Dexin; Wang, Jun; Wang, Fu; Sun, Baode; Dong, Anping; Li, Fei; Bührig-Polaczek, Andreas

2016-11-16

Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS) and single crystal (SX) hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys

Directory of Open Access Journals (Sweden)

Jianping Hong

2016-11-01

Full Text Available Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS and single crystal (SX hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

Stress strain modelling of casting processes in the framework of the control volume method

DEFF Research Database (Denmark)

Hattel, Jesper; Andersen, Søren; Thorborg, Jesper

1998-01-01

Realistic computer simulations of casting processes call for the solution of both thermal, fluid-flow and stress/strain related problems. The multitude of the influencing parameters, and their non-linear, transient and temperature dependent nature, make the calculations complex. Therefore the nee......, the present model is based on the mainly decoupled representation of the thermal, mechanical and microstructural processes. Examples of industrial applications, such as predicting residual deformations in castings and stress levels in die casting dies, are presented...... for fast, flexible, multidimensional numerical methods is obvious. The basis of the deformation and stress/strain calculation is a transient heat transfer analysis including solidification. This paper presents an approach where the stress/strain and the heat transfer analysis uses the same computational...... domain, which is highly convenient. The basis of the method is the control volume finite difference approach on structured meshes. The basic assumptions of the method are shortly reviewed and discussed. As for other methods which aim at application oriented analysis of casting deformations and stresses...

Effect of solidification rate on the microstructure and microhardness of a melt-spun Al-8Si-1Sb alloy

International Nuclear Information System (INIS)

Karakoese, E.; Keskin, M.

2009-01-01

The properties of rapidly solidified hypoeutectic Al-8Si-1Sb alloy, produced by melt-spinning technique at a different solidification rates, were investigated using the X-ray diffraction (XRD), the optical microscopy (OM), the scanning electron microscopy (SEM) together with the energy dispersive spectroscopy (EDS), the differential scanning calorimetry (DSC) and the microhardness technique. The properties of rapidly solidified ribbons were then compared with those of the chill-casting alloy. The results show that rapid solidification has influence on the phase constitution of the hypoeutectic Al-8Si-1Sb alloy. The phases present in the hypoeutectic Al-8Si-1Sb ingot alloy were determined to be α-Al, fcc Si and intermetallic AlSb phases whereas only α-Al and fcc Si phases were identified in the melt-spinning alloy. The rapid solidification has a significant effect on the microstructure of the hypoeutectic Al-8Si-1Sb alloy. Particle size in the microstructure of the ribbons is too small to compare with particle size in the microstructure of the ingot alloy. Moreover, the significant change in hardness occurs that is attributed to changes in the microstructure.

Effect of solidification rate on the microstructure and microhardness of a melt-spun Al-8Si-1Sb alloy

Energy Technology Data Exchange (ETDEWEB)

Karakoese, E. [Erciyes University, Institute of Science, 38039 Kayseri (Turkey); Keskin, M. [Erciyes University, Institute of Science, 38039 Kayseri (Turkey); Erciyes University, Physics Department, 38039 Kayseri (Turkey)], E-mail: keskin@erciyes.edu.tr

2009-06-24

The properties of rapidly solidified hypoeutectic Al-8Si-1Sb alloy, produced by melt-spinning technique at a different solidification rates, were investigated using the X-ray diffraction (XRD), the optical microscopy (OM), the scanning electron microscopy (SEM) together with the energy dispersive spectroscopy (EDS), the differential scanning calorimetry (DSC) and the microhardness technique. The properties of rapidly solidified ribbons were then compared with those of the chill-casting alloy. The results show that rapid solidification has influence on the phase constitution of the hypoeutectic Al-8Si-1Sb alloy. The phases present in the hypoeutectic Al-8Si-1Sb ingot alloy were determined to be {alpha}-Al, fcc Si and intermetallic AlSb phases whereas only {alpha}-Al and fcc Si phases were identified in the melt-spinning alloy. The rapid solidification has a significant effect on the microstructure of the hypoeutectic Al-8Si-1Sb alloy. Particle size in the microstructure of the ribbons is too small to compare with particle size in the microstructure of the ingot alloy. Moreover, the significant change in hardness occurs that is attributed to changes in the microstructure.

Effect of carbon additions on the as-cast microstructure and defect formation of a single crystal Ni-based superalloy

International Nuclear Information System (INIS)

Al-Jarba, K.A.; Fuchs, G.E.

2004-01-01

In an effort to reduce grain defects in large single crystal Ni-base superalloy components, carbon is intentionally added. In this study, the effect of carbon additions on the microstructure and solidification defect formation of a model Ni-based superalloy, LMSX-1, was examined. The results show that the tendency of the alloy to form all types of solidification defects decreased as the carbon content increased. The as-cast microstructures also exhibited a decrease in the amount of γ-γ' eutectic structure and an increase in the volume fraction of carbides and porosity, as the carbon content was increased. The carbides formed in these alloys were mostly of script-type MC carbides which formed continuous, dendritic networks in the interdendritic region. Microprobe analysis of the as-cast structures showed that the partitioning coefficients did not change with carbon additions. Therefore, the reduction in defect formation with increasing carbon content could not be attributed to changes in segregation behavior of alloying elements. Instead, the presence of these carbides in the interdendritic regions of the alloy appeared to have prevented the thermosolutal fluid flow

Aluminum alloy weldability. Identification of weld solidification cracking mechanisms through novel experimental technique and model development

Energy Technology Data Exchange (ETDEWEB)

Coniglio, Nicolas

2008-07-01

solidification range, refinement in grain size from 63 to 51 {mu}m, centerline columnar grains disappearance, and decreased cooling rate from 113 to 89 C/s. Moreover, in order to make direct comparison with literature, castings of controlled mixtures of alloys 6060 and 4043 were also investigated, thereby simulating weld metal composition under controlled cooling conditions. Castings showed a different trend than welds with small increases in silicon content (i.e. increase in 4043 filler dilution) resulting in huge effect on microstructure, no effect on liquidus temperature, drop in solidus temperature from 577 C to 509 C, increase in quantity of interdendritic constituent from 2% to 14%, and different phase formation. Binary {beta}-Al{sub 5}FeSi, Mg{sub 2}Si, and Si phases are replaced with ternary {beta}-Al{sub 5}FeSi, {pi}-Al{sub 8}FeMg{sub 3}Si{sub 6}, and a low melting quaternary eutectic involving Mg{sub 2}Si, {pi}, and Si. Also, variation of the cooling conditions in castings revealed the existence of a critical cooling rate, above which the solidification path and microstructure undergo a major change. Cracking Model. Implementing the critical conditions for cracking into the Rappaz- Drezet-Gremaud (RDG) model revealed a pressure drop in the interdendritic liquid on the order of 10{sup -1} atm, originating primarily from straining conditions. Since, according to literature, a minimum of 1,760 atm is required to fracture pure aluminum liquid (theoretical), this demonstrates that cavitation as a liquid fracture mechanism is not likely to occur, even when accounting for dissolved hydrogen gas. Instead, a porosity-based crack initiation model has been developed based upon pore stability criteria, assuming that gas pores expand from pre-existing nuclei. Crack initiation is taken to occur when stable pores form within the coherent dendrite region, critical to crack initiation being weld metal hydrogen content. Following initiation, a mass-balance approach developed by Braccini

Modelling of melting and solidification transport phenomena during hypothetical NPP severe accidents

International Nuclear Information System (INIS)

Sarler, B.

1992-01-01

A physical and mathematical framework to deal with the transport phenomena occuring during melting and solidification of the hypothetical NPP severe accidents is presented. It concentrates on the transient temperature, velocity, and species concentration distributions during such events. The framework is based on the Mixture Continuum Formulation of the components and phases, cast in the boundary-domain integral shape structured by the fundamental solution of the Laplace equation. The formulation could cope with various solid-liquid sub-systems through the inclusion of the specific closure relations. The deduced system of boundary-domain integral equations for conservation of mass, energy, momentum, and species could be solved by the boundary element discrete approximative method. (author) [sl

Laser welding of SSM Cast A356 aluminium alloy processed with CSIR-Rheo technology

CSIR Research Space (South Africa)

Akhter, R

2006-01-01

Full Text Available Samples of aluminium alloy A356 were manufactured by Semi Solid Metals HPDC technology, developed recently in CSIR, Pretoria. They were butt welded in as cast conditions using as Nd: YAG laser. The best metal and weld microstructure were presented...

Method and apparatus for improved melt flow during continuous strip casting

Science.gov (United States)

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

1991-11-12

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

Radioactive waste solidification material

International Nuclear Information System (INIS)

Nishihara, Yukio; Wakuta, Kuniharu; Ishizaki, Kanjiro; Koyanagi, Naoaki; Sakamoto, Hiroyuki; Uchida, Ikuo.

1992-01-01

The present invention concerns a radioactive waste solidification material containing vermiculite cement used for a vacuum packing type waste processing device, which contains no residue of calcium hydroxide in cement solidification products. No residue of calcium hydroxide means, for example, that peak of Ca(OH) 2 is not recognized in an X ray diffraction device. With such procedures, since calcium sulfoaluminate clinker and Portland cement themselves exhibit water hardening property, and slugs exhibit hydration activity from the early stage, the cement exhibits quick-hardening property, has great extension of long term strength, further, has no shrinking property, less dry- shrinkage, excellent durability, less causing damages such as cracks and peeling as processing products of radioactive wastes, enabling to attain highly safe solidification product. (T.M.)

RSP Tooling Technology

Energy Technology Data Exchange (ETDEWEB)

None

2001-11-20

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 general concept involves converting a mold design described by a CAD file to a tooling master using a suitable rapid prototyping (RP) technology such as stereolithography. A pattern transfer is made to a castable ceramic, typically alumina or fused silica (Figure 1). This is followed by spray forming a thick deposit of a tooling alloy on the pattern to capture the desired shape, surface texture, and detail. The resultant metal block is cooled to room temperature and separated from the pattern. The deposit's exterior walls are machined square, allowing it to be used as an insert in a standard mold base. The overall turnaround time for tooling is about 3 to 5 days, starting with a master. Molds and dies produced in this way have been used in high volume production runs in plastic injection molding and die casting. A Cooperative Research and Development Agreement (CRADA) between the Idaho National Engineering and Environmental Laboratory (INEEL) and Grupo Vitro has been established to evaluate the feasibility of using RSP Tooling technology for producing molds and dies of interest to Vitro. This report summarizes results from Phase I of this agreement, and describes work scope and budget for Phase I1 activities. The main objective in Phase I was to demonstrate the feasibility of applying the Rapid Solidification Process (RSP) Tooling method to produce molds for the manufacture of glass and other components of interest to Vitro. This objective was successfully achieved.

Mobile concrete solidification systems for power reactor waste

International Nuclear Information System (INIS)

Tchemitcheff, E.; Bordas, Y.

1990-01-01

In late 1988 SGN received an order from Electricite de France (EDF) for the construction of a mobile concrete solidification system to process secondary system resins generated by the P'4 and N4 series PWR power plants in France. This order was placed in view of SGN's experience with low- and medium-level radioactive waste treatment and conditioning over a period of almost 20 years. In addition to the construction of fixed waste processing facilities using more conventional technologies, SGN has been involved in application of the mobile system concept to the bituminization process in the United States, which led to the construction and commissioning of two transportable systems in collaboration with its American licensee US Ecology. It has also conducted large-scale R ampersand D on LLW/MLW concrete solidification, particularly for ion exchange resins. 5 figs

Method of plastic solidification of radioactive wastes

International Nuclear Information System (INIS)

Oikawa, Yasuo; Tokimitsu, Fujio.

1986-01-01

Purpose: To prevent occurrence of deleterious cracks to the inside and the surface of solidification products, as well as eliminate gaps between the products and the vessel inner wall upon plastic solidification processing for powdery or granular radioactive wastes. Method: An appropriate amount of thermoplastic resins such as styrenic polymer or vinyl acetate type polymer as a low shrinking agent is added and mixed with unsaturated polyester resins to be mixed with radioactive wastes so as to reduce the shrinkage-ratio to 0 % upon curing reaction. Thus, a great shrinkage upon hardening the mixture is suppressed to prevent the occurrence of cracks to the surface and the inside of the solidification products, as well as prevent the gaps between the inner walls of a drum can vessel and the products upon forming solidification products to the inside of the drum can. The resultant solidification products have a large compression strength and can sufficiently satisfy the evaluation standards as the plastic solidification products of radioactive wastes. (Horiuchi, T.)

Influence of Modification and Casting Technology on Structure of IN-713C Superalloy Castings

Directory of Open Access Journals (Sweden)

Binczyk F.

2016-09-01

Full Text Available The paper presents the results concerning impact of modification (volume and surface techniques, pouring temperature and mould temperature on stereological parameters of macrostructure in IN713C castings made using post-production scrap. The ability to adjust the grain size is one of the main issues in the manufacturing of different nickel superalloy castings used in aircraft engines. By increasing the grain size one can increase the mechanical properties, like diffusion creep resistance, in higher temperatures. The fine grained castings. on the other hand, have higher mechanical properties in lower temperatures and higher resistance to thermal fatigue. The test moulds used in this study, supplied by Pratt and Whitney Rzeszow, are ordinarily used to cast the samples for tensile stress testing. Volume modification was carried out using the patented filter containing cobalt aluminate. The macrostructure was described using the number of grains per mm2, mean grain surface area and shape index. Obtained results show strong relationship between the modification technique, pouring temperature and grain size. There was no significant impact of mould temperature on macrostructure.

THE EFFECT OF PREPARATION CONDITIONS OF RAPIDLY SOLIDIFIED IRON BASED GRANULES ON PROPERTIES OF COMPOSITE MATERIAL FORMED BY CASTING TECHNOLOGY

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A. S. Kalinichenko

2017-01-01

Full Text Available The variety of requirements for friction pairs requires the development of different technologies for the production of tribological materials with reference to the operation modes. Composite materials obtained by the casting technology have been successfully applied for the normalization of the thermomechanical state of the steam turbines. These composites consist of the matrix based on copper alloys reinforced with cast iron granules. Because the structure and properties of cast iron are determined by the conditions of their production studies have been conducted on determination of preparation conditions on grain structure and properties of the synthesized composite material. Using an upgraded unit for production of granules technological regimes were determined providing narrow fractional composition. It has been found that granules formed are characterized with typical microstructure of white cast iron containing perlite and ledeburite. Microhardness of pilot cast iron granules is characterized by high values (from 7450 up to 9450 MPa and depends on the size of the fraction. Composite materials obtained using experimental granules had a microhardness of the reinforcing cast iron granules about 3500 MPa, and a bronze matrix – 1220 MPa, which is higher than the hardness of the composite material obtained by using the annealed DCL-1granules (2250 MPa. Metal base of experimental granules in the composite material has the structure of perlitic ductile iron with inclusions of ferrite not exceeding 10–15% and set around a flocculent graphite. As a result, the increase of physical-mechanical properties of finished products made of composite material is observed. 

Effect of Bi on graphite morphology and mechanical properties of heavy section ductile cast iron

Directory of Open Access Journals (Sweden)

Song Liang

2014-03-01

Full Text Available To improve the mechanical properties of heavy section ductile cast iron, bismuth (Bi was introduced into the iron. Five castings with different Bi content from 0 to 0.014 wt.% were prepared; and four positions in the casting from the edge to the center, with different solidification cooling rates, were chosen for microstructure observation and mechanical properties test. The effect of the Bi content on the graphite morphology and mechanical properties of heavy section ductile cast iron were investigated. Results show that the tensile strength, elongation and impact toughness at different positions in the five castings decrease with a decrease in cooling rate. With an increase in Bi content, the graphite morphology and the mechanical properties at the same position are improved, and the improvement of mechanical properties is obvious when the Bi content is no higher than 0.011wt.%. But when the Bi content is further increased to 0.014wt.%, the improvement of mechanical properties is not obvious due to the increase of chunky graphite number and the aggregation of chunky graphite. With an increase in Bi content, the tensile fracture mechanism is changed from brittle to mixture ductile-brittle fracture.

The Evolution of Cast Microstructures on the HAZ Liquation Cracking of Mar-M004 Weld

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Yi-Hsin Cheng

2018-01-01

Full Text Available The causes of liquation cracking in the heat-affected zone (HAZ of a cast Mar-M004 superalloy weld were investigated. X-ray diffraction (XRD, electron probe microanalyzer (EPMA, and electron backscatter diffraction (EBSD were applied to identify the final microconstituents at the solidification boundaries of the cast alloy. Fine borides and lamellar eutectics were present in front of some γ-γ′ colonies, which were expected to be liquefied prematurely during welding. The metal carbide (MC enriched in Nb, Hf; M3B2 and M5B3 borides enriched in Cr and Mo; and lamellar Ni-Hf intermetallics were mainly responsible for the induced liquation cracking of the Mar-M004 weld, especially the MC carbides. Scanning electron microscope (SEM fractographs showed that the fracture features of those liquation cracks were associated with the interdendritic constituents in the cast superalloy.

Thermal cooling effects in the microstructure and properties of cast cobalt-base biomedical alloys

Science.gov (United States)

Vega Valer, Vladimir

Joint replacement prosthesis is widely used in the biomedical field to provide a solution for dysfunctional human body joints. The demand for orthopedic knee and hip implants motivate scientists and manufacturers to develop novel materials or to increase the life of service and efficiency of current materials. Cobalt-base alloys have been investigated by various researchers for biomedical implantations. When these alloys contain Chromium, Molybdenum, and Carbon, they exhibit good tribological and mechanical properties, as well as excellent biocompatibility and corrosion resistance. In this study, the microstructure of cast Co-Cr-Mo-C alloy is purposely modified by inducing rapid solidification through fusion welding processes and solution annealing heat treatment (quenched in water at room temperature. In particular the effect of high cooling rates on the athermal phase transformation FCC(gamma)↔HCP(epsilon) on the alloy hardness and corrosion resistance is investigated. The Co-alloy microstructures were characterized using metallography and microscopy techniques. It was found that the as cast sample typically dendritic with dendritic grain sizes of approximately 150 microm and containing Cr-rich coarse carbide precipitates along the interdendritic boundaries. Solution annealing gives rise to a refined microstructure with grain size of 30 microm, common among Co-Cr-Mo alloys after heat treating. Alternatively, an ultrafine grain structure (between 2 and 10 microm) was developed in the fusion zone for specimens melted using Laser and TIG welding methods. When laser surface modification treatments were implemented, the developed solidification microstructure shifted from dendritic to a fine cellular morphology, with possible nanoscale carbide precipitates along the cellular boundaries. In turn, the solidified regions exhibited high hardness values (461.5HV), which exceeds by almost 110 points from the alloy in the as-cast condition. The amount of developed athermal

Influence of the crystallization condition on Al–Si–Cu casting alloys structure

OpenAIRE

L.A. Dobrzański; W. Borek; R. Maniara

2006-01-01

Purpose: The purpose of this paper is to show the effect of solidification rate on microstructural features,hardness and microhardness of Al–Si–Cu alloys in as cast state.Design/methodology/approach: The main base of the paper is to compare the properties of aluminium castalloys of ACAlSi7Cu, ACAlSi7Cu2 and ACAlSi7Cu4. Microstructural features were characterised using lightoptical microscopy. For rapid determination of the parameters: grains size and Secondary Dendrite Arm Spacing– SDAS were ...

Casting of microstructured shark skin surfaces and possible applications on aluminum casting parts

Directory of Open Access Journals (Sweden)

Todor Ivanov

2011-02-01

Full Text Available Within the project Functional Surfaces via Micro- and Nanoscaled Structures?which is part of the Cluster of Excellence 揑ntegrative Production Technology?established and financed by the German Research Foundation (DFG, an investment casting process to produce 3-dimensional functional surfaces down to a structural size of 1 μm on near-net-shape-casting parts has been developed. The common way to realize functional microstructures on metallic surfaces is to use laser ablation, electro discharge machining or micro milling. The handicap of these processes is their limited productivity. The approach of this project to raise the efficiency is to use the investment casting process to replicate microstructured surfaces by moulding from a laser-microstructured grand master pattern. The main research objective deals with the investigation of the single process steps of the investment casting process with regard to the moulding accuracy. Actual results concerning making of the wax pattern, suitability of ceramic mould and core materials for casting of an AlSi7Mg0.3 alloy as well as the knock-out behavior of the shells are presented. By using of the example of an intake manifold of a gasoline race car engine, a technical shark skin surface has been realized to reduce the drag of the intake air. The intake manifold consists of an air-restrictor with a defined inner diameter which is microstructured with technical shark skin riblets. For this reason the inner diameter cannot be drilled after casting and demands a very high accuracy of the casting part. A technology for the fabrication and demoulding of accurate microstructured castings are shown. Shrinkage factors of different moulding steps of the macroscopic casting part as well as the microscopic riblet structure have been examined as well.

Method of storing solidification products

International Nuclear Information System (INIS)

Tani, Yutaro.

1985-01-01

Purpose: To enable to efficiently and satisfactorily cool and store solidification products of liquid wastes generated from the reactor spent fuel reprocessing process by a simple facility. Method: Liquid wastes generated from the reactor spent fuel reprocessing process are caused to flow from the upper opening to the inside of a spherical canistor. The opening of the spherical canistor is welded with a lid by a remote control and the liquid wastes are tightly sealed within the spherical canistor as glass solidification products. Spherical canistors having the solidification products tightly sealed therein are sent into and stored in a hopper by the remote control. Further, a blower is driven upon storing to suck cooling air from the cooling air intake port to the inside of the hopper to absorb the decay heat of radioactive materials in the solidification products and the air is discharged from the duct and through the stack to the atmosphere. (Kawakami, Y.)

3-D Analysis of Graphite Nodules in Ductile Cast Iron Using FIB-SEM

DEFF Research Database (Denmark)

D'Angelo, Luca; Jespersen, Freja N.; MacDonald, A. Nicole

Ductile cast iron samples were analysed in a Focused Ion Beam Scanning Electron Microscope, FIB-SEM. The focussed ion beam was used to carefully remove layers of the graphite nodules to reveal internal structures in the nodules. The sample preparation and milling procedure for sectioning graphite...... inside the nodules, their orientation in relation to the graphite and the chemistry of the inclusions is analysed and described. Formation of the structures during solidification and subsequent cooling to room temperature is discussed....

Micro-scale thermocapillary convection with solidification

International Nuclear Information System (INIS)

Yang, W.J.; Liu, J.C.; Chai, A.T.

1991-01-01

This paper reports on an experimental study performed on heat transfer in sessile drops of lysozyme solutions with solidification. Solidification inside the sessile drop is initiated by means of the center cooling method. The internal flow behavior and solidification front movement are observed using a microscope-video monitor system. Results are obtained for lysozyme, and buffer solutions, and water, representing media possessing surface tension coefficients. It is disclosed that the time history of the solidification front movement can be divided into two stages; initial and stable. In the stable stage, the front movement x follows the power-law behavior x = Ct n . C is an empirical constant, and t denotes time. The exponent n takes on a value close to unity in the stable stage

Method of processing solidification product of radioactive waste

International Nuclear Information System (INIS)

Daime, Fumiyoshi.

1988-01-01

Purpose: To improve the long-time stability of solidification products by providing solidification products with liquid tightness, gas tightness, abrasion resistance, etc., of the products in the course of the solidification for the treatment of radioactive wastes. Method: The surface of solidification products prepared by mixing solidifying agents with powder or pellets is entirely covered with high molecular polymer such as epoxy resin. The epoxy resin has excellent properties such as radiation-resistance, heat resistance, water proofness and chemical resistance, as well as have satisfactory mechanical properties. This can completely isolate the solidification products of radioactive wastes from the surrounding atmosphere. (Yoshino, Y.)

Study of ultrasonic melt treatment on the quality of horizontal continuously cast Al-1%Si alloy.

Science.gov (United States)

Li, Xin-Tao; Li, Ting-Ju; Li, Xi-Meng; Jin, Jun-Ze

2006-02-01

The fluctuation of the melt temperature in a tundish was measured during casting and experiments were conducted to investigate the effects of ultrasonic melt treatment on the surface quality and solidification structures of Al-1%Si ingots. The results show that the uniformity of melt temperature was enhanced with the application of ultrasonic melt treatment. When the ultrasonic power is 1,000W, the surface quality was evidently improved and grains of cast ingots were refined. Moreover, EPMA analysis was adopted to study the relationship between the ultrasonic power and boundary segregation of Si element. The result shows that boundary segregation is suppressed with the increase of ultrasonic power and the phenomenon was theoretically interpreted.

Hot tearing susceptibility of binary Mg–Y alloy castings

International Nuclear Information System (INIS)

Wang, Zhi; Huang, Yuanding; Srinivasan, Amirthalingam; Liu, Zheng; Beckmann, Felix; Kainer, Karl Ulrich; Hort, Norbert

2013-01-01

Highlights: ► Quantitatively and qualitatively assessing hot tearing susceptibility for different alloys. ► Monitoring the hot tearing propagation process. ► Detecting the hot tearing initiation/onset temperature. ► Recording the stress and strain evolution during the casting solidification and the subsequent cooling. - Abstract: The influence of Y content on the hot tearing susceptibility (HTS) of binary Mg–Y alloys has been predicted using thermodynamic calculations based on Clyne and Davies model. The calculated results are compared with experimental results determined using a constrained rod casting (CRC) apparatus with a load cell and data acquisition system. Both thermodynamic calculations and experimental measurements indicate that the hot tearing susceptibility as a function of Y content follows the “λ” shape. The experimental results show that HTS first increases with increase in Y content, reaches the maximum at about 0.9 wt.%Y and then decreases with further increase the Y content. The maximum susceptibility observed in Mg–0.9 wt.%Y alloy is attributed to its coarsened columnar microstructure, large solidification range and small amount of eutectic at the time of hot tearing. The initiation of hot cracks is monitored during CRC experiments. It corresponds to a drop in load increment on the force curves. The critical solid fractions at which the hot cracks are initiated are in the range from 0.9 to 0.99. It is also found that it decreases with increasing the content of Y. The hot cracks propagate along the dendritic or grain boundaries through the interdendritic separation or tearing of interconnected dendrites. Some of the formed cracks are possible to be healed by the subsequent refilling of the remained liquids

The solidification and structure of Al-17wt.%Si alloy modified with intermetallic phases containing Ti and Fe

Directory of Open Access Journals (Sweden)

J. Piątkowski

2011-10-01

Full Text Available The article describes the process of casting and solidification of Al-17wt.%Si alloy that have been modified with composite powdercontaining the intermetallic phases of Ti and Fe. The chemical and phase composition of the applied modifier was described with thefollowingformula:FeAlx–TiAlx–Al2O3. Applying the method of thermal analysis ATD, the characteristic parameters of the solidificationprocess were determined, and exo-and endothermic effects of the modifying powder on the run of the silumin solidification curves wereobserved. By the methods of light, scanning, and X-ray microscopy, the structure of alloy and the chemical composition of the dispersionhardening precipitates were examined. A change in the morphology of Al-Si eutectic from the lamellar to fibrous type was reportedtogether with changes in the form of complex eutectics of an Al-Si-Ti and Al-Si-Fe type and size reduction of primary silicon crystals.

Solidification process for toxic and hazardous wastes. Second part: Cement solidification matrices

International Nuclear Information System (INIS)

Donato, A.; Arcuri, L.; Dotti, M.; Pace, A.; Pietrelli, L.; Ricci, G.; Basta, M.; Cali, V.; Pagliai, V.

1989-05-01

This paper reports the second part of a general study carried out at the Nuclear Fuel Division aiming at verifying the possible application of the radioactive waste solidification processes to industrial hazardous wastes (RTN). The cement solidification of several RTN types has been taken into consideration, both from the technical and from the economic point of view. After a short examination of the Italian juridical and economical situation in the field, which demonstrates the need of the RTN solidification, the origin and characteristics of the RTN considered in the study and directly provided by the producing industries are reviewed. The laboratory experimental results of the cementation of RTN produced by gold manufacturing industries and by galvanic industries are reported. The cementation process can be considered a very effective mean for reducing both the RTN management costs and the environmental impact of RTN disposal. (author)

Casting of Hearth Plates from High-chromium Steel

Directory of Open Access Journals (Sweden)

Drotlew A.

2014-12-01

Full Text Available The paper presents the results of studies on the development of manufacturing technologies to cast hearth plates operating in chamber furnaces for heat treatment. Castings made from the heat-resistant G-X40CrNiSi27-4 steel were poured in hand-made green sand molds. The following operations were performed: computer simulation to predict the distribution of internal defects in castings produced by the above mentioned technology with risers bare and coated with exothermic and insulating sleeves, analysis of each variant of the technology, and manufacture of experimental castings. As a result of the conducted studies and analysis it was found that the use of risers with exothermic sleeves does not affect to a significant degree the quality of the produced castings of hearth plates, but it significantly improves the metal yield.

In Situ Study of Microstructure Evolution in Solidification of Hypereutectic Al-Si Alloys with Application of Thermal Analysis and Neutron Diffraction

Science.gov (United States)

Sediako, Dimitry G.; Kasprzak, Wojciech

2015-09-01

Understanding of the kinetics of solid-phase evolution in solidification of hypereutectic aluminum alloys is a key to control their as-cast microstructure and resultant mechanical properties, and in turn, to enhance the service characteristics of actual components. This study was performed to evaluate the solidification kinetics for three P-modified hypereutectic Al-19 pct Si alloys: namely, Al-Si binary alloy and with the subsequent addition of 2.8 pct Cu and 2.8 pct Cu + 0.7 pct Mg. Metallurgical evaluation included thermodynamic calculations of the solidification process using the FactSage™ 6.2 software package, as well as experimental thermal analysis, and in situ neutron diffraction. The study revealed kinetics of solid α-Al, solid Si, Al2Cu, and Mg2Si evolution, as well as the individual effects of Cu and Mg alloying additions on the solidification path of the Al-Si system. Various techniques applied in this study resulted in some discrepancies in the results. For example, the FactSage computations, in general, resulted in 281 K to 286 K (8 °C to 13 °C) higher Al-Si eutectic temperatures than the ones recorded in the thermal analysis, which are also ~278 K (~5 °C) higher than those observed in the in situ neutron diffraction. None of the techniques can provide a definite value for the solidus temperature, as this is affected by the chosen calculation path [283 K to 303 K (10 °C to 30 °C) higher for equilibrium solidification vs non-equilibrium] for the FactSage analysis; and further complicated by evolution of secondary Al-Cu and Mg-Si phases that commenced at the end of solidification. An explanation of the discrepancies observed and complications associated with every technique applied is offered in the paper.

Gating Systems for Sizeable Castings from Al Alloys Cast into Ceramic Moulds

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I. Stachovec

2012-04-01

Full Text Available In contrast to casting to conventional non-reusable “sand” moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly on the basis of experience. However, this approach is not sustainable with ever growing demands on quality of castings and also the economy of their fabrication as well as with new types of complex sizeable castings introduced to the production gradually (by new customers from the aircraft industry above all any more. The simulation software may be used as a possible tool for making the process of optimising gating systems more effective.

Solidification and vitrification life-cycle economics study

International Nuclear Information System (INIS)

Gimpel, R.F.

1992-01-01

Solidification (making concrete) and vitrification (making glass) are frequently the treatment methods recommended for treating inorganic or radioactive wastes. Ex-situ solidification and vitrification are the competing methods for treating in excess of 450 000 cm 3 of low-level radioactive and mixed wastes at the Fernald Environmental Management Project (FEMP) located near Cincinnati, Ohio. This paper summarizes a detailed study done to: (1) compare the economics of the solidification and vitrification processes, (2) determine if the stigma assigned to vitrification is warranted and, (3) determine if investing millions of dollars into vitrification development, along with solidification development, at Fernald is warranted

Microstructure formation in partially melted zone during gas tungsten arc welding of AZ91 Mg cast alloy

International Nuclear Information System (INIS)

Zhu Tianping; Chen, Zhan W.; Gao Wei

2008-01-01

During gas tungsten arc (GTA) welding of AZ91 Mg cast alloy, constitutional liquid forms locally in the original interdendritic regions in the partially melted zone (PMZ). The PMZ re-solidification behaviour has not been well understood. In this study, the gradual change of the re-solidification microstructure within PMZ from base metal side to weld metal side was characterised. High cooling rate experiments using Gleeble thermal simulator were also conducted to understand the morphological change of the α-Mg/β-Mg 17 Al 12 phase interface formed during re-solidification after partial melting. It was found that the original partially divorced eutectic structure has become a more regular eutectic phase in most of the PMZ, although close to the fusion boundary the re-solidified eutectic is again a divorced one. Proceeding the eutectic re-solidification, if the degree of partial melting is sufficiently high, α-Mg re-solidified with a cellular growth, resulting in a serrated interface between α-Mg and α-Mg/β-Mg 17 Al 12 in the weld sample and between α-Mg and β-Mg 17 Al 12 (fully divorced eutectic) in Gleeble samples. The morphological changes affected by the peak temperature and cooling rate are also explained

TiC reinforced cast Cr steels

Energy Technology Data Exchange (ETDEWEB)

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

2006-06-01

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

TiC-reinforced cast Cr steels

Science.gov (United States)

Doğan, Ö. N.; Hawk, J. A.; Schrems, K. K.

2006-06-01

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

Assessment of the possibility of utilisation of used ceramic moulds originated from the investment casting technology

Directory of Open Access Journals (Sweden)

M. Holtzer

2009-04-01

Full Text Available Review of wastes generated by investment casting technology and discussion on possibilities of disposal of the largest quantity waste from this technology - used ceramic mould is presented in the paper. Preliminary examinations of disintegration process of used ceramic mould conducted in various testing conditions were performed in the frame of presented research. Applied system of disintegration doesn’twarrant obtained material to be suitable for reuse in production of ceramic moulds. Investigations of the inter-phase boundary: ceramicmould-casting were performed to examine environmental harmfulness of used ceramic moulds. Additionally ecologic assessment of spentmoulds by means of it’s elution in the aspect of qualifying possibilities of it’s disposal were performed. Gained results qualify the waste from ceramic mould to storage in deposits for neutral wastes.

The influence of buoyant forces and volume fraction of particles on the particle pushing/entrapment transition during directional solidification of Al/SiC and Al/graphite composites

Science.gov (United States)

Stefanescu, Doru M.; Moitra, Avijit; Kacar, A. Sedat; Dhindaw, Brij K.

1990-01-01

Directional solidification experiments in a Bridgman-type furnace were used to study particle behavior at the liquid/solid interface in aluminum metal matrix composites. Graphite or siliconcarbide particles were first dispersed in aluminum-base alloys via a mechanically stirred vortex. Then, 100-mm-diameter and 120-mm-long samples were cast in steel dies and used for directional solidification. The processing variables controlled were the direction and velocity of solidification and the temperature gradient at the interface. The material variables monitored were the interface energy, the liquid/particle density difference, the particle/liquid thermal conductivity ratio, and the volume fraction of particles. These properties were changed by selecting combinations of particles (graphite or silicon carbide) and alloys (Al-Cu, Al-Mg, Al-Ni). A model which considers process thermodynamics, process kinetics (including the role of buoyant forces), and thermophysical properties was developed. Based on solidification direction and velocity, and on materials properties, four types of behavior were predicted. Sessile drop experiments were also used to determine some of the interface energies required in calculation with the proposed model. Experimental results compared favorably with model predictions.

Improvement of Artistic Cast Production System

Directory of Open Access Journals (Sweden)

Władysiak R.

2017-09-01

Full Text Available The paper presents the technology and organization of the artistic cast production. On the basis of the actual cast production system, the manufacturing process was shown, in particular sand–piece moulding, which is a very important process and a time-consuming part of the entire manufacture of the casts. The current state of the production process as well as the organization of the work and production technology were analysed with the use of methods and techniques of production improvement, the Lean Manufacturing concept and computer systems. The results of the analysis and studies were shown with use of schemes and graphs of the layout of the production resources, a flow chart of the production process, value stream mapping, and a costs table for the production and modernization of the moulding stage. The work has shown that there are possibilities to improve the artistic cast production system. This improvement leads to increased productivity, lower production costs of artistic casts and increased competitiveness of the foundry.

Solidification and vitrification life-cycle economics study

International Nuclear Information System (INIS)

Gimpel, R.F.

1992-01-01

Solidification (making concrete) and vitrification (making glass) are frequently the treatment methods recommended for treating inorganic or radioactive wastes. Solidification is generally perceived as the most economical treatment method, whereas vitrification is considered (by many) as the most effective of all treatment methods. Unfortunately, vitrification has acquired the stigma that it is too expensive to receive further consideration as an alternative to solidification in high volume treatment applications. Ex situ solidification and vitrification are the competing methods for treating in excess of 450,000 m 3 of low-level radioactive and mixed waste at the Fernald Environmental Management Project (FEMP or simply, Fernald) located near Cincinnati, Ohio. This paper s a detailed study done to: compare the economics of the solidification and vitrification processes; determine if the stigma assigned to vitrification is warranted; determine if investing millions of dollars into vitrification development, along with solidification development, at Fernald is warranted. Common parameters were determined and detailed life-cycle cost estimates were made. Incorporating the unit costs into a computer spreadsheet allowed 'what if' scenarios to be performed. Some scenarios investigated included variation of: remediation times, amount of wastes treated, treatment efficiencies, electrical and material costs and escalation

Effect of copper addition and section thickness on the mechanical and physical properties of grey cast iron

International Nuclear Information System (INIS)

Malik, F.A.; Zahid, M.; Hassan, M.A.; Sheikh, M.A.; Alam, S.; Qazi, M.A.

1995-01-01

Copper is a graphitizer at the stage of solidification and it acts as antiferritizer during transformation cooling range. Due to this, copper additions to grey cast iron prevent at formation of free ferrite in heavy sections. It also reduces the chilling in thin sections, therefore uniform structure is imparted to grey iron by the copper addition. This gives the appropriate strength and hardness properties to grey iron. Thus copper addition gives certain advantages in relation to the machinability and wear resistance which are important for many engineering properties requires by high duty cast iron. The application of copper as allying element is acceptable due to its price and availability as compared to other alloying elements. (author)

The mechanism of hot crack formation in Ti-6A1-4V during cold crucible continuous casting

Directory of Open Access Journals (Sweden)

Hongsheng DING

2004-08-01

Full Text Available Hot crack is one of common defects in castings, which often results in failure of castings. This work studies the formation of hot cracks during cold crucible continous casting by means of experiments and thoretical analysis. The results show that the hot crack occurs on the surface and in the circumference of ingots, where the solidified shell and solidification front meet each other. The tendency of hot cracking decreases with the increase of withdrawal velocities in some extent. The hot crack is caused mainly by friction force between the shell and the crucible inner wall, and it takes place when the stress resulting from friction exceeds the tensile strength of the shell. The factors affecting the hot cracks are analyzed and verified. In order to decrease the tendency of hot cracks, technical parameters should be optimized.

Critical Thinking on the Introduction of Digitization Within Engineering Training Systems in the Manufacturing Stage of Cast Parts

Science.gov (United States)

Lehene, T. R.; Samoilă, V.; Soporan, V. F.; Pădurețu, S.; Vescan, M. M.

2018-06-01

The paper aims to present a methodology for the analysis of the engineering training systems at the manufacturing stage of castings through critical engineering thinking. Its use [4, 5] requires the development of procedures capable of responding to the problems faced by engineering training in terms of acquiring the tools and procedures. The structure of the analysis took into consideration the following aspects: the motivation to use the proposed procedure, considerations on the engineering behavior, the design of the reasoning adapted to the analysis of the engineering training systems, the determination of the correlations in the processes of obtaining the cast products, the definition and calibration of the digital experiment, the definition and analysis of the factors influencing the last solidification area (the nature of the alloy, the shape of the mold and the casting geometry).

Solidification process for sludge residue

International Nuclear Information System (INIS)

Pearce, K.L.

1998-01-01

This report investigates the solidification process used at 100-N Basin to solidify the N Basin sediment and assesses the N Basin process for application to the K Basin sludge residue material. This report also includes a discussion of a solidification process for stabilizing filters. The solidified matrix must be compatible with the Environmental Remediation Disposal Facility acceptance criteria

Phase-field simulation of peritectic solidification closely coupled with directional solidification experiments in an Al-36 wt% Ni alloy

International Nuclear Information System (INIS)

Siquieri, R; Emmerich, H; Doernberg, E; Schmid-Fetzer, R

2009-01-01

In this work we present experimental and theoretical investigations of the directional solidification of Al-36 wt% Ni alloy. A phase-field approach (Folch and Plapp 2005 Phys. Rev. E 72 011602) is coupled with the CALPHAD (calculation of phase diagrams) method to be able to simulate directional solidification of Al-Ni alloy including the peritectic phase Al 3 Ni. The model approach is calibrated by systematic comparison to microstructures grown under controlled conditions in directional solidification experiments. To illustrate the efficiency of the model it is employed to investigate the effect of temperature gradient on the microstructure evolution of Al-36 wt% Ni during solidification.

Measurement of Mechanical Coherency Temperature and Solid Volume Fraction in Al-Zn Alloys Using In Situ X-ray Diffraction During Casting

Science.gov (United States)

Drezet, Jean-Marie; Mireux, Bastien; Kurtuldu, Güven; Magdysyuk, Oxana; Drakopoulos, Michael

2015-09-01

During solidification of metallic alloys, coalescence leads to the formation of solid bridges between grains or grain clusters when both solid and liquid phases are percolated. As such, it represents a key transition with respect to the mechanical behavior of solidifying alloys and to the prediction of solidification cracking. Coalescence starts at the coherency point when the grains begin to touch each other, but are unable to sustain any tensile loads. It ends up at mechanical coherency when the solid phase is sufficiently coalesced to transmit macroscopic tensile strains and stresses. Temperature at mechanical coherency is a major input parameter in numerical modeling of solidification processes as it defines the point at which thermally induced deformations start to generate internal stresses in a casting. This temperature has been determined for Al-Zn alloys using in situ X-ray diffraction during casting in a dog-bone-shaped mold. This setup allows the sample to build up internal stress naturally as its contraction is prevented. The cooling on both extremities of the mold induces a hot spot at the middle of the sample which is irradiated by X-ray. Diffraction patterns were recorded every 0.5 seconds using a detector covering a 426 × 426 mm2 area. The change of diffraction angles allowed measuring the general decrease of the lattice parameter of the fcc aluminum phase. At high solid volume fraction, a succession of strain/stress build up and release is explained by the formation of hot tears. Mechanical coherency temperatures, 829 K to 866 K (556 °C to 593 °C), and solid volume fractions, ca. 98 pct, are shown to depend on solidification time for grain refined Al-6.2 wt pct Zn alloys.

Segregation and microstructure evolution in chill cast and directionally solidified Ni-Mn-Sn metamagnetic shape memory alloys

Science.gov (United States)

Czaja, P.; Wierzbicka-Miernik, A.; Rogal, Ł.

2018-06-01

A multiphase solidification behaviour is confirmed for a range of Ni-rich and Ni-deficient Ni-Mn-Sn induction cast and directionally solidified (Bridgman) alloys. The composition variation is primarily linked to the changing Mn/Sn ratio, whereas the content of Ni remains largely stable. The partitioning coefficients for the Ni50Mn37Sn13 and Ni46Mn41.5Sn12.5 Bridgman alloys were obtained according to the Scheil equation based on the composition distribution along the longitudinal cross section of the ingots. Homogenization heat treatment performed for 72 h at 1220 K turned out sufficient for ensuring chemical uniformity on the macro- and microscale. It is owed to a limited segregation length scale due to slow cooling rates adopted for the directional solidification process.

Multiscale modeling of the solidification microstructure evolution in the presence of ultrasonic stirring

International Nuclear Information System (INIS)

Nastac, Laurentiu

2012-01-01

Ultrasonic treatment (UST) was studied to improve the quality of cast ingots as well as to control the solidification microstructure evolution. Ultrasonically-induced cavitation consists of the formation of small cavities (bubbles) in the molten metal followed by their growth, pulsation and collapse. These cavities are created by the tensile stresses that are produced by acoustic waves in the rarefaction phase. The cavitation threshold pressure for nucleation of the bubbles may decrease with increasing the amount of dissolved gases and especially with the amount of inclusions in the melt. A UST model was developed to predict the ultrasonic cavitation and acoustic streaming. The developed UST modeling approach is based on the numerical solution of Lilley model (that is founded on Lighthills's acoustic analogy), fluid flow, and heat transfer equations, and mesoscopic modeling of the grain structure. The UST model was applied to study the solidification of Al-based alloys) under the presence of ultrasound. It is found that the predicted ultrasonic cavitation region is relatively small, the acoustic streaming is strong and thus the created/survived bubbles/nuclei are transported into the bulk liquid quickly. The predicted grain size under UST condition is at least one order of magnitude lower than that without UST, which is in excellent agreement with the experimental data.

Use of freeze-casting in advanced burner reactor fuel design

Energy Technology Data Exchange (ETDEWEB)

Lang, A. L.; Yablinsky, C. A.; Allen, T. R. [Dept. of Engineering Physics, Univ. of Wisconsin Madison, 1500 Engineering Drive, Madison, WI 53711 (United States); Burger, J.; Hunger, P. M.; Wegst, U. G. K. [Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover, NH 03755 (United States)

2012-07-01

This paper will detail the modeling of a fast reactor with fuel pins created using a freeze-casting process. Freeze-casting is a method of creating an inert scaffold within a fuel pin. The scaffold is created using a directional solidification process and results in open porosity for emplacement of fuel, with pores ranging in size from 300 microns to 500 microns in diameter. These pores allow multiple fuel types and enrichments to be loaded into one fuel pin. Also, each pore could be filled with varying amounts of fuel to allow for the specific volume of fission gases created by that fuel type. Currently fast reactors, including advanced burner reactors (ABR's), are not economically feasible due to the high cost of operating the reactors and of reprocessing the fuel. However, if the fuel could be very precisely placed, such as within a freeze-cast scaffold, this could increase fuel performance and result in a valid design with a much lower cost per megawatt. In addition to competitive costs, freeze-cast fuel would also allow for selective breeding or burning of actinides within specific locations in fast reactors. For example, fast flux peak locations could be utilized on a minute scale to target specific actinides for transmutation. Freeze-cast fuel is extremely flexible and has great potential in a variety of applications. This paper performs initial modeling of freeze-cast fuel, with the generic fast reactor parameters for this model based on EBR-II. The core has an assumed power of 62.5 MWt. The neutronics code used was Monte Carlo N-Particle (MCNP5) transport code. Uniform pore sizes were used in increments of 100 microns. Two different freeze-cast scaffold materials were used: ceramic (MgO-ZrO{sub 2}) and steel (SS316L). Separate models were needed for each material because the freeze-cast ceramic and metal scaffolds have different structural characteristics and overall porosities. Basic criticality results were compiled for the various models

Use of solidification/stabilization treatment technology for environmental remediation in the United States and Canada

International Nuclear Information System (INIS)

Wilk, C.M.

2002-01-01

In the United States (U.S.) Solidification/Stabilization (S/S) treatment is used to treat hazardous wastes for disposal, and in the remediation/site restoration of contaminated land. S/S is also an increasingly popular technology for Brownfields (industrial property) redevelopment since treated wastes can often be left on-site and to actually improve the site's soil for subsequent construction. The U.S. Environmental Protection Agency (EPA) considers S/S to be an established treatment technology. EPA has identified S/S treatment as Best Demonstrated Available Treatment Technology (BDAT) for at least 57 commonly produced industrial wastes (Resource Conservation and Recovery Act (RCRA)-listed hazardous wastes) and has selected S/S treatment for 25% of its Superfund (abandoned or uncontrolled) site remediation projects. S/S treatment involves mixing a binding reagent into the contaminated media or waste. Successful treatment is accomplished through physical changes to the waste form, and often, chemical changes to the hazardous constituents themselves. Commonly used S/S binding reagents in include portland cement, cement kiln dust, lime, lime kiln dust and fly ash. These materials are used alone or in combination. Proprietary reagents are also beginning to be marketed and used in the U.S. and Canada. This paper will discuss: (a) applicability of the technology to various wastes, (b) basic cement chemistry relating to S/S, (c) tests used to design treatability studies and to verify treatment, (d) basics on implementation of the technology in the field, and (e) examples of actual projects. (author)

Techniques for the solidification of high-level wastes

International Nuclear Information System (INIS)

1977-01-01

The problem of the long-term management of the high-level wastes from the reprocessing of irradiated nuclear fuel is receiving world-wide attention. While the majority of the waste solutions from the reprocessing of commercial fuels are currently being stored in stainless-steel tanks, increasing effort is being devoted to developing technology for the conversion of these wastes into solids. A number of full-scale solidification facilities are expected to come into operation in the next decade. The object of this report is to survey and compare all the work currently in progress on the techniques available for the solidification of high-level wastes. It will examine the high-level liquid wastes arising from the various processes currently under development or in operation, the advantages and disadvantages of each process for different types and quantities of waste solutions, the stages of development, the scale-up potential and flexibility of the processes

Interaction of Multiple Particles with a Solidification Front: From Compacted Particle Layer to Particle Trapping.

Science.gov (United States)

Saint-Michel, Brice; Georgelin, Marc; Deville, Sylvain; Pocheau, Alain

2017-06-13

The interaction of solidification fronts with objects such as particles, droplets, cells, or bubbles is a phenomenon with many natural and technological occurrences. For an object facing the front, it may yield various fates, from trapping to rejection, with large implications regarding the solidification pattern. However, whereas most situations involve multiple particles interacting with each other and the front, attention has focused almost exclusively on the interaction of a single, isolated object with the front. Here we address experimentally the interaction of multiple particles with a solidification front by performing solidification experiments of a monodisperse particle suspension in a Hele-Shaw cell with precise control of growth conditions and real-time visualization. We evidence the growth of a particle layer ahead of the front at a close-packing volume fraction, and we document its steady-state value at various solidification velocities. We then extend single-particle models to the situation of multiple particles by taking into account the additional force induced on an entering particle by viscous friction in the compacted particle layer. By a force balance model this provides an indirect measure of the repelling mean thermomolecular pressure over a particle entering the front. The presence of multiple particles is found to increase it following a reduction of the thickness of the thin liquid film that separates particles and front. We anticipate the findings reported here to provide a relevant basis to understand many complex solidification situations in geophysics, engineering, biology, or food engineering, where multiple objects interact with the front and control the resulting solidification patterns.

Pressing Speed, Specific Pressure and Mechanical Properties of Aluminium Cast

Directory of Open Access Journals (Sweden)

Gaspar S.

2016-06-01

Full Text Available Recent research in the process of aluminum alloy die castings production, which is nowadays deeply implemented into the rapidly growing automobile, shipping and aircraft industries, is aimed at increasing the useful qualitative properties of the die casting in order to obtain its high mechanical properties at acceptable economic cost. Problem of technological factors of high pressure die casting has been a subject of worldwide research (EU, US, Japan, etc.. The final performance properties of die castings are subjected to a large number of technological factors. The main technological factors of high pressure die casting are as follows: plunger pressing speed, specific (increase pressure, mold temperature as well as alloy temperature. The contribution discusses the impact of the plunger pressing speed and specific (increase pressure on the mechanical properties of the casting aluminum alloy.

Method of reprocessing radioactive asphalt solidification products

International Nuclear Information System (INIS)

Nakaya, Iwao; Murakami, Tadashi; Miyake, Takafumi; Inagaki, Yuzo.

1986-01-01

Purpose: To obtain heat-stable solidification products and decrease the total volume thereof by modifying the solidified form by the reprocessing of existent radioactive asphalt solidification products. Method: Radioactive asphalt solidification products are heated into a fluidized state. Then, incombustible solvents such as perchloroethylene or trichloroethylene are added to a dissolving tank to gradually dissolve the radioactive asphalt solidification products. Thus, organic materials such as asphalts are transferred into the solvent layer, while inorganic materials containing radioactive materials remain as they are in the separation tank. Then, the inorganic materials containing the radioactive materials are taken out and then solidified, for example, by converting them into a rock or glass form. (Kawakami, Y.)

Breaking through the strength-ductility trade-off dilemma in an Al-Si-based casting alloy.

Science.gov (United States)

Dang, B; Zhang, X; Chen, Y Z; Chen, C X; Wang, H T; Liu, F

2016-08-09

Al-Si-based casting alloys have a great potential in various industrial applications. Common strengthening strategies on these alloys are accompanied inevitably by sacrifice of ductility, known as strength-ductility trade-off dilemma. Here, we report a simple route by combining rapid solidification (RS) with a post-solidification heat treatment (PHT), i.e. a RS + PHT route, to break through this dilemma using a commercial Al-Si-based casting alloy (A356 alloy) as an example. It is shown that yield strength and elongation to failure of the RS + PHT processed alloy are elevated simultaneously by increasing the cooling rate upon RS, which are not influenced by subsequent T6 heat treatment. Breaking through the dilemma is attributed to the hierarchical microstructure formed by the RS + PHT route, i.e. highly dispersed nanoscale Si particles in Al dendrites and nanoscale Al particles decorated in eutectic Si. Simplicity of the RS + PHT route makes it being suitable for industrial scaling production. The strategy of engineering microstructures offers a general pathway in tailoring mechanical properties of other Al-Si-based alloys. Moreover, the remarkably enhanced ductility of A356 alloy not only permits strengthening further the material by work hardening but also enables possibly conventional solid-state forming of the material, thus extending the applications of such an alloy.

Development of the continuous casting technology for fabrication of the tubular fuels

International Nuclear Information System (INIS)

Kim, H. S.; Lee, Y. S.; Kim, C. K.; Lee, D. B.; Oh, S. J.

2003-01-01

In the irradiation test of the U-Mo dispersed nuclear fuel that is used as nuclear fuels for research reactors, it was recognized that the swelling due to reaction between U-Mo particle and Al matrix caused some failures of the fuel claddings. The development of new style nuclear fuel that could minimize the reaction between U-Mo particles and Al matrix was needed. Tube style nuclear fuel was judged to be suitable as new style nuclear fuel. We targeted to make U-Mo tube of diameter 10mm, thinner than 1mm thick, because temperature distribution of tube style nuclear fuel will be expected to have a good performance. We used continuous casting technology to make tube style nuclear fuel. In this research, we have tried to make tube using copper before we make U-Mo tube style nuclear fuel by continuous casting method. As a result of the experiment, we succeeded to make copper tube of diameter 10mm, thickness 1mm

Passivity of the bars manufactured using current technologies: laser-sintering, casting, and milling

Science.gov (United States)

Popescu, Diana; Popescu, Sabin; Pop, Daniel; Jivanescu, Anca; Todea, Carmen

2014-01-01

Implant overdentures are often selected as therapeutic options for the treatment of edentulous mandibles. "Passive-fit" between the mesostructures and the implants plays an important role in the longevity of the implant-prosthetic assembly in the oral cavity. "Mis-fit" can cause mechanical or biological complications. The purpose of this test was to investigate the passive adaptation of the bars manufactured through different technologies, and in this respect two bars (short and long) were fabricated by each process: laser-sintering, milling, casting. The tensions induced by tightening the connection screw between the bars and the underlying implants were recorded using strain gauges and used as measuring and comparing tool in testing the bars' "passivity". The results of the test showed that the milled bars had the best "passive-fit", followed by laser-sintered bars, while cast bars had the lowest adaptation level.

Cast iron for reactor technology - special structural and mechanical properties

International Nuclear Information System (INIS)

Janakiev, N.

The graphitic phase, its formation and the effect on the mechanical properties of cast iron used for reactor shielding are described. Tensile strength, bending strength and Brinell hardness were studied. With the specimen wall thickness of 400 mm the average measured tensile strength was 180 N/mm 2 , which satisfies the given requirements as do the values of bending strength and material hardness. As against materials 200 mm in thickness, graphite was found by metallographic tests to be of a significantly coarser structure, which may be explained by slower cooling. Tensile strength was also tested for nodular cast irons and lamellar graphite cast irons. It was shown that compression increased with decreasing specimen diameter at constant pressure, at a constant diameter compression increased nearly in proportion to compressive stress. No significant differences were found if compressive stress was 80% of fracture stress. The modulus of elasticity was found to decrease with increasing graphite content while it was found to increase with fine graphite lamellae at the same carbon concentration. It also decreased with increasing straining. A Mo-alloyed cast iron was found to show slower creep rates at a compressive stress of up to 90 N/mm 2 (calculated to the same initial strengths) than Cu-alloyed cast iron. Upon increasing compressive stress to 140 N/mm 2 and creep time to more than 2000 hours, the creep behaviour of Cu-alloyed cast iron was better. Coarser perlite is likely to be more creep resistant than fine perlite. In neutron irradiation of cast iron a clear trend towards hardening was found due to the effect of neutrons on the cast iron structure. (J.B.)

Fulltext PDF

Indian Academy of Sciences (India)

Casting and Solidification Technology (CASTEC) Research Group, Department of Mechanical ... final product. ... liquid or semi-solid part, alloys satisfy that condition and .... Fracture development of specimen at left notch, centre and right notch.

Combined effect of non-equilibrium solidification and thermal annealing on microstructure evolution and hardness behavior of AZ91 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Zhou, Z.Z.; Yang, W., E-mail: weiyang@mail.nwpu.edu.cn; Chen, S.H.; Yu, H.; Xu, Z.F.

2014-06-15

Non-equilibrium solidification of commercial AZ91 magnesium alloy was performed by copper mold spray-casting technique and the thermal stability property of as-formed meta-stable microstructure was investigated by subsequent annealing at different temperatures and times. Remarkable grain refinement appears with increasing cooling rate during solidification process, which is accompanied by a visible cellular/dendrite transition for the grain morphology of primary phase. Moreover, the non-equilibrium solidified alloy exhibits obvious precipitation hardening effect upon annealing at 200 °C, and the precipitation mode of β-Mg{sub 17}Al{sub 12} phase changes from discontinuous to continuous with extending isothermal time from 4 h to 16 h, which generates an increase of resultant micro-hardness value. After solid solution treatment at the elevated temperature of 420 °C, the volume fraction of β-Mg{sub 17}Al{sub 12} phase decreases and a notable grain growth phenomenon occurs, which give rise to a reduction of hardness in comparison with that of as-quenched alloy.

Precision casting into disposable ceramic mold – a high efficiency method of production of castings of irregular shape

OpenAIRE

Уваров, Б. И.; Лущик, П. Е.; Андриц, А. А.; Долгий, Л. П.; Заблоцкий, А. В.

2016-01-01

The article shows the advantages and disadvantages of precision casting into disposable ceramic molds. The high quality shaped castings produced by modernized ceramic molding process are proved the reliability and prospects of this advanced technology.

Low level waste solidification practice in Japan

International Nuclear Information System (INIS)

Sakata, S.; Kuribayashi, H.; Kono, Y.

1981-01-01

Both sea dumping and land isolation are planned to be accomplished for low level waste disposal in Japan. The conceptual design of land isolation facilities has been completed, and site selection will presently get underway. With respect to ocean dumping, safety surveys are being performed along the lines of the London Dumping Convention and the Revised Definitions and Recommendations of the IAEA, and the review of Japanese regulations and applicable criteria is being expedited. This paper discusses the present approach to waste solidification practices in Japan. It reports that the bitumen solidification process and the plastic solidification process are being increasingly used in Japan. Despite higher investment costs, both processes have advantages in operating cost, and are comparable to the cement solidification process in overall costs

SUPERFUND TREATABILITY CLEARINGHOUSE: BDAT FOR SOLIDIFICATION/STABILIZATION TECHNOLOGY FOR SUPERFUND SOILS (DRAFT FINAL REPORT)