Modeling the Solidification of Multicomponent Alloys with Convection

Modeling the Solidification of Multicomponent Alloys with Convection PDF Author: Marc C. Schneider
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 388

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Modeling the Solidification of Multicomponent Alloys with Convection

Modeling the Solidification of Multicomponent Alloys with Convection PDF Author: Marc C. Schneider
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 388

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Book Description


Interactive Dynamics of Convection and Solidification

Interactive Dynamics of Convection and Solidification PDF Author: S.H. Davis
Publisher: Springer Science & Business Media
ISBN: 940112809X
Category : Science
Languages : en
Pages : 262

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Book Description
The phase transformation from liquid to solid is a phenomenon central to a wide range of manufacturing and natural processes. The presence of phase transformation can drive convection in the melt through the liberation of latent heat, the rejection of solute, and the change of density upon freezing. The fluid mechanics itself can playa central role; the phase transformation can be strongly altered by convective transport in the liquid through the modification of the thermal and solutal environment of the solid-liquid interface; these local fields control the freezing characteristics at the interface. The convection can be generated naturally by buoyancy forces arising from gradients of temperature and concentration in the liquid, by density changes upon freezing, and by thermocapillary and solutocapillary forces on liquid-solid interfaces. The interactive coupling between solidification and convection forms the subject of this volume. Such coupled processes are significant on a large range of scales. Among the applications of interest are the manufacture of single crystals, the processing of surfaces using laser or molecular beams, and the processes of soldering and welding. One wants to understand and predict macrosegregation in castings, transport and fractionation in geological and geophysical systems, and heat accumulation in energy redistribution and storage systems. This volume contains papers presented at the NATO Advanced Research Workshop on "Interactive Dynamics of Convection and Solidification" held in Chamonix, France, March 8-13, 1992.

Phase Change with Convection: Modelling and Validation

Phase Change with Convection: Modelling and Validation PDF Author: Tomasz A. Kowalewski
Publisher: Springer
ISBN: 3709127645
Category : Technology & Engineering
Languages : en
Pages : 277

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Book Description
This unique volume offers a review of state-of-the-art modelling methods of phase change problems, numerical and experimental methods used in the field. It combines the experience of theoreticians with those using numerical tools for modelling problems of solidification.

Multiscale Modeling of Solidification of Multi-component Alloys

Multiscale Modeling of Solidification of Multi-component Alloys PDF Author: Lijian Tan
Publisher:
ISBN:
Category :
Languages : en
Pages : 438

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Book Description
Modeling solidification in the micro-scale is computationally intensive. To overcome this difficulty, a method combining features of front-tracking methods and fixed-domain methods is developed. To explicitly track the interface growth and shape of the solidifying crystals, a front-tracking approach based on the level set method is implemented. To easily model the heat and momentum transport, a fixed-domain method is implemented assuming a diffused freezing front where the liquid fraction is defined in terms of the level set function. The fixed-domain approach, by avoiding the explicit application of essential boundary conditions on the freezing front, leads to an energy conserving methodology that is not sensitive to the mesh size. Techniques including fast marching, narrow band computing and adaptive meshing are utilized to speed up computations. The model is used to investigate various phenomena in solidification including two- and three-dimensional dendrite growth of pure material and alloys, eutectic and peritectic solidification, convection effects on crystal and dendrite growth, planar/cellular/dendritic transition, interaction between multiple dendrites, columnar/equiaxed transition and etc. Interaction between thousands or even millions of crystals gives the overall behavior of the solidification process and defines the properties of the final product. A multiscale model based on a database approach is developed to investigate alloy solidification. Appropriate assumptions are introduced to describe the behavior of macroscopic temperature, macroscopic concentration, liquid volume fraction and microstructure features. These assumptions lead to a macroscale model with two unknown functions: liquid vol- ume fraction and microstructure features. These functions are computed using information from microscale solutions of selected problems. A computationally efficient model, which is different from the microscale and macroscale models, is utilized to find relevant sample problems. The microscale solution of the relevant sample problems is then utilized to evaluate the two unknown functions (liquid volume fraction and microstructure features) in the macroscale model. The temperature solution of the macroscale model is further used to improve the estimation of the liquid volume fraction and microstructure features. Interpolation is utilized in the feature space to greatly reduce the number of required sample problems. The efficiency of the proposed multiscale framework is demonstrated with numerical examples that consider a large number of crystals. A computationally intensive fully-resolved microscale analysis is also performed to evaluate the accuracy of the multiscale framework. (Abstract).

Phase Transformations in Multicomponent Melts

Phase Transformations in Multicomponent Melts PDF Author: Dieter M. Herlach
Publisher: John Wiley & Sons
ISBN: 3527624058
Category : Technology & Engineering
Languages : en
Pages : 435

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Book Description
Bringing together the concerted efforts of the multicomponent materials community in one decisive reference work, this handbook covers all the important aspects from fundamentals to applications: thermodynamics, microscopic processes, solidification, simulation and modeling. As such, it provides a vital understanding of melt and solidification processes, treating all simulation techniques for continuous and discrete systems, such as molecular dynamics, Monte Carlo, and finite elements calculations.

Theoretical Analysis of Diffusion of Solutes During the Solidification of Alloys

Theoretical Analysis of Diffusion of Solutes During the Solidification of Alloys PDF Author: Carl Wagner
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 36

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Thermodynamic and Solidification Modeling Coupled with Experimental Investigation of the Multicomponent Aluminum Alloys

Thermodynamic and Solidification Modeling Coupled with Experimental Investigation of the Multicomponent Aluminum Alloys PDF Author: Xinyan Yan
Publisher:
ISBN:
Category :
Languages : en
Pages : 284

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Book Description


Modeling and Simulation of Microstructure Evolution in Solidifying Alloys

Modeling and Simulation of Microstructure Evolution in Solidifying Alloys PDF Author: Laurentiu Nastac
Publisher: Springer Science & Business Media
ISBN: 1402078323
Category : Technology & Engineering
Languages : en
Pages : 298

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Book Description
The aim of Modeling and Simulation of Microstructure Evolution in Solidifying Alloys is to describe in a clear mathematical language the physics of the solidification structure evolution of cast alloys. The concepts and methodologies presented here for the net-shaped casting and the ingot remelt processes can be applied, with some modifications, to model other solidification processes such as welding and deposition processes. Another aim of the book is to provide simulation examples of the solidification structure modeling in some crucial commercial casting technologies as well as to provide practical techniques for controlling the structure formation during the solidification processes.

Bulk Metallic Glasses and Their Composites

Bulk Metallic Glasses and Their Composites PDF Author: Muhammad Musaddique Ali Rafique
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110747235
Category : Technology & Engineering
Languages : en
Pages : 203

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Book Description
The book provides a comprehensive state-of-the-art review on the topic of bulk metallic glass matrix composites and understanding of mechanisms of development of composite microstructure. It discusses mechanisms of formation and toughening both during conventional casting routes and additive manufacturing. The second edition encompasses new studies and highlights advancement in mechanical properties, characterization, processing and applications.

Solidification

Solidification PDF Author: Jonathan A. Dantzig
Publisher: EPFL Press
ISBN: 2940222975
Category : Technology & Engineering
Languages : en
Pages : 711

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Book Description
Solidification is one of the oldest processes for producing complex shapes for applications ranging from art to industry, and remains as one of the most important commercial processes for many materials. Since the 1980s, numerous fundamental developments in the understanding of solidification processes and microstructure formation have come from both analytical theories and the application of computational techniques using commonly available powerful computers. This book integrates these developments in a comprehensive volume that also presents and places them in the context of more classical theories. This second edition highlights the key concepts within each chapter to help guide the reader through the most important aspects of the topics. The figures are now in color, in order to improve the visualization of phenomena and concepts. Recent important developments in the field since the first edition was published have also been added. The three-part text is aimed at graduate and professional engineers. The first part, Fundamentals and Macroscale Phenomena, presents the thermodynamics of solutions and then builds on that subject to motivate and describe equilibrium phase diagrams. Transport phenomena are discussed next, focusing on the issues of most importance to liquid-solid phase transformations, then moving on to describing in detail both analytical and numerical approaches to solving such problems. The second part, Microstructure, employs these fundamental concepts for the treatment of nucleation, dendritic growth, microsegregation, eutectic and peritectic solidification, and microstructure competition. This part concludes with a chapter describing the coupling of macro- and microscopic phenomena in microstructure development. The third and final part describes various types of Defects that may occur, with emphasis on porosity, hot tearing and macrosegregation, presented using the modeling tools and microstructure descriptions developed earlier.