Download or read book A Two Dimensional Simulation of Grain Structure Growth Within Substrate and Fusion Zone During Direct Metal Deposition written by Jingwei Zhang and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this chapter, a predictive multiscale model based on a cellular automaton (CA)-finite element (FE) method has been developed to simulate thermal history and microstructure evolution during metal solidification for direct metal deposition (DMD) process. The macroscopic FE calculation that is validated by the thermocouple experiment is developed to simulate the transient temperature field and cooling rate of single layer and multiple layers. In order to integrate the different scales, a CA-FE coupled model is developed to combine with thermal history and simulate grain growth. In the mesoscopic CA model, heterogeneous nucleation sites, grain growth orientation and rate, epitaxial growth, remelting of preexisting grains, metal addition, grain competitive growth and columnar to equiaxed phenomena are simulated. The CA model is able to show the entrapment of neighboring cells and the relationship between undercooling and the grain growth rate. The model predicts the grain size and morphological evolution during the solidification phase of the deposition process. The developed "decentered polygon" growth algorithm is appropriate for the nonuniform temperature field. Finally, the single- and multiple-layer DMD experiments are conducted to validate the characteristics of grain features in the simulation.
Download or read book Additive Manufacturing of High performance Metals and Alloys written by Igor Shishkovsky and published by BoD – Books on Demand. This book was released on 2018-07-11 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freedoms in material choice based on combinatorial design, different directions of process optimization, and computational tools are a significant advantage of additive manufacturing technology. The combination of additive and information technologies enables rapid prototyping and rapid manufacturing models on the design stage, thereby significantly accelerating the design cycle in mechanical engineering. Modern and high-demand powder bed fusion and directed energy deposition methods allow obtaining functional complex shapes and functionally graded structures. Until now, the experimental parametric analysis remains as the main method during AM optimization. Therefore, an additional goal of this book is to introduce readers to new modeling and material's optimization approaches in the rapidly changing world of additive manufacturing of high-performance metals and alloys.
Download or read book Fundamentals of Solidification written by Wilfried Kurz and published by . This book was released on 1992 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recommended Values of Thermophysical Properties for Selected Commercial Alloys written by K. C. Mills and published by Woodhead Publishing. This book was released on 2002 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of Metal Grain Growth in Laser Powder Bed Fusion Process Using Phase Field Thermal Coupled Model written by Zhida Huang and published by . This book was released on 2019 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM) comparing to traditional manufacture method possess higher flexibility. For metal Additive Manufacturing, approaches to improve products qualities have been intensively studied. Powder Bed Fusion (PBF) is a metal Additive Manufacturing method which manufactures products with high density. The PBF process, involving multiple physical phenomena, is controlled by several parameters such as laser power, scanning speed, material properties, etc. Due to the complexity of the PBF process numerical simulation is very necessary for understanding its mechanism. Simulations of PBF process are categorized depending on their scope of dimension, among which microscopic simulation usually emphasis grain development process and microstructures. Phase Field method is widely employed in microstructure simulation. By solving a set of PDE Phase Field method could represent an interfacial structure using a set of variables called Order Parameters. Models describing the grain growth process in a fixed temperature has been developed. In this work, the Phase Field model is coupled with thermal information to simulate the grain growth process in the melt pool of the PBF process. During the simulation, the computational area for Phase Field calculation and the magnitude of the driving force of Order Parameters are defined using temperature distribution. And the change of Order Parameters also generates latent heat. Finite Element Method is employed in order to execute the simulation on irregular geometry. Operator splitting scheme is applied for higher efficiency and accuracy. The convergence and boundary conditions implement are validated. Columnar shaped cells structures resembling experiment result are simulated.
Download or read book Grain Growth Phenomena in Films written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A statistical model of microstructural evolution is developed for the evolution of grain structure during deposition. In cases where the atomic mobility on the surface greatly exceeds that in the bulk of the film, the bulk microstructure may be viewed as static while all of the evolution is controlled by the free surface. This leads naturally to a two-dimensional model of microstructural evolution. Since the surface is advancing at a constant rate during deposition there is a linear relationship between time in the two-dimensional model and depth in the film. A Monte Carlo computer simulation technique is described which models the evolution of microstructure in this way. Various driving forces are included. Simulated microstructures in the plane of the film and in the plane perpendicular to the free surface are shown.
Download or read book Computational Welding Mechanics written by John A. Goldak and published by Springer Science & Business Media. This book was released on 2006-07-04 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Welding Mechanics (CWM) provides readers with a complete introduction to the principles and applications of computational welding including coverage of the methods engineers and designers are using in computational welding mechanics to predict distortion and residual stress in welded structures, thereby creating safer, more reliable and lower cost structures. Drawing upon years of practical experience and the study of computational welding mechanics the authors instruct the reader how to: - understand and interpret computer simulation and virtual welding techniques including an in depth analysis of heat flow during welding, microstructure evolution and distortion analysis and fracture of welded structures, - relate CWM to the processes of design, build, inspect, regulate, operate and maintain welded structures, - apply computational welding mechanics to industries such as ship building, natural gas and automobile manufacturing. Ideally suited for practicing engineers and engineering students, Computational Welding Mechanics is a must-have book for understanding welded structures and recent technological advances in welding, and it provides a unified summary of recent research results contributed by other researchers.
Download or read book Texture Analysis in Materials Science written by H.-J. Bunge and published by Elsevier. This book was released on 2013-09-03 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: Texture Analysis in Materials Science Mathematical Methods focuses on the methodologies, processes, techniques, and mathematical aids in the orientation distribution of crystallites. The manuscript first offers information on the orientation of individual crystallites and orientation distributions. Topics include properties and representations of rotations, orientation distance, and ambiguity of rotation as a consequence of crystal and specimen symmetry. The book also takes a look at expansion of orientation distribution functions in series of generalized spherical harmonics, fiber textures, and methods not based on the series expansion. The publication reviews special distribution functions, texture transformation, and system of programs for the texture analysis of sheets of cubic materials. The text also ponders on the estimation of errors, texture analysis, and physical properties of polycrystalline materials. Topics include comparison of experimental and recalculated pole figures; indetermination error for incomplete pole figures; and determination of the texture coefficients from anisotropie polycrystal properties. The manuscript is a dependable reference for readers interested in the use of mathematical aids in the orientation distribution of crystallites.
Download or read book Metals Abstracts written by and published by . This book was released on 1995 with total page 1192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lattice Gas Cellular Automata and Lattice Boltzmann Models written by Dieter A. Wolf-Gladrow and published by Springer. This book was released on 2004-10-19 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lattice-gas cellular automata (LGCA) and lattice Boltzmann models (LBM) are relatively new and promising methods for the numerical solution of nonlinear partial differential equations. The book provides an introduction for graduate students and researchers. Working knowledge of calculus is required and experience in PDEs and fluid dynamics is recommended. Some peculiarities of cellular automata are outlined in Chapter 2. The properties of various LGCA and special coding techniques are discussed in Chapter 3. Concepts from statistical mechanics (Chapter 4) provide the necessary theoretical background for LGCA and LBM. The properties of lattice Boltzmann models and a method for their construction are presented in Chapter 5.
Download or read book Large Scale Statistics for Computational Verification of Grain Growth Simulations with Experiments written by and published by . This book was released on 2002 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is known that by controlling microstructural development, desirable properties of materials can be achieved. The main objective of our research is to understand and control interface dominated material properties, and finally, to verify experimental results with computer simulations. We have previously showed a strong similarity between small-scale grain growth experiments and anisotropic three-dimensional simulations obtained from the Electron Backscattered Diffraction (EBSD) measurements. Using the same technique, we obtained 5170-grain data from an Aluminum-film (120 [mu]m thick) with a columnar grain structure. Experimentally obtained starting microstructure and grain boundary properties are input for the three-dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 C. Characterization of the structures and properties of grain boundary networks (GBN) to produce desirable microstructures is one of the fundamental problems in interface science. There is an ongoing research for the development of new experimental and analytical techniques in order to obtain and synthesize information related to GBN. The grain boundary energy and mobility data were characterized by Electron Backscattered Diffraction (EBSD) technique and Atomic Force Microscopy (AFM) observations (i.e., for ceramic MgO and for the metal Al). Grain boundary energies are extracted from triple junction (TJ) geometry considering the local equilibrium condition at TJ's. Relative boundary mobilities were also extracted from TJ's through a statistical/multiscale analysis. Additionally, there are recent theoretical developments of grain boundary evolution in microstructures. In this paper, a new technique for three-dimensional grain growth simulations was used to simulate interface migration by curvature driven motion. This method utilizes gradientweighted moving finite elements (GWMFE) combined with algorithms for performing topological reconnections on the evolving mesh. We have previously showed a strong similarity between small-scale grain growth experiments and anisotropic three-dimensional simulations obtained from the EBSD measurements. Using the same technique, we obtained 5170-grain data from a thin Aluminum film with a columnar grain structure and compared the computational results with experiments.
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Additive Manufacturing of High performance Metals and Alloys Modeling and Optimization written by Igor V. Shishkovsky and published by . This book was released on 2018 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freedoms in material choice based on combinatorial design, different directions of process optimization, and computational tools are a significant advantage of additive manufacturing technology. The combination of additive and information technologies enables rapid prototyping and rapid manufacturing models on the design stage, thereby significantly accelerating the design cycle in mechanical engineering. Modern and high-demand powder bed fusion and directed energy deposition methods allow obtaining functional complex shapes and functionally graded structures. Until now, the experimental parametric analysis remains as the main method during AM optimization. Therefore, an additional goal of this book is to introduce readers to new modeling and material's optimization approaches in the rapidly changing world of additive manufacturing of high-performance metals and alloys.
Download or read book Computer Simulation of Grain Growth in Two Dimensions written by Caroline L. Howe and published by . This book was released on 1987 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts Index written by and published by . This book was released on 1995 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Welding Metallurgy written by Sindo Kou and published by John Wiley & Sons. This book was released on 2003-03-31 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: Updated to include new technological advancements in welding Uses illustrations and diagrams to explain metallurgical phenomena Features exercises and examples An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.
Download or read book Evolution of 2D Potts Model Grain Microstructures from an Initial Hillert Size Distribution written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Grain growth experiments and simulations exhibit self-similar grain size distributions quite different from that derived via a mean field approach by Hillert [1]. To test whether this discrepancy is due to insufficient anneal times, two different two-dimensional grain structures with realistic topologies and Hillert grain size distributions are generated and subjected to grain growth via the Monte Carlo Potts Model (MCPM). In both cases, the observed self-similar grain size distributions deviate from the initial Hillert form and conform instead to that observed in MCPM grain growth simulations that start from a random microstructure. This suggests that the Hillert grain size distribution is not an attractor.
