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Simulating Microstructure Evolution Of Realistic 3d Aluminum Alloy Polycrystal During Large Plastic Deformation At Elevated Temperature
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Book Synopsis Simulating Microstructure Evolution of Realistic 3D Aluminum Alloy Polycrystal During Large Plastic Deformation at Elevated Temperature by : Jing Lu
Download or read book Simulating Microstructure Evolution of Realistic 3D Aluminum Alloy Polycrystal During Large Plastic Deformation at Elevated Temperature written by Jing Lu and published by . This book was released on 2006 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modelling Microstructure-property Relationships in Polycrystalline Metals Using New Fast Fourier Transform-based Crystal Plasticity Frameworks by : Jaspreet Singh Nagra
Download or read book Modelling Microstructure-property Relationships in Polycrystalline Metals Using New Fast Fourier Transform-based Crystal Plasticity Frameworks written by Jaspreet Singh Nagra and published by . This book was released on 2019 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present thesis develops several new full-field, fast Fourier transform (FFT)-based crystal plasticity modelling tools for microstructure engineering. These tools are used to explore elasto-viscoplastic deformation, localized deformation, 3D grain morphology, microstructure evolution, dynamic recrystallization and their effects on formability of polycrystalline metals with particular attention paid to sheet alloys of aluminum and magnesium. The new FFT-based crystal plasticity models developed in this work overcome several inherent problems present in the well-known crystal plasticity finite element method (CP-FEM) and elasto-viscoplastic fast Fourier transform method (EVP-FFT) in solving representative volume element (RVE)-based problems. The new models have demonstrated significant fidelity in simulating various deformation phenomena in polycrystalline metals and prove to be faster and accurate alternatives for obtaining full-field solutions of micromechanical fields in aluminum and magnesium sheet alloys. In particular to the aluminum alloys, which are currently replacing heavier steel parts in the automotive industry, the sheet aluminum alloys have significantly improved corrosion resistance and strength-to-weight properties in comparison to steel. However, aluminum alloys are still outperformed by steel in terms of formability. To improve the formability of an aluminum sheet, one method is to develop physics-based predictive computational tools, which can accurately and efficiently predict the behavior of aluminum alloys and thus allow designing the microstructure with desired properties. Accordingly, in first part of this thesis, a novel numerical framework for modelling large deformation in aluminum alloys is developed. The developed framework incorporates the rate-dependent crystal plasticity theory into the fast Fourier transform (FFT)-based formulation, and this is named as rate tangent crystal plasticity-based fast Fourier transform (i.e., RTCP-FFT) framework. This framework is used as a predictive tool for obtaining stress-strain response and texture evolution in new strain-paths with minimal calibration for aluminum alloys. The RTCP-FFT framework is benchmarked against an existing FFT-based model at small strains and finite element-based model at large strains, respectively, for the case of an artificial Face Centered Cubic (FCC) polycrystal. The predictive capability as well as the computational efficiency of the developed framework are then demonstrated for aluminum alloy (AA) 5754. In the second part of this thesis, the RTCP-FFT framework, developed earlier, is coupled with the Marciniak and Kuczynski (MK) approach to establish a new full-field framework for generating forming limit diagrams (FLDs) of aluminum sheet alloys, e.g., AA3003 and AA5754. The new coupled framework is able to investigate the complex effects of grain morphology, local deformation, local texture and grain interactions on the predictions of forming limit strains. This study reveals that among the various microstructural features, the grain morphology has the strongest effect on the predicted FLDs for aluminum alloys. Furthermore, this study also suggests that the FLD predictions can be significantly improved if the actual grain structure of the material is properly accounted for in the crystal plasticity models. In addition to aluminum alloys, magnesium alloys are getting significant attention by the automotive industry due to their light weight and high specific strength. However, the automotive industry has not been able to take full advantage of the lightweight characteristic of magnesium alloys because of their poor formability at room temperature. Therefore, to enhance the workability and restore their ductility, the magnesium alloys are formed at elevated temperature. High temperature forming of magnesium alloys is often accompanied by dynamic recrystallization (DRX), which allows the final microstructure, as well as the properties of the material (e.g., initial grain size, initial texture, etc.), to be controlled. Therefore, DRX coupled with a full-field crystal plasticity FLD framework can be used as a tool to design microstructure of a material. Since it would be beneficial to be able to redesign the material properties of magnesium alloys using physics-based computational tools than using physical experiments, this work takes a step ahead towards such an outcome by presenting a new framework that predicts DRX and models its effects on the formability of magnesium alloys. Accordingly, in the third part of this thesis, a new full-field, efficient and mesh-free numerical framework, to model microstructure evolution, dynamic recrystallization (DRX) and formability in hexagonal closed-packed (HCP) metals such as magnesium alloys at warm temperatures, is developed. This coupled framework combines three new FFT-based approaches, namely: (a) crystal plasticity modelling of HCP alloys, (b) DRX model, and (c) MK model. First, a rate tangent-fast Fourier transform-based elasto-viscoplastic crystal plasticity constitutive model for HCP metals (RTCP-FFT-HCP) is developed. Then, it is coupled with a probabilistic cellular automata (CA) approach to model DRX. Furthermore, this new model is coupled with the Marciniak-Kuczynski (M-K) approach to model formability of magnesium alloys at elevated temperatures. The RTCP-FFT-HCP model computes macro stress-strain response, twinning volume fraction, micromechanical fields, texture evolution and local dislocation density. Nucleation of new grains and their subsequent growth is modeled using the cellular automata approach with probabilistic state switching rule. This framework is validated at each level of the coupling for magnesium sheet alloy, AZ31. First, the RTCP-FFT-HCP model is validated by comparing the simulated macro stress-strain responses under uniaxial tension and compression with experimental measurements at room temperature. Furthermore, the texture evolution predicted with the new model is compared with experiments. The predictions show a good agreement with experiments with high degree of accuracy. Next, the forming limit diagrams (FLDs) are simulated at 100 C, 200 C and 300 C, respectively, for AZ31 sheet alloy considering the effects of DRX. The predicted FLDs show very good agreement with the experimental measurements. The study reveals that the DRX strongly affects the deformed grain structure, grain size and texture evolution and also highlights the importance accounting for DRX during FLD simulations at high temperatures.
Book Synopsis DDSim, a Hierarchical, Probabilistic, Multiscale Damage and Durability Simulation Methodology by : John M. Emery
Download or read book DDSim, a Hierarchical, Probabilistic, Multiscale Damage and Durability Simulation Methodology written by John M. Emery and published by . This book was released on 2007 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Dissertation Abstracts International by :
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Severe Plastic Deformation and Thermomechanical Processing: Nanostructuring and Properties by : Andrea Bachmaier
Download or read book Severe Plastic Deformation and Thermomechanical Processing: Nanostructuring and Properties written by Andrea Bachmaier and published by MDPI. This book was released on 2021-02-11 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Severe plastic deformation (SPD) is a very attractive research field for metallic materials because it provides new possibilities for manufacturing nanostructured materials in large quantities and allows microstructural design on different hierarchical levels. The papers included in this issue address the following topics: novel SPD processes as well as recent advancements in established processing methods, microstructure evolution and grain refinement in single- and multi-phase alloys as well as composites, strategies to enhance the microstructure stability at elevated temperatures, mechanically driven phase transformations, surface nanostructuring, gradient and multilayered materials, and mechanical and physical properties of SPD-processed materials.
Book Synopsis Journal of Engineering Materials and Technology by :
Download or read book Journal of Engineering Materials and Technology written by and published by . This book was released on 2008 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Large Plastic Deformation of Crystalline Aggregates by : Cristian Teodosiu
Download or read book Large Plastic Deformation of Crystalline Aggregates written by Cristian Teodosiu and published by Springer. This book was released on 2014-05-04 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a comprehensive view of the present ability to take into account the microstructure and texture evolution in building up engineering models of the plastic behaviour of polycrystalline materials at large strains. It is designed for postgraduate students, research engineers and academics that are interested in using advanced models of the mechanical behaviour of polycrystalline materials.
Book Synopsis Crystal Plasticity Finite Element Methods by : Franz Roters
Download or read book Crystal Plasticity Finite Element Methods written by Franz Roters and published by John Wiley & Sons. This book was released on 2011-08-04 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the leading experts in computational materials science, this handy reference concisely reviews the most important aspects of plasticity modeling: constitutive laws, phase transformations, texture methods, continuum approaches and damage mechanisms. As a result, it provides the knowledge needed to avoid failures in critical systems udner mechanical load. With its various application examples to micro- and macrostructure mechanics, this is an invaluable resource for mechanical engineers as well as for researchers wanting to improve on this method and extend its outreach.
Book Synopsis Microstructure Prediction of Severe Plastic Deformation Manufacturing Processes for Metals by : Ninggang Shen
Download or read book Microstructure Prediction of Severe Plastic Deformation Manufacturing Processes for Metals written by Ninggang Shen and published by . This book was released on 2018 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the research presented in this thesis has been to develop a physics-based dislocation density-based numerical framework to simulate microstructure evolution in severe plastic deformation (SPD) manufacturing processes for different materials. Different mechanisms of microstructure evolution in SPD manufacturing processes were investigated and summarized for different materials under dynamic or high strain rates over a wide temperature range. Thorough literature reviews were performed to clarify discrepancies of the mechanism responsible for the formation of nanocrystalline structure in the machined surface layer under both low-temperature and high-temperature conditions. Under this framework, metallo-thermo-mechanically (MTM) coupled finite element (FE) models were developed to predict the microstructure evolution during different SPD manufacturing processes. Different material flow stress responses were modeled subject to responsible plastic deformation mechanisms. These MTM coupled FE models successfully captured the microstructure evolution process for various materials subjected to multiple mechanisms. Cellular automaton models were developed for SPD manufacturing processes under intermediate to high strain rates for the first time to simulate the microstructure evolution subjected to discontinuous dynamic recrystallization and thermally driven grain growth. The cellular automaton simulations revealed that the recrystallization process usually cannot be completed by the end of the plastic deformation under intermediate to high strain rates. The completion of the recrystallization process during the cooling stage after the plastic deformation process was modeled for the first time for SPD manufacturing processes at elevated temperatures.
Book Synopsis Investigating the Evolution of Grain Scale Microstructure During Large Plastic Deformation of Polycrystalline Aluminum by : Abhishek Bhattacharyya
Download or read book Investigating the Evolution of Grain Scale Microstructure During Large Plastic Deformation of Polycrystalline Aluminum written by Abhishek Bhattacharyya and published by . This book was released on 2002 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Polycrystal Simulations of Texture Evolution During Deformation Processing by :
Download or read book Polycrystal Simulations of Texture Evolution During Deformation Processing written by and published by . This book was released on 1998 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Some recent research on the hot deformation of aluminum alloys has indicated that at elevated temperatures, slip occurs on {110}110 systems in addition to the usual {111}110 systems active at lower temperatures. The effect of these additional slip systems on the texture evolution of aluminum single and polycrystals is studied using finite element simulations. The crystals are deformed in plane strain compression, and the constitutive response is modeled using crystal plasticity to track the reorientation of the crystals. By discretizing each crystal with a large number of elements, the non-uniform deformations due to local inhomogeneities and interactions with neighboring crystals are modeled. The resulting textures and microstructures are examined with regard to effect of including the additional systems, initial orientation of the single crystals, and stability of the cube orientation.
Book Synopsis Modeling Microstructural Evolution During Recrystallization of Hot Rolled High Strength Aluminum Alloy 7050 by : Khaled F. M. Adam
Download or read book Modeling Microstructural Evolution During Recrystallization of Hot Rolled High Strength Aluminum Alloy 7050 written by Khaled F. M. Adam and published by . This book was released on 2015 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Finally, to prove the benefits of integrating the experiment into the simulation model and make the simulation more realistic an initial structure was obtained a real as-deformed microstructure by Electron Back scatter diffraction (EBSD) as well as the second phase particles distribution was determined by Backscattered Electrons (BSE).
Book Synopsis Prediction of Crystallographic Texture Evolution and Anisotropic Stress-strain Response During Large Plastic Deformation in Alpha-titanium Alloys by : Xianping Wu
Download or read book Prediction of Crystallographic Texture Evolution and Anisotropic Stress-strain Response During Large Plastic Deformation in Alpha-titanium Alloys written by Xianping Wu and published by . This book was released on 2006 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new Taylor-type polycrystalline model has been developed to simulate the evolution of crystallographic texture and the anisotropic stress-strain response during large plastic deformation in [alpha]-titanium alloys at room temperature. Crystallographic slip, deformation twinning, and slip inside twinned regions were all considered as contributing mechanisms for the plastic strain in the model. This was accomplished by treating the dominant twin systems in a given crystal as independent grains once the total twin volume fraction in that crystal reached a predetermined saturation value. The newly formed grains were allowed to independently undergo further slip and the concomitant lattice rotation, but further twinning was prohibited. New descriptions have been established for slip and twin hardening and the complex coupling between them. Good predictions were obtained for the overall anisotropic stress-strain response and texture evolution in several different monotonic deformation paths on annealed, initially textured samples of two different chemical compositions of [alpha]-titanium alloys. The polycrystalline plasticity model presented here is built on the Taylor assumption of uniform deformation gradient in all of the constituent grains. The effects of this gross simplification have been evaluated by comparing the predicted stress and strain distributions between Taylor model and the more sophisticated finite element models that relax the assumption of the uniform strain. The anisotropy of the plastic behavior was observed to strongly influence the deviation of the Taylor model predictions from the finite element model predictions when comparing the stress and strain distributions in deformed polycrystalline [alpha]-titanium with initially random texture.The slip parameters established using the crystal plasticity model developed here were utilized in a novel spectral framework, called Microstructure Sensitive Design (MSD), for constructing elastic-plastic property closures in hexagonal polycrystals. The main focus was on the influence of the crystallographic texture (in the hcp polycrystals) on the components of the macroscale anisotropic elastic stiffness, macroscale anisotropic tensile yield, and the macroscale R-ratios (ratio of the transverse strains in tensile deformation mode) exhibited by the material.
Book Synopsis A New Crystal Plasticity Formulation to Simulate Large-strain Plasticity of Polycrystalline Metals at Elevated Temperatures by : Edward D. Cyr
Download or read book A New Crystal Plasticity Formulation to Simulate Large-strain Plasticity of Polycrystalline Metals at Elevated Temperatures written by Edward D. Cyr and published by . This book was released on 2017 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation explores the plasticity polycrystalline metals, with particular attention paid to aluminum and its alloys. Specifically aluminum Al-Mg sheet alloys, which are currently replacing steel parts for panel and some structural componentry in the automotive industry. At the forefront of this transition, is the problem of poor room-temperature formability of the aluminum sheet when compared to its steel counterparts. A promising solution to this has been the use of warm-forming to increase formability, preventing redesign of automotive parts from steel to aluminum (Li and Ghosh, 2003). In this thesis, a new constitutive framework and methodology is developed to accurately model elevated temperature behaviour of polycrystalline aluminum. This study describes a picture of the physics behind slip dominated deformation in polycrystalline metals, and the mechanical characterization techniques used to determine modeling parameters for crystal plasticity. A review on modeling techniques and published work on the versatility of crystal plasticity theory and application is also presented. An initial model is then developed for a fully temperature dependent crystal plasticity framework. The model employs a generic hardening law to study the effect of temperature on material hardening, and conclusions are made on the lack of microstructural correlation between the model and physical behaviour of the material. The same framework is then implemented in the well known Marciniak-Kuzynski (1967) based limit strain formulation as an application study with Chang and Asaro (1981) type hardening. Temperature dependency is studied and formability is predicted for different aluminum alloys. The study reveals that, again, phenomenological-based hardening is only satisfactory for predicting elevated-temperature behaviour, and results are very sensitive to model input parameters. In the second half of this dissertation, a physical model is carefully developed from fundamental dislocation theories. The model is formulated on the basis of accumulation of dislocations as the dominating strengthening mechanism in polycrystals, introduces recovery as a thermally activated process leading to temperature dependent softening. The model is used to study temperature dependency of slip deformation in pure aluminum, and the correlation between physical processes and model parameters. The model is able to capture and predict deformation response, as well as suggest explanation to the influence of temperature on microstructural behaviour. Finally, the model is applied to study the temperature dependency of microstructural parameters in 5xxx series Al-Mg sheet alloys. Experimental data is used to characterized material parameters at warm forming temperatures, and the model is used to predict stress-strain response. The model is then used to discuss the effect of temperature on two different alloys and suggests explanation on the microstructural causes leading to variation hardening behaviour between the two alloys over the temperature range studied. The work then concludes the improvement of model predictability, and the utility of such a model in microstructural design.
Book Synopsis Computational Materials Science by : Dierk Raabe
Download or read book Computational Materials Science written by Dierk Raabe and published by Wiley-VCH. This book was released on 1998-10-27 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling and simulation play an ever increasing role in the development and optimization of materials. Computational Materials Science presents the most important approaches in this new interdisciplinary field of materials science and engineering. The reader will learn to assess which numerical method is appropriate for performing simulations at the various microstructural levels and how they can be coupled. This book addresses graduate students and professionals in materials science and engineering as well as materials-oriented physicists and mechanical engineers.
Book Synopsis Severe Plastic Deformation by : Burhanettin Altan
Download or read book Severe Plastic Deformation written by Burhanettin Altan and published by Nova Publishers. This book was released on 2006 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been already well established that the nanostructured materials (materials with a grain size of 100mm or less) is the future materials. Nanostructured materials possess properties superior to those of conventional, coarse grained materials. Hence designing potentially cost efficient and environmentally friendly products with better performance is a possibility. Among others, nanostructured materials exhibit increased strength, hardness and ductility and provide an opportunity for superplastic forming. When all the procedures in use for the production of nanostructured materials are examined, only severe plastic deformation (SPD) processes exhibit a potential for producing relatively large samples suitable for industrial applications. In this monograph, the state-of-the-art on severe plastic deformation methods is presented in one volume. The monograph is organised into eight chapters, each of which contains papers on different aspect of severe plastic deformation methods prepared by the experts in this field. The topics covered in the monograph are structure formation, phase transformation, superplasticity, mechanical properties of nanostructured materials, electronic and magnetic properties of nanostructured materials, deformation analysis, novel SPD methods, commercialisation of ECAE method.
Book Synopsis Early Microstructural Evolution and Deformation Behavior in Solution Heat Treated Aluminum-lithium Alloys by : Shelly Midori Miyasato
Download or read book Early Microstructural Evolution and Deformation Behavior in Solution Heat Treated Aluminum-lithium Alloys written by Shelly Midori Miyasato and published by . This book was released on 1991 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
