金属再结晶织构的相场模拟与择优取向机制

项目名称： 金属再结晶织构的相场模拟与择优取向机制

项目编号： No.51271204

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 李赛毅

作者单位： 中南大学

项目金额： 80万元

中文摘要： ：本项目基于相场动力学研究晶体学取向和应变储能等因素的序参量表示方式及相应相场方程的构建，引入晶界能和晶界迁移率的分子动力学计算，提出再结晶形核择优取向的能量原则，建立再结晶退火织构与组织演变的相场模型，以更好反映再结晶过程中的物理行为、定量预测再结晶织构的演变；选取具有不同层错能的面心立方金属，进行多种变形路径和变形程度的塑性加工，研究退火过程中的再结晶行为和织构及组织演变，确立通过电子背散射衍射和X 射线衍射相结合以确定模拟所需初始条件的方法；结合实验和模拟结果，深入探讨晶粒在形核和长大阶段的择优取向机制及其物理本质、层错能的影响。相关理论和实验成果的取得将进一步揭示材料结构特性与状态及退火条件对再结晶行为的影响规律和机理，丰富和发展金属材料再结晶理论和建模与仿真技术，为有效控制材料的退火织构、组织及性能提供重要的理论依据和方法。

中文关键词： 再结晶；织构；形核；晶界；分子动力学

英文摘要： This project aims to develop a model for texture evolution in recrystallization annealing of metals based on phase field kinetics. For this purpose, we investigate the expression of order parameters for factors such as crystalligraphic orientations and strain stored energy and the construction of corresponding phase field equations. A method for including the calculation of grain boundary energy and grain boundary mobility from molecular dynamics into the phase field framework is established. A energy principle for the determination of preferential grain orientations during nucleation is proposed. As validations, face-centered cubic metals with different stacking fault energies are subjected to plastic deformation up to various strain levels along various strain paths. The recrystallization behavior and the corrsponding texture and microstructure developments are investigated. A method to determine the initial conditions needed for the simulations from electron-back scattering diffraction and X-ray diffraction is established.The formation mechanisms of preferred orientations during nucleation and growth and the underlying physics are investigated by comparing the experimental and modeling results. The theoretical and experimental results can bring insight into the effect of structural characteristics, processing

英文关键词： Recrystallization；Texture；Nucleation；Grain boundary；Molecular dynamics