基于晶界迁移率与晶界能各向异性的晶粒生长元胞自动机模拟

基于晶粒长大的理论模型,结合曲率机制与概率性转变规则,建立了晶界迁移率与晶界能各向异性条件下的二维元胞自动机模型,利用该模型对晶粒等温条件下的生长过程进行了模拟,分析了晶粒长大的组织演变与动力学特征、晶粒尺寸和晶粒边数的分布,对比了晶界迁移率各向异性、晶界能各向异性对晶粒生长的影响。结果表明:晶界迁移率与晶界能各向异性条件下晶粒形态演变遵循晶粒正常长大的规律,相对晶粒尺寸偏离正态分布,晶粒边数分布不具有时间不变性特点,小角度取向差三叉晶界平衡角偏离120°;与各向同性相比,晶界迁移率与晶界能各向异性条件下晶粒的生长速率明显减慢,单独考虑晶界迁移率各向异性对晶粒生长的影响不大,晶界能各向异性对晶粒生长的影响大于晶界迁移率各向异性的影响;模拟结果符合晶粒生长动力学理论和相关文献的结论。

Cellular Automata Simulation for Grain Growth Based on Anisotropic Grain Boundary Mobility and Grain Boundary Energy

Based on the theoretical model of grain growth,combined with the curvature mechanism and probabilistic transition rules,a 2D cellular automata(CA) model was built under the conditions of anisotropic grain boundary mobility and grain boundary energy.This CA model was used to simulate the grain growth under isothermal condition,the microstructure evolution and kinetics characteristics as well as the grain size and edge number distributions were analyzed,and the effects of grain boundary mobility anisotropy and grain boundary energy anisotropy on grain growth were studied.The results show that the microstructure evolution was in accordance with the normal grain growth law,the relative distributions of grain size deviated from normal distribution and the grain edge number distribution was not time-dependent,the equilibrium angle of triple junctions grain boundary with small angle misorientations was 120°.Comparing with the isotropy,the anisotropic grain boundary mobility and grain boundary energy obviously decreased the grain growth rate,but the grain boundary mobility anisotropy alone did not significantly change the grain growth.The effect of grain boundary energy anisotropy on grain growth was greater than that of grain boundary mobility anisotropy.The simulation results corresponded with the theory of grain growth kinetics and the conclusion from relevant literature.