(1. 广西大学 物理科学与工程技术学院，南宁 530004；
2. 中国科学院 国际材料物理中心，沈阳 110016)
摘 要: 结合多态相场(MSPF)模型与晶体畸变模型，获得变形镁合金初始变形晶粒组织以及合金内部的非均匀储存能分布，计算模拟不同退火温度条件下的再结晶形核和晶粒长大的微观演化过程，分析退火温度对再结晶晶粒长大和晶粒尺寸的影响，对比不同时刻的再结晶晶粒分布特征。结果表明：在相同的变形条件下，位错密度高的区域，如晶界附近，储存能较高，再结晶形核最先在高储存能区域出现，并通过合并与吞噬机制长大；而在变形晶粒内部，储存能较低且分布相对均匀，再结晶过程中形核长大较慢。不同退火温度下晶粒尺寸权重概率的分布表明：低温下会出现双峰结构和异常晶粒长大现象；高温下晶粒长大较快，晶粒尺寸分布向大尺寸方向变化且趋于均匀。
关键字: 镁合金；相场模型；再结晶；晶粒长大；塑性变形
（1. College of Physics Science and Engineering, Guangxi University, Nanning 530004, China;
2. International Center for Materials Physics, Chinese Academy of Science, Shenyang 150016, China）
Abstract:The multi-state phase field (MSPF) model coupling with lattice deformation model were used to obtain the initial grain microstructure of deformation magnesium alloy and inhomogeneous stored energy distribution and simulate the evolution of the recrystallization nucleation and grain growth at different annealing temperatures. The effect of annealing temperature on grain growth during recrystallization was analyzed, and the feature of grain size distribution at different times was investigated. The results indicate that, under the same deformation conditions, there are relatively high stored energy at high dislocation density regions, e.g. around grain boundaries, where the preferred recrystallization nucleation sites form. Because the stored energy within the deformed grain is relatively low and uniform, the recrystallization nucleation and grain growth process are slower. The weighted frequency distributions of grain size at different temperatures show that it exhibits a bimodal distribution and abnormal grain growth phenomenon at low temperature, while grains grow up fast and grain size distribution moves to large scale and to be homogeneous at high temperature.
Key words: Mg alloy; phase field model; recrystallization; grain growth; plastic deformation
