(1. 上海交通大学 轻合金精密成型国家工程研究中心，上海 200030；2. 長岡技術科学大学 機械系，新潟 940-2188，日本)
摘 要: 根据元胞自动机的模拟结果研究了AZ91合金热压缩过程中的再结晶动力学。结果表明，随着应变量增加，再结晶分数增加；随着变形温度升高，再结晶速率加快。稳态组织的平均晶粒尺寸与Zener-Hollomom参数成反比，指数为−0.05。压缩过程中，所有晶粒的平均尺寸迅速下降后缓慢减小至稳态值，原始晶粒平均尺寸呈线性减小为0，再结晶晶粒平均尺寸先增加至某一峰值后缓慢下降至稳态值。基体内同时存在的多次再结晶现象使得流变曲线呈单峰特征。
关键字: AZ91合金；元胞自动机；动态再结晶；动力学
（1. National Engineering Research Center of Light Alloy Net Forming,Shanghai Jiao Tong University, Shanghai 200030, China;2. Department of Mechanical Engineering, Nagaoka University of Technology, Niigata 940-2188, Japan）
Abstract:The kinetics of dynamic recrystallization (DRX) during the hot compression process of AZ91 magnesium alloy was investigated based on the cellular automata simulation. The simulation results indicate that the fraction of DRX increases with strain increase and the velocity of DRX increases with process temperature increase. The relationship between the average grain size in the final microstructure and Zener-Hollomom parameter follows an inverse power law with the exponent of −0.05. During a compression process, the average size of total grains decreases rapidly in an initial stage, and then slowly to a steady value; the average size of initial grains decreases linearly to zero; the average size of recrystallized grains increases to a peak value and then decreases slowly to a steady value. Multi-cycle recrystallizaiton occurs concurrently in the matrix, resulting in a single peak on each flow curve.
Key words: AZ91 alloy; cellular automata; dynamic recrystallizaiton; kinetics
