A two-dimensional cellular automaton (CA) model was established on MATLAB platform for quantitative and topographic simulation of the microstructure evolution of magnesium alloy ZM21 during hot deformation. A probabilistic approach was employed to improve the grain topology accuracy of discrete simulation method. Not only the average grain size but also more details including the grain size distribution of the measured microstructure were reflected in the initial conditions of CA simulation. Quantitative relationship between the parameters defined in the CA model and actual deformation condition was built to increase the applicability of the established model. The dynamic recrystallization (DRX) of magnesium alloy ZM21 was predicted using the CA model. Simulation results, including grain topology, average grain size, grain size distribution and DRX fraction were obtained and compared with experimental results. The good agreement between simulated and experimental results indicated that the established CA model is reliable to predict the microstructure evolution during the hot deformation of magnesium alloy. The influences of initial grain size and its distribution on the microstructure evolution were investigated. It indicated that fine and homogeneous microstructure at initial stage is favorable for the DRX process in hot deformation of magnesium alloy.

在MATLAB平台上建立了二维细胞自动机（CA）模型，对镁合金ZM21在热变形过程中的组织演化进行了定量和形貌模拟。采用概率方法提高离散仿真方法的晶粒拓扑精度。CA模拟的初始条件不仅反映了平均晶粒尺寸，而且还反映了包括所测微结构的晶粒尺寸分布在内的更多细节。建立了CA模型中定义的参数与实际变形条件之间的定量关系，以提高所建立模型的适用性。使用CA模型预测了镁合金ZM21的动态重结晶（DRX）。模拟结果，包括晶粒拓扑，平均晶粒尺寸，获得了晶粒尺寸分布和DRX分数，并将其与实验结果进行了比较。模拟结果与实验结果吻合良好，表明所建立的CA模型能够可靠地预测镁合金热变形过程中的组织演变。研究了初始晶粒尺寸及其分布对组织演变的影响。结果表明，镁合金热变形初期细小且均匀的组织有利于DRX过程。研究了初始晶粒尺寸及其分布对组织演变的影响。结果表明，镁合金热变形初期细小且均匀的组织有利于DRX过程。研究了初始晶粒尺寸及其分布对组织演变的影响。结果表明，镁合金热变形初期细小且均匀的组织有利于DRX过程。