Modeling of dynamic recrystallization of magnesium alloy using cellular automata considering initial topology of grains
Modeling of dynamic recrystallization of magnesium alloy using cellular automata considering initial topology of grains
复制标题
考虑晶粒初始拓扑的使用元胞自动机的镁合金动态再结晶建模
DOI：
10.1016/j.msea.2017.11.024
复制
发表时间：
2018-01-10
期刊：
影响因子：
6.4
通讯作者：
Qian, Lingyun
中科院分区：
文献类型：
--
作者：
Wang, Lixiao;Fang, Gang;Qian, Lingyun
在MATLAB平台上建立了二维元胞自动机（CA）模型，对ZM21镁合金热变形过程中的微观组织演变进行了定量和形貌模拟。采用概率方法提高了离散模拟法的药柱拓扑精度。CA模拟的初始条件不仅反映了平均晶粒尺寸，还反映了所测组织的晶粒尺寸分布等更多细节。建立了元胞自动机模型中定义的参数与实际变形条件之间的定量关系，提高了模型的适用性。利用CA模型对ZM21镁合金的动态再结晶进行了预测。得到了模拟结果，包括晶粒拓扑结构，平均晶粒尺寸，晶粒尺寸分布和动态再结晶分数，并与实验结果进行了比较。模拟结果与实验结果吻合良好，表明所建立的元胞自动机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，在镁合金热变形过程中，初始阶段组织细小均匀有利于动态再结晶过程的进行。
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.