纯镍动态再结晶过程的元胞自动机模型

Modeling dynamic recrystallization of pure nickel by cellular automaton

将冶金学基本原理与元胞自动机方法相结合,建立了动态再结晶过程微观组织演变的实时计算模型。模型考虑到时间因素的影响,时间步长Δt定义为元胞尺寸与最大晶界移动速率的比值,每一时间步内每个元胞的位错密度随应变按一定规律增长。结果表明,利用此模型可以很好地模拟大应变速率下的动态再结晶过程微观组织变化,并能预测再结晶晶粒大小和热加工过程应力随应变的变化。

A real-time calculating model used for the simulation of microstructure evolution during dynamic recrystallization process was proposed by coupling the fundamental metallurgical principles with the cellular automata （CA） method. It considered the effect of the time, which was defined as the ratio of the cell size and the maximum grain movement velocity. During each time step, the dislocation density of every cell increased with strain as the law. The results show that it could simulate the variation of microstructure well for different strain rates during dynamic recrystallization process, and can predict the grain size of R grains and the flow stress variation with strain during the hot working process.