纯铜动态再结晶过程的元胞自动机模拟

基于热加工过程金属学原理,建立了一类改进动态再结晶二维元胞自动机模型,模拟了加工硬化,动态回复、形核及再结晶晶粒长大等一系列过程.利用该模型可得到整个热加工过程流变应力变化,晶粒的形态、晶粒取向及大小.流变应力的大小可由基体与再结晶晶粒位错密度的平均值计算.采用该模型对不同应变,应变率及温度下纯铜动态再结晶过程进行了模拟,模拟结果与相同热变形条件下纯铜实验结果吻合较好.

MODELING DYNAMIC RECRYSTALLIZATION OF PURE COPPER USING CELLULAR AUTOMATON METHOD

Based on the fundamental metallurgical principles of metal hot working process, a two-dimensional dynamic recrystallization(DRX) model of pure copper was built up by using cellular automata(CA) to simulate the microstructural evolution during thermomechanical processing with DRX. It could calculate the variation of the flow stress, the orientation and mean size of recrystallization grains(R-grains). The flow stress was evaluated from the average dislocation density of the matrix and all the R-grains. The dynamic recrystalization process for different strains, strain rates, temperatures were simulated. The predictions agree well with experimental results for pure copper at the same hot working condition. The model provides an elementary link for the microscopic dislocation activities, mesoscopic grain boundary movement dynamics, and macroscopic hot working parameters, and paves the way for the multiscale modeling in the future.