基于位错演化模型纳米晶块体材料晶粒的演变

Grain size evolution of nano-micro-crystalline materials based on dislocation density model

利用试验及数值仿真方法研究了工业纯铝在等径角挤压变形过程中晶粒的尺寸变化。数值仿真过程引入位错演化模型,对纯铝等径角挤压过程中晶粒尺寸的演化进行了模拟。研究结果表明,基于位错演化模型,经4道次剪切变形仿真后纯铝出现纳米级晶粒。数值仿真结果与试验对比显示,两者结果一致,说明利用数值仿真可以预测等径角挤压块体材料晶粒尺寸的演变过程。

The grain sizes of the metal materials have the important effect on the properties of those materials. The grain refinement of the pure Aluminum was investigated by the experimental and numerical method during ECAP （Equal Channel Angular Processing）. The evolution of grain size was simulated by the finite element method during ECAP and the dislocation evolution model was introduced into the simulation. The results show that the grain size, which reaches nanometer, produced after the shearing deformation of four passes during ECAP. Compared with the experimental results, it is also found that the gain size of the simulation is greatly similar to that of the experiment after shearing deformation of each pass.