三叉晶界对晶粒长大影响的相场法模拟

Effect of Triple Junction on Grain Growth Simulated by Phase Field Model

采用相场法研究了正常晶粒长大和三叉晶界控制的晶粒长大特征,揭示了三叉晶界对晶粒长大的影响。结果表明,在正常晶粒长大过程中,三边形晶粒面积随时间线性减小,晶粒形貌具有自相似性;在三叉晶界控制的晶粒长大过程中,演化后期三边形晶粒面积与时间明显偏离线性关系,较小的三叉晶界迁移率对晶界运动具有拖曳作用,二面角强烈依赖于三叉晶界迁移率和晶粒尺寸。研究结果与其他理论以及实验结果相吻合。

The grain growth characteristics 6f normal grain and triple-junction （TJ）-controlled grain were simulated by phase field method. The effects of triple junction on the grain growth were revealed. The results show that the area of three-sided grain （A） decreases linearly with time increasing and the grain morphology is self-similar during normal grain growth process. A clear deviation from the linear relation of A -t curve appears during the final stage of TJ-controlled grain growth. A small TJ mobility exerts a dragging effect on the grain boundary （GB） motion and dihedral angle depends strongly on the TJ mobility and grain size. The results are in agreement with other theoretical and experimental ones.