相场法模拟凝固过程中界面效应对晶粒形核的影响

Phase-field Simulation of Interface Effect during Grain Nucleation of Solidification Processing

采用连续相场模型对晶粒形核过程进行模拟,从动力学角度考虑,引入类似于纳米颗粒的界面效应,分析它对形核过程的影响;同时研究形核过程中晶核的析出、形核数目变化、晶界厚度变化以及晶核生长的特点。结果表明,界面效应为形核过程提供驱动力,促使晶核的快速长大;形核过程中晶核数目随时间逐渐增多,晶核尺寸逐渐增大,晶核生长速度较快,同时晶粒位向取向参数的变化反映了晶粒尺寸和晶界厚度的变化。

In the present investigation a phase field model was used to analysis the processing of grain nucleation, and the nano-liked interface effect was introduced to describe the influence of the nucleation from grain growth kinetics. The precipitation of nuclei, the change of the nuclei number, the thickness of grain boundary and the feature of grain growth were studied at the same time. The simulation results show that the interface effect provides the driving power for nuclei growth, and the number of nuclei increases with prolonging of time, the radii of nuclei increase and the growth of nuclei changes fast. The distribution of the radius orientation reflects the change of grain boundary thickness and the grain size.