相场模型模拟强界面能各向异性作用下晶体生长

Phase-field Method Simulation of the Crystal Growth with Strongly Surface Tension Anisotropy

用Eggleston等提出的方案对界面能各向异性函数进行重整化处理,并使用相场模型对强各向异性情形下的晶体生长进行了模拟。在晶体平衡形态模拟中再现了晶向缺失现象,并与理论预测结果相一致。在自由枝晶生长过程中,当各向异性低于临界值时,枝晶生长速度随着各向异性系数增大而增大;在临界值附近生长速度突然降低5%;当高于临界值时生长速度又开始增加直到在0.20处达到最大值,其后基本不变。

The crystal growth morphology and behavior in strongly surface-tension anisotropy circumstance is investigated numerically using the phase-field method in two dimensions.In order to describe the strongly surface tension anisotropy in solid-liquid interface,the anisotropy function is regularized with Eggleston et al.proposed formula.In the equilibrium crystal shape simulation the phenomena of orientation missing have been quantitatively reproduced.During the free dendrite growth procedure,as the anisotropy below the critical value,the growth velocity increases with the anisotropy.When the anisotropy is across the critical value,the growth velocity dropped down about 5 percent.While the anisotropy higher than the critical value,the growth rate increases again with the anisotropy until reaches the maximum at 0.20,and then keep unchanged.