相场模型模拟液固界面各向异性作用下自由枝晶生长

采用自适应有限元方法求解相场模型，分别对界面能各向异性和界面动力学各向异性条件下自由枝晶生长过程进行了模拟.计算表明两种各向异性均显著影响枝晶的生长，随着各向异性的增大枝晶尖端生长速度增大，尖端半径降低. 两种各向异性对自由枝晶生长有着不同形式的影响，在界面能各向异性条件下，枝晶生长稳定性系数与各向异性系数成幂函数关系；而在动力学各向异性条件下，稳定性系数与各向异性系数成线性关系. 关键词： 界面能各向异性 动力学各向异性 自由枝晶生长 相场模型

Phase-field modeling of the effect of liquid-solid interface anisotropies on free dendritic growth

Based on the adaptive finite element method， the phase-field model has been employed to simulate the free dendritic growth process governed by capillary anisotropy or kinetic anisotropy. It is illustrated that the free dendritic growth depends sensitively on the degree of the capillary anisotropy or kinetic anisotropy of the solid-liquid interface. As the anisotropies are enhanced， the dendrite tip growth velocity increases， but the dendrite tip radius decreases. These two kinds of anisotropies have different effects on the free dendritic growth behaviors. Under the capillary anisotropic condition， there is a power law relationship between the stability parameter and the capillary anisotropy parameter. And under the kinetic anisotropic condition， there is a linear relationship between the stability parameter and the capillary anisotropy parameter.