元胞自动机方法模拟枝晶生长

为了能够准确反映具有明显界面的枝晶生长过程，利用元胞自动机方法模拟了凝固过程中固液两相具有不同热物理性质的枝晶生长.在模拟过程中发现，凝固过程中溶质易于富集在枝晶臂之间，同时随着凝固时间的延长，界面前沿的溶质浓度梯度和温度梯度逐渐下降.利用模拟所得的枝晶尖端半径与理论计算的相比较，发现随着枝晶尖端速度的增加，枝晶尖端半径逐渐下降，模拟与理论结果符合较好，偏差小于1μm. 关键词： 枝晶生长 凝固 偏析 模拟

Modeling of dendritic growth by means of cellular automaton method

In order to reflect the characteristic of sharp interface during the d endritic growth process, cellular automaton method is used to simulate the dendr ite evolution. In this method the different physical properties in both solid an d liquid phases are adopted to reflect the different heat_transfer rate. The simulated results show that there is solute micro-segregation between the two p rimary dendritic arms. In addition，the solute concentration gradient and temper ature ahead of the solid/liquid interface decrease gradually with increasing solidification time. Comparing the simulated radius of the dendritic tip with the theore tical radius, we obtain that the simulated results fit the theoretical radius well, and the deviation is less than 1μm.