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建立了用于模拟立方晶系合金三维枝晶生长的改进元胞自动机模型。该模型将枝晶尖端生长速率、界面曲率和界面能各向异性的二维方程扩展到三维直角坐标系,从而能够描述三维枝晶生长形貌演化。应用本模型模拟在确定温度梯度和抽拉速度条件下三维柱状晶生长过程的一次臂间距调整机制和不同择优取向柱状晶之间的竞争生长。使用NH4Cl?H2O透明合金进行凝固实验,模拟结果和实验结果吻合较好。
An improved cellular automata model was established for simulating the three-dimensional dendrite growth of cubic alloys. The model extends the two-dimensional equation of dendritic tip growth rate, interfacial curvature and interfacial anisotropy to a three-dimensional rectangular coordinate system so that the evolution of the three-dimensional dendrite growth morphology can be described. The model was used to simulate the adjustment mechanism of the primary arm spacing and the competition growth between different preferential orientation columnar crystals under the conditions of temperature gradient and drawing speed. Solidification experiments were carried out using NH4Cl? H2O transparent alloy. The simulation results agree well with the experimental results.