铝合金三维枝晶生长相场模拟

以相场模型为基础，耦合热噪声，对三维铝合金枝晶生长进行模拟计算．考虑到三维模拟计算量大，赋值计算单元界面标志，在界面处引入噪声，而不是全局引入噪声，加快了计算速度．在多相场模型中选用了不同的生长最优方向，与实际情况更加符合．计算结果表明，加入热噪声是二次枝晶臂产生的原因之一，加入热噪声不影响尖端的稳态行为．

SIMULATION OF 3-D DENDRITIC GROWTH OF ALUMINUM ALLOY BY PHASE FIELD MODEL

Based on the phase field model, the three-dimensioned numerical simulation of the dendritic growth of aluminum alloy was studied by coupling with heat noise. Since 3-D numerical simulation takes too much calculation, to speed up the calculation, heat noise was introduced only on the cell interfaces instead of the whole cell. Different optimized growing directions were introduced in multi-phase-field equations, which makes the simulation more coincident with the practical way. The simulation result was compared with those obtained experimentally and indicated that the introduction of heat noise is one of the causations which triggered the growth of the secondary arm, but doesn't influence the tip operating state.