强迫对流下各相场参数对枝晶生长的影响

利用耦合流场的相场模型，以Ni—Cu二元合金为例研究各相场参数对金属凝固过程中枝晶生长的影响。结果表明：对流对枝晶形貌影响很大，上游枝晶的枝晶臂最长，下游枝晶臂最短，整个枝晶呈现非对称形貌；对流速度越大，上游枝晶生长越快；各向异性系数越大，主枝枝晶臂越瘦长；扰动的引入可以促进枝晶二次枝晶臂的生长，但基本上不影响枝晶尖端稳态行为。

Effects of phase field parameters on dendritic growth under a forced convection

The phase-field model which couples the flow field is used to simulate the dendrite growth in a Ni-Cu binary alloy. The effects of Phase-field parameters on dendritic crystal growth were studied. The result shows that： the dendritic shape changed dramatically, the branch of upstream dendritic crystal was the longest while the downstream the shortest, and the horizontal branch was between the two; the larger velocity of convection was, the quicker of the dendrite tip velocity; the larger anisotropy parameter was, the thinner the branch of main dendrite; the noise could trigger the growth of the second arms, but not influence the tip operating state.