相场参数对强制流动下等温合金枝晶生长的研究

Effects of Phase Field Parameters on Dendritic Growth in Isothermal Binary Alloy with a Forced Convection

基于相场方法对强制流动下的等温合金的凝固过程进行了数值模拟,研究了流速、过饱和度、耦合参数、各向异性参数对枝晶生长形貌的影响。结果表明,强制流动下的晶核生长为非对称的枝晶,上游方向的枝晶臂尖端生长得到促进、下游和垂直流方向的受到抑制,且垂直臂随着流速的增加逐渐向上游方向倾斜生长;此外,结果还表明,在一定流速下,随着过冷度、耦合参数、各向异性值的增大,上游、垂直流和下游方向的枝晶臂尖端稳态速度均呈递增趋势。

Numerical simulation based on phase field method was presented to describe solidification process of isothermal binary alloy with a forced convection. Effects of forced convection,supersaturation,coupling parameters and anisotropy values on dendritic growth were observed. The results indicate that crystal nuclei grows to an asymmetrical dendrite with a forced convection,in which upstream arm tip growth is promoted and downstream as well as perpendicular arm tip growth is inhibited,furthermore,perpendicular arm tip increasingly grows tiltedly towards the upstream direction with increasing in forced flow. In addition,with increasing in supersaturation,coupling parameters and anisotropy values,steady growth velocity of dendritic arm tip in upstream,perpendicular and down stream direction are increased.