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基于Karma模型和Eggleston修正强界面能各向异性的方法,建立HCP材料的强界面能各向异性相场模型。采用有限差分法对控制方程进行数值求解,模拟研究HCP材料的枝晶生长行为。结果表明:枝晶形貌呈现出明显的六重对称性,界面方向不连续,导致在主枝和侧枝的尖端出现棱角。当界面能的各向异性强度低于临界值(1/35)时,枝晶尖端稳态生长速度随着各向异性强度的增加而增加;当界面能各向异性强度值超过临界值时,尖端稳态生长速度降低0.89%;当进一步增加各向异性强度值时,尖端稳态速度增加且在各向异性强度值为0.04时达到极大值,随后减小。
Based on the Karma model and Eggleston’s method of modifying the anisotropy of the strong interface, a strong interfacial anisotropy phase field model of HCP material is established. The governing equations were numerically solved by finite difference method, and the dendrite growth behavior of HCP materials was simulated. The results show that the morphology of dendrites shows obvious six-fold symmetry, and the interface orientation is discontinuous, resulting in the appearance of edges on the tips of main branches and collateral branches. When the anisotropy of interfacial energy is lower than the critical value (1/35), the steady-state growth rate of dendrite tip increases with the increase of anisotropy strength. When the interfacial anisotropy intensity exceeds the critical value, The tip steady-state growth rate decreased by 0.89%. When the anisotropic intensity was further increased, the tip steady-state velocity increased and reached a maximum when the anisotropy intensity was 0.04 and then decreased.