【摘要】 基于相场与温度场耦合的相场法原理对Ni-Cu二元合金枝晶长大过程进行二维数值模拟。研究了不同过冷度和各向异性系数等相场参数对枝晶生长的影响,最后采用加入非平衡扰动的方式,进行了二次及三次枝晶生长的模拟。模拟结果表明:随着过冷度的增加,越有利于侧向分枝的生长;各项异性γ系数影响枝晶尖端的稳态行为,γ越大,枝晶生长速度越大,侧向分枝越发达,二次枝晶间距越小。更多还原

【Abstract】 An anisotropic phase field model which coupling the temperature -field and phase-field is used to carry out 2-D numerical simulation of dendrite growth of Ni-Cu alloy by choosing different values of undercooling and anisotropy coefficients. A disturbance to simulate fluctuations at the interface is added to simulate the growth of secondary and third dendrites. The calculated results indicate that it is advantageous to the growth of the sidebranches if the undercoding is increased; the anisotropy parameter γ affects the steady state of the dendrite tip. The larger the γ is, the quicker the dendrite tip growth velocity is, the more developed the sidebranches are and the smaller the DAS is.更多还原