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用相场法模拟了过冷纯物质二次枝晶的生长过程,并定量地研究了过冷度、各向异性、热扰动振幅等参数对二次枝晶的影响.通过加入热扰动,相场法能更真实地模拟过冷熔体中二次枝晶的生长,计算得到的二次枝晶间距和幅值与由Wentzel_Kramers_Brillouin方法得到的结果符合较好.模拟结果表明,过冷度和各向异性对二次枝晶有较大影响.当过冷度增大时,二次枝晶间距随之减小;当各向异性增大时,二次枝晶间距随之增大,但二次枝晶幅值则随之减小.热扰动振幅主要影响二次枝晶幅值,而对二次枝晶间距影响较弱.
The phase-field method was used to simulate the growth process of secondary dendrites and the effects of parameters such as supercooling degree, anisotropy and thermal disturbance amplitude on secondary dendrites were quantitatively studied. By adding thermal perturbation, The field method can simulate the growth of secondary dendrites more accurately in subcooled melt, and the calculated secondary dendrite spacing and amplitude agree well with the results obtained by Wentzel_Kramers_Brillouin method. The simulation results show that the supercooling degree and When the degree of undercooling increases, the secondary dendrite spacing decreases. When the anisotropy increases, the secondary dendrite spacing increases, but the second The amplitude of the secondary dendrites decreases, the amplitude of the thermal disturbance mainly affects the amplitude of the secondary dendrites, but has a weaker effect on the secondary dendrite spacing.