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采用耦合溶质场、温度场的相场模型,对金属镍凝固过程中枝晶生长进行模拟,研究了过冷度和耦合度对枝晶生长速度及形貌的影响。结果表明:过冷度和耦合度比较小时,整个枝晶形貌近似球形,枝晶生长速度随着过冷度和耦合度的增加而增加,主枝的增长速度优于其他方向,整个枝晶由开始近似球形慢慢变为星形;随过冷度继续增大,主枝的生长优势慢慢消失,出现更多侧枝,整体形貌又开始向球形过渡,直至第二侧枝速度赶上主枝,第三侧枝则完全消失。
The phase field model of coupled solute field and temperature field was used to simulate the growth of dendrite during the solidification of nickel metal. The effects of supercooling degree and coupling degree on the growth rate and morphology of dendrite were studied. The results show that when the degree of undercooling and coupling are small, the morphology of the dendrites is nearly spherical, and the growth rate of dendrite increases with the increase of the degree of undercooling and coupling. The growth rate of the main branch is superior to other directions. The dendrite As the degree of undercooling continues to increase, the growth advantage of the main branch gradually disappears, more lateral branches appear and the overall appearance begins to transition to the spherical shape again until the speed of the second lateral branch catch up with the main Branches, the third branch is completely disappeared.