二元合金定向凝固的三维相场模拟

Three-dimensional phase-field simulation of directional solidification of binary alloy

利用三维相场模型对Al-Cu二元合金定向凝固过程进行数值模拟,研究定向凝固过程中固液界面前沿的变化规律和胞晶的粗化机制,分析不同过冷度对界面形态的影响.结果表明:在定向凝固过程中,胞晶的粗化是熔化和合并共同作用的结果;定向凝固过程中,随着过冷度的减小,定向凝固中的固液界面形态易向平界面发展.

Three-dimensional simulation of directional solidification of Al-Cu binary alloy is conducted by using phase field method, the variation pattern of the leading edge of solid-liquid interface and the coarsening mechanism of cellular crystal in the process of directional solidification are investigated, and the influence of undercooling degree on interface morphology is analyzed. The results of investigation show that cellular crystal coarsening is the result of the interaction of melting with merging during the directional solidification process. With the decrease of the undercooling degree, the solid-liquid interface morphology tends to develop into planar interface during the directional solidification process.