难混溶合金凝固过程中宏观偏析形成的数值模拟

NUMERICAL SIMULATION OF MACRO-SEGREGATION FORMATION DURING SOLIDIFICATION PROCESS OF IMMISCIBLE ALLOYS

基于分离粒子法,建立了一个模拟难混溶合金凝固过程中第二相宏观偏析形成过程的模型,此模型考虑了实际凝固过程中的诸多因素,包括形核,扩散长大,Ostwald熟化,Brownian碰撞以及运动碰撞的影响,对Al-30％In合金的模拟结果与实验结果吻合较好,反映了所建立模型较好的理论预测能力。

Based on particle separation method, this paper developed a numerical model for simulating the formation of the macro-segregation of the second phase during the solidification process of immiscible alloys. This model reflects the real solidification process well and can easily consider the effects of the nucleation, diffusional growth, Ostwald ripening, Brownian collision and moving collision of the second phase droplets even under the variable temperature condition. The simulated results to Al-30%In (mass fraction) hypermonotectic alloy, especially the distribution of the volume fraction and the particle size on the cross-section of the casting are in good agreement with experimental results, which shows that the model established has a good predictive ability.