【摘要】 在群体动力学的基础上,提出了描述Cu-13.5%Sn(质量分数)合金雾化液滴凝固过程的动力学模型;并将其与液滴的传热方程和运动方程相耦合,对雾化液滴的冷却凝固过程进行了模拟分析,探讨了液滴尺寸、气体初始速度、熔体过热度和初生相与异质形核基底间润湿角对液滴凝固行为的影响.模拟结果表明:本模型能够很好地描述雾化液滴的凝固过程;液滴冷却至一定温度开始形核,随后晶粒长大;液滴直径越小,冷却速度越快,液滴内晶粒数量密度就越高,凝固结束时晶粒亦越细小.形核润湿角和熔体过热度的增加,导致液滴内晶粒数量密度降低,晶粒半径增大;而气体初始速度的增加,有利于液滴内晶粒细化.更多还原

【Abstract】 Based on the population dynamic method a model has been developed to describe the solidification process and the thermal histories of gas-atomized droplets. The model is coupled with the droplets’ heat transfer controlling equation and the droplets’ motion controlling equation, and used in Cu-13.5%Sn (mass fraction) alloy. The effects of the droplet size, the initial gas velocity, the superheat of the melt and the wetting angle between the primary phase and the catalyzing substrate for heterogeneous nucleation on droplet solidification behaviors were discussed.更多还原