论文部分内容阅读
通过气体雾化技术研究了Cu100-XFeX(X=15,20,30和40)合金的凝固行为.考虑少量相液滴形核、扩散长大、空间迁移、凝固界面与液滴间的相互作用以及体积分数等共同影响因素,建立了能描述该类合金凝固组织演变动力学模型.将数学模型与雾化液滴飞行过程中运动、传热和传质的控制方程相耦合,给出了数值求解方法,模拟计算了Cu基亚稳难混溶合金液-液相分离过程.结果表明:富Fe粒子的平均尺寸随着Fe含量的增加而增大;少量相液滴形核发生在基体熔体过饱和度峰值附近;随着冷却速度的增大,雾化液滴中少量相液滴的形核率增大,但平均半径减小;少量相液滴在Marangoni迁移和与固/液界面相互排斥共同作用下,向雾化液滴中心迁移,使雾化粉末最终形成壳型组织结构.
The solidification behavior of Cu100-XFeX (X = 15, 20, 30 and 40) alloys was investigated by gas atomization technique. Considering the small amount of phase droplet nucleation, diffusion growth, spatial migration, the interaction between solidification interface and droplet As well as the volume fraction and other common factors, a kinetic model describing the evolution of the solidified microstructure of the alloy was established. Coupling the mathematical model with the governing equations of motion, heat transfer and mass transfer during atomized droplet flight, numerical values Solution method was used to simulate the liquid-liquid phase separation process of Cu-based metastable hard alloy.The results show that the average size of Fe-rich particles increases with the increase of Fe content. With the increase of cooling rate, the nucleation rate of small amount of droplets in atomized droplets increased, but the average radius decreased. Small amount of droplets in Marangoni migration and the solid / liquid interface Mutual exclusion together, to the center of atomized droplets migration, the final formation of atomized powder shell structure.