零维液态金属快速凝固过程的热力学和动力学

Thermodynamics and Kinetics in the Process of Rapid Solidification of the Zero Dimensional Metal Droplets

分析了零维液态金属快速凝固过程中的热流规律，计算了零维液滴在真空条件下的冷却速度，并建立了零维液滴单晶形核的过冷度方程．结果表明：零维液滴的凝固过程由形核前所达到的过冷和系统向环境的散热共同控制；零维液滴在真空条件下的冷却速度在１０５～１０８Ｋ／ｓ之间．

The heat flow during rapid solidification of zero dimensional metal droplets was analyzed. The cooling rate of the zero dimensional metal droplets was calculated. The undercooling equation for the zero dimensional metal droplets to form a single nucleation was established. The results indicate that the rapid solidification effects of the zero dimensional metal droplets are limited by the undercooling achieved before nucleation occurs and the external rate of heat extration. Under the vacuum condition, the cooling rate of the zero dimensional metal droplets is between 10 5K/s and 10 8K/s.