Study on undercooling of metal droplet in rapid solidification

A mathematical model for the undercooling of the metal droplet during the rapid solidification is established, by which the factors that influence the undercooling of the metal droplet during the rapid solidification are analyzed, and the parameter zeta=sigma(3)(SL)/(T-L Delta H-2) is defined as the impact factor of the undercooling for the droplet solidification. Different undercoolings of droplets induced by various rapid solidification conditions are mainly ascribed to the change of the impact factor. Moreover, it is shown that the larger of zeta the higher the relative undercooling can be gained. Meanwhile, the parameters such as solid-liquid interfacial energy sigma(SL) and latent heat of solidification Delta H also vary with the rapid solidification conditions of droplets.