凝固过程中的颗粒推斥

颗粒推斥是材料在固液相变过程中的基础问题之一，界面自由能的传统理论难以解释在金属基复合材料制备过程中的颗粒推斥现象，作者提出了固液界面前沿的流体流动是颗粒推斥的主要原因之一，并给出颗粒滚动及颗粒速度两种作用机制，推导出颗粒推斥条件判据，并以实验验证流体流动的作用机制及颗粒推斥理论判据。

ON THE PARTICLE PUSHING DURING SOLIDIFICATION

Particle pushing is one of the basic problems involved during solid-liquid phase transformation. Classical theory suggested that particle pushing is governed by the surface energy interactions, but this theory could not used to explain particle pushing occurring during the production of some metal-matrix composites. the authors propose that particle pushing is a result of fluid flow that occurs at the front of the solid-liquid interface. Two mechanisms for particle pushing as a result of fluid flow are presented and the criteria for particle pushing are derived. Experiments, carried out to verify the mechanisms and the criteria,show good agreement with theoretical model.