颗粒被凝固前沿排斥的临界速度模型

通过对颗粒增强金属基复合材料凝固过程中温度场，、质量分数场变化以及凝固前沿形状改变的数值模拟，建立了颗粒被凝固前沿排斥或捕获的临界速度模型，当凝固前沿的推进速度小于颗粒被凝固前沿所排斥／捕获的临界速度时，颗粒被凝固前沿所捕获的现象不会发生，并且在临界速度模型中保持其它参数为旧，而只考虑合金质量分数的影响时，发现随着合金质量分数的逐渐增加，颗粒被凝固前所排斥／捕获的临界速度逐渐减小。

The Critical Velocity Model for Pushing of Particles by the Solidification Front

The critical velocity model for pushing or engulfment of particles by the solidification front has been established by evaluating the distortions for the temperature and concentration fields and the consequent changes in solidification front morphology for particle reinforcement metal matrix composites. The phenomenon of particle being engulfment by solidification front can not occur when the pushing velocity of the solidification front is less than the critical velocity. It is found that with the increasing of the alloy content the critical velocity for pushing or engulfment of particles by the solidification front decreases when other parameters are kept constant and only the alloy content is considered.