自由共晶生长的多相场等温数值模拟

Multi-Phase Field Simulation of Isothermal Free Binary Eutectic Growth

摘要:

采用Nestler多相场模型，模拟了给定不同数目与形态的核心及随机形核等不同初始条件下的自由共晶生长过程，研究了自由共晶生长机制；由固相体积分数随转变时间的对数关系曲线考察了Avrami指数的变化，证实自由共晶生长过程中存在3种生长机制：扩散控制生长、层片耦合生长及调幅分解生长，并且自由共晶生长过程实际是3种生长机制相互转变的过程。

Abstract:

The multi-phase field model of Nestler is used to simulate the free growth of isothermal binary eutectic and to study the growth mechanisms under different initial nucleation conditions, including the given quantity and morphology of nucleus and the stochastic nucleation. The variety of Avrami exponent calculated through the relationship between solid volume fraction and transition time demonstrates that there are three possible eutectic growth mechanisms, i.e. the diffusion limited growth, the lamellar growth and the spinodal decomposition growth. And the process of free eutectic growth is the transition process of the three growth mechanisms from one to another.