Monte Carlo方法模拟晶粒在气-液-固三相体系下的各向异性生长

Monte Carlo Simulation for the Anisotropic Grain Growth Process in Vapor-Liquid-Solid Triphase

基于Monte Carlo方法,建立了气-液-固三相体系下晶粒生长的传质路径;根据最小能量原理,确立了最优和非最优生长取向上能量值的选取准则;采用各向异性的液-固和固-气界面能,对陶瓷晶粒的生长进行了二维模拟,并探讨了各向异性界面能量差值对晶粒形貌的影响规律。结果表明,在状态点发生相变时,引入寻找能量最低状态的过程,不仅消除了液相分布不合理现象,且晶粒边界更平直,形状更规则,质点在晶粒最优生长方向上的生长几率明显高于非最优方向;随着各向异性界面能差值的增加,晶粒的长径比基本呈线性变化,各向异性生长更突出。

In this paper,the traditional random walk way of Monte Carlo Potts model was improved and the mass transfer process of grain growth in vapor-liquid-solid system was developed,the energy criterion was determined based on the minimum energy principle and the liquid sintered β-Si3N4 ceramic grain growth process was simulated by with the anisotropic interfacial energy of liquid-solid and vapor-solid.The results show that due to the criterion of minimum energy principle was added when phase transformation take place during the random walk process,the liquid phase distribution is more reasonable and the grain boundary become more plat.The more the difference value of anisotropic interfacial energy is,the more the anisotropic degree.