Mo_2FeB_2基金属陶瓷液相烧结过程中硬质相晶粒生长的蒙特卡罗模拟

Monte Carlo Simulation on Grain Growth of the Ceramic Phase in Mo_2FeB_2-based Cermets during the Liquid Phase Sintering

采用反应硼化烧结法制备了Mo_2FeB_2基金属陶瓷,通过蒙特卡罗模拟方法对Mo_2FeB_2基金属陶瓷在液相烧结过程中硬质相晶粒的生长进行了研究。模拟中分析了蒙特卡罗步、液相体积分数和固液界面能对硬质相晶粒形貌的影响,并通过扫描电镜(SEM)研究了Mo_2FeB_2基金属陶瓷显微组织中硬质相晶粒的形貌。将模拟结果同实验结果进行了对比,结果表明:硬质相晶粒生长受界面反应控制。硬质相晶粒平均长径比增大主要来源于高温液相烧结过程中硬质相不同晶面与液态粘接相之间的固液界面能的相对较大的差值。修正后的模拟结果与实验结果具有较好的一致性。

Mo_2FeB_2-based cermet was prepared by reaction boronizing sintering process. Monte Carlo simulation was used to study the grain growth of the ceramic phase in Mo_2FeB_2-based cermets during the liquid phase sintering. The effects of the Monte Carlo steps, the liquid volume fractions, and the values of interface energy on the grains morphology of the ceramic phase were analyzed during the simulation, respectively. The grains morphology of the ceramic phase in Mo_2FeB_2-based cermets was studied by the scanning electron microscopy（SEM）. The simulation results were compared with the experimental results. It showed that the grain growth of the ceramic phase was controlled by interface reaction. In addition,the increase of the mean aspect ratio of the ceramic grain was due to the big difference in the solid-liquid interface energies between the different crystal planes of ceramic grain and the liquid binder phase during high temperature liquid phase sintering stage. The modified simulated results are in good agreement with the experimental results.