Monte Carlo simulation of microstructure evolution in nano-composite ceramic tool materials

The formation of microstructure of nano-composite ceramic materials is a complicated process, which is controlled by many factors such as components, the size and content of nano-particles as well as sintering process. Monte Carlo Potts′ model is widely applied to simulate the microstructure evolution during the solid-phase sintering process of ceramics due to its simplicity and flexibility. In this paper, a new Monte Carlo Potts′ model for the sintering process of two-phase nano-composite ceramic materials is proposed. In this model, the driving forces for grain-boundary migration are the interfacial energy between two phases and the boundary energy inside each phase, and the grain growth process for different sizes and area fractions of nano-particles is successfully investigated in the absence of pores. The simulation results show that the nano-phase can pin the matrix phase and reduce the growth rate of matrix phase during the microstructure evolution, this effect becomes stronger with the addition of smaller size or higher area fraction nano-particles. It is also observed that the nano-phase can influence the microstructure type of nano-composite ceramic, smaller nano-particles are predominantly in intragranular positions, whereas larger nano-particles retain in intergranular positions. The simulation results are in accordance with the experiment results.