Phase field simulation of template growth process in textured ceramics

The microstructure evolution of a template particle in a polycrystalline matrix during the templated grain growth process was simulated by a phase field approach. An initial microstructure including a rectangle (representing the template particle) and many circles (representing the matrix particles) was established with MATLAB software. The effects of the size and aspect ratio of the template particle on the development of microstructure were investigated by setting different areas and perimeters of the rectangle, respectively. When the aspect ratio >1, it was found that the template particle grew preferentially in the perpendicular direction rather than in the lateral direction along the casting plane. This could be attributed to the greater interface area between the large template and small matrix particles in the perpendicular direction. The results of the calculations indicated that there was a growth advantage for the template particle when its size was 3.46 times than that of the matrix particles in the two-dimensional system. The growth rate mainly depended on the aspect ratio of the template particle rather than on the template size. The simulation results gave a guiding principle for optimizing the process parameters, such as initial size and aspect ratio of template particle, when preparing highly textured ceramics.