Three-dimensional computer simulation of anisotropic grain growth in ceramics

Anisotropic abnormal grain growth in ceramics was simulated by a three-dimensional Monte Carlo computer model. Microstructures similar to experimental ones were obtained and the influence of energy anisotropy and the number of anisotropically growing grains on microstructure development were studied. It was shown that a single grain with higher interaction energy in certain directions, embedded in a matrix of normally growing grains, grows anisotropically in the form of platelets or whiskers, depending on the spatial energy distribution. Observed growth rates in both promoted and unpromoted directions were constant, but different due to the different growth mechanisms. Faceted grain boundaries were observed. Simulation with low number of anisotropically growing grains showed bimodal microstructures before grain impingement. After grain impingement thickening of the grains took place until ail the avail able space was consumed. Results of the three-dimensional simulations agree well with a previous two-dimensional simulation and with experimental results. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.