The influence of phase transformation on grain growth behavior wasinvestigated by annealing dense, fine-grained alpha- and beta-siliconnitride ceramics with or without large alpha- or beta-grain addition.The microstructural development was evaliiated quantitatively andstatistically using image analysis. Bimodal microstrucnires weredeveloped by the abnormal grain growth from both phasetransformation-induced beta-nuclei and added beta-nuclei. Aspectratios of grains in alpha-materials were larger than those inbeta-materials. The grain growth rate of added beta-nuclei inalpha-materials were larger than tbose in beta-materials. It wasshown that the grain growth was accelerated by α/β phasetransformation.
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