Grain growth in ceramics

Grain growth of ceramics is sensitively affected by various factors such as porosity, impurities, sintering aid, nonstoichiometry etc, and hence it is often difficult to describe quantitatively the grain growth behavior. However, the situation has gradually been improved in recent years because various high-purity ceramic powders are produced. In this report, the grain growth is briefly discussed from the data of several engineering ceramics with near theoretical density, which are fabricated from high-purity, easily-sinterable raw powders. The subjects included are the effect of MgO-doping into Al2O3, the role of zirconia dispersion in Al2O3-ZrO2 composites, the cation's partitioning in ZrO2 ceramics, and the strain enhancement of grain growth.