MECHANISM OF GRAIN-GROWTH OF BETA-SIALON

The mechanism for grain growth of beta-SiAlON has been investigated by annealing high-density beta-SiAlON-YAG materials at 1650-degrees-C. A n observed decrease in grain growth with increasing weight fraction of liquid confirms a diffusion-controlled growth mechanism in the system . The grain-growth mechanism is further characterized by the developme nt of large elongated grains in addition to smaller grains. After prol onged heating, an equilibrium maximum grain size is developed causing a homogenization of the microstructure.