Abstract
To investigate the effect of microwave heating on grain growth behavior in silicon nitride ceramics, microwave annealing was carried out using a microwave radiation frequency of 28GHz. A comparative study of silicon nitride annealed by microwave and by conventional heating was done using scanning elec tron microscopy (SEM) observation and image analysis. Results show that microwave annealing is more effective in enhancing the grain growth and in producing the bi-modal microstructure than conventional heating. In particular, the growth along the c-axis was more remarkable due to the local and selective heating of the liquid phase by the microwave.
