In the present work the effect of the microwave hybrid fast sintering of mullite-Al2O3 with non-stoichiometric mullite composition was investigated. Samples were fast sintered using a range of microwave power from 1.2 to 2.1 kW. The mullitization process of the silica-rich composition was faster than that of the alumina-rich composition. Alumina-rich mullite showed higher densities and smaller grain size than alumina-poor mullite. It was concluded that the microwave hybrid sintering of mullite was very sensitive to composition.
mullite; microwave heating; fast sintering; microstructure
