Effects of different Si3N4 starting powders and sintering conditions on the grain morphology and mechanical properties of ?-SiAlON ceramics

Abstract

The preparation of ?-SiAlON microstructures by ß-Si3N4 starting powder or by applying nucleation step during sintering was studied. The application of sintering cycles on nucleation effect and the effect of different Si3N4 starting powders on the grain morphology of ?-SiAlON ceramics and mechanical properties were investigated. Nucleation occured during the dwell time above eutectic temperature. The elongation in the grain was due to the pre-sintering cycles prior the final sintering at 1800°celcius. The results showed that the toughness was improved by the elongated grain morphology.