Effect of Heating Rate on Transition Liquid-Phase Sintering of β′-o′ Sialon Ceramics

The transition liquid-phase sintering is assumed to be a dominant densification mechanism of β′-o′ sialon. The liquid is formed by the reaction between silicon nitride, alumina and oxidized layer on the surface of silicon nitride particles. To study the effect of heating rate on densification of β′-o′ sialon, green compacts of a silicon nitride powder and boehmite sol were prepared. The density of sintered β′-o′ sialons increased with increasing the heating rate. From the above result, it was considered that the transition liquid phase formed by the sintering with a high heating rate survives at a higher formaion temperature than the case with a low heating rate.