Influence of sintering aids on pressureless sintering of Sialon ceramics

The pressureless sintering process adding Y 2O 3 and Y 2O 3+La 2O 3 as sintering aids was studied. It was found that a Sialon ceramic adding 6% Y 2O 3 as sintering aid was sintered to over 99% TD when sintered at 1750℃ for 1h. Y 2O 3 can partially be replaced by La 2O 3, and the best sintering temperature of Y La Sialon is a little higher than that of Y Sialon. The phase structure studies of Y La Sialon showed that La can restrain the growth of α ′ and YAG phase in Sialon. The effect of chemical mixing is not as good as that of mechanical mixing because of transformation of γ Al 2O 3 to α Al 2O 3 in the sintering process and other factors. [