In Situ Analysis of the Liquid Phase Sintering Process of alpha-SiC Ceramics

The densification process of liquid phase sintered SiC ceramics with Al 2 O 3 and Y 2 O 3 as sintering additives was investigated by in situ measurement apparatus combined with conventional methods. The shrinkage curve, morphology of the sample and liquid phase formation process simulation were observed by high temperature in-situ observation furnace. The relative density, flexural strength and microstructure evolution were characterized by analysis of samples sintered at temperatures ranging from 1640 to 1920 at 40 interval. The obvious temperature that liquid phase began to function was confirmed between 1640 to 1680. The classical liquid phase sintering theory was testified. Highly-densified SiC ceramics were obtained by being sintered at 1880, of which the relative density was (99.46 0.37)%, and the flexural strength was (650 26) MPa.