Densification of liquid phase sintered silicon carbide

The densification and phase formation of liquid phase sintered silicon carbide (LPSSiC) with 10wt.% additives were investigated. The ratio of the Al(sub 2)O(sub 3)/Y(sub 2)O(sub 3)-additives was changed between 4:1 and 1:2. Densification was carried out by hot pressing and gas pressure sintering. The different densification routes result in different major grain boundary phases-aluminates in gas pressure sintered materials and silicates in hot pressed samples. Thermodynamic calculations were carried out to determine the amount of liquid phase during densification and for the interpretation of the results.