The mechanical properties of silicon carbide ceramics fabricated by injection moulding process were investigated. The ceramic injection-moulding formulations with 50 vol% β-SiC powders containing 6 wt% $Al_2O_3$ and 4 wt% $Y_2O_3$ as starting additives and polypropylene as the main organic component were injection-moulded under identical conditions. Paraffin wax and stearic acid were used as minor binder and lubricant, respectively.
After the injection-moulded bodies debinded at 520℃ for 3 h in $H_2$ atmosphere were sintered at 2000℃ for 3 h in the flowing Ar atmosphere, the fully densified SiC ceramics with the relative density of more than 99% was obtained. The microstructure of densified SiC ceramics was composed of plate like grains. The flexural strength was 500 MPa, and the estimated toughness was 6.2 $MPam\frac{1}{2}$. The enhanced fracture toughness was attributed to the crack deflection and bridging mechanism by plate like grains.
