Spark olasma sintering of silicon carbide

Silicon carbide (SIC) ceramics with submicron silicon carbide as raw material and Al₂O₃ and Y₂O₃ as sintering additives were fabricated by spark plasma sintering (SPS). The densification process of the materials was analyzed, and the effects of sintering temperature, sintering pressure and time on the densification and mechanical properties were investigated. It is found that the SiC with a relative density of 99.1% can be achieved when the sintering temperature, sintering pressure and holding time are 1 600℃, 50 MPa and 5 min, respectively. The mechanical properties of the sintered SiC are HV 2550 in hardness, 8.34 MPa·m^1/2 in fracture toughness and 684 MPa in bending strength.