Mechanical properties of silicon carbide sintered with additive Y3Al5O12

Abstract In this work, silicon carbide ceramics were sintered by using Y 3 Al 5 O 12 as a sintering additive, and its mechanical properties were investigated. The sintering condition of hot-pressing is 1800 °C, 2 h, vacuum atmosphere. The amounts of Y 3 Al 5 O 12 as a additives was 3, 5 and 7 wt%. Effects of Y 3 Al 5 O 12 as an additive on mechanical properties of SiC ceramics were evaluated. And the effect of heat treatment was also investigated. Mechanical properties (density, flexural strength, hardness, fracture toughness) of SiC ceramics showed an upward tendency with increment of the additive. The flexural strength of SiC samples sintered by Y 3 Al 5 O 12 additive was about 630 MPa, and it was increased up to 720 MPa by an annealing treatment at 1200 °C for 2 h in oxidation atmosphere.