Mechanical properties of silicon carbide sintered with additive Y3Al5O12

In this work, silicon carbide ceramics were sintered by using Y3Al5O12 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 Y3Al5O12 as a additives was 3, 5 and 7 wt%. Effects of Y3Al5O12 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 Y3Al5O12 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.