Microstructure and mechanical properties of silicon carbide pressureless sintered with oxide additives

It is known that SiC powders can be densified at relatively low temperatures (1850–2000 °C) with some oxide additions. In this work the densification behavior, microstructure and mechanical properties (bending strength, fracture toughness, hardness) of SiC ceramics pressureless sintered with different additions chosen from oxide groups: Al2O3 + Y2O3, Al2O3 + Y2O3 + MgO, were investigated. It was found that oxide additives facilitate densification of sinters and significantly improve mechanical properties of SiC ceramics. The best activating oxide additions have been identified.