Fracture phenomena of sintered alpha-SiC

The aim of the present work was: to prepare high-strength, sintered α-SiC ceramics which could be used for high-temperature engineering applications, and to use the fracture mechanics data obtained to suggest how these ceramics might be developed further. Fracture toughness and flexural strength data are given for sintered α-SiC ceramics using carbon and B or Al as sintering aids. The slow crack growth behaviour of Al-doped SiC is reported. Strength and toughness were found to be largely independent of the type and concentration of the sintering aid, but the slow crack growth behaviour was significantly affected. (author)