Fabrication and evaluation of the self-crack healing and mechanical properties of mullite/spinel/SiC composite

Recently ceramics (such as mullite, SiC, Spinel) have becomes the key materials for industrial applications including turbo charger rotors, bearings, diesel engine components and cutting tools due to their excellent tribological, anti-corrosion, creep resistant, wear resistant, and high strength at high temperature. However, regardless of their suitable properties, the low mechanical and brittle nature of these materials limits their application in industrial. The self-healing ceramics introduced as the ceramics with high ability of improving the surface cracks which leads to improve the mechanical properties. In this study, the first, the mechanical alloying was applied to synthesize the mullite/spinel ceramics nano-structure powder. To study the effect of SiC on mechanical properties and crack-healing ability of this composite, the mullite/spinel nano structure powder was mixed with 10-30wt% SiC nano structure powder. The obtained results showed that the adding of 20wt% SiC nano-structure powder to mullite/spinel composite improved the self-healing ability of composite as compared to monolithic mullite/spinel composite. Also by adding the SiC the improving in mechanical properties was observed and the strength recovery happened for this specimens.