On the use of TiC as high-temperature healing particles in alumina based composites

We report on the use of TiC particles as high temperature healing agent in alumina based composites. The selection of TiC was based on a theoretical analysis of its high temperature stability in contact with Al2O3, its volumetric expansion upon oxidation and the adhesion between the reaction product TiO2 with Al2O3. Fully dense 15 and 30 vol.% TiC-Alumina composites were made by Spark Plasma Sintering. Initial damage was produced by Vickers indentations. The strength recovery was determined for temperatures between 400 and 800 °C. The mechanical measurements were complemented by microstructural characterization of the base material and the healed cracks.