Abstract
Self-propagating high temperature synthesis combined with direct consolidation technique was used to synthesize high density Al2O3/TiC composites from mixture of TiO2, Al and graphite powders. The effect of controlled amount of zirconia and iron addition on the density, microstructure and the mechanical properties of the composites was investigated. The results revealed that, addition of either 1.0mol zirconia or 5.0wt% of iron metal powder led to a significant decrease in the sample porosity from 7.0 to less than 1.0vol% together with a remarkable enhancement in the microhardness from 6.0 to 11.0 and 12.0GPa with 1.0mol zirconia and 5.0wt% iron additions, respectively. Moreover, the fracture toughness increased from 3.5 to 6.0 and 7.0MPam1/2 with 1.0mol zirconia and 15wt% iron additions, respectively. However, addition of 1.0mol zirconia with 5.0wt% iron powder led to a composite with higher porosity and reduced mechanical properties.