Preparation, microstructures and properties of Al2O3–TiC composites

Al2O3–TiC composites with various amounts of TiC, from 16 to 30 vol.%, were pressureless-sintered using 1 wt.% Al as an additive. The electrical conductivity, Vickers hardness, fracture toughness and wear resistance of the composites were studied. The hardness and toughness increased gradually with the increase of TiC volume fraction. The electrical conductivity increased with the increase of TiC volume fraction and increased about 10 orders of magnitude as the TiC volume fraction changed from 0.20 to 0.23. A sample whose TiC volume fraction is 0.23, which is close to its percolation threshold, had the best wear resistance.