Microstructure and properties of Al2O3–TiC nanocomposites fabricated by spark plasma sintering from high-energy ball milled reactants

In situ synthesis of Al2O3–TiC nanocomposite powders from a mixture of titanium, graphite, and Al2O3 powders by high-energy ball milling (HEBM) and its consolidation through spark plasma sintering (SPS) were investigated. After being milled for 25 h at ambient temperature, the powder mixtures were mainly composed of homogeneous nanosized Al2O3 particle and amorphous TiC solid solution. The relative density of the samples consolidated by SPS technique in vacuum at 1480 °C for 4 min reached 99.2%. The final products exhibited very fine microstructure, and the grain sizes of Al2O3 and TiC were about 400 nm and 200 nm, respectively, with a flexure strength of 944 ± 21 MPa, Vickers hardness 21.0 ± 0.3 GPa, fracture toughness 3.87 ± 0.2 MPa m1/2, and electrical conductivity 1.2787 × 105 S m−1.