Densification and mechanical properties of TiC by SPS-effects of holding time, sintering temperature and pressure condition

The influence of sintering temperature, holding time and pressure condition on densification and mechanical properties of bulk titanium carbide (TiC) fabricated by SPS sintering has been systematically investigated. Experimental data demonstrated that relative density and Vickers hardness (HV) increase with sintering temperature and holding time, but fracture toughness (KIC) was not significantly influenced by sintering parameters. The HV and relative density of samples consolidated by SPS technique at 1600 °C for 5 min under 50 MPa pressure (applied entire sintering cycle) reached 30.31 ± 2.23 GPa and 99.90%, respectively. HV values of ∼24-30 GPa and KIC of ∼3.7-5 MPa m1/2 were obtained in all bulk samples with relative densities of 95.61-99.90% when fabricated under various conditions presented above, without abnormal grain growth. More pronounced effects of pressure condition on grain growth (promoted by grain-boundary diffusion) than on densification were observed. The relationship of fracture toughness and fracture mode is also discussed.