Effect of TiO2 on sinterability and physical properties of pressureless sintered Ti3AlC2 ceramics

TiO 2 was selected as effective sintering aid for pressureless sintering of Ti 3 AlC 2 ceramics in this study. The addition of only 5 wt% TiO 2 largely promotes the densification and nearly dense Ti 3 AlC 2 ceramic was obtained by pressureless sintering at 1500 °C. Significant strengthening and toughening effects were observed with the addition of TiO 2 . High Vickers hardness , flexural strength and fracture toughness of 3.22 GPa, 298 MPa and 6.2 MPa m −1/2 , respectively, were achieved in specimen pressureless sintered with 10 wt% TiO 2 . Additionally, the addition of 5 wt% TiO 2 had no deleterious effect on the excellent oxidation resistance of Ti 3 AlC 2 ceramic under 1200 °C water vapor atmosphere, while addition of 10 wt% TiO 2 accelerates the oxidation rate by two orders of degree.