B4C-TiB2 Composites via Reactive Hot Pressing

B 4 C/TiB 2 ceramic composites having 5-10-15 vol % TiB 2 have been prepared via reactive hot pressing of B 4 C, TiO 2 and C powder mixture. Reactive hot pressing were carried out at 2273 K and 2373 K applying 50 MPa pressure under argon atmosphere for 1 hour. The effect of TiB 2 amount of composite and sintering temperature on sintering behavior and some mechanical properties of reactive hot pressed composites were investigated. The highest theoretical density that could be achieved, being 99.6 %, was with the composite having 5 % TiB 2 following reactive hot pressing at 2000C applying 50 MPa pressure under argon atmosphere for 1 hour. The highest strength level achieved with the same composite (B 4 C-5 vol.% TiB 2 ) was 450 MPa. The fracture toughness of the composite was found to be 4.2 MPa. m" 2 . Increasing TiB 2 content in composites led to increasing porosity in B 4 C-TiB 2 samples and decreasing mechanical properties.