B4C-TiB2 Composites via Reactive Hot Pressing

B4C/TiB2 ceramic composites having 5-10-15 vol % TiB2 have been prepared via reactive hot pressing of B4C, TiO2 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 TiB2 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 % TiB2 following reactive hot pressing at 2000 degrees C applying 50 MPa pressure under argon atmosphere for 1 hour. The highest strength level achieved with the same composite (B4C-5 vol.% TiB2) was 450 MPa. The fracture toughness of the composite was found to be 4.2 MPa. m(1/2). Increasing TiB2 content in composites led to increasing porosity in B4C-TiB2 samples and decreasing mechanical properties.