Pressureless sintering of B4C–TiB2 composites with Al additions

The effects of Al addition on pressureless-sintering of B4C–TiB2 composites were studied. Different amounts of Al from 0% to 5 wt.% were added to B4C–TiB2 mixtures (containing up to 30 wt.% TiB2) and the samples were pressureless sintered at 2050 °C and 2150 °C under Ar atmosphere. Physical, microstructural and mechanical properties were analysed and correlated with TiB2 and Al additions and sintering temperature. Addition of Al to B4C–TiB2 results in increased shrinkage upon sintering and final relative density and lower porosity, the effect is being more evident when both Al and TiB2 are present. Fracture strength, elastic modulus and fracture toughness of 450 MPa, 500 GPa and 6.2 MPa.m1/2, respectively were measured.