Self-propagating high temperature combustion synthesis of TiC/TiB2 ceramic–matrix composites

TiC/TiB2 ceramic–matrix composites were produced by self-propagating high temperature combustion syntheses combined with pseudo hot isostatic pressing using Ti, B4C and carbon powder. The results of XRD and SEM analysis showed that the final product was pure and no unreacted B4C, Ti or carbon appeared. The microstructure of synthesized products consisted of the clubbed TiB2 grains and equiaxed or irregular TiC grains. The optimal ratio with Ti:B4C=3:1 of the reactant powder was determined by experiments. The maximum relative density, hardness value, compression strength and bending strength was attained for TiC–2TiB2 ceramic when the delay time is 5 s, keeping pressure time is 5 s and the pressure is 160 MPa, which is higher than TiC–TiB2 and 2TiC–TiB2 ceramics. The introduction of more clubbed TiB2 grains into TiC/TiB2 ceramics resulted in a drastic increase in the fracture toughness for TiC–2TiB2 synthesized compacts.