Synthesis and Characterization of TiB₂–SiC Ceramic Composite Produced Through Spark Plasma Sintering

The ceramic matrix is quite rigid and strong, but its fracture toughness has to be increased in order to fully realize its potential possibilities. This difficulty can be resolved by developing ceramic matrix composites (CMCs). CMCs have been processed to realize quasi-ductile fracture behavior and advantages of monolithic ceramics at high temperature. From different CMCs, TiB₂–SiC CMC is used in automotive brakes, cutting tools, propulsion engine exhaust, etc. In the present study, TiB₂–SiC CMCs with varying SiC particle reinforcement of 0, 5, 10, 15 vol.% were synthesized using powder metallurgy (P/M) consolidation method with the help of spark plasma sintering (SPS) furnace at IIT, Madras. Raw materials particles sizes are TiB₂ (average size of 14 µm-matrix) and SiC (average size of 1 µm-reinforcement). SPS process parameters used were sintering temperature 1450 °C, 40 MPa pressure with 10 min as hold off time. Microstructural analysis was carried out using scanning electron microscope (SEM) to observe the homogeneous distribution of reinforcement over the matrix. From the characterization studies, the CMC specimen with 15% SiC gave a good fracture toughness of 6.3 MPa√m and vickers hardness of 22.1 GPa.