Effects of TiC content on the microstructure and properties of B4C–TiB2–graphite composites by reactive hot pressing

B 4 C–TiB 2 –graphite ceramic composites were fabricated via reactive hot pressing using B 4 C and TiC as the raw materials. With an increase in the TiC content, the grain size of B 4 C decreased continuously because B 4 C grain growth was inhibited by the TiB 2 and C reaction products. However, excessive TiC content caused an increase in TiB 2 and graphite grain size and the formation of TiB 2 –graphite agglomerates. When the composition of the ceramic composite was 95.1 wt%B 4 C–3.9 wt%TiB 2 –1.0 wt%graphite, the Vickers hardness and bending strength was optimized at 34.9 GPa and 688 MPa, respectively. The results showed that crack deflection is the main toughening mechanism of B 4 C–TiB 2 –graphite ceramic composites, and the effect of TiB 2 –graphite on crack propagation is particularly significant. When the composition of the ceramic composite was 75.6 wt%B 4 C–19.4 wt%TiB 2 –5.0 wt%graphite, the fracture toughness was optimized at 6.77 MPa·m 1/2 . These results provide guidelines on how to effectively control the combined properties of B 4 C–TiB 2 –graphite ceramic composites in future investigations.