Microstructure and mechanical properties of B4C-TiB2-SiC composites fabricated by spark plasma sintering

Boron carbide ceramics have broad application prospects due to their excellent performance. However, their poor sinterability and low fracture toughness limit their application, especially in the field of bulletproof armor. In this work, B4C-TiB2-SiC composites were successfully prepared by spark plasma sintering (SPS) with B4C, TiB2, and SiC powder mixtures. The effects of different SiC contents on the mechanical properties and microstructure of B4C-TiB2-SiC composites were investigated. The B4C-TiB2-SiC composites with 15 wt% SiC combined a relative density of 98.43%, a fracture toughness of 4.17 MPa M-1/2, as well as Vickers hardness of 30.07 GPa. The addition of SiC can increase the toughness of B4C-TiB2 -SiC composites while maintaining high hardness. The main reason for this behavior is grain refinement of B4C and TiB2 due to the pinning effect of the SiC phase.