Preparation of TiB2-SiC composites toughened with interlocking microstructure by self-assembled TiB2 plates

The spark plasma sintering (SPS) technique was found to effectively improve the mechanical properties of TiB2-SiC ceramic by forming a unique interlocking structure. This study investigated the phase transition process of the hexagonal micro-platelets TiB2 powders with self-assembled structure during the molten-salt-mediated carbothermal reduction and its effect on promoting the mechanical properties of TiB2-based ceramics. It was found that the SPS approach ensured a highly densified TiB2-SiC ceramics with enhanced Vickers hardness of 21.0±1.3 GPa and fracture resistance of 7.8±0.3 MPa.m1/2. The performance enhancement of the resultant TiB2-SiC composite was attributed to the interlocking structure from the original anisotropic TiB2 powders, which could effectively absorb the energy and facilitate the crack deflection.