Preparation of highly-dense TiB2 ceramic with excellent mechanical properties by spark plasma sintering using hexagonal TiB2 plates

Highly-dense TiB2 ceramic with excellent mechanical properties including Vickers hardness of 24.2 GPa and fracture toughness of 7.3 MPa.m1/2 is fabricated by spark plasma sintering of hexagonal TiB2 plates. Compared with the commercial TiB2 powder, the TiB2 plate is verified to have satisfying sinterability as well as the potential in promoting the mechanical properties of TiB2 ceramics. The graphite and boron-rich carbide formed in situ at the grain boundary of TiB2, which has remarkable effects on promoting the stress releases in the crack tip and enhancing the resistance to crack propagation.