Single-phase W2B5 ceramic enabled remarkable performance via spark plasma sintering-high-frequency (SPS-HF) process

The preparation of dense single-phase boride ceramics has always been a challenge. In this paper, single-phase W 2 B 5 ceramic with excellent performance was successfully prepared using W 2 B 5 powder and SPS-HF technology. Under the sintering condition of 1800 °C and 50 MPa, a nearly dense W 2 B 5 ceramic material with excellent mechanical properties was obtained. The relative density of the as-sintered W 2 B 5 ceramic achieved 96.72 % without any sintering additive. Additionally, the Vickers hardness , fracture toughness as well as bending strength were 30 GPa (9.8 N), 5.39 MPa·m 1/2 and 522.7 MPa, respectively. The outstanding hardness and bending strength of W 2 B 5 ceramic could be attributed to its monophase W 2 B 5 structure and high densification degree. The primary fracture mode of W 2 B 5 ceramic was transgranular fracture , and the toughening mechanisms included crack deflection, crack bridging, and crack branching.