Densification behavior and mechanical properties of the spark plasma sintered monolithic TiB₂ ceramics

Monolithic TiB₂ ceramics with fine-grained microstructures and good mechanical properties were synthesized by spark plasma sintering (SPS) technique under a pressure of 50MPa, with heating rate of 150°C/min, and sintering temperature ranging from 1200°C to 1800°C. Microstructures, mechanical properties, and densification behavior of the ceramics were investigated. Results indicate that TiB₂ ceramics sintered at 1800°C provide the optimal combination of dense microstructure and excellent properties, including the relative density of 97.6%, the microhardness of 29.6±2.5GPa, the flexural strength of 538±45MPa, and the fracture toughness of 5.2±0.4MPam^1/2. The dense microstructure is the main factor to improve the mechanical properties of the TiB₂ ceramics synthesized by SPS process.