Synthesis and mechanism of TiB2–TiN ceramic composites by high-pressure method.

Using pure Ti and hexagonal-BN powder as raw materials, TiB 2 –TiN ceramic composites were synthesized by high-pressure method at 5.0 GPa and 1400–1800 °C. The phase composition, microstructure, density and hardness of TiB 2 –TiN ceramic composites were analyzed. The results shown that when the pressure was constant, the synthesis temperature had an important effect on the phase composition of the samples. When TiB 2 –TiN ceramic composites synthesized at 1800 °C for 30 min, the relative density reached 96.2% and the maximum Vickers hardness reached 17.9 GPa with the load of 4.9 N. The grain size of the TiB 2 –TiN ceramic composites changed with the change of synthesis temperature, which resulted in the change of density and hardness. [ABSTRACT FROM AUTHOR]