Influence of nitrogen vacancy defects incorporation on densification behaviour of spark plasma sintered non-stoichiometric TiN 1−x

Highly nitrogen deficient non-stoichiometric TiN_1−x powders within nitrogen vacancy defects (0.3<1−x<0.5) were prepared through mechanical alloying and consolidated through spark plasma sintering. Increasing nitrogen vacancy defects promoted densification behaviour of TiN_1−x. Nitrogen vacancies accelerated material transport and diffusion during sintering. The altered strong covalent bonding nature of TiN_1−x was believed to enhance the sinterability. TiN_1−x (1−x = 0.32) ceramic reached relative density of 98.8%, Vickers hardness of 17.0 GPa and grain size of 200–300 nm after sintering at 1000°C, 40 MPa and 10 min.