Mechano-chemical synthesis of stoichiometric titanium nitride powder for cutting tool applications

Abstract Non-oxide titanium nitride (TiN) powder for cutting tool applications was pyrometallurgically synthesized via the carbo-nitridation reduction process by direct reduction of low-grade ilmenite in a nitrogen-controlled atmosphere. Mechanical activation, through which particle size reduction in the as-mixed samples was achieved, yielded the desired results. In order to monitor the reaction kinetics and observe the rate of weight loss of the reacting species, thermal analysis was conducted on the as-mixed samples. The reduction product, which contains iron (Fe) and titanium nitride (TiN), was leached in a hydrochloric acid solution. The as-leached powder (pure TiN) obtained after the acid treatment was characterized using XRD and FESEM. The results of the XRD and FESEM analyses show that the synthesized powder after the acid treatment contains a stoichiometric TiN of 4.249Å lattice parameter. No significant presence of other impurities was observed in the EDX result except a negligible trace of carbon, which can be advantageous in cutting tools for tribological purposes. The overall result shows that the synthesised TiN powder compares favourably with the known commercially available TiN powders.