Preparation of Titanium Nitride: Microwave‐Induced Carbothermal Reaction of Titanium Dioxide

Abstract

Carbothermal reduction and nitridation of TiO 2 was performed in a 2 kW, 2.45 GHz microwave furnace. Carbon, generally added for the removal of oxygen from TiO 2 lattice also served as the low‐temperature susceptor in these experiments. At temperatures >1200°C, the mixtures started reacting vigorously (self‐burn), which was never observed with the respective pure compounds. In the self‐burning state, the minimum duration required for complete titanium nitride transformation was ∼20 min with stoichiometric amounts of carbon. With excess C, the transformation duration dropped to just 1 min. CO removal and subsequent Ni fixation occur more directly in microwave‐induced reactions than in conventional nitridation procedures. Intermediate formation of successive Magneli phases (Ti 2 n O 2 n −1 ) was not found in the microwave‐induced reactions. The combination of microwave processing and combustion makes this route of economical interest.