Preparation of Titanium-Chromium Nitride by Gas Nitriding of the Explosion Products of Cr-Coated Ti Wire

Abstract

Titanium-chromium nitride nanopowders were prepared by the electrical explosion of the Cr-coated Ti wires in argon and nitrogen gases and subsequent nitriding treatments. The explosion product of the Cr-coated Ti wire in argon gas consisted of α-Ti, TiCr₂ and Ti-rich β phases. They transformed into single phase (Ti,Cr)N by the nitriding treatment at 1100°C. On the other hand, the explosion product of Cr-coated Ti wire in nitrogen gas consisted of TiN, Cr₂N, and a few nanometer-sized (Ti,Cr)N particles. The particles transformed into the mixture of TiN and (Ti,Cr)N by the nitriding treatment at 1100°C. In this case, the pre-existing TiN in the explosion product was stable during nitriding and remained intact to coexist with newly-formed (Ti,Cr)N. The (Ti,Cr)N particles prepared by nitriding of the explosion product of Cr-coated Ti wire in nitrogen gas had 34.21 at% Ti, which was somewhat lower than 41.27 at% Ti of the (Ti,Cr)N produced by nitriding of the explosion product of Cr-coated Ti wire in argon gas. This is probably because high thermal stability of the pre-existing TiN in the explosion product of Cr-coated Ti wire in nitrogen gas creates a local titanium deficiency in the formation of (Ti,Cr)N particles.