Nanostructured TiN powder prepared via an integrated mechanical and thermal activation

A new process for large-scale production of nanostructured TiN powder is described in this paper. In this process TiO2 and graphite are used as the starting materials and the carbothermic reduction and the simultaneous nitriding reaction are enhanced by high-energy milling prior to the reactions. The product from this process is nanostructured TiN powder. It is found that under the same nitridation condition, 100% TiN is formed for TiO2 and graphite powder mixtures with high-energy milling, whereas no TiN is obtained for powder mixtures without milling. Furthermore, more TiN is formed as the time of high-energy milling increases. The enhanced carbothermic reduction and nitridation process have been related to the reduced crystallite size, large grain boundary area, large specific surface area; presence of amorphous phases and the increased defect concentration in the powder mixture introduced by high-energy milling. (C) 2000 Elsevier Science S.A. All rights reserved.