Process optimization for production of ultrafine titanium carbonitride by magnesium reduction

The ultrafine titanium carbonitride particles (TiC0.7N0.3) below 100 nm in mean size were successfully synthesized by Mg-thermal reduction process. The nanostructured sub-stoichimetric titanium carbide (TiC0.7) particles were produced by the magnesium reduction at 1163 K of gaseous TiCl4 + xC(2)Cl(4) and the vacuum heat treatments were performed for five hours to remove residual magnesium and magnesium chloride mixed with TiC0.7. And final TiC0.7N0.3 phase was obtained by nitrification under normal nitrogen gas at 1373 K for 2 h. The high quality of crystal form of TiC0.7N0.3 with the purity above 99.5% and the level near 0.1 mass% oxygen, were produced. We discovered in particular that the temperature lower than 1123 K in vacuum treatment helped to produce the finer and uniform TiCN particles. (C) 2009 The Ceramic Society of Japan. All rights reserved.