Preparation of fine titanium nitride powders

In order to find out the reaction processes and a series of morphology for the titanium nitride powders obtained from the vapor phase reaction of TiCl4 and NH3, experiments have been carried out in the temperature range between 200 deg C and 1200 deg C and under the pressure of atmosphere and 4.9 KPa. The reaction products and thermally decomposed powders obtained at various temperatures under the pressure of atmosphere and 4.9 KPa have been investigated by means of X-ray diffraction, TGA and electron microscopy. In the vapor phase reaction, TiNCl started forming at about 350 deg C, and TiN did at about 500 deg C. On the other hand, in the thermal decomposition reaction of the products obtained at about 200 deg C, TiN started forming at about 450 deg C either under the ammonia or the argon gas flow. Under atmospheric pressure the titanium powder of approximate particle size 0.05 μm was obtained at 1200 deg C from the vapor phase reaction, whereas 0.02 μm or less titanium nitride powder was obtained at the same temperature under the pressure of 4.9 KPa. (Author)