Effect of Nickel as Catalyst on the Activation of Titanium Hydride (TiH2) to Titanium Trichloride (TiCl3)

Abstract

Abstract Titanium hydride (TiH2) uses as a raw material in powder metallurgy method to produce titanium powder. The novel method was introduced to synthesize TiH2 from reaction between titanium (Ⅳ) chloride (TiCl4) and magnesium hydride (MgH2). The critical step in synthesize of TiH2 in this method, is formation of titanium (Ш) chloride (TiCl3) during reactions in the system. The reaction between synthesized TiH2 powder and excess TiCl4 gas in the system can result in the formation of TiCl3. In this study, effect of nickel (Ni) metal and ammonium chloride (NH4Cl) as catalyst was investigated on formation of TiCl3 under hydrogen atmosphere. Statistical design of experiment (DOE) method was applied to examine the effect of catalyst at various conditions. The main including factors were reaction time, temperature and amount of catalyst. It was observed that change in the amount of Ni had the most significant effect on weight loss of TiH2. The results of DOE analysis showed that maximum weight loss reached at temperature of 250 °C, 120 minutes reaction time and 0.1 molar ratio of Ni/NH4Cl. Samples were characterized with X-Ray Diffraction analysis. The results confirmed that excess amount of TiCl4 in the system led to formation of TiH2 to TiCl3, which is not favourable in production of TiH2 powder.