Thermodynamic Investigation of Titanium Hydride Formation from Reduction of Titanium (Ⅳ) Chloride with Magnesium Hydride in Presence of Hydrogen Atmosphere

Abstract

Thermodynamic assessment and experimental investigation for formation of titanium hydride (TiH2) from reduction of titanium tetrachloride (TiCl4) with magnesium hydride (MgH2) were carried out under hydrogen atmosphere. In this method, TiH2 production at low temperature was investigated, which can be used for further dehydrogenation process in titanium powder metallurgy. The effects of temperature, time, amount of titanium trifluoride (TiF3) as catalyst, and ball milling time of MgH2 on reduction process were evaluated. The range of each parameters were set to 250-350°C for temperature, 2-4 hr for reaction time, 4-10 wt% for TiF3, and 1-2 hr for ball milling time. The phase transformations after reduction process were studied by X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analyziz. The morphology of powders was analyzed by scanning electron microscope (SEM). The results showed that titanium trichloride (TiCl3) was formed as major product in experiments for the above conditions. However, with increasing the reaction time above 10hr, characterization study of the final products confirmed the formation of TiH2 as major product. Our findings indicated that producing of TiH2 from reduction of TiCl4 with MgH2 at low temperature was feasible and could lead to low cost synthesis method for TiH2 for titanium powder production.