MgO-assisted deoxygenation enabling the production of low-oxygen TiH2 powder

The production of low-oxygen fine titanium powder is crucial for powder metallurgy but remains challenging due to severe sintering during high-temperature deoxidation. In this study, we address this issue by introducing MgO as a novel dispersant in the hydrogen-assisted magnesium reduction (HAMR) process for deoxidizing fine TiH 2 powder. The effects of MgO addition on the oxygen content, powder morphology, and chemical state were systematically investigated. The results demonstrate that MgO effectively inhibits particle agglomeration and sintering by forming nanoscale inert barriers between TiH 2 particles. Consequently, well-dispersed deoxidized powder was obtained. The oxygen content of the deoxidized powder exhibits a non-monotonic dependence on MgO addition, initially decreasing and then increasing. Surface chemistry analysis reveals the partial reduction of the native oxide film, with a shift of Ti species from higher (Ti 4+ , Ti 3+ ) to lower valence states (Ti 2+ , Ti). Under optimized conditions (750°C, 9 h, mass ratios of TiH 2 :Mg:MgCl 2 :MgO = 1:0.18:0.3:0.2), fine TiH 2 powder with good dispersibility and a low oxygen content of 0.0831 wt% was successfully obtained. This work provides a practical strategy for producing low-oxygen fine titanium powder from cost-effective precursors.