Titanium powder prepared by a rapid exothermic reaction

In this paper, a combustion process (CS) to produce titanium powder from titanium oxide and magnesium exothermic mixture (TiO2 + Mg) was developed successfully. The precursor material (TiO2) mixed with variable amounts of reducing reagent (Mg), were charged into a metallic cup, and a self-sustaining combustion was initiated by an electrically heated metallic wire, in an argon atmosphere. Depending on the reaction parameters (magnesium concentration, inert gas pressure and sample diameter) the thermocouples registered temperature between 1200 and 1750 °C. The slightly sintered solid, consisted of MgO, Mg and Ti phases, were obtained after the combustion reaction, and titanium powder was recovered by leaching the combustion product with acid. The size of Ti particles was controlled by Mg concentration: at 2.0 ≤ α ≤ 3.0 (here α is mole number of Mg) titanium particles between 1 and 5 μm were obtained, whereas homogenous fine powder with a particle size less than 1 μm was synthesized from 3.5 to 4.0 mol Mg containing mixture. Depending on the synthesis conditions the amount of oxygen in purified titanium powder was 2.0–7.6 wt%.