Preparation of low-oxygen-containing Ti-48Al-2Cr-2Nb alloy powder by direct reduction of oxides
(School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract: A high-purity Ti-48Al-2Nb-2Cr alloy powder with an oxygen content as low as 0.0572 wt.% and a particle size of <150 μm was produced from a mixture of TiO2, Al2O3, Nb2O5, and Cr2O3 powders through reduction with magnesium and deoxidation with calcium. The phase and composition of the products were analyzed. The final product mainly included γ-TiAl and minor α2-Ti3Al phases, and Ti, Al, Cr, and Nb were homogenously distributed in the powder with a mole ratio of 49.73:43.51:2.05:1.98. The reduction and deoxidation mechanisms were investigated by thermodynamic modeling using the HSC Chemistry software and Pandat software based on the Ti alloy database.
Key words: titanium aluminide; powder; reduction; oxide