Low-oxygen Ti-6Al-4V alloy powder synthesized by an aluminothermic reduction combined with deoxidation process.

A novel aluminothermic reduction combined with deoxidation process was developed in this research to prepare low-oxygen Ti-6Al-4V alloy powder. First, with Al and Al-V alloy powders as reducing agents and additives, crude Ti-6Al-4V alloy powder was fabricated by reduction-vacuum distillation using Na 2 TiF 6 as a titanium source. The aluminothermic reduction process was investigated by TG-DSC technique, and the thermal kinetic parameters of the reaction process were calculated by the Kissinger method. The oxygen content of the crude Ti-6Al-4V alloy powder with a coral-like porous structure was detected as 0.366 %. Furthermore, the existential states of the oxygen contained in the crude product powder was analyzed using XPS. The results indicated that the oxygen existed in three chemical states: metal oxides, defective oxygen, and adsorbed oxygen. Therefore, the deoxygenation of the crude Ti-6Al-4V alloy powder with calcium as a deoxidizer was carried out at 900 °C. As a result, the final Ti-6Al-4V powder with an oxygen content of approximately 822 ppm could be obtained. The contents of Ti, Al, V, Fe, and O in the obtained Ti-6Al-4V powders met the requirements of GB/T 3620.1−2016. This work had demonstrated the feasibility of preparing Ti-6Al-4V alloy powder by the novel aluminothermic reduction combined with deoxidation process. • Low-oxygen Ti-6Al-4V powder was prepared from metallurgical-grade materials by a short process with non-pollution. • Mechanism and kinetic analysis of the rapid exothermic reduction process were preliminary investigated. • The oxygen content in the final Ti-6Al-4V powder can be as low as 822 ppm. • A short process for preparing of low-oxygen Ti-6Al-4V powder was proved to be feasible. [ABSTRACT FROM AUTHOR]