Calcium hydride synthesis of Ti–Nb-based alloy powders

Abstract

The metallothermic (calcium hydride) synthesis of Ti–Nb alloy powders alloyed with tantalum and zirconium is experimentally studied under various conditions. Chemical, X-ray diffraction, and metallographic analyses of the synthesized products show that initial oxides are completely reduced and a homogeneous β-Ti-based alloy powder forms under the optimum synthesis conditions at a temperature of 1200°C. At a lower synthesis temperature, the end products have a high oxygen content. The experimental results are used to plot the thermokinetic dependences o formation of a bcc solid solution at various times of isothermal holding of Ti–22Nb–6Ta and Ti–22Nb–6Zr (at %) alloys. The physicochemical and technological properties of the Ti–22Nb–6Ta and Ti–22Nb–6Zr alloy powders synthesized by calcium hydride reduction under the optimum conditions are determined.