Article ID: MA201808
Alloy of composition Ti–5Ta–2Nb (numbers in mass%) was synthesised directly from the corresponding mixed metal oxides via the FFC-Cambridge process. Compacted powder discs of TiO2–Ta2O5–Nb2O5 were cathodically polarised against a graphite anode in a molten CaCl2 electrolyte, and the effect of various process parameters on the synthesis of the alloy was investigated. The samples retained their disc-type shape throughout the oxide-to-metal conversion under appropriate processing conditions. XRD analysis showed that the electrochemically prepared alloy existed as single-phase α-Ti and changed into dual-phase (α+β)-Ti upon heat treatment. SEM/EDX analysis revealed a nodular porous microstructure and confirmed the intended chemical composition. Backscattered SEM analysis after heat treatment provided direct evidence of micron-sized β-phase precipitates at the boundaries of the α-phase particles. Microhardness of the heat-treated alloy compared well with literature data for the same material prepared by conventional metallurgical methods. Overall, the study has demonstrated the feasibility of the single-step electrochemical fabrication of Ti–5Ta–2Nb alloy bodies directly from oxides for structural application.