The Production of Ti–Mo Alloys from Mixed Oxide Precursors via the FFC Cambridge Process

Abstract

Ti–15wt%Ti–15wt% Mo alloys were produced via the electrochemical deoxidation of (Ti,Mo)O2(Ti,Mo)O2 precursors (formed by sintering TiO2TiO2 and MoO2MoO2 blended powders) in a molten CaCl2CaCl2 electrolyte at 1173 K via the Fray–Farthing–Chen (FFC) Cambridge process. The reduction of (Ti,Mo)O2(Ti,Mo)O2 was characterized by analyzing several partially reduced samples taken periodically through the deoxidation process. Fully metallic samples were retrieved after 9 h of reduction. This relatively short reduction time relative to that documented in pure TiO2TiO2 was attributed to the early formation of a conductive (Ti,Mo)O2(Ti,Mo)O2 network. TiO2TiO2 is known to reduce through its lower oxides sequentially to form Ti. However, it was found that the presence of Mo reduced the number of lower Ti oxides traversed during reduction. This was believed to be beneficial as fewer crystallographic changes take place. The slowest step in the reduction of TiO2TiO2 is known to be the deoxidation of Ti; this step was accelerated as Mo stabilized β Ti at oxygen contents approaching TiO.