Effect of phase composition on the corrosion behavior of Ti-xMo alloy films

The corrosion behavior of Ti-xMo alloy films was investigated by preparing a series of Ti-xMo (x = 0, 4, 11, 20 wt%) alloy films using non-equilibrium magnetron sputtering ion plating technology. XRD and TEM results show that these films have obvious phase composition, which are single α phase, α + β phase and single β phase, respectively. The composition of passivation film of alloy thin films is analyzed by XPS analysis method. The passivation film can be divided into inner passivation film and outer passivation film. The corrosion behavior of Ti-xMo alloy films in a 3.5 wt% NaCl solution was investigated through the electrochemical impedance spectroscopy (EIS). The findings suggest that the corrosion resistance of Ti-xMo alloy films is not only influenced by the Mo content but also governed by the composition of phases. Due to the absence of α/β interfaces in its structure and higher Mo content, the Ti20Mo alloy film with a single β phase exhibits superior corrosion resistance compared to Pure-Ti film with a single α phase and Ti4Mo and Ti-11 alloy films with an α + β phase.