Photo-electrochemical investigation of anodic oxide films on cast Ti–Mo alloys. I. Anodic behaviour and effect of alloy composition

2009

Abstract The anodic behaviour of cast Ti–Mo alloys, having different Mo contents (6–20 wt.%), was investigated in acidic and neutral aerated aqueous solutions. All sample showed a valve-metal behaviour, owing to formation and thickening of barrier-type anodic oxides displaying interference colours. Growth kinetics of passive films is influenced by both anodizing electrolyte and composition of the starting alloy. This last parameter was found to change also the solid-state properties of the films, explored by photoelectrochemical and impedance spectroscopy experiments. Thicker films ( U f  = 8 V/MSE) grown on alloys richer in Mo showed more resistive character and a photocurrent sign inversi…