Passivity study of titanium alloy TA2 in simulated seawater solution
Xiaojia Yang, Xuan Li, Zhiyong Liu, Cuiwei Du, Qian Wang, Xiaogang Li
Abstract
In the present work, we introduced a novel way to study the Tafel slope of titanium in passive state based on potentiodynamic test with a break by potentiostatic polarization. The power law model as well as surface analysis methods such as AES and XPS were also introduced to character the thickness and composition of the film. Results indicate that the Tafel slope of titanium electrode in the passive state increases with the applied overpotential. The anodizing constant is found to be equal to about 0.24∼0.46 Å/s and 4∼10 Å/V. The results showing highly consistent with AES and XPS results. The passive film are mainly composed of TiO2 predominantly outer layer, and titanium sub-oxide, Ti(OH)x predominantly inner layer.