Fushimi K.,Hokkaido University |
Kurauchi K.,Hokkaido Universityp |
Ikeyama H.,Hokkaido Universityp |
Kitagawa Y.,Hokkaido University |
And 4 more authors.
Journal of Solid State Electrochemistry | Year: 2015
Photo-corrosion of an anodized titanium surface in 0.05 mol dm−3 sulfuric acid solution was investigated by using an in situ electrochemical ellipso-microscope. Irradiation of ultra-violet (UV) light on an anodized surface, which showed a patch-like bright image on an ellipso-microscopic view due to non-uniform growth of the oxide film, under potentiostatic polarization allowed the flow of a photo-induced anodic current and changed the brightness and patch pattern in the image. This indicates that the irradiation promotes photo-electrochemical reaction, resulting in a change in the thickness and/or structure of the oxide film on the surface. The film change was dependent not only on power density of the irradiation light but also on applied potential during the irradiation and crystallographic orientation of the substrate. Pitting initiation during potentiodynamic polarization in the acid with bromide ions was also monitored using the ellipso-microscope. The irradiation resulted in pitting initiation at lower potentials than those in a non-irradiated condition. © 2015, Springer-Verlag Berlin Heidelberg.