Corrosion resistance of Ti-6Al-4V alloy after diverse surface treatments

Results of the influence of diverse initial surface treatment methods on corrosion resistance of Ti-6Al-4V ELI alloy after anodic oxidation are presented in the work. The initial surface treatment consisted of: shot peening, mechanical polishing, sandblasting and electrolytical polishing. The pre-prepared samples were divided into groups and anodized. As a result of the anodization, different colors were obtained: yellow, violet, blue and celadon. Sample preparation conditions were the same for all the groups. Pitting corrosion tests were realized with the use of the potentiodynamic method by means of recording anodic polarization curves. On the basis of the recorded curves, the characteristic values of corrosion resistance were determined. For the given variants of surface treatment, the XPS (X-ray Photoelectron Spectroscopy) method was applied in order to appoint the chemical composition of the formed layer. Before and after corrosion tests, SEM (Scanning Electron Microscopy) observations were carried out.