Enhancement of pure titanium localized corrosion resistance by anodic oxidation

The corrosion behavior of commercially pure titanium (UNS R50400) was investigated in presence of aggressive, bromides containing, species; reported to cause severer localized corrosion compared to chlorides. To enhance localized corrosion resistance of the metal, several surface treatments were performed. Samples anodized at potentials between 10 V and 200 V were characterized in term of oxide thickness and morphology and tested with potentiodynamic analyses in NH4Br. This treatment was found to greatly enhance corrosion resistance of titanium but it suffers localized removal of the oxide due to wrong handling of the part before their installation. For this reason, another treatment, suitable for in-situ surface recovering was developed through chemical oxidation in NaOH 10 M.