Anodization treatments to increase commercially pure titanium corrosion resistance

Titanium owes its astounding corrosion resistance to a thin, compact oxide layer that is formed spontaneously when the metal is exposed to the environment. However, even titanium can be subject to corrosion in very aggressive environments. To enhance its corrosion resistance, it is possible to exploit the same mechanism that leads to the formation of the protective oxide layer and force its growth with an external contribution. This result can be obtained both with anodic and chemical oxidation. This study compares corrosion resistance enhancement after anodizing treatment up to 200 V with chemical oxidation in NaOH and H2O2 10M. Process variables like final anodizing voltage, chemical species used for oxidation, treatment duration and temperature, were studied to optimize the process and reach the higher corrosion resistance possible. Moreover, thermal treatment were exploited after chemical oxidation to a further increase in corrosion resistanc