Pitting corrosion on anodized titanium: Effect of halides

Titanium corrosion resistance is high in the majority of environments. However, titanium is susceptible to different forms of corrosion, if exposed to high concentrated halides containing solutions. To face this corrosion problem, expensive titanium alloys are used. An alternative method, consisting of electrochemical anodizing treatment, which promote the formation of a compact titanium oxide on the surface, could be applied to increase titanium corrosion resistance. In this work, titanium samples anodized at 20V in H2SO4 0.5M have been tested in sodium fluorides, chlorides, bromides, and iodides at 0.5 and 2.0M in order to define halides aggressiveness.