Surface treatment to improve corrosion resistance of pure titanium

The corrosion behavior of pure titanium UNS R50250 and UNS R50400 were investigated and compared with electrochemical behavior of Ti-0.2Pd and Ti-0.3Mo-0.8Ni alloys (UNS R52400 and UNS R53400 respectively). Surface treatments, especially anodic oxidations, were conducted in order to enhance the corrosion resistance of pure titanium up to the corrosion resistance of titanium alloys one. Samples were then tested with potentiodynamic analyses in chloride and fluoride containing solutions, in order to find critical pitting potentials for each condition and treatment. The results show that, despite all anodization treatments increased titanium corrosion resistance to different extents, no treatment was able to increase it up to UNS R52400 level. A suggestion on the best anodization procedure to increase corrosion resistance while maintaining ease of treatment is given based on potentiodynamic test results.