Electrochemical Characteristics of Titanium and its Alloys

The electrochemical behavior of beta titanium alloy, Ti-12Mo-6Zr-2Fe alloy has been characterized in phosphate buffer saline solution at the physiological temperature and the results have been compared with that of commercially pure titanium (grade 1-alpha) and Ti-6Al-4V (alpha & beta). The impedance data for the alloys was found to fit a two-time constant circuit model. The alloys are attacked by chloride ions from PBS solution, but eventually they are able to reconstruct the depleted oxide layer. In the passivation range, the alloys show a marked increase in the barrier resistance, confirmed from EIS results, but at further higher overpotentials, the barrier layer becomes defective, resulting in a decrease in the barrier layer resistance values. The corrosion potentials of the reverse scan curves for the alloys are anodic to the corrosion potentials of the forward scan curves, which signifies a high pitting corrosion resistance of these alloys.