Evaluation of corrosion resistance of nanotubular oxide layers on the Ti13Zr13Nb alloy in physiological saline solution

Evaluation of corrosion resistance of the self-organized nanotubular oxide layers on the Ti13Zr13Nb alloy, has been carried out in 0.9% NaCl solution at the temperature of 37°C. Anodization process of the tested alloy was conducted in a solution of 1M (NH4)2SO4 with the addition of 1 wt.% NH4F. The self-organized nanotubular oxide layers were obtained at the voltage of 20 V for the anodization time of 120 min. Investigations of surface morphology by scanning transmission electron microscopy (STem) revealed that as a result of the anodization under proposed conditions, the single-walled nanotubes (SwNTs) can be formed of diameters that range from 10 to 32 nm. Corrosion resistance studies of the obtained nanotubular oxide layers and pure Ti13Zr13Nb alloy were carried out using open circuit potential, anodic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. It was found that surface modification by electrochemical formation of the selforganized nanotubular oxide layers increases the corrosion resistance of the Ti13Zr13Nb alloy in comparison with pure alloy.