Corrosion performance and surface analysis of Ti-Ni-Pd-Ru-Cr alloy in nitric acid solution

The corrosion resistance of Ti-0.4Ni-0.015Pd-0.025Ru-0.14Cr (AKOT Ti) and commercially pure titanium (CP Ti) has been studied in different concentrations of 6, 9 and 11.5 M HNO3, and boiling 15.65 M In both CP Ti and AKOT Ti alloy, the open circuit potential and corrosion potential are shifted to more noble potential with increasing concentrations. However, passive current density decreases with increasing concentration. Lower corrosion rate was observed in AKOT Ti (similar to 0.075 mm/y) compared to CP Ti (similar to 0.22 mm/y) in boiling 15.65 M HNO3 after 240 h. The mechanisms by which dissolved titanium ions affect the corrosion are also discussed. (C) 2014 Elsevier Ltd. All rights reserved.