Electrochemical and passive characterization of a beta type Ti45Zr38Al17 cast rod in nitric acid medium

Electrochemical behavior of the recently developed beta-type Ti–38 at% Zr–17 at% Al (TZA) alloy has been studied in nitric acid medium for applications in nuclear reprocessing plant. Potentiodynamic polarization and electrochemical impedance studies revealed that the passive film formed on the TZA alloy was highly protective in nature. Mott–Schottky analysis of the passive film formed on TZA alloy showed n-type semiconducting properties. The electrochemical data confirmed the superior corrosion resistance of TZA alloy as the passive film formed exhibited better properties than that of the commercial pure Ti. XPS analyses confirmed that the stable passivity of TZA alloy in nitric acid was due to the formation of thick and protective passive layer, predominantly of ZrO2 with TiO2.

► Electrochemical studies were carried out on Ti45Zr38Al17 alloy in nitric acid, aiming for applications in nuclear fuel reprocessing plants.
► Potentiodynamic polarization and EIS results confirmed the superior corrosion resistance of Ti45Zr38Al17 alloys compared to commercial pure Ti.
► Mott–Schottky analysis of the passive film showed n-type semiconducting properties with a donor density in the order of 1020 cm−3.
► XPS analyses indicated that the origin of passivity of Ti45Zr38Al17 alloys in nitric acid is due to a thick ZrO2-based passive layer mixed with TiO2.