Corrosion Susceptibility of Passive Films on 1060, 2024, and 5083 Aluminum Alloys: Experimental Study and First-Principles Calculations

The corrosion characteristics of passive films on 1060, 2024 and 5083 aluminum alloys formed in citric acid solution are studied in Cl--containing solutions by combining scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The passive film on 1060 pure Al exhibits the best corrosion resistance while the presence of alloying elements (Cu and Mg) in the passive films reduce the corrosion resistance of the passive films on 2024 and 5083 Al alloys. According to first-principles calculations, Cu/Mg doping ?-Al2O3 surfaces are looser and more reactive than pure ?-Al2O3 (110) surface, and Cl adsorption behavior is changed in Cu/Mg doping ?-Al2O3 surfaces. This illuminates the difference of corrosion resistances of 1060, 2024 and 5083 aluminum alloys from the aspects of the passive film structure and interaction of chlorine ions with the passive films.