A morphological and electrochemical comparison of the corrosion process of aluminum alloys under simulated acid rain conditions

The corrosion behavior of aluminum 6060 and 6082 alloys was examined by scanning electron microscopy (SEM), atomic force microscopy (AFM) and dynamic electrochemical impedance spectroscopy (DEIS) after exposure to simulated acid rain for 1, 5, 24 and 48 h. The electrochemical parameters obtained from DEIS were compared with the AFM and SEM studies. Results showed that DEIS is a sensitive technique detecting even very moderate changes in charge -transfer resistance (R-ct); it exhibits a very good correlation with surface morphological changes in relation to exposure time. This research also demonstrated the importance of performing corrosion measurements after a longer time period. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.