Electrochemical Characterization of Intermetallic Compounds in AA2024-T3 and Localized Corrosion Morphology of Al-Cu-Mg at Elevated Temperature.

摘要

The localized corrosion behavior of Al-Cu-Mg alloy AA2024-T3 (Al-4.4Cu-2.5Mg-0.6Mn) at temperatures from 10 to 70 oC was characterized using a range of experimental techniques and approaches. Foremost among these was a characterization of the electrochemical behavior of constituent particles present in the alloys. The range of intermetallic compound particles types found in AA2024-T3 were represented by a proxy subset of intermetallic compounds including: Al2CuMg, Al7Cu2Fe, Al20Cu2Mn3, Al2Cu. An Al 4wt.%Cu binary solid solution alloy was examined as a matrix analog. The effect of rare earth metal and vanadate corrosion inhibitors on localized corrosion behaviors was also examined. The electrochemical methods used in this work included collections of polarization curves, open circuit measurements and electrochemical impedance spectroscopy. Data from these electrochemical measurements was compared to the corrosion morphology after exposure to solutions.