Corrosion resistance of tartaric-sulfuric acid anodized AA2024-T3 sealed with Ce and protected with hybrid sol–gel coating

Abstract

2024 aluminum alloys are widely used in the aerospace industry due to properties as lightweight, high specific strength and durability. However, they are prone to localized corrosion due to its high amount of intermetallics. A promising method to protect the exposed metal surface is to use eco-friendly alternative corrosion inhibitors in combination with a barrier coating system. In this study, a treatment in an aqueous solution with the addition of cerium ions has been proposed and its effects on the corrosion resistance of the AA2024-T3 alloy were investigated. Samples were anodized, hydrothermally treated in aqueous solutions, containing or not cerium ions at the boiling temperature and then coated with sol-gel. The effect of Ce ions in the characteristics of the surface film formed, such as morphology and corrosion resistance, was investigated by scanning electron microscopy and electrochemical impedance spectroscopy (EIS). The EIS results showed that the addition of Ce(III) ions improved the corrosion resistance of the AA 2024-T3 TSA anodized and hydrothermally treated.