Effect of a Kind of Metal Cation on Corrosion Mechanism of A3003 Aluminum Alloy in Tap Water

Abstract

Effect of a kind of metal cation on corrosion mechanism of A3003 aluminum alloy in tap water was investigated by electrochemical techniques and immersion corrosion tests. Corrosion rate of the aluminum alloy decreased with increase in a hardness of cation, except for Mg2+. XPS analyses showed metal cations, classified as a hard acid in tap water were incorporated in hydroxides on the aluminum alloy. The results suggest that the incorporated cations have corrosion inhibitory effect (e.g., Ca2+ and Zn2+) or corrosion promotive effect (e.g., Mg2+). These different effects can be explained by difference in molar volume between hard metal cation's hydroxide and aluminum hydroxide.