Effects of hydrophobic surface modification and hydrogen peroxide passivation on the corrosion behavior of aluminum

Abstract

In this study, aluminum surface with superior corrosion resistance and hydrophobic properties was prepared by simple and low cost method. Aluminum surfaces were fabricated by hydrochloric acid etching, hydrogen peroxide passivation, and stearic acid modification treatment. The hydrogen peroxide treatment increased the amount of oxygen on the oxide layer of aluminum surface and improved the corrosion resistance. A rough and hierarchical structure was formed on aluminum surface by hydrochloric acid etching, and the alkyl chain of stearic acid was chemically grafted onto the aluminum surface, which changes the hydrophilic surface to hydrophobic. The hydrophobic properties of aluminum were analyzed by measuring the water contact angle, and the results showed that the water contact angle increased significantly to 143˚compared to that of the untreated specimen. Finally, corrosion resistance of fabricated aluminum surface was analyzed by potentiodynamic test and electrochemical impedance spectroscopy in sea water condition. As a result, corrosion resistance of the aluminum modified with hydrogen peroxide and stearic acid was improved 25 times compared to untreated specimens in a sea water environment.