Corrosion resistance of silane-modified hydroxide zinc carbonate film on AZ31 magnesium alloy

Abstract

The corrosion resistance of magnesium alloys can be improved using functional surface modification such as hydrophobic treatment. In this study, a hierarchical hydroxide zinc carbonate (HZC) film was fabricated on AZ31 magnesium alloy via a simple chemical-bath deposition process using urea aqueous solution. The morphologies, compositions and corrosion resistance of the hydrophobic film were analyzed using scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectrometer, and electrochemical measurements as well. The results revealed that the HZC film displayed flower-like protrusions and had a thickness of approximately 100 um. The fluoroalkylsilane (FAS)-modified HZC film exhibited a hydrophobic property with a water contact angle of 131.3°. The FAS/HZC film significantly improved the corrosion resistance of the AZ31 alloy due to hierarchical structures and hydrophobic modification.