Influence of surface pre-treatment on the deposition and corrosion properties of hydrophobic coatings on a magnesium alloy

Abstract

Calcium stearate based hydrophobic coatings were deposited on pre-treated Mg alloy substrates. The influence of four different pre-treatments including plasma electrolytic oxidation (as prepared and etched), anodizing and hydrothermal treatment was studied. The results indicate that the pre-treatments have strong influences on the morphology, thickness, and wettability of the coatings, without affecting their phase composition. The coating system based on the etched plasma electrolytic oxidation pretreatment shows the best corrosion resistance in a simulated body fluid. The superior protection effect is mainly related to the differences in the morphologies and thickness of the pre-treatment layers. (C) 2016 Elsevier Ltd. All rights reserved.