Effective PEO/Silane pretreatment of epoxy coating applied on AZ31B Mg alloy for corrosion protection

In this study, a PEO/Silane/Epoxy three-layer coating was introduced as an effective protection system for the preservation of Mg alloy. Cerium nitrate was used as an inhibitor in the (plasma electrolytic oxidation) PEO coating structure and was coated with a silane layer containing various volume ratios of tetraethoxysilane (TEOS) and gamma-amino propyltriethoxysilane (APTES). Electrochemical impedance spectroscopy (EIS) and adhesion tests were performed on three-layer coating samples. Protective properties of PEO coating as well as PEO/ Epoxy coating was improved by applying the silane film as the interfacial layer, with the T50/A50 saline film showing the best protective performance.