소수성 코팅 및 오일 침지 방법을 이용한 AZ31B 마그네슘 합금의 내식성 향상

Abstract

Magnesium and its alloys have very low reduction potential and are prone to corrosion, so surface treatment to improve corrosion resistance is essential for practical applications. Plasma Electrolytic Oxidation(PEO) treatment, one of the surface treatments of magnesium alloys, forms a stable oxide on the surface using the hot discharge phenomena produced by applying high voltage/current within the electrolyte. The oxide film is responsible for preventing direct contact between magnesium alloy and corrosive materials. However, Pores and cracks in the oxide layer produced during the discharge process and hydrophilicity of oxide film give magnesium alloy insufficient corrosion resistance, so additional surface treatments are required. In this study, we applied hydrophobic coating and oil-impregnation to plasma electrolytic oxidation of magnesium alloy. Simple hydrophobic treatment could improve the hydrophobicity and corrosion resistance of PEO treated magnesium alloy. By inhibiting the penetration of corrosive materials through oil-impregnation, it can not only indicate high corrosion resistance but also indicate durability in corrosive solutions.