Hydrophobic epoxy resin coating with ionic liquid conversion pretreatment on magnesium alloy for promoting corrosion resistance

Liting Guo^1,2，Changdong Gu^1,2，Jie Feng³，Jiangping Tu^1,2

1. School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University2. Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province3. College of Materials Science & Engineering, Zhejiang University of Technology

摘 要：A hydrophobic epoxy resin coating with an environmental-friendly deep eutectic solvent（DES）-based conversion pretreatment was proposed to enhance the corrosion resistance of magnesium alloys. The hydrophobic epoxy resin coatings on the AZ31B magnesium alloy with and without the DES-based conversion pretreatment were thoroughly compared. It is found that the DES-based conversion film on the AZ31B magnesium alloy is mainly composed of MgH₂, MgO and MgCO₃. Furthermore, the conversion film possesses porous structure, which provides more anchor points for the following epoxy resin coating.However, without the DES-conversion pretreatment, the epoxy resin is difficult to be attached on the substrate during the dip-coating process. The double layered hybrid coating system promotes the corrosion resistance of the magnesium alloys significantly, which can be ascribed to the unique architecture and component including the hydrophobicity of the surface layer, the dense and interlocked epoxy resin,and the corrosion resistant DES-based conversion pretreatment.

关键词：