制备及耐腐蚀性能
(1. 华南理工大学 机械与汽车工程学院，广州 510640；
2. 华南理工大学 国家金属材料近净成形工程技术研究中心，广州 510640)
摘 要: 采用微弧氧化技术和有机镀膜技术相结合的复合处理方法实现Mg-Mn-Ce镁合金表面改性，获得超疏水复合膜层，研究微弧氧化膜的表面特征、有机镀膜电化学反应过程、复合膜层的润湿特性和耐腐蚀性能。结果表明：镁合金经微弧氧化处理后由于微弧氧化膜表面呈微纳多孔结构，表现为超亲水特性，其蒸馏水的静态接触角接近0°；在微弧氧化膜上经有机镀膜后，其形成的有机薄膜的静态接触角高达173.3°，表现出优良的超疏水特性。镁合金经微弧氧化处理后具有良好的耐腐蚀性能，经有机镀膜超疏水复合处理后，耐腐蚀性能得到进一步提高。复合膜层在3.5% NaCl溶液中，与基体相比动电位极化腐蚀电流密度减小了3个数量级、而电化学阻抗提高了3个数量级，耐腐蚀性能明显改善。微弧氧化与有机镀膜相结合的复合处理使镁合金表面在实现超亲水−超疏水功能转换的同时显著提高镁合金的耐腐蚀性能。
关键字: Mg-Mn-Ce镁合金；微弧氧化；有机镀膜；超疏水；耐腐蚀性
（1. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China;
2. National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials,
South China University of Technology, Guangzhou 510640, China）
Abstract:The super-hydrophobic duplex-treated film on the surface of Mg-Mn-Ce magnesium alloy was achieved by duplex treatment combined with techniques of micro-arc oxidation (MAO) and developed polymer plating, and its surface was modified. The surface characteristics of MAO film, electrochemical reaction process of polymer plating, wettability and corrosion behavior of duplex-treated film were investigated. The results show that the film treated by MAO on magnesium alloy surface becomes super-hydrophilic due to its micro and nano porous structure, and its static contact angle (CA) of distilled water is nearly 0°. After polymer plating on surface of MAO film with polymeric film, the character of super-hydrophobic is realized and behaves well with CA of 173.3°. The good property of corrosion resistance is obtained by MAO treatment, and the corrosion resistance is further improved after super-hydrophobic duplex treatment through polymer plating on the surface of MAO film. Compared to the corrosion resistance of bare magnesium alloy, the corrosion current density from potentiodynamic polarization measurement decreases by three orders of magnitude, and the electrochemical impedance from electrochemical impedance spectroscopy (EIS) increases by three orders of magnitude in 3.5% NaCl aqueous solution of duplex-treated film. Therefore, the duplex treatments by MAO and polymer plating on surface of the magnesium alloy are considered to realize functional transfer from super-hydrophilic to super-hydrophobic and improve its corrosion resistance greatly.
Key words: Mg-Mn-Ce magnesium alloy; micro-arc oxidation; polymer plating; super-hydrophobicity; corrosion resistance
