AZ91表面阴极电沉积超疏水涂层的构建及其腐蚀行为研究

Poor corrosion resistance of magnesium alloys restricts their application. A novel idea of the design of coating system on AZ91 is advanced, and this surface protection layer exhibits both super-hydrophobicity and corrosion self-healing property. The super-hydrophobic coating was fabricated by one-step cathodic deposition. The adjustment and control of the microstructure and composition of the coating will be achieved, and the introducing of corrosion-inhibition ions of cerium into the coating which will contribute to the great improvement of the corrosion resistance of AZ91. The microstructure of coatings, both with cerium ions introducing and without theintroducing, will be studied in detail. The effect of composition of the electrolyte on the formation of the coating will be also studied. The role played by the metal ions and the organic alkyl acids will be revealed and the interaction between the metal ions and the organic alkyl acids will be also illuminated. The microstructure evolution and the corrosion behavior of the coatings will be investigated. The factors induced the corrosion fatigue of the coatings will be explored. Both the relationship between the microstructure and the corrosion performance and the corrosion mechanism of the super-hydrophobic coating will be revealed. Finally an idea and theory will be provided for the development new type of corrosion-resistant coating system.

针对镁合金在应用中耐蚀性差的瓶颈问题，本项目以广泛应用的AZ91为研究对象，提出获得兼具超疏水性及腐蚀自修复能力的表面涂层设计思路。相对于传统多步法工艺，本项目利用阴极电沉积方法实现了在AZ91表面单步构建微米/纳米尺度上分等级结构的超疏水涂层。通过改变电沉积工艺对镁表面涂层组织结构的调整与控制，并通过向涂层中引入具有缓蚀作用的铈离子进而大幅度提高镁的耐腐蚀性能。深入系统地研究AZ91表面超疏水涂层（有无添加铈离子）的微观组织结构，掌握电沉积溶液中金属阳离子及有机酸种类对超疏水涂层形成的影响规律，揭示涂层形成过程中金属阳离子与有机酸根离子的作用本质及铈离子对涂层组织结构与疏水性的影响。研究涂覆镁合金在NaCl溶液中的组织演化与腐蚀行为，建立涂层微观组织结构与腐蚀性能之间的内在联系，阐明超疏水涂层的腐蚀机制，为镁合金表面新型耐蚀涂层体系的开发提供设计思路和理论依据。

针对镁合金在应用中耐蚀性差的瓶颈问题，本项目以广泛应用的镁合金为研究对象，提出获得兼具超疏水性及腐蚀自修复能力的表面涂层设计思路，采用阴极电沉积方法在其表面构建超疏水涂层，主要关注预处理工艺、稀土离子添加对涂层微观组织结构以及腐蚀行为的影响规律。与传统多步法工艺相比，本项目利用阴极电沉积方法实现了在镁合金表面单步构建微米/纳米尺度上分等级结构的超疏水涂层。通过改变电沉积工艺对镁表面涂层组织结构的调整与控制，并通过向涂层中引入具有缓蚀作用的铈离子进而显著提高镁的耐腐蚀性能。深入系统地研究AZ91表面超疏水涂层（有无添加铈离子）的微观组织结构，掌握电沉积溶液中金属阳离子及有机酸种类对超疏水涂层形成的影响规律，揭示涂层形成过程中金属阳离子与有机酸根离子的作用本质及铈离子对涂层组织结构与疏水性的影响。研究涂覆镁合金在NaCl溶液和模拟体液中的组织演化与腐蚀行为，建立涂层微观组织结构与耐腐蚀性能间的内在联系，阐明超疏水涂层的腐蚀机制，为镁合金表面新型耐蚀涂层体系的开发提供设计思路和理论依据。