The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries. The conventional epoxy coating easily forms many intrinsic defects during the solidification process, which cannot provide sufficient protection. In the current study, we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties, via the spin-assisted assembly technique. The outer layer is functionalized graphene (FG) in waterborne epoxy resin (WEP) and the inner layer is Ce-based conversion (Ce) film. The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability. The Ce film connects the outer layer with the substrate, showing the transition effect. The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy, and the wear rate is decreased by ∼90%. The improved corrosion resistance is attributed to the labyrinth effect (hindering the penetration of corrosive medium) and the obstruction of galvanic coupling behavior. The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration, which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.

镁合金较差的耐腐蚀性和耐磨性严重限制了其在各个行业的潜在应用。传统的环氧涂层在固化过程中容易形成许多固有缺陷，不能提供足够的保护。在目前的研究中，我们通过自旋辅助组装技术在镁合金上设计了一种具有增强的抗腐蚀/磨损性能的双层环氧复合涂层。外层为水性环氧树脂 (WEP) 中的功能化石墨烯 (FG)，内层为 Ce 基转化 (Ce) 薄膜。FG 片材可以均匀地分散在环氧树脂基体中，以填补固有缺陷并提高阻隔能力。Ce薄膜将外层与基板连接起来，呈现出过渡效应。Ce/WEP/FG复合涂层的腐蚀速率比裸镁合金低2131倍，磨损率降低～90%。改进的耐腐蚀性归因于迷宫效应（阻碍腐蚀介质的渗透）和电流耦合行为的阻碍。FG片与阻挡层的协同效应在实现多功能集成化方面展现出巨大潜力，将为镁合金新型复合保护涂层的开发开辟一条新途径。