Abstract The proposed work aims to improve the comprehensive properties of the composite coating by adding different content of graphene into the coating solution. Firstly, the formulation of the coating solution was determined by the L16(45) orthogonal test. Secondly, the conventional properties of the coating were tested using the optical microscope and micro-vickers hardness tester. Thirdly, the corrosion resistance of the coating was tested by the rapid ammonium nitrate corrosion test, immersion test, and neutral salt spray test. The changes of the microstructure and composition of the coating before and after corrosion were observed and analyzed using the scanning electron microscope, energy dispersive spectrometer, X-ray diffractometer, and Raman spectrometer, and the Tafel polarization curves and electrochemical impedance spectroscopy of the composite coatings with different graphene contents were tested by electrochemical experiments. The results show that the hardness of the coating increases with the increase in the content of graphene. Graphene intercalates between zinc and aluminum powders in a flaky structure, which reduces the appearance of voids and enhances the protection of chromium-free Dacromet coatings, slows down the penetration of electrolyte solutions and effectively slows down the penetration of corrosive media. The addition of a small amount of graphene can increase the corrosion potential and decrease the corrosion current density of the chromium-free Dacromet coating, the Nyquist low frequency of the coating is higher in the same period and the salt spray resistance of the coating is the best.

中文翻译：

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石墨烯增强无铬达克罗涂层综合性能测试与分析

摘要 本研究旨在通过在涂层溶液中加入不同含量的石墨烯来提高复合涂层的综合性能。首先，通过L16(45)正交试验确定包衣溶液的配方。其次，使用光学显微镜和显微维氏硬度计测试了涂层的常规性能。第三，通过快速硝酸铵腐蚀试验、浸泡试验和中性盐雾试验测试涂层的耐腐蚀性能。用扫描电子显微镜、能谱仪、X射线衍射仪和拉曼光谱仪观察和分析腐蚀前后涂层组织和成分的变化，并通过电化学实验测试了不同石墨烯含量的复合涂层的塔菲尔极化曲线和电化学阻抗谱。结果表明，涂​​层的硬度随着石墨烯含量的增加而增加。石墨烯以片状结构夹在锌粉和铝粉之间，减少了空隙的出现，增强了对无铬达克罗涂层的保护，减缓了电解质溶液的渗透，有效减缓了腐蚀介质的渗透。添加少量石墨烯可提高无铬达克罗涂层的腐蚀电位并降低腐蚀电流密度，