Abstract Improvement of corrosion resistance is one of the main goals in developing plasma electrolytic oxidation (PEO) ceramic coatings on AZ31 magnesium alloys. In this study, ceramic coatings were deposited on AZ31 magnesium alloys by PEO technique in electrolytes containing 10 g/l sodium phosphate (Na3PO4) and 1.5 g/l sodium hydroxide (NaOH) at different concentrations of ZnO nanoparticles and current density of 7.1 A/dm2 for 10 min. To investigate the corrosion behavior of the samples, they were placed in Hank's solution, while Tafel polarization and electrochemical impedance spectroscopy (EIS) were used. X-ray diffraction (XRD) together with field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS) techniques were employed to investigate the coatings. XRD results showed that the prepared PEO layers mainly consist of ZnO, Mg, and Mg3(PO4)2 phases. Corrosion test results showed that the use of ZnO nanoparticles improved the corrosion resistance of PEO ceramic coatings in Hank's solution. In contrast, the best result was obtained by using the electrolyte containing 6 g/l ZnO nanoparticles with a corrosion current density of 0.08 µA/cm2 and corrosion potential of -1.4615 VAg/AgCl. Also, EIS results showed the corrosion resistance of the mentioned coating as 1.05 × 106 Ω.cm2.

中文翻译：

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ZnO纳米颗粒的掺入对AZ31镁合金等离子电解氧化技术陶瓷涂层腐蚀行为的影响

摘要 提高耐腐蚀性是在 AZ31 镁合金上开发等离子体电解氧化 (PEO) 陶瓷涂层的主要目标之一。在这项研究中，陶瓷涂层通过 PEO 技术在含有 10 g/l 磷酸钠 (Na3PO4) 和 1.5 g/l 氢氧化钠 (NaOH) 的电解质中以不同浓度的 ZnO 纳米粒子和 7.1 A/ 电流密度沉积在 AZ31 镁合金上。 dm2 10 分钟。为了研究样品的腐蚀行为，将它们置于 Hank 溶液中，同时使用 Tafel 极化和电化学阻抗谱 (EIS)。X射线衍射（XRD）与场发射扫描电子显微镜（FESEM）和能量色散光谱（EDS）技术一起被用来研究涂层。XRD 结果表明制备的 PEO 层主要由 ZnO、Mg 和 Mg3(PO4)2 相组成。腐蚀试验结果表明，ZnO 纳米颗粒的使用提高了 PEO 陶瓷涂层在 Hank 溶液中的耐腐蚀性。相比之下，最好的结果是使用含有 6 g/l ZnO 纳米颗粒的电解液，其腐蚀电流密度为 0.08 µA/cm2，腐蚀电位为 -1.4615 VAg/AgCl。此外，EIS 结果表明上述涂层的耐腐蚀性为 1.05 × 106 Ω.cm2。最好的结果是使用含有 6 g/l ZnO 纳米粒子的电解液，腐蚀电流密度为 0.08 µA/cm2，腐蚀电位为 -1.4615 VAg/AgCl。此外，EIS 结果表明上述涂层的耐腐蚀性为 1.05 × 106 Ω.cm2。最好的结果是使用含有 6 g/l ZnO 纳米粒子的电解液，腐蚀电流密度为 0.08 µA/cm2，腐蚀电位为 -1.4615 VAg/AgCl。此外，EIS 结果表明上述涂层的耐腐蚀性为 1.05 × 106 Ω.cm2。