The wide application of Mg is hindered by its low corrosion resistance, especially for recycled Mg. In this work, a novel plasma electrolytic oxidation (PEO) process was conducted on a recycled Mg alloy with a high content of Al (~ 2.3 wt%), which results in a polycrystalline PEO coating. The PEO coating displays a three-layered structure with a uniform elemental distribution. Unlike the outer layer decorated by channels of micrometre scales, the middle layer mainly contains submicron-sized pores associated with plasma discharges, whereas the fine pores originated from oxygen evolution were detected in the inner layer. The electrochemical measurements, hydrogen evolution tests and salt spray tests were conducted, indicating the superior corrosion resistance of PEO-coated recycled Mg alloy. Hence, the purposed PEO method could dramatically enhance the corrosion resistance of recycled Mg, which may broaden its application in the future.

镁的广泛应用受到其低耐腐蚀性能的阻碍，尤其是再生镁。在这项工作中，对具有高 Al 含量（~2.3 wt%）的回收镁合金进行了一种新的等离子体电解氧化（PEO）工艺，从而形成了多晶 PEO 涂层。PEO 涂层显示出具有均匀元素分布的三层结构。与由微米级通道装饰的外层不同，中层主要包含与等离子体放电相关的亚微米级孔隙，而在内层检测到源自析氧的细孔。进行了电化学测量、析氢试验和盐雾试验，表明 PEO 涂层再生镁合金具有优异的耐腐蚀性能。因此，