Plasma electrolytic oxidation (PEO) coatings on AZ91 Mg alloy were sealed in calcium nitrate solutions at different pH values (3, 4 and 5). Sodium dodecyl sulfate (SDS) was added to study the effect of SDS on the corrosion resistance of the sealed coatings. The microstructure, chemical composition and corrosion resistance of the coatings were investigated by means of SEM, XPS, XRD and electrochemical corrosion tests. The corrosion performance of the coatings was improved due to precipitation of Ca-containing precipitate. Low pH and SDS addition enhanced hydroxyapatite precipitation and produced hydrophobic coatings with worse paint adhesion but better corrosion resistance.

将AZ91 Mg合金上的等离子电解氧化（PEO）涂层密封在不同pH值（3、4和5）的硝酸钙溶液中。加入十二烷基硫酸钠（SDS）以研究SDS对密封涂层耐腐蚀性的影响。通过SEM，XPS，XRD和电化学腐蚀试验研究了涂层的微观结构，化学成分和耐蚀性。由于含钙沉淀物的沉淀，涂层的腐蚀性能得以改善。添加低pH值和SDS可以增强羟基磷灰石的沉淀，并产生疏水性涂层，其涂料附着力较差，但耐腐蚀性更好。