目的 优化Mg-Al LDH/MAO涂层的制备工艺，提高铝合金的耐蚀性。方法 将微弧氧化样置于不同pH溶液中，在不同反应时间和反应温度下，采用原位生长法在2024铝合金表面制备层间含NO3–的MgAl-LDHs/MAO复合涂层。借用SEM、EDS、XRD研究LDH/MAO的微观组织结构，并利用电化学法表征MgAl-LDH/MAO复合涂层试样的腐蚀行为，揭示复合涂层的耐蚀机理以及最优异的工艺条件。结果 pH值为6和7的溶液制备出的涂层，生成了少量的LDHs，多数集中在孔洞附近，且生长不完全。相比之下，pH值为9的溶液制备出的涂层生成的片状水滑石更多，且较均匀，腐蚀电流较低，腐蚀电位较高。反应时间为12 h时，生成的水滑石较少，只有部分孔洞处会看到一些；反应时间为24 h和48 h制得的合金形貌相差不大，水滑石皆明显多于12 h的样品，且更加均匀。反应温度为180 ℃和220 ℃的合金形成的LDHs较多、较均匀，且生长较好，呈现很明显的片状结构。结论 弱碱的制备环境、反应温度的升高和反应时间的延长，促进了水滑石的生成，所得Mg-Al LDH/MAO复合涂层有效地改善了2024铝合金的耐蚀性。

The work aims to optimize the preparation process of Mg-Al LDH/MAO coating and improve the corrosion resistance of aluminum alloy. The micro-arc oxidation samples were placed in different pH solutions. Under different reaction time and at different reaction temperature, MgAl-LDH/MAO composite coating containing NO3– between layers was successfully prepared by in-situ growth method on the surface of 2024 aluminum alloy. The microstructure of LDH/MAO was studied by SEM, EDS and XRD. The corrosion behavior of MgAl-LDH/MAO composite coating samples was characterized by electrochemical method, revealing the corrosion resistance mechanism of the composite coating and the best process conditions. The coatings prepared in solutions with pH=6 and pH=7 produced a small amount of LDHs, mostly concentrated near the pores and incompletely grown. The coating prepared by the solution with pH=9 had more uniform flaky hydrotalcite, lower corrosion current and higher corrosion potential. When the reaction time was 12 h, only some holes produced LDHs. The morphology of the alloy prepared by the reaction time of 24 h and 48 h was not much different, the hydrotalcite was obviously more than that of 12 h, and was more uniform; the LDHs formed by the alloy with the reaction temperature of 180 ℃ and 220 ℃ were more uniform and the growth was better, which had Obvious sheet structure. The results show that the preparation environment of weak base, the increase of reaction temperature and the prolongation of reaction time promote the preparation of Mg-Al LDH/MAO composite coating, which effectively improves the corrosion resistance of 2024 aluminum alloy.