Abstract: ［Objective］To improve the corrosion resistance of magnesium alloys.［Methods］A composite coating consisting of a magnesium hydroxide bottom layer and a calcium silicate（CaSiO .） top layer was constructed on AZ91D magnesium alloy using a one-step hydrothermal method. Theinfluence of reaction conditions on the structure and performance of the coating was systematicallyinvestigated. The optimal preparation parameters were determined by regulating the hydrothermalreaction temperature and time. Coating performance was comprehensively evaluated using polarizationcurves，electrochemical impedance spectroscopy（EIS），and immersion weight loss tests.［Results］The prepared coatings significantly enhanced the corrosion resistance of the substrate under all investigatedreaction conditions. The corrosion current density of the best-performing sample was approximatelyfour orders of magnitude lower than that of the uncoated alloy. Furthermore，the coating maintained a stable structure during prolonged exposure to a corrosive environment，demonstrating excellent corrosion resistance.［Conclusion］This hydrothermal coating strategy provides a green，efficient，and feasible approach for surface protection of magnesium alloys.

Key words: magnesium alloy, composite coating, silicate, corrosion resistance, one-stephydrothermal

摘要： 【目的】提升镁合金的耐腐蚀性。【方法】采用一步水热法在 AZ91D镁合金表面构建了底层为氢氧化镁，表层为硅酸盐（ CaSiO₃）的复合涂层，并系统研究了反应条件对涂层结构与性能的影响。通过调控水热反应温度与时间，确定了最优制备参数。结合极化曲线、电化学阻抗谱（ EIS）及浸泡失质量测试对涂层性能进行了综合评估。【结果】所制备涂层在不同反应条件下均显著提升了基体的耐腐蚀性，最佳样品的腐蚀电流密度相比裸合金降低了约 4个数量级，并在长时间腐蚀环境中保持稳定结构，表现出优异的耐腐蚀性。【结论】该水热涂层策略为镁合金表面防护提供了一种绿色、高效的可行途径。

关键词: 镁合金, 复合涂层, 硅酸盐, 耐腐蚀, 一步水热法

CLC Number: 

• TQ635