A superhydrophobic ceria-based composite coating is developed to improve anticorrosion properties of AZ61 magnesium alloy, fabricating via chemical conversion method followed by hydrothermal treatment. The cerium conversion coating has a block structure with microcracks. After the hydrothermal treatment, a dense CeO₂ layer, porous CeO₂ nanorods, and stearic absorbing layers are grown stepwise on the conversion coating. And the composite coating is hydrophobic or even superhydrophobic and has almost no microcracks. As the hydrothermal reaction time increases, the water contact angle of the composite coating first increases and then decreases, and it reaches the maximum value of 152° after hydrothermal treatment for 4 h. Both the dense CeO₂ layer and the superhydrophobic stearic absorbing layer can effectively prevent the electrolyte from contacting the substrate; the corrosion current density of the superhydrophobic composite coating is lower than that of the hydrophilic composite coating and the cerium conversion coating, and has the best corrosion resistance.

中文翻译：

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镁合金超疏水氧化铈基复合涂层的制备及性能

开发了一种超疏水二氧化铈基复合涂层，以提高 AZ61 镁合金的防腐性能，通过化学转化方法制造，然后进行水热处理。铈转化涂层具有带微裂纹的块状结构。水热处理后，致密的CeO ₂层、多孔CeO ₂纳米棒和硬脂酸吸收层在转化涂层上逐步生长。并且复合涂层具有疏水性甚至超疏水性，几乎没有微裂纹。随着水热反应时间的增加，复合涂层的水接触角先增大后减小，水热处理4 h后达到最大值152°。致密的 CeO ₂层和超疏水硬脂酸吸收层可有效防止电解质与基材接触；超疏水复合涂层的腐蚀电流密度低于亲水复合涂层和铈转化涂层，耐腐蚀性能最好。