Coatings are playing an important role in corrosion mitigation of magnesium alloys, and in this study, a facile and eco-friendly chemical deposition process is proposed to improve the corrosion resistance of magnesium-neodymium alloys. The mixture of 1.5 mol/L KH₂PO₄ solution and 1.2 mol/L CaCl₂ solution is used for reaction solution, and ultrasound is introduced into the process for assisting the chemical deposition. After 40 minutes of the surface treatment, the surface and cross-sectional morphologies are observed by scanning electron microscope (SEM), which reveals that a layer of dense coating is formed on Mg alloy. Energy-dispersive X-ray spectroscopy (EDS) and X-ray Diffraction (XRD) are further combined to analyze the coating, and it is thereby confirmed that this coating mainly consists of CaHPO₄·2H₂O. Electrochemical tests and soaking experiments are conducted to evaluate the corrosion resistance of the treated samples in simulated concrete pore solutions. Both the untreated and treated samples have a good corrosion resistance in the Cl^- free simulated concrete pore solution, but their corrosion behavior is influenced by the introduction of Cl^- in this study. Fortunately, the coating can protect the substrate effectively in the Cl^- containing simulated concrete pore solution. In summary, it provides a possible way for magnesium alloys to improve their corrosion resistance when they are used in building engineering.

中文翻译：

---

超声辅助化学沉积提高镁合金在含氯模拟混凝土孔溶液中的耐腐蚀性

涂层在减轻镁合金腐蚀方面发挥着重要作用，在本研究中，提出了一种简便、环保的化学沉积工艺来提高镁-钕合金的耐腐蚀性能。1.5 mol/L KH ₂ PO ₄溶液和1.2 mol/L CaCl ₂的混合物溶液为反应液，在此过程中引入超声波辅助化学沉积。表面处理40分钟后，通过扫描电子显微镜（SEM）观察表面和横截面形貌，表明在镁合金上形成了一层致密的涂层。进一步结合能量色散 X 射线光谱 (EDS) 和 X 射线衍射 (XRD) 对涂层进行分析，从而证实该涂层主要由 CaHPO ₄ ·2H ₂ O组成。电化学测试和浸泡实验进行评估处理样品在模拟混凝土孔隙溶液中的耐腐蚀性。未经处理和处理过的样品在 Cl ^-自由模拟混凝土孔隙溶液，但在本研究中，它们的腐蚀行为受引入 Cl ^{- 的}影响。幸运的是，涂层可以在CL有效地保护基体^-包含模拟混凝土孔隙溶液。综上所述，它为镁合金在建筑工程中提高其耐蚀性提供了一种可能的途径。