Wang Ye, Wu Guosong
College of Mechanics and Materials, Hohai University, Nanjing 211100, China.
Scanning. 2021 Jul 16;2021:5462741. doi: 10.1155/2021/5462741. eCollection 2021.
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 KHPO solution and 1.2 mol/L CaCl 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 CaHPO·2HO. 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.
涂层在镁合金的腐蚀减缓方面发挥着重要作用，在本研究中，提出了一种简便且环保的化学沉积工艺来提高镁钕合金的耐腐蚀性。使用1.5 mol/L KHPO溶液和1.2 mol/L CaCl溶液的混合物作为反应溶液，并在该过程中引入超声辅助化学沉积。经过40分钟的表面处理后，通过扫描电子显微镜（SEM）观察表面和横截面形态，结果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·2HO组成。进行了电化学测试和浸泡实验，以评估处理后样品在模拟混凝土孔隙溶液中的耐腐蚀性。未处理和处理后的样品在无Cl的模拟混凝土孔隙溶液中均具有良好的耐腐蚀性，但在本研究中它们的腐蚀行为受到Cl引入的影响。幸运的是，该涂层在含Cl的模拟混凝土孔隙溶液中能有效保护基体。总之，这为镁合金在建筑工程中使用时提高其耐腐蚀性提供了一种可能的途径。
