胆碱基氨基酸离子液体对AZ91D镁合金在NaCl溶液中的缓蚀性能

Assessment of corrosion inhibition performance of choline based amino acid ionic liquids for AZ91D magnesium alloy in NaCl solution

合成了三种胆碱基水溶性离子液体(ILs),即[Ch][MOPS]、[Ch][Phe]和[Ch][Trp]。研究了在0.5%NaCl溶液中,这三种ILs缓蚀剂对AZ91D镁合金的缓蚀性能。电化学测试结果表明,这三种缓蚀剂均对AZ91D镁合金表现出良好的缓蚀性能,缓蚀效率依次为[Ch][MOPS]<[Ch][Phe]<[Ch][Trp]。在缓蚀剂浓度为0.7 mmol/L时,[Ch][Trp]的缓蚀效率最高可达87.1%。结合扫描电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)等系列表征测试,分析了三种阴离子的结构特点,并且提出了在ILs存在下AZ91D镁合金表面形成均匀颗粒保护膜的机制,为AZ91D镁合金提供了良好的缓蚀保护作用。

In this work,choline based water-soluble ionic liquids(ILs),namely[Ch][MOPS],[Ch][Phe]and[Ch][Trp],were synthesized.Then,their corrosion inhibition performances on AZ91D Mg alloys in 0.5%NaCl solution were evaluated.The electrochemical test results demonstrate that the three inhibitors exhibit good corrosion inhibition performance,with corrosion inhibition efficiency in the order of[Ch][MOPS]<[Ch][Phe]<[Ch][Trp].The highest inhibition efficiency of[Ch][Trp]can reach 87.1%when the concentration of inhibitor is 0.7 mmol/L.The structural characteristics of three anions were analyzed by combining a series of characterization tests such as scanning electron microscopy(SEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).Meanwhile,the mechanism of forming a uniform particle protective film on the surface of AZ91D Mg alloy in the presence of ILs was proposed,which can provide a good inhibition performance and protection effect for AZ91D Mg alloy.