常温下铝合金阳极氧化膜的镧-有机酸复合封闭技术

Lanthanum-organic acid composite sealing technique of aluminum alloy anodized film at room temperature

为实现铝合金阳极氧化膜的常温快速封闭,将硫酸镧与单宁酸、酒石酸、硼酸和柠檬酸分别复配,对阳极氧化膜进行封闭。利用X射线光电子能谱(XPS)和能量色散X射线谱仪(EDS)谱图对表面及断面进行元素分析,电化学阻抗谱、Tafel试验进行耐蚀性能分析。结果表明,采用硫酸镧1 g/L、单宁酸5 g/L,在25℃、25 min条件下能够得到平整、致密的封闭效果,其耐蚀性能显著提升;并根据以上结果分析了镧-有机酸复合封闭的机理。

Studied the rapid sealing technology of aluminum alloy anodizing film at room temperature.Lanthanum sulfate was mixed with tannic acid,tartaric acid,boric acid and citric acid respectively,and the anodic oxide film was sealed by these four sealing methods.The element composition of surface and cross section was analyzed by X-ray photoelectron spectroscopy(XPS)and energy dispersive Xray spectrometer(EDS)spectrum.Electrochemical impedance spectroscopy and Tafel test were used to analyze the corrosion resistance performance.The results showed that using 1 g/L lanthanum sulfate and 5 g/L tannic acid,a flat and dense sealing effect can be achieved under 25℃ and 25 min.The corrosion resistance of the sample has significantly improved.Based on the above results,the mechanism of lanthanum organic acid composite sealing was analyzed.