铝合金表面红色Ce-Se化学转化膜r成分与耐蚀性研究

摘要

In this paper, the new Ce-Se conversion coating has been formed on the surface of aluminum alloy by using the cerium salt and selenide as the main salt. The corrosion resistances of the coatings were tested by polarization curves and electrochemical impedance spectroscopy, performed on the electrochemical workstation. Furthermore, the conversion coating surface morphology, composition and structure were studied by the scanning electron microscope ( SEM ) , energy spectrum ( EDS ) , and X-ray photoelectron spectrometer ( XPS) . The result showed the corrosion current decreased one orders of magnitude, compared to the substrate, suggestive of the improvement of the polarization resistance of Ce-Se conversion coating. In addition, the self-corrosive potential moves to positive direction.The SEM indicated the surface of the conversion coating exhibits many spherical shape particles with uniform crack.The results of the EDS and XPS uncovered the ingredient of the conversion coating are C, O, F, Na, Mg, Se, Ce elemnets, etc.%本文在室温条件下用铈盐和硒化物作为主盐,在铝合金表面制备了一种新型有色铈硒化学转化膜.利用电化学工作站测试了转化膜的极化曲线、阻抗谱;用扫描电子显微镜(SEM)、能谱分析(EDS)和X射线光电子能谱分析(XPS)等观察分析了转化膜的表面形貌、成分与结构.结果表明,铝合金经Ce-Se化学转化膜处理后,其极化电阻较空白铝合金有较大幅度的提升,自腐蚀电流降低了一个数量级,自腐蚀电压正移,铝合金的耐蚀性能得到显著的提升;扫描电子显微镜(SEM)观察表明,该转化膜层具有良好的连续性,表面有微凹与微凸起伏,且带有圆球形颗粒;通过能谱(EDS)和X射线光电子能谱分析(XPS)表明,铝合金Ce-Se转化膜的主要组成元素有Se、Ce、O、F、Na、Mg、C等.