(北京科技大学 材料学系，北京 100083)
摘 要: 观察了经300 ℃退火并分别快冷和慢冷的铝箔表面的电化学腐蚀结构。 利用二次离子质谱仪检测了铝箔表面区域Fe、 Si、 Cu、 Mg等微量元素的分布。 结果显示: Mg在铝箔外表面的富集高于铝箔内部4个数量级， Fe、 Si的富集程度约高2个数量级， 而Cu则不足1个数量级。 退火后慢速冷却会造成富集于表面的微量元素偏聚于晶界和位错周围， 从而会加重腐蚀结构的不均匀性并降低铝箔的比电容。
关键字: 铝箔； 微量原子； 腐蚀； 微观结构； 电解电容器
（ Department of Materials, University of Science and Technology Beijing, Beijing 100083, China）
Abstract: The surface corrosion structures of aluminum foils, which were annealed at 300 ℃ followed by rapid and slow cooling respectively, were observed after electrochemical etching. The distributions of microelements Fe, Si, Cu and Mg in the surface layer were also determined by secondary ion mass spectrometer. It is found that the Mg content at external surface is increased exponentially over the four orders of magnitude in comparison with that in center layer. The corresponding contents of Fe and Si are increased about two orders of magnitude; while the content of Cu is increased lower than one order of magnitude. The slow cooling after annealing will lead to stronger segregation of microelements around the grain boundaries and dislocations in the surface, which aggravates the inhomogeneity of corrosion structure and results in low specific capacity.
Key words: aluminum foil; microelement; corrosion; microstructure; electrolytic capacitor
