电解质中微量金属离子对高纯铝箔直流电蚀特征的影响

Influences of trace metal ions in electrolyte on the etching characteristics of high purity aluminum foil under DC current

在盐酸-硫酸-硝酸电解质体系下,分別加入微量Cu^(2+)、Fe^(3+)、Zn^(2+)等金属离子,并采用直流方式对高纯铝箔进行电化学侵蚀,研究了改性后的电解质溶液对高纯铝箔电蚀过程的影响。结果表明:在硫酸-盐酸-硝酸电解体系中加入微量Cu^(2+)后,能够和铝发生置换反应生成铜单质沉积在铝箔表面,形成Cu-Al微电池反应,促进铝箔腐蚀,隧道孔密度增大,隧道孔长度从10μm增长到30μm,220V化成的比容提高了78%-220%;加入Fe^(3+)后,不能形成微电池反应,对铝箔腐蚀没有明显影响;加入Zn^(2+)后,能够形成Zn-Al微电池反应,促进铝箔腐蚀,但促进效果弱于加入Cu^(2+)。

The effect of Ca^2＋, Fe^3＋, Zn^2＋ on etching process of high purity aluminum foil in H2SO4-HCl-HNO3 under DC current were studied. It is proved that, after adding Cu^2＋ into electrolyte solution, a replacement reaction occurrs and copper elementary substance generates on aluminum foil. The etching process is promoted due to the formation of Cu-AI galvanic local cells, the length of tunnels is increased from 10 μm to 30 μm, and the capacitance formed at 220 V, is increased by 78%-220%; Fe^3＋ has no significant effect on the corrosion reaction; after adding Zn^2＋ into electrolyte solution, the etching process is promoted due to the formation of Zn-Al galvanic local cells, but the promoting effect is less significant compared with that condition adding Cu^2＋.