电解质中微量金属离子对高纯铝箔直流电蚀特征的影响

摘要

The effect of Cu2+, Fe3+, Zn2+ on etching process of high purity aluminum foil in H2SO4-HCl-HNO3under DC current were studied. It is proved that, after adding Cu2+ 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-Al galvanic local cells, the length of tunnels is increased from10 μm to30 μm, and the capacitance formed at 220 V, is increased by 78%-220%; Fe3+ has no significant effect on the corrosion reaction; after adding Zn2+ 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 Cu2+.%在盐酸-硫酸-硝酸电解质体系下，分别加入微量Cu2+、Fe3+、Zn2+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Cu2+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，220 V化成的比容提高了78%~220%；加入Fe3+后，不能形成微电池反应，对铝箔腐蚀没有明显影响；加入Zn2+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Cu2+。