The Effect of Aluminum Ions on the DC Etching of Aluminum Foil

Abstract

A study has been made of the electrochemical etching of 99.99% aluminum foils at a current density of 50 mA cm−2in AlCl3–HCl solutions (1 m Cl−) at 80 °C. The solutions were made by dissolving metallic aluminum into 1m HCl solution, to give a Cl− concentration of 1 m. The number density of etch tunnels and the homogeneity of tunnel length decreased, and the mean pit size and its standard deviation increased with increasing Al3+ concentration. The results were discussed based on potential transients at a current density of 50 mA cm−2, current–potential curves at a scan rate of 10 m Vs−1 and electrochemical impedance spectra.