The effect of aluminum ions on the DC etching of aluminum foil

A study has been made of the electrochemical etching of 99.99% aluminum foils at a current density of 50 mA/sq cm in AlCl3-HCl solutions (1 M Cl(-)) at 80DGC. The solutions were made by dissolving metallic aluminum into 1 M 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 Al(3+) concentration. The results were discussed based on potential transients at a current density of 50 mA/sq cm, current potential curves at a scan rate of 10 mV/s and electrochemical impedance spectra.