SETT ATT PA ELEKTROLYTISK VEG FERGA FOREMAL AV ALUMINIUM

摘要

An aluminum article is colored by forming an oxidized coating thereon by usual anodizing treatment and subsequently subjecting the treated article to electrolysis in a metal salt-containing electrolytic bath with current having a discontinuous distorted wave. The current includes alternating positive current portions and negative current portions, at least the negative portion having a conduction angle controlled by a thyristor, the positive current portions being thereby rendered larger than the negative current portions.