Optimization of Electrolyte Solution Formula and Electrode Plate Material for Electrolytic Multi-Coloring of Anodized Film on Aluminum

In order to prepare a multi-coloring anodized film on aluminium alloy in the same electrolyte solution, an orthogonal experiment scheme was designed to find the effect of electrolyte solution composition upon the blue grey and dark green electrolytic coloring, and a typical electrolyte solution formula was optimized. In addition, the influences of electrode material and arrangement in the electrolytic cell on the coloring unformity were also studied. It is found that the electrolyte solution composed of 4~5 g/L SnSO4, 12 g/L NiSO4 and 16~20 g/L H2SO4 could meet the requirements of the multi-coloring for the anodized film, and the substitution of stainless steel electrode plate by Sn metal could avoid the white powder deposition on the plate, as well as the use of double cathode plates is helpful for improving the coloring uniformity of the anodized film.