Corrosion resistance of 6063 aluminum alloy by anodizing treatment in a phosphoric acid, boric acid and oxalic acid baths with SEM and TAFEL study

Corrosion resistance specimens of 6063 aluminum alloy were investigated during anodizing in sulfuric acid, sulfuric acid/ boric acid and sulfuric acid/ boric acid/ oxalic acid baths using electrochemical impedance (EIS) techniques, Tafel extrapolation, SEM micrographs and optical microscopy images. After anodizing that by changing of the time during the anodizing different thicknesses of aluminum oxide Nano-layer was formed on the aluminum surface. The corrosion resistance behavior of the 6063 aluminum alloy showed by increasing the thickness of the Nano-oxide layer in each of the three supports reduces the corrosion rate, increasing the load transfer resistance and thus reduce the influence of attacker ions into the aluminum. The obtained results indicated that the corrosion resistance increased in the order of sulfuric acid/ oxalic acid/ boric acid> sulfuric acid/ oxalic acid> sulfuric acid for anodized piece.

کلیدواژه ها:

6063 aluminum alloy ، Electrochemical impedance ، Tafel extrapolation method ، Nano-layer