Properties of electrochemical impedance and surface characteristics of anodized AA 6061

This paper was intended to figure out the corrosion resistance and surface morphology of AA6061 that is anodized with 1M phosphoric acid and cathode titanium in several potential variations. The surface morphology was examined by scanning electron microscopy (SEM), the surface roughness was investigated by Portable Surface Roughness Tester and finally the corrosion resistance was analyzed by the electrochemical impedance spectroscopy (EIS). The surface morphology showed that an increased potential of electricity supplied during the anodizing process leads to enlarged pore size larger or equitable to that occuring on the surface of the specimen, leading to decreased surface roughness values. Surface roughness tests indicated the lowest roughness values achieved from the anodizing with 30V potential was 0.674 μm. From the data, XRD showed the most significant influence on the process of anodizing, visible from the top of the resulting diffraction. As the potential increases, the intensity will decrease while the plane increases. The examination of corrosion resistance with EIS showed that the first step in the process of anodizing is an increase of Relp associated with an increased area coated by a layer of oxide.