study of morphology and composition of nickel coatings on aluminum anodic oxide

One of the main characteristic of aluminum is a resistant oxide layer formed on the surface. Oxide layer thickness can be increased by anodizing process; whereas its corrosion resistance and mechanical properties can be improved. It is important to make oxide layer on aluminum surface to enhance the adhesion of pigments in coloring aluminum.In this study, aluminum alloy specimens anodized in sulfuric acid electrolyte to produce porous nano structured aluminum oxide (AAO) layer. The characteristics of AAO were optimized by process parameters such as concentration of electrolyte, voltage and time. Then specimens were coated by electrochemical deposition in a solution containing nickel ions.The effect of nickel deposition duration on the morphology and composition of coating was investigated, using energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) and electrochemical tests. The diameters of pores were estimated 11-50 nm and the metal was deposited on the bottom of pores. Different shade was produced in electrolytic coloring process by different deposition time. Increasing the deposition time makes coating darker, due to increasing the deposited metal

کلیدواژه ها:

aluminium anodic oxide ، anodizing ، electrochemical deposition ، nickel