Fabrication of Anodized Electroplating Aluminum Coatings

Aluminum film containing nano-porous was prepared on 304 stainless steel surface by combining electroplating from ionic liquids and anodizing in 0.5 mol/L sulfuric acid solution. The microstructure and morphology of electroplating aluminum coating on stainless steel were investigated by means of SEM, EDS and XRD. The results showed that a compact and well adherent aluminum coating was obtained under the conditions of 55 ℃, current density of 20~25 mA/cm2 and addition of toluene for volume fraction of 1.25%. The results showed that with the increase of the current density, the size of aluminum grains decreased. After anodic oxidation of the electroplating aluminum coat for different times, the surface of the coating exhibited nanometer micro pores. XRD results showed that the coating was composed of Al and amorphous Al2O3. With the extension of anodic oxidation time, the content of Al decreased, the content of amorphous Al2O3 increased, the thickness of oxidation film and the diameter of pores observed on the stainless steel surface also increased.