Polishing methods for formation nanoporous anodized alumina

In the manufacture of the porous anodic aluminum oxide (PAAO) matrix, its quality and structural perfection primarily depend on both the grade of the aluminum alloy of the substrate and the quality of the surface. For the manufacture of PAAO, aluminum foil of high-purity aluminum with a content of 99.999% is mainly used. The technological scheme for obtaining highly organized porous aluminum oxide includes preliminary preparation of the foil surface of A9 alloy with an aluminum content of 99.91% by electrolytic plasma and electrochemical polishing methods in this work. Processing made it possible to obtain a surface with roughness parameters Ra = 0.008–0.038 microns. PAAO samples were obtained by double electrochemical anodizing of the prepared foil in 0.5 M oxalic acid, at a voltage of 60 V and a temperature of 25 °C and examined by scanning electron microscopy.