Electrochemical Corrosion of Bulk Nanocrystalline Aluminum in Acidic Sodium Sulfate Solutions at Room Temperature

Abstract

The corrosion properties of metallic materials are usually associated with the compactness of the oxide film and electrochemical parameters, such as corrosion potential, corrosion current density, pitting potential, etc. The valence electron configurations of metallic materials can also affect their corrosion properties because the nature of their corrosion processes involves the exchange and transportation of valence electrons between metallic atoms and ions. In the present work, the electrochemical corrosion of bulk nanocrystalline aluminum (BN-Al) produced by severe rolling technique and its conventional polycrystalline aluminum (CP-Al) counterpart in 0.01, 0.05, and 0.1 M HCl + 0.25 M Na2SO4 solutions at room temperature was studied by potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy. The uniform and pitting corrosion resistances of BN-Al were simultaneously enhanced in comparison with those of CP-Al. The ion adsorption in oxide films along depth p...