Corrosion of Pure Aluminium in Hydrochloric Acid Solutions of Different Concentrations

摘要

Using the potentiodynamic and galvanostatic methods and electrochemical impedance measurements, the electrochemical behaviour of pure aluminium in HCl solutions of different concentrations was studied. The resistance of aluminium against corrosion in solutions with low concentrations of HCl can be attributed to a rapidly formed surface oxide. The presence of chloride ions creates extensive localized attack. The impedance diagrams show a large semi-circular capacitive loop at high frequency, which is then followed by a large inductive region. The low frequency inductive loop is always observed in acidic media and have attributed to the relaxation of adsorbed species like H_(ads)~+.