Study of the corrosion behaviour of AA5083 aluminium samples subjected to ECAP and cryogenic treatment

In this work the corrosion behaviour of AA5083 aluminium alloy (Al-Mg), initially subjected to a heat treatment of solubilization (380°C for 1h) and then to a severe plastic deformation (SPD), through the Equal Channel Angular Pressing (ECAP), was studied. Some samples were subjected to cryogenic treatment before the ECAP process. The aim of this experimentation was to carry out an electrochemical characterization of the aluminium alloy, evaluating the influence of grain refinement obtained by ECAP and of solubilization and cryogenic treatments on the corrosion behaviour of the material. The analysis of the corrosion resistance of the different samples was performed at room temperature by means of electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy tests) in an aqueous solution at 0.1 M Cl- at pH 2. The experimental results show that in these conditions, the corrosion behaviour of the different samples is more or less the same and consequently neither the cryogenic treatment nor the refinement produced by ECAP influence the corrosion resistance of the alloy.