Corrosion behavior of Al/Mg/Al multilayered composite elaborated by accumulated roll bonding

The corrosion behavior of an Al1050/AZ31/Al1050 multilayered hybrid composite fabricated by the accumulated roll bonding (ARB) technique up to six cycles in a 3.5 wt.% NaCl solution was studied through potentiodynamic polarization tests (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM-EDS), Raman spectroscopy and X-ray diffraction (XRD). In order to deeply apprehend the corrosion resistance and corrosion products of the Al1050/AZ31/Al1050 multilayered hybrid composite, almost similar investigation was performed on the Al1050/Al1050/Al1050 multilayered sample elaborated by ARB up to one cycle. Potentiodynamic polarization plots and electrochemical impedance spectroscopy show that the corrosion rate is strongly affected by the ARB strain level. A higher corrosion rate and reduced polarization resistance are evidenced compared to the Al1050/Al1050/Al1050 multilayered sample. The AZ31 layers seem to dominate the corrosion process. Raman and XRD analyses confirm the presence of the main corrosion product of Mg(OH)2 and the absence of any chloride such as (Mg(OH)2)center dot MgCl2.