Corrosion Behavior of AA5038 Nanostructured Aluminum Alloy Produced by Accumulative Roll-Bonding

Accumulative roll bonding is the only severe plastic deformation process for the industrial production of ultrafine grained sheets with desirable mechanical properties. In the present research, corrosion behavior of nanostructured 5083 Aluminum alloy produced by Accumulative Roll Bonding (ARB) was carried out in 3.5% NaCl solution. Potentiodynamic Polarization tests and electrochemical impedance spectrometry were used to evaluate corrosion behavior of samples and immersion test was applied to evaluate intergranular corrosion behavior. The ARB process was successfully performed up to 6 cycles on 5083 aluminum alloy sheet. In early stages of ARB process, main grains were isolated by boundaries resulted from transformation and then layer structure composed of layer boundaries parallel to the rolling direction was created by increasing ARB cycle. By increasing the cycles distance between layer boundaries is decreased and finally by increasing strain more up to four cycles a structure made up of grains with nano grain size was obtained in result of occurrence of In-situ recrystallization. According to the electrochemical corrosion tests, by increasing number of passes in ARB process, the corrosion current density and corrosion rate was increased. Immersion test also revealed that the aluminum alloy annealed in 413°C and ARB samples are not sensitive to intergranular corrosion.