Effects of severe plastic deformation on the corrosion behavior of aluminum alloys

Effects of severe plastic deformation on the corrosion behaviors of Al alloys containing precipitates have been investigated. Al and its alloys were severely deformed by equal-channel angular pressing (ECAP) processes and the corrosion behaviors of the Al alloys were evaluated by means of potentiodynamic polarization in a neutral buffer solution containing 0.002 M chloride ion. Introduction of huge plastic deformation to both of Al-5.4 wt% Ni and Al-5 wt% Cu alloys increased pitting potential. In contrast, ECAP treatment of 4N pure Al resulted in a decrease in open circuit potential, slight increase of passive current and shift of pitting potential to the negative direction. The influence of the change in microstructures caused by severe plastic deformation was investigated.