Anodic behavior of Al–Bi and Al–Sb alloys in 3% NaCl solution

Abstract

The methods of polarization curves and scanning electron microscopy are used to study the pitting corrosion resistance of Al-Bi (up to 4 wt.% Bi) and Al-Sb (up to 20 wt.% Sb) binary alloys in a 3% NaCl solution. With concentration of the alloying element to 0.1 wt.%, current density decreases and corrosion slows down. With higher concentrations of antimony and bismuth, the early passivation current density increases and the active region reduces on potentiodynamic curves. This indicates that the corrosion resistance of aluminum alloys decreases with greater content of the other phase (Bi or Sb).