Inhibiting corrosion of aluminum alloy 5083 through Vibrio species biofilm

Highlights: • Vibrio species show corrosion inhibitory effect against AA 5083 in the simulated marine environment. • Vibrio species decrease the corrosion rate and increase the pitting potential of AA 5083. • The pit depth is significantly decreased in the presence of Vibrio biofilm. • Oxygen may be consumed up by the respiration of the Vibrio biofilm. • Mature biofilms act as a diffusion barrier to prevent the pentration of chloride ions. Microbiologically influenced corrosion inhibition (MICI) of aluminum alloy (AA) 5083 by three representative Vibrio species were evaluated using electrochemical, surface analysis and surface characterization techniques. Interestingly, all the bacteria exhibited profound inhibitory effect on the corrosion of AA5083 in the chloride-containing culture medium. The MICI mechanism of tested Vibrio species is that mature biofilms acted as a diffusion barrier to prevent the penetration of corrosive chloride and consumed up the diffused oxygen by their aerobic respiration. Thus, the biofilm increased the passive range and inhibited the localized attack on the AA5083 surfaces.