Corrosion inhibition of pure aluminium and AA2014‐T6 alloy by strontium chromate at low concentration

The influence of a low concentration of strontium chromate on the corrosion inhibition of superpure aluminium and AA2014-T6 aluminium alloy in 0.6 m chloride solution has been investigated to simulate the leaching process of inhibitors from coatings. The potential-time and polarisation behaviour show influences on both the anodic and cathodic kinetics on the superpure aluminium surface. However, predominant cathodic inhibition was observed for the AA2014-T6 aluminium alloy. It was evident that chromium species were reduced at cathodic second phase particles, forming a thin passive film at the cathodic sites, which blocks the oxygen reduction reaction and, consequently, provides effective corrosion inhibition. Copyright © 2015 John Wiley & Sons, Ltd.