An Initial Exploration of Corrosion Inhibition of AA6061 and AA7075 by Aqueous Vanadates

摘要

Aqueous tetrahedrally coordinated vanadate species have been recognized as corrosion inhibitors of AA2024-T3. Inhibition is primarily attributed to the suppression of the oxygen reduction reaction on Cu-containing intermetallics. This work focuses on whether aqueous vanadates provide similar inhibition to other wrought precipitation age-hardened aluminum alloys like AA6061-T6 and AA7075-T6, which contain less Cu than AA2024-T3. A combination of open circuit potential measurements, potentiodynamic polarization experiments, and exposure tests in dilute vanadate and vanadate-free NaCl solutions indicate that vanadates provide the strongest inhibition on AA2024-T3 and AA7075-T6 with relatively less inhibition observed on AA6061-T6.