Computational study of cathodic reaction activity on intermetallic particles and solute clusters in aluminum alloys

Localized corrosion remains a critical challenge limiting the durability and service life of aluminum (Al) alloys. Coarsened intermetallic particles (IMPs), formed during casting and heat treatment, can act as strong cathodic sites and significantly influence the corrosion behavior of Al alloys. In this study, first-principles calculations are performed to examine the oxygen reduction reaction (ORR) activities of Cu- and Fe-based solute clusters and representative IMPs in 2xxx, 6xxx, and 7xxx series aluminum alloys. Our results reveal that Al 7 Cu 2 Fe exhibits particularly high ORR activity, making it especially detrimental to corrosion resistance. Finally, through a systematic elemental screening across the periodic table, we discover that boron (B) can be preferentially incorporated into Al 7 Cu 2 Fe relative to the Al matrix and can effectively suppresses the cathodic reaction on the Al 7 Cu 2 Fe surface. These findings provide atomic-level insights and strategies for improving the corrosion resistance of Al alloys in industrial applications.