Corrosion evolution of different grain configurations in 7050 Al alloy and its influence on mechanical properties

• Relationship between grain configurations and corrosion behavior of 7050-T7415 aluminum alloy was revealed. • Clarified the impact of corrosion kinetics on the loss of mechanical properties. • Confirmed that the occurrence of IGC is dominated by GBPs and the corrosion sensitivity of HAGB/LAGB. • Low-angle grain boundaries serve as the principal sites for the initiation and propagation of exfoliation corrosion. Corrosion behavior of 7050-T7451 aluminum (Al) alloy in a salt spray environment was investigated, with a particular focus on the relationship between grain configurations and corrosion behavior, highlighting the mechanisms of exfoliation corrosion formation and propagation. Low-angle grain boundaries, characterized by high strain energy, serve as principal sites for the initiation and propagation of this form of corrosion. Intergranular corrosion is primarily driven by the dealloying of grain boundary precipitates. While the chemical composition of the corrosion product film remained largely unchanged, its altered corrosion kinetics significantly influenced the loss of mechanical properties of the material.