High strength Al–Cu–Li alloy with enhanced atmospheric corrosion resistance developed by cold rolling tailored precipitation

This work developed an Al–Cu–Li alloy with improved strength, ductility, and atmospheric corrosion resistance through tailoring the precipitation behavior via dislocation engineering. Atmospheric corrosion is more dangerous than corrosion in solution due to the formation of electrolyte droplets. Intergranular corrosion intensifies in gap regions between large droplets, forming deep cavities in T6-treated alloy, while the cold-rolled alloy exhibited superior corrosion resistance with corrosion depth reduced by 59%. Dislocations introduced by cold rolling restricted T₁ (Al₂CuLi) precipitation at grain boundaries. The dislocation-controlled homogeneous precipitation reduced corrosion potential difference between grain boundaries and the grain interior, suppressing intergranular corrosion and cavity growth.