The influence of artificial ageing on the corrosion behaviour of a 2050 aluminium–copper–lithium alloy

• The corrosion behaviour of the 2050 Al–Cu–Li alloy was studied.
• Its corrosion behaviour was linked to the distribution of T1 precipitates.
• The copper content in solid solution also influenced its corrosion behaviour.
• In the T34 metallurgical state, the alloy was susceptible to intergranular corrosion.
• During ageing at 155 °C, the alloy became susceptible to intragranular corrosion.

The influence of artificial ageing on the corrosion behaviour of the recently developed 2050 Al–Cu–Li aluminium alloy in chloride-containing solutions was studied. Corrosion tests showed that artificial ageing changed the corrosion morphology of the alloy from intergranular to intragranular and decreased the corrosion potential of the alloy. Transmission electron microscopy observations combined with small-angle X-ray scattering measurements were used to establish a link between the distribution of T1 precipitates and the corrosion behaviour.