Evolution of aging precipitates in an Al–Li alloy with 1.5 wt% Li concentration

Transmission electron microscope and selected area electron diffraction were employed to characterise the precipitates in 2A97 Al–Li alloy with 1.5 wt% Li concentration, which were aged at 150°C (with 6% pre-deformation) and 165°C (without pre-deformation) for various time. The diameter of the plate-like T1, δ′/GP/δ′ and δ′/θ'/δ′ precipitates were measured to analyse the precipitate evolution during ageing treatment. We find the pre-deformation has a significant effect on the T1, δ′/GP/δ′, δ′/θ'/δ′ and cubic precipitates, which improves the nucleation of T1 precipitates but suppress the other precipitates. The findings herein provide the guidance to tailor the microstructure of 2A97 alloy through artificial ageing treatment, which can facilitate the future alloy design. •The evolution of precipitates in 2A97 Al–Li alloy with 1.5 wt% Li concentration during artificial ageing was investigated.•Pre-deformation has significant effect on the T1, δ′/GP/δ′, δ′/θ'/δ′ and cubic precipitates of 2A97 alloy.•The cubic precipitates only exist in the long time aged 2A97 alloy without pre-deformation.