Evolution of texture and precipitates in Al–Cu–Li alloy during deformation and heat treatment and its effect on anisotropy

Al–Li alloy offersa great advantage over traditional alloys and it is the ideal material for today's aerospace industry. Therefore, here we examined the Al–Cu–Li alloy as the third generation of Al–Li alloy. Deformation and heat treatment on the texture and precipitate type and distribution of Al–Cu–Li alloy were studied by mechanical properties test, XRD, and TEM analysis. The effect of texture and precipitate on the plane anisotropy of yield strength was discussed. The results showed thatBrass texture was mainly formed in the deformation process. On the one hand, increasethe pass deformation or cross rolling,the total volume fraction of the texture (S{123}〈634〉, G{011}〈100〉, {011}〈011〉) was increased, which lowered thesheet anisotropy. While on the other hand, the δ′ phase precipitated rapidly during solution treatment and easily caused a coplanar slip, increasing plane anisotropy. However, owing to the difference distribution of the aged precipitated T₁ on the two group of {111} habit plane, the strengthening effect of the Al–Cu–Li alloy sheet was weak at 45° direction, but stronger atthe rolling direction (0°) and transverse direction (90°). (paper)