Effect of heat treatment on the phase composition, the texture, and the mechanical properties of a V1461 (Al–Cu–Li) alloy

The heterogeneity of the phase composition, the texture, and the mechanical properties in various zones and directions of plates (thickness T = 80 mm) in a V1461 (Al–Cu–Li) alloy has been studied. It is noted that the strength characteristics are maximal in the median cross section (ultimate strength and yield strength are 570 and 540 MPa, respectively); in the cross section at 0.25T, these values are 530 and 490 MPa, respectively; in the height direction, they are only 490 and 440 MPa. The studies of texture show that an intense one-component texture, which is similar to the matrix and δ' phases, is observed in a medium plate layer of thickness (0.3–0.35)T; the {011} texture plane is parallel to the plate plane with the dominant “brass” {110}〈112〉 texture. Hardness is shown to increase from HRB70 after aging at 120°C for 20 h to HRB85 after three-step aging at 120°C, 20 h + 140°C, 24 h + 150°C, 24 h. It is shown that aging at 120 and 140°C is accompanied by the precipitation of the Θ' phase along with the δ' phase, and aging at 150°C also leads to the precipitation of the T1 phase.