Evolution of microstructure and texture during severe plastic deformation of the aluminium alloy AA2099

In this work, the effect of high-pressure torsion (HPT) deformation has been investigated for solution-treated (ST) AA2099 aluminium alloy. The strength of the alloy has been found to increase with deformation to an equivalent strain (ε_eq) ~ 27, beyond which it saturates. X-ray line profile analysis and transmission electron microscopy (TEM) revealed an increase in dislocation density and a decrease in grain size till this strain level, beyond which saturation in hardness and grain size occurs. Homogeneous microstructural and mechanical properties are obtained in the steady state regime. A grain refinement down to ~ 80 nm of the HPT-processed specimen in the steady state regime takes place from an initially coarse-grained specimen. The mechanism of grain refinement could be identified primarily as continuous dynamic recrystallization (CRDX). Texture of the HPT material at lower strain levels (~ 1.8 and ~ 3.5) consists of strong \({A}_{1}^{*}\) $A_1^{\ast }$ and \({A}_{2}^{*}\) $A_2^{\ast }$ simple shear components with very weak \(B\) $B$ -fibre. Along with ideal components of shear texture, non-ideal components are also observed. Further, increase in strain results in randomization of texture. The weakening of texture at higher strain and the formation of non-ideal texture components is facilitated by grain refinement along with the dynamic precipitation in this alloy.