Effects of low-strain amplitude severe plastic deformation on AA6013 at ambient temperature

Abstract In this study, contrary to the conventional approach, severe plastic deformation (SPD) was applied at room temperature and under low strain, revealing notable results. AA6013, an aluminum alloy widely used for its high strength-to-weight ratio, was subjected to multi-directional forging (MDF), an SPD technique. Despite the low deformation rates in the MDF process, cold deformation led to significant microstructural refinement, enhancing mechanical properties. Following four cycles, improvements in the material’s mechanical properties were assessed through compression and hardness tests. At the same time, microstructural evolution was analyzed using optical microscopy (OM), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and X-ray diffraction (XRD). The effects of pre-SPD heat treatment and the SPD process on microstructural evolution were examined at both micro and nano scales, with a particular focus on grain and crystal structures. The results demonstrated that SPD not only reduced grain and crystal sizes but also rendered them more uniform, leading to consistent improvements in mechanical properties. Furthermore, the MDF process, applied up to four cycles, was numerically modeled, and the results were compared with experimental findings.