Simultaneous enhancement of mechanical and fatigue properties in 2xxx aluminum alloys via microstructural uniformity induced by cyclic plasticity

• • The cyclic strengthened (CS) sample achieves a superior combination of strength and ductility compared to peak-aged (PA) sample, overcoming the strength-ductility trade-off; precipitation strengthening remains dominant, with dislocation and solid solution strengthening contributing significantly. • • Despite similar ultimate tensile strength (UTS) to PA, the CS sample exhibits markedly improved fatigue strength and fatigue ratio, attributed to the absence of precipitate-free zones (PFZs) that minimizes strength gradient between grain interiors and boundaries. • • The cyclic plasticity treatment induces a highly uniform microstructure, suppressing strain localization and promoting homogeneous strain partitioning during cyclic loading, thereby enhancing fatigue resistance. • • The study provides quantitative analysis of strengthening mechanisms, confirming that cyclic plasticity is a promising strategy for simultaneous enhancement of mechanical and fatigue properties in high-strength Al alloys.