Defect‐Regulated Precipitation Enables Ultrahigh Strength‐Ductility Synergy in a FeCoCrNi‐Based High‐Entropy Alloy

A thermomechanical strategy based on rolling‐annealing cyclic (RAC) was developed to regulate defect architecture and precipitation behavior in a (FeCoCrNi) 94 Al 3 Ti 3 high‐entropy alloy. Intermediate annealing during rolling enables progressive grain refinement and introduces a high density of twins, stacking faults, and dislocations, forming a uniform defect network. After subsequent aging, coherent L1 2 nanoprecipitates are formed throughout the FCC matrix, with local defect–precipitate coupling promoted by the pre‐existing defect network. As a result, the alloy attains an ultrahigh ultimate tensile strength of ∼2.1 GPa with ∼10% ductility, whereas the RAC‐3 condition already exhibits an excellent strength–ductility combination of ∼1.8 GPa and ∼18%. Quantitative analysis reveals that defect‐mediated strengthening dominates, whereas precipitation contributes additional strength. The synergy between defect engineering and controlled precipitation stabilizes strain hardening and enables a superior strength–ductility balance with improved reliability.