Abstract: Here, Guinier-Preston (GP) zones were, for the first time, induced in a Cu-Al alloy through Zr microalloying combined with heavy warm rolling and short-time annealing. Benefiting from the synergy of high-density annealing nanotwins, GP zones, and their interactions with stacking faults (SFs), the alloy achieved an exceptional strength-ductility balance, with a yield strength of 950 MPa and an elongation above 10 %, comparable to or even surpassing conventional high-strength copper alloys. The GP zone-SF interaction promotes stress homogenization by preventing dislocation pile-up at grain or phase boundaries, while also sustaining strain hardening during later stages of deformation.

Key words: Cu-Al alloys, Mechanical properties, GP zone, Nanotwin, Stacking fault