Improving creep-age forming ability of AA2219 alloy using asymmetrical rolling

The impacts of asymmetric rolling (ASR) and cold rolling (CR) on the creep-aging behavior of AA2219 alloys were revealed by creep deformation experiments, tensile tests, electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). The ASR specimens under creep stress condition of 1.2σ_0.2 (σ_0.2 is the yield strength) displayed a 50% higher creep strain than the CR specimens. At a creep stress of 0.5σ_0.2, the ASR specimens demonstrated remarkably mechanical properties, with a tensile strength of 525 MPa, a yield strength of 338 MPa, and an elongation of 15.2%. This enhancement can be ascribed to the effective grain refinement and promotion of recrystallization after ASR. Notably, ASR resulted in the formation of higher cube textures and a denser forest dislocation structure compared with CR. Additionally, ASR specimens demonstrated a higher density of dispersive, smaller θ′ precipitates and larger average Taylor factors compared with CR specimens.