EFFECT OF HOMOGENIZATION AND PRECIPITATION TREATMENTS ON THE HOT WORKABILITY OF AN ALUMINUM ALLOY-AA2024

Hot-torsion tests have been carried out at 310 and 370 °C (at a strain rate of 1 s-1) on an AA2024 aluminium alloy homogenized for 8 h at between 420 and 520 °C and either just water quenched or air cooled and aged at 290 or 350 °C. The flow curves exhibited a large peak stress σp and work softening with low strain εf to fracture in the quenched condition. The peak and work softening were reduced and the ductility improved as either the aging temperature or the deformation temperature was increased. The homogenizing temperature had a large effect on σp but little effect on εf for deformation at 310 °C, whereas at 370 °C there was little effect on σp but a large effect on εf which was much higher. The above effects arise from the relative amounts of solute and dynamic precipitation after various treatments at different test temperatures. © 1990.