Effect of aging on structure and strength of high pressure torsion processed 2024 aluminum alloy

Pre-quenched samples with a diameter of 20 mm and a thickness of 1 mm, cut from commercial hot-pressed rod of the 2024 aluminum alloy, were severely deformed by high-pressure torsion (HPT) with 10 revolutions under a pressure of 6 GPa at room temperature and then annealed for up to 50 hours in the temperature range of 100-190 °C. It was found that the post-deformation annealing at relatively low temperatures and/or short times can result in the alloy aging and 10-15% increased hardness. However, the conventional regimes of artificial aging of the alloy according to T6 heat treatment led to a sharp drop in its strength due to recovery and recrystallization of the matrix and simultaneous overaging. The nature of the revealed structural and property relations is discussed.