Improved mechanical properties of 2024 aluminum alloys by electric pulse assisted rolling and subsequent aging
Fang Liu, Fulin Zhu, Wandong Yang, Qi Wang, Yiyou Tu
Abstract
This study investigates the microstructural evolution and mechanical property modulation of 2024 aluminum alloy (70 % rolling reduction) through electro-pulse assisted rolling (EPAR, initial current density of 10 A/mm 2 ) and subsequent aging treatment. Results indicate that EPAR-induced electron wind force generates supplementary free energy, substantially accelerating dynamic recrystallization. Specifically, the recrystallization fraction is increased to 42.6 %, accompanied by a reduction in low-angle grain boundaries to 79 %. The dominant texture transitions from < 111 > Cubic to E{111} < 110>, with a 52 % reduction in texture intensity. Additionally, dislocation density decreases from 3.42 × 10 15 m −2 in conventional rolling to 3.18 × 10 15 m −2 , transitioning from entangled configurations to uniformly distributed dislocation walls aligned with the rolling direction. During 185 °C aging, the beneficial dislocation structure and reduced precipitation activation energy in EPAR-processed specimens shorten peak aging time, achieving ultimate tensile strength of 670.9 ± 31.7 MPa and elongation of 6.6 ± 0.2 %. Strength enhancement arises from synergistic effects of precipitation strengthening (average precipitate thickness: 1.62 nm) and dislocation interactions, while improved ductility correlates with homogeneous precipitate distribution. This research establishes a theoretical framework and technical strategy for streamlined production of high-strength, high-toughness aluminum alloys.