Tailoring the microstructure and mechanical properties of the final Al-Mn foils by different intermediate annealing process

In this work, two different intermediate annealing processes, single-step annealing (SSA, 530 °C/15 h) and two-step annealing (TSA, 450 °C/5 h + 530 °C/15 h), were used to tailor microstructure before cold-rolling and annealing of the final twin-roll cast Al-Mn foils. The recrystallization behavior and mechanical properties during annealing of severely cold-rolled foils were systematically studied. Our results show that discontinuous recrystallization occurs in SSA-foils during annealing at 150-310 °C, in contrast with continuous recrystallization in TSA-foils. The continuous recrystallization develops much finer grains (∼1.35 μm) in the TSA-foils than those by discontinuous recrystallization in the SSA-foils (∼14.7 μm). The texture components in cold-rolled TSA-foils hardly change (retained rolling-textures) after continuous recrystallization, while those in the cold-rolled SSA-foils mainly transform into a strong cube component {001} 〈100〉 after discontinuous recrystallization. Finally, a maximized elongation to fracture of ∼23.9% was achieved in the TSA-foil, much higher than that of the SSA-counterparts, ∼8.3%. The relationships between the microstructure and mechanical properties were discussed.