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 coldrolling 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（;.35 μm） in the TSA-foils than those by discontinuous recrystallization in the SSA-foils（;4.7 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;3.9%was achieved in the TSA-foil, much higher than that of the SSA-counterparts,;.3%. The relationships between the microstructure and mechanical properties were discussed.

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 coldrolling 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.