Shear banding behavior of AA2099 Al-Li alloy in asymmetrical rolling and its effect on recrystallization in subsequent annealing

AA2099 Al-Cu-Li alloys were rolled by both asymmetrical and conventional rolling to a total thickness reduction of 80% at room temperature. Microstructure and texture evolution through thickness of rolling sheets were comprehensively investigated. Results show that large shear stress in ASR sample gave rise to a distortion of grain structure and a remarkable work hardening at region close to fast rolled surface. Shear banding behavior was largely promoted by ASR and various types of shear bands with higher density were observed. The shear bands triggered a kink of grain structure during rolling process. The kink behavior was related to the tilt angle and width of shear bands. The shear bands exhibited large tilt angle and width gave rise to a more significant kink of the grain structure nearby. Recrystallization during subsequent annealing was also promoted by ASR. Shear bands became favorable nucleation sites for rolled material. Growth advantage of some nuclei inside shear bands had a stronger influence on the recrystallized texture in AA2099 rolled sheets.