Microstructural Evolution and Dynamic Recrystallization Behavior of the Homogenized 2195 Al–Li Alloy During Hot Deformation

The thermal deformation behavior in homogenized 2195 Al–Li alloy was studied at different deformation temperatures (370–520 °C and strain rates (0.001–1 s −1 ). The flow stress decreases with decreasing strain rate or increasing temperature. The significant decrease in flow stress from 370 to 420 °C is related to the fact that movements of dislocations and (sub)grain boundaries at low temperatures are hindered by the dynamic precipitation of numerous fine secondary phases (mainly Al 2 CuLi (T 1 ) phases). Meanwhile, it was found that flow localization regions appear in the microstructure at 370 °C/1 s −1 . Besides, DRX and DRV increase with decreasing lnZ (Zener–Hollomon parameter) values, particularly for lnZ values less than 26.32 (520 °C/0.1 s −1 ). The DRX mechanism was discussed for different lnZ based on the variation of misorientation angle and the characteristics of different DRXs. The DDRX is dominant when lnZ ≥ 30.70; CDRX and DDRX dominate at 30.70 > lnZ > 26.32; CDRX mainly occurs at lnZ ≤ 26.32; when lnZ value decreases to 21.72, DRX grains with the characteristics of CDRX and GDRX appear. Graphical Abstract