Hot deformation behavior and microstructure evolution of the spray deposited and secondary hot extruded 2195 Al-Li alloy

This work aims to investigate the influence of hot deformation parameters on the micro-structure evolution and deformation behavior of the extruded 2195 Al-Li alloy, as well as to explore its optimized hot deformation windows based on the hot compression tests carried out on a Gleeble-1500 thermo-mechanical simulator in the temperature range 370-520 ? and with the strain rate of 0.001-10 s(-1). The results revealed that the extruded 2195 Al-Li alloy plate with a large aspect ratio had a lower deformation activation energy with respect to the spray deposited and as-cast 2195 Al-Li alloys owing to the existence of a large number of coarse second phases and LAGBs in the extruded plate. The optimized hot deformation temperature of the alloy ranged from 405 ? to 490 ? with a strain rate from 0.001 to 0.1 s(-1). Hot deformation under the optimized conditions led to the occurrence of continuous dynamic recrystallization and resultant microstructure refinement. Although the occurrence of continuous dynamic recrystallization weakened the < 101 > deformation texture, but triggered another texture component with < 001 >//ND. Deformation at low temperature and high strain rate induced flow instability due to insufficient dynamic softening. In addition, the flow instability at a temperature higher than 490 ? arose from partial remelting of Al2Cu phase along grain boundaries. The work can provide an effective guidance for the designation of secondary hot processing of the extruded 2195 Al-Li alloy. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigates the influence of hot deformation parameters on the microstructure evolution and deformation behavior of the extruded 2195 Al-Li alloy. The optimized hot deformation conditions lead to continuous dynamic recrystallization and microstructure refinement. The presence of large second phases and liquid-like grain boundaries in the extruded plate results in a lower deformation activation energy.