Hot deformation mechanisms of a solution-treated Al-Li-Cu-Mg-Zr alloy

The deformation behavior and microstructural changes accompanying the dynamic restoration process were investigated in Al-Li-based alloys. The flow stresses for alloys tested under different hot torsional deformation conditions were found to depend on strain rate through a sinh function and on temperature through an Arrhenius behavior. Transmission electron microscopy was used to characterize the change in subgrain size with the conditions of deformations during hot processing. A large number of helical dislocation, prismatic loops and Orowan loop formation after deformation at 500 °C and 400 °C were observed. The density of these defects depended on the temperature of deformation and strain rate.