A physical-based constitutive model to describe the strain-hardening and dynamic recovery behaviors of 5754 aluminum alloy

Plane strain hot compression tests of 5754 aluminum alloy were conducted on a Gleeble-3500 thermo-mechanical simulator under various conditions. These tests simulated flat rolling to investigate how hardening and softening behaviors respond to controlled parameters, such as the deformation temperature and strain rate. This data allowed the parameters for the hot rolling process to be optimized. The restoration mechanism primarily proceeds via dynamic recovery, as shown by the deformed microstructure analysis and strain-stress curves. The dislocation density was used as internal state variable to develop a physical constitutive model, which characterized the evolution of the dislocation density caused by strain-hardening and dynamic recovery behaviors. The relationship between the flow stress and the dislocation density could be quantified with this model. The strain-hardening and softening behavior was analyzed in detail by Kocks-Mecking type plots. Furthermore, the relevant material coefficients were expressed as functions related to the temperature and the strain rate. The experimental flow stress was found to be in close agreement with the calculated, which confirms that the model developed herein can represent the flow behaviors of the 5754 aluminum alloy effectively.