Mechanistic modelling of cryo-deformation and post-annealing of aluminium

Abstract

Dynamic recovery (DRV) occurs through severe plastic deformation (SPD) of high-stacking fault energy metals, even at room temperature. SPD at sub-zero or relatively low temperatures, namely cryo-deformation, has long been employed to confer enhanced mechanical properties due to the suppression of DRV. In this paper, mechanistic models with a metallurgical sense are investigated for low- and room-temperature SPD (200 and 300 K) and post-annealing of aluminium. Cellular substructure as well as cross-slip and climb effects are considered in the modelling of SPD. A model based on stored energy is also used for the contribution of dislocation density to post-annealing behaviour. The predicted flow stress curve is fitted the experimental results perfectly. The mechanistic modelling of SPD has demonstrated a multi-stage work-hardening behaviour, which entails more details such as the mutual effects of DRV and dynamic recrystallisation. The annealing experimental results are in line with the post-annealing model outputs.