Improve the Mechanical Properties of Mg–3Al–1Zn Alloy via Simultaneous Annealing and Loading

Abstract

A strengthening phenomenon has been demonstrated in the Mg–3Al–1Zn (AZ31) alloy after simultaneous annealing and loading at 180 °C. The microstructural analysis reveals that a few second-phase particles appear in the material after direct annealing at 180 °C for 20 h. However, a higher quantity of the second-phase particles (Al12Mg17) is observed in the alloy after simultaneous annealing and loading. Further, a high stress is observed to be more beneficial for the precipitation of the particles. It is speculated that the stress applied during annealing can provide a better condition for the nucleation of the precipitates. The enhanced extent of precipitates may play a significant role in preventing the dislocation gliding, thus, leading to a strengthening effect. The observed phenomenon may also provide a novel strategy for strengthening the magnesium alloys.