Investigation of deformation dynamics in a wrought magnesium alloy

• Deformation mechanisms are characterized in a Mg alloy during strain path changes.
• The neutron diffraction measurement is conducted under a continuous loading condition.
• The combined EVPSC-TDT model is employed to predict the deformation dynamics.
• No detwinning activities are observed during unloading.

In the present research, the real-time in-situ neutron diffraction measurements under a continuous-loading condition and elastic–viscoplastic self-consistent (EVPSC) polycrystal modeling were employed to study the deformation dynamics and the effect of the deformation history on plastic deformation in a wrought magnesium alloy. The experimental results reveal that pre-deformation delays the activation of the tensile twinning during the subsequent compression, mainly resulting from the residual strains. Detwinning does not occur until the applied stress exceeds the tensile yield strength during the reverse loading. It is believed that the grain rotation plays an important role in the elastic region during the reverse loading. The EVPSC model, which has been recently updated by implementing the twinning and detwinning model, was employed to characterize the deformation mechanism during the strain-path changes. The simulation result predicts well the experimental observation from the real-time in-situ neutron diffraction measurements. The present study provides a new insight of the nature of deformation mechanisms in a hexagonal close-packed (HCP) structured polycrystalline wrought magnesium alloy, which has significant implications for future work on studying the deformation mechanisms of HCP-structured materials.