Influence of grain stresses on the mechanical behavior of textured AZ31 magnesium alloy studied using neutron diffraction

This study investigates the plastic deformation mechanisms in the textured AZ31 magnesium alloy through experimental analysis and modeling. Stress evolution at the grain level was examined using the crystallite group method (CGM) and angle dispersive neutron diffraction, providing insights into the anisotropic activation of slip and twin systems under different loading conditions. The analysis was conducted for four deformation modes: compression along the normal direction (ND), compression at 30° from ND, compression along the rolling direction (RD), and tension along RD. The resolved shear stress (RSS) and critical resolved shear stress (CRSS) evolution for individual grains allowed for the determination of hardening parameters based on the Voce law. The elasto-plastic self-consistent (EPSC) model, refined to account for intergranular interactions, accurately reproduced macroscopic stress-strain behavior. The study also examined texture evolution and twin fraction development, confirming the transition from initial softening of the sample compressed along RD to strengthening due to twinning. The established set of plastic deformation parameters enables accurate predictions of material behavior at both the micro- and macroscopic scales for all considered modes of deformation. These findings contribute to a better understanding of AZ31 alloy elastic-plastic properties under different loading conditions.

This work was financed by a grant from the National Science Centre (NCN), No. UMO-2023/49/B/ST11/00774.