Crystallographic slips and twinning activity in AZ31 magnesium alloy during different modes of deformation on the basis of diffraction experiment and modelling - research data

This study investigates the plastic deformation mechanisms of AZ31 magnesium alloy under different loading conditions using in situ neutron diffraction and the Crystallite Group Method (CGM). The main objective is to experimentally determine the Critical Resolved Shear Stresses (CRSS) and describe the hardening behaviour of various slip and twinning systems. Tensile test was performed along the rolling direction, while compression tests were conducted along the normal direction, rolling direction, as well as at 30° and 60° to the ND, enabling the assessment of the anisotropic mechanical response. The CGM allowed direct determination of grain-level stresses for preferred crystallographic orientations, leading to unambiguous CRSS values and, notably, an improved estimate for the basal slip system from a compression test along a direction deviated at 30° from the ND. These experimentally derived CRSS values, along with the evolution of Resolved Shear Stresses (RSS), were used to validate and calibrate the Elastic-Plastic Self-Consistent (EPSC) model adapted to hexagonal crystal structures. The model successfully reproduced the activation sequence of deformation mechanisms, including slip and twinning, as well as the evolution of texture and twin volume fraction during RD compression. Model tuning involved optimization of Voce hardening parameters and grain interaction factors, resulting in accurate predictions across multiple loading paths. The combined experimental-modelling approach enhances understanding of plastic anisotropy in AZ31 alloy and improves the predictive capability of the EPSC framework for magnesium alloys subjected to different loadings.