Using synchrotron radiation XRD technique to investigate active slip systems during tensile deformation in pure magnesium

Abstract

Active slip systems in pure magnesium specimens with different grain sizes were investigated by the in-situ X-ray diffraction (XRD) technique during tensile testing. From the XRD measurement results, the inhomogeneous strain anisotropy formed by dislocations was obtained. Inhomogeneous strain anisotropy differs in each slip system because hexagonal close-packed metals such as magnesium have anisotropic elasticity. In this study, the dislocation amounts belonging to each active slip system were evaluated utilizing this difference. Coarse-grained specimens had isotropic inhomogeneous strain corresponding to basal slip. Fine-grained specimens showed high elongation and had anisotropic inhomogeneous strain. It is considered that the improvement in ductility occurred by non-basal slip activation near grain boundaries, which increased with grain refinement. Similarly, the ratio of non-basal slip evaluated from the crystal rotation axis increased in the fine-grained specimens.