Effect of the loading mode on the evolution of the deformation mechanisms in randomly textured magnesium polycrystals – Comparison of experimental and modeling results

• Macroscopic yield is accompanied by increase of non-basal dislocations.
• The slip is more significant in compression than that in tension.
• Good agreement between EPSC modeling data and in-situ experiments.

A detailed analysis of the loading mode dependence of the deformation mechanisms in randomly textured cast magnesium is presented. An elasto-plastic self-consistent model (EPSC) is used to model the dislocation slip and twinning activity, respectively. The results are quantitatively compared with experimental data obtained by in-situ neutron diffraction (ND) and acoustic emission (AE). Both EPSC calculations and ND line profile analysis show an increased activity of prismatic slip with increasing strain and a loading mode dependence of the activation of the second-order pyramidal slip. The AE measurements and the modeling indicate a difference in the number of nucleated twin variants and the twinned volume in tension and compression.