THE USE OF ACOUSTIC EMISSION AND NEUTRON DIFFRACTION TO REVEAL THE ACTIVE DEFORMATION MECHANISMS IN POLYCRYSTALLINE MAGNESIUM AND COMPARISON TO THEORETICAL MODELING

摘要

A detailed analysis of the loading mode dependence of thedeformation mechanisms in randomly textured cast magnesium ispresented. An elasto-plastic self-consistent model (EPSC) is usedto model the evolution of the dislocation structure and twinning.The results are quantitatively compared with experimental dataobtained by in-situ neutron diffraction (ND) and acoustic emission(AE) methods. Both EPSC calculations and ND line profileanalysis show an increased activity of prismatic slip withincreasing strain and a loading mode dependence of the activity ofthe second-order pyramidal slip. The AE measurements and themodeling indicate different amount of nucleated twin variants andtwinned volume in tension and compression, respectively.