Strengthening mechanisms acting in the extruded Mg-based LPSO phase

Abstract

Plastic deformation behavior of extruded alloy mainly composed of long-period stacking ordered phase (LPSO-phase) was examined by compression test, as a function of extrusion ratio, temperature and loading orientation. The yield stress showed a strong loading orientation dependence and the values were much higher along the extrusion direction (0°-orientation) than those along the direction inclined 45° with respect to the extrusion direction (45°-orientation), irrespective of the extrusion ratio. In the deformation along the 45°-orientation the basal slip predominantly occurred in all the specimens. In the deformation along the 0°-orientation, on the other hand, formation of deformation kink band was accompanied in addition to the basal slip, and its formation frequency was different depending on the extrusion ratio. The influence of the variation in texture as a function of extrusion ratio, and in addition the influence of kink deformation bands introduced in the alloy during the extrusion process to the plastic deformation behavior and mechanical properties are quantitatively discussed.