Characterization of active deformation mechanisms in Mg alloys with LPSO phase

Abstract

The WZ21 and the WZ72 magnesium alloys containing long period stacking ordered (LPSO) phase extruded with an extrusion ratio of 4:1 at 350◦C. The microstructure was analyzed by scanning electron microscopy using electron backscattered diffraction. Both alloys exhibit bimodal microstructure of the Mg matrix and elongated LPSO phase along the extrusion direction. Using kernel average misorientation (KAM) maps it was shown that the dynamic recrystallization starts at the grain boundaries of the initial coarse grains. Both alloys exhibit fiber basal texture. The maxima of the basal planes are reduced by increasing content of alloying elements. Uniaxial compression tests along extrusion direction with concurrent acoustic emission measurements were performed to reveal mechanical properties and active deformation mechanisms of the studied alloys. The acoustic emission source mechanisms were identified by statistical analysis of the raw acoustic emission signal.