Analysis of the Microstructure Role in the Yield Asymmetry of Extruded Mg-LPSO Alloys Using In Situ Diffraction Experiments

The effect of microstructure and processing parameters on the mechanical behavior of extruded Mg-Y-2x-Zn-x alloys containing different volume fractions of the long-period stacking order (LPSO) phase is evaluated using in situ diffraction experiments. The Mg-LPSO extruded alloys exhibit a microstructure consisting of a mixture of fine dynamically recrystallized alpha-Mg grains, highly oriented non-recrystallized coarse alpha-Mg grains with the basal plane parallel to the extrusion direction, and particles of the LPSO phase elongated in the extrusion direction. The volume fraction of dynamically recrystallized alpha-Mg grain areas tends to increase as the volume fraction of the LPSO phase and the processing stress increase. In situ diffraction experiments have allowed the understanding of the elastic-plastic behavior of non-DRXed and DRXed grains, and their individual contribution to the macroscopic deformation of magnesium alloys containing LPSO phases and, consequently, the reverse tension-compression asymmetry.

Automated summary

This study evaluates the influence of microstructure and processing parameters on the mechanical behavior of extruded Mg-Y-2x-Zn-x alloys containing the long-period stacking order (LPSO) phase. The volume fraction of dynamically recrystallized alpha-Mg grains increases with the volume fraction of the LPSO phase and processing stress.