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- Englisch (3)
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- LPSO (1)
- LPSO Phase (1)
- Magnesium alloy (1)
- Mg-Y-Zn Alloy (1)
- Neutron Diffraction (1)
- plasticity (1)
The evolution of the internal strains during in situ tension and compression tests has been
measured in an MgY2Zn1 alloy containing long-period stacking ordered (LPSO) phase using
neutron diffraction. The alloy was extruded at two different temperatures to study the influence
of the microstructure and texture of the magnesium and the LPSO phases on the deformation
mechanisms. The alloy extruded at 623 K (350 °C) exhibits a strong fiber texture with the basal
plane parallel to the extrusion direction due to the presence of areas of coarse non-recrystallised
grains. However, at 723 K (450 °C), the magnesium phase is fully recrystallised with grains
randomly oriented. On the other hand, at the two extrusion temperatures, the LPSO phase
orients their basal plane parallel to the extrusion direction. Yield stress is always slightly higher
in compression than in tension. Independently on the stress sign and the extrusion temperature,
the beginning of plasticity is controlled by the activation of the basal slip system in the dynamic
recrystallized grains. Therefore, the elongated fiber-shaped LPSO phase which behaves as the
reinforcement in a metal matrix composite is responsible for this tension–compression asymmetry.
Room temperature mechanical behavior of extruded Mg–Y–Zn alloys with varying fractions of LPSO phase was studied in tension and compression along the extrusion direction. The microstructure is characterized by elongated LPSO fibers along the extrusion direction within the magnesium matrix. Moreover, the magnesium matrix presents a bimodal grain structure with dynamically-recrystallized grains and deformed, elongated grains with the basal plane parallel to the extrusion direction. The beginning of plasticity depends on the volume fraction of deformed and DRX grains. Alloys with low volume fraction of LPSO phase(o10vol%),with a high volume fraction of deformed grains, show the typical behavior of extruded magnesium alloys where yield stress in tension is higher than in compression. This effect is, however, reversed as the volume fraction of the LPSO phase increases since DRX grains are majority.
Room temperature mechanical behavior of extruded Mg–Y–Zn alloys with varying fractions of LPSO phase was studied in tension and compression along the extrusion direction. The microstructure is characterised by elongated LPSO fibers along the extrusion direction within the magnesium matrix. Moreover, the magnesium matrix presents a bimodal grain structure with dynamically-recrystallized grains and deformed, elongated grains with the basal plane parallel to the extrusion direction. The beginning of plasticity depends on the volume fraction of deformed and DRX grains. Alloys with low volume fraction of LPSO phase (<10 vol%), with a high volume fraction of deformed grains, show the typical behavior of extruded magnesium alloys where yield stress in tension is higher than in compression. This effect is, however, reversed as the volume fraction of the LPSO phase increases since DRX grains are majority.