Microstructures of Long-Period Stacking Ordered Phase of Mg–Zn–Y Alloy

Abstract

The microstructures of ¡-Mg, long-period stacking ordered (LPSO) phases, and kink bands in a MgYZn alloy were observed by transmission electron microscopy (TEM). The results showed that extruded Mg 97 Zn 1 Y 2 alloy included different kinds of phases: 2H-Mg, 2H-Mg with many stacking faults, 14H and 18R. Kink bands tended to occur in areas where there were many intermetallic compounds. The element distribution of Zn/Y/Mg in the LPSO phase including kink boundaries was also analyzed by scanning TEM energy dispersive X-ray spectroscopy. The results showed that the concentrations of atomic Zn/Y decreased, while the concentration of atomic Mg increased at kink boundaries. This can be understood in terms of the dislocation structure of kink boundaries where extended a-dislocations lying on sequential stacking faults in the LPSO phase cause the annihilation of Zn/Y-rich stacking faults between two partial dislocations.

Analysis of kink boundaries in deformed synchronized long-period stacking ordered magnesium alloys

“…1d. The concentration of Mg increases along the kink boundaries of the LPSO phase, as reported in a previous paper [14]. Fig.…”

“…2 shows a schematic illustration of the formation process of the wedge-shaped kinks due to compression along the basal plane of the LPSO phase. This illustration of the wedge-shaped kinks was suggested by Romanov et al [15], who stated that misorientation [14]. bands that end in the material are wedge shaped, and that their tips frequently exit at the surface.…”

“…Fig. 1d shows a HAADF-STEM image of the bending kink bands of the LPSO phases of Mg 97 Zn 1 Y 2 as reported in a previous paper [14]. The kink boundaries are indicated by the red dotted arrows.…”

Microstructures, mechanical properties and corrosion behaviors of Mg–Y–Zn–Zr alloys with specific Y/Zn mole ratios

“…are observed around kink bands (shown in Fig. 4), these intermetallic compounds can be regarded as an factor to the kink formation [35]. On the other hand, the broken a-Mg by extrusion could retard the basal slip of the X-phase, which could also contribute to the kink formation.…”

Deformation Analysis of the Long-Period Stacking-Ordered Phase by Using Molecular Dynamics Simulations: Kink Deformation under Compression and Kink Boundary Migration under Tensile Strain

“…These features are in agreement with TEM observations. 7,26) The misorientation angle of the kink boundary at the top of the model is about 24°. In contrast, the sum of the slip vectors contributing to the rotation around the z-axis (along the dotted line shown in Fig.…”