抄録
Inhomogeneous deformation behavior in a magnesium alloy which is almost occupied by long-period stacking order (LPSO) phase has been investigated by using high-precision marker method and TEM. Particular emphasis is laid on the aspect of a microstructure called "kink" generated characteristically in the LPSO phase. Mg alloys containing Zn and rare earth elements such as Y or Gd have a characteristic microstructure including the LPSO phase and the usual hcp matrix phase. The superior mechanical properties of the Mg alloy should be closely related not only to the microstructural inhomogeneity induced by the difference in the deformability of the dual phases but also to the characteristic deformation behavior of LPSO phase. The hard LPSO phase should contribute to the increase of yield and tensile strength. A characteristic microstructure called "kink" was generated by working such as extrusion in the LPSO phase, which raise the strength of LPSO phase. In order to clarify the details of kinking behavior, high-precision marking method using electron beam lithography has been employed. After compression test, many wedge-shape microstructures accompanying large distortion of markers were observed on the specimen surface, which indicates that the kinking occurred by the compression test. In addition, TEM observation revealed that basal plane was bended in the area including the kinks. The formation mechanism of such microstructural inhomogeneity in the LPSO phase is discussed.
