Contributions of multimodal microstructure in the deformation behavior of extruded Mg alloys containing LPSO phase

Hagihara, Koji*; Mayama, Tsuyoshi*; Yamasaki, Michiaki*; Harjo, S.   ; Tokunaga, Toko*; Yamamoto, Kazuki*; Sugita, Mika*; Aoyama, Kairi*; Gong, W.   ; Nishimoto, Soya*

The unique control mechanisms of the plastic deformation of two-phase extruded alloy composed of Mg and long-period stacking ordered (LPSO) phase were clarified by comparison with those of other Mg solid-solution alloys, focusing on the question of why do the Mg/LPSO two-phase alloys exhibit both large elongation and high strength? The stress-strain curves for each grain in the alloys could be imaginary estimated using neutron diffraction analysis during the tensile test. The results demonstrate that the deformation behaviors of the worked and recrystallized grains are significantly different in all the Mg-extruded alloys owing to the strong plastic anisotropy in Mg with hexagonal close-packed (hcp) structure. Therefore, the deformation behavior is controlled by a composite-like deformation mechanism, even in single-phase Mg solid-solution alloys.