In-situ and ex-situ investigation of deformation behaviors of a dual-phase Mg-Ni-Y alloy

The relationship between the deformation behaviors of the bulk alpha-Mg and Long Period Stacking Ordered (LPSO) phases is important for the design of high-strength alloys. In this work, the deformation behaviors of dual-phase Mg alloy which contains alpha-Mg and 18R-LPSO phases are investigated by in-situ tensile scanning electron mi-croscopy and ex-situ transmission electron microscope. The results show that the 18R phase accounting for 11.3 vol.% provides 23.0% deformation of the overall alloy. At the early stage of deformation, the stacking faults are bent to coordinate twinning deformation through the slip of basal dislocations in the alpha-Mg matrix, while the kinking deformation 18R induces the kinking deformation of Mg slices. At the end of deformation, large numbers of T2-type stacking faults are generated. These deformation behaviors improve the ductility of the alloy. This work provides a novel strategy to design the high strength and good ductility dual-phase Mg alloys.

Automated summary

The deformation behaviors of a dual-phase Mg alloy containing α-Mg and 18R-LPSO phases were investigated in this study. The 18R phase, accounting for 11.3 vol.%, contributed to 23.0% of the overall alloy deformation. The coordinated twinning deformation of α-Mg matrix through the slip of basal dislocations and the kinking deformation of Mg slices induced by the 18R phase were observed during the early stage of deformation. At the end of deformation, a large number of T2-type stacking faults were generated, improving the ductility of the alloy. This work provides a novel strategy for designing high-strength and good ductility dual-phase Mg alloys.