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

Abstract

The relationship between the deformation behaviors of the bulk α-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 α-Mg and 18R-LPSO phases are investigated by in-situ tensile scanning electron microscopy 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 α-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.