Role of Zn addition on the microstructure and tensile property in Mg–Mn–Nd alloys

Abstract

The role of Zn addition (1, 2 wt%) on the microstructural characteristics and tensile properties of the extruded Mg–1Mn–1Nd (MN11) alloy is discussed. The addition of Zn negligibly influences the particle type; however, Zn addition causes un–homogeneous distribution structure firstly and then develops homogeneous structure because of the change of size and distribution of Mg12Nd particles. The MZN111 sheet shows higher yield strength (YS) along the extrusion direction (ED), and lower YS along the transverse direction (TD), compared to the MN11 sheet. This improvement is attributed to the Zn solute atoms via solid-solution strengthening effect, while the reduction is ascribed to the formation of TD–orientation texture and coalescence of dynamic recrystallized (DRXed) grains. As the Zn content increases to 2 wt%, The MZN121 sheet with highest strength can be ascribed to the homogeneous distribution of finest grains via the grain–boundary strengthening effect and more Zn solute atoms via solid–solution strengthening effect. The increased size of Mg12Nd particles with 1 wt% Zn content and coalescence of DRXed grains, which can significantly reduce the ductility of MZN111 sheet. Further, the ductility enhancement of the MZN121 sheet is mainly due to the homogeneous distribution of fine grains and homogeneous alignment of Mg12Nd particles.