Revealing the influence of Zr micro-alloying and hot extrusion on a novel high ductility Zn–1Mg alloy

Abstract In this work, a novel high ductility Zn-1Mg alloy was fabricated by Zr (zirconium) micro-alloying followed by hot extrusion. The results revealed that the addition of Zr could refine the microstructure and induce the formation of Zn22Zr phase in as-cast Zn-1Mg alloy. Moreover, the as-extruded Zn-1Mg-0.5Zr alloy was composed of a typical bimodal microstructure, the Zn22Zr phase can effectively stimulate the dynamic recrystallization (DRX) behavior via particle-stimulated nucleation (PSN) mechanism and promote multiple slip during hot extrusion process. At the same time, compared with the as-extruded Zn-1Mg alloy, the as-extruded Zn-1Mg-0.5Zr alloy exhibited a more satisfactory combination of strength and ductility, the ultimate tensile strength (UTS) increased from 215 MPa to 260 MPa and the elongation dramatically increased from 18.5% to 36.5%. The strengthening-toughening mechanisms were systematically analysed in this work.