A high strength GW94 alloy with fully recrystallized microstructure and equiaxed ultrafine grains of submicron size was produced by multiaxial forging and ageing. The alloy exhibits an ultimate tensile strength of 377 MPa, proof stress of 295 MPa and elongation to failure of 21.7%. The ductility is improved in comparison with that of the conventional extrusion processing. Superplastic ductility is achieved in tensile testing at 573 K with a maximum elongation of 450%. These high ductility and high strength are attributed to the coexistence of fully recrystallized grains and nanoscale Mg5(Gd, Y) particles dynamically precipitated at grain boundaries.%采用多向锻造及人工时效制备高强度高塑性GW94合金.该合金具有完全再结晶组织和亚微米级超细等轴晶,其抗拉强度、屈服强度及伸长率分别为377 MPa,295 MPa和21.7%.与传统挤压工艺相比,多向锻造显著提高材料的塑性.在573 K下拉伸时,该合金表现出超塑性,其最大伸长率为450%.GW94合金的高强度和高塑性是由完全再结晶晶粒和在晶界处动态析出Mg5(Gd,Y)纳米颗粒的共同作用.
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