Enhancement of ductility in high strength Mg-Gd-Y-Zr alloy
(1. State Key Laboratory for Corrosion and Protection, Institute of Metal Research,
Chinese Academy of Sciences, Shenyang 110016, China;
2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China)
Chinese Academy of Sciences, Shenyang 110016, China;
2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China)
Abstract: 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.
Key words: Mg-Gd-Y alloy; ductility; multiaxial forging; microstructure; dynamic precipitate