To resolve the strength-ductility trade-off problem for high-strength Mg alloys, we prepared a high performance Mg-8Gd-3Y-0.5 Zr (wt%) alloy with yield strength of 371 MPa, ultimate tensile strength of 419 MPa and elongation of 15.8%. The processing route involves extrusion, pre-deformation and aging, which leads to a bimodal structure and nano-precipitates. Back-stress originated from the deformation-incompatibility in the bimodal-structure alloy can improve ductility. In addition, dislocation density in coarse grains increased during the pre-deformation strain of 2%, and the dislocations in coarse grains can promote the formation of chain-like nano-precipitates during aging treatment. The chain-like nano-precipitates can act as barriers for dislocations slip and the existing mobile dislocations enable good ductility.

为了解决高强度Mg合金的强度-延展性折衷问题，我们制备了一种高性能Mg-8Gd-3Y-0.5 Zr（wt％）合金，屈服强度为371 MPa，极限抗拉强度为419 MPa，伸长率是15.8％。该加工路线涉及挤出，预变形和老化，这导致双峰结构和纳米沉淀。由双峰结构合金的变形不相容性引起的背应力可以改善延展性。另外，在2％的变形前应变期间，粗大晶粒中的位错密度增加，并且粗大晶粒中的位错可以促进时效处理过程中链状纳米沉淀的形成。链状纳米沉淀物可作为位错滑移的屏障，现有的移动位错可实现良好的延展性。