Mg alloys with superior strength-ductility synergy is highly desired for applications. In this study, the as-extruded Mg-Nd-Zn-Zr (JDBM) alloy rod was subjected to single-pass drawing over a range of temperature 200 ∼ 600 °C to enhance the properties. After drawing, a more homogeneous and refined microstructure developed because of dynamic recrystallization (DRX) and dynamic precipitation (DP). With the increase of drawing temperature, grain sizes increased first and then decreased due to the competition of grain nucleation and growth, while the sizes of the secondary phase particles varied in the same way. And a nearly basal texture evolved from a rare earth texture of the as-extruded sample. The yield strength of the as-drawn samples increased by ∼2.2 times with a sacrifice of elongation to fracture at different level. The high yield strength mainly originats from grain boundary and dislocation strengthening. An optimal combination of high yield strength (∼301 MPa) and good ductility (elongation to fracture of ∼19 % and improved strain hardening capacity) was obtained after drawing at 500 °C. The yield strength enhancement is mainly derived from texture and dislocation strengthening. Grain and secondary phase particle refinement, large volume fraction of low angle grain boundaries and reduced geometrically necessary dislocations are considered to be beneficial to the good ductility. In addition, a novel method has been proposed to fabricate materials with superior strength-ductility synergy by deformation with large strain at high temperatures to activate severe DP.

中文翻译：

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通过高温拉拔实现 Mg-Nd-Zn-Zr 合金棒的卓越强度-延展性协同效应

具有优异强度-延展性协同作用的镁合金是应用领域非常需要的。在这项研究中，挤压态 Mg-Nd-Zn-Zr (JDBM) 合金棒在 200 ∼ 600 °C 的温度范围内进行单道拉拔，以提高性能。拉拔后，由于动态再结晶（DRX）和动态沉淀（DP），形成了更加均匀和细化的微观结构。随着拉拔温度的升高，由于晶粒形核和长大的竞争，晶粒尺寸先增大后减小，而第二相颗粒的尺寸也随之变化。几乎基础的织构是从挤压样品的稀土织构演变而来的。拉制样品的屈服强度增加了约 2.2 倍，但牺牲了不同程度的断裂伸长率。高屈服强度主要来源于晶界强化和位错强化。在 500 °C 拉拔后，获得了高屈服强度（~301 MPa）和良好延展性（断裂伸长率~19%，应变硬化能力提高）的最佳组合。屈服强度的增强主要来源于织构强化和位错强化。晶粒和第二相颗粒的细化、小角度晶界的大体积分数和减少的几何必要位错被认为有利于良好的延展性。此外，还提出了一种新方法，通过高温下大应变变形以激活严重的DP来制造具有优异强度-延展性协同作用的材料。