Developing metallic structural materials with ultrahigh strength and exceptional ductility remains a significant challenge due to the trade-off between both properties. This study presents a heterogeneous-structured high-entropy alloy achieving a superior combination of strength and ductility compared to the reported heterogeneous-structured high entropy alloys through deformation and strain hardening in the non-recrystallized regions. The cold rolling followed by annealing at 760 °C resulted in a heterogeneous microstructure consisting of a small fraction of ultrafine recrystallized grains and extensive non-recrystallized regions, with a significant amount of L12 precipitates throughout the alloy. The architected microstructure led to a significant enhancement of yield strength through mechanisms including dislocation strengthening, L12 strengthening, and grain boundary strengthening. During the deformation, the non-recrystallized regions accommodated substantial strain through the reactivation of pre-existing deformation bands and the synergistic deformation of the FCC and L12 phases, thereby markedly enhancing ductility. Moreover, the metastable FCC matrix underwent FCC→BCC phase transformation, leading to the formation of numerous short-range BCC domains, which further contributed to the pronounced strain hardening. Consequently, the alloy annealing at 760 °C achieved a yield strength of 1.73 GPa, an ultimate strength of 2.05 GPa, and an elongation of 21.0 %. This study underscores a novel strategy for the concurrent enhancement of strength and ductility and provides valuable insights for the design of high-performance alloys.

中文翻译：

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通过在非均质结构高熵合金的非再结晶区域进行变形和应变硬化，实现具有超高强度的卓越延展性


由于这两种特性之间的权衡，开发具有超高强度和出色延展性的金属结构材料仍然是一项重大挑战。本研究提出了一种非均相结构高熵合金，与已报道的非均相结构高熵合金相比，通过在非再结晶区域的变形和应变硬化，实现了强度和延展性的优越组合。冷轧后在 760 °C 下退火，产生了由少量超细再结晶晶粒和广泛的非再结晶区域组成的异质微观结构，整个合金中含有大量的 L12 沉淀物。构建的微观结构通过位错强化、L12 强化和晶界强化等机制显着提高了屈服强度。在变形过程中，非再结晶区域通过重新激活预先存在的变形带以及 FCC 和 L12 相的协同变形承受了相当大的应变，从而显着提高了延展性。此外，亚稳态 FCC 基体经历了 FCC→BCC 相变，导致形成许多短距离 BCC 结构域，这进一步促进了明显的应变硬化。因此，合金在 760 °C 下退火实现了 1.73 GPa 的屈服强度、2.05 GPa 的极限强度和 21.0% 的伸长率。本研究强调了一种同时提高强度和延展性的新策略，并为高性能合金的设计提供了有价值的见解。