A simplified strategy is implemented to obtain the comprehensive strength-ductility synergy in the NiFeCoAl medium-entropy alloy (MEA) through one-pass cold-rolling (∼80%) and annealing without pre-homogenization treatment. The MEA annealed at 800 ℃ (A800) consists of disordered face-centered-cubic (FCC) matrix (γ) with ordered FCC nanoscale precipitates (γ’ and γ’), displaying ultimate tensile strength (UTS) of 895 MPa coupled with uniform elongation (UE) of 29%. It is found the selective distribution behavior of nanoscale γ’ and γ’ as full recrystallization (FR) precipitates within partial recrystallization (PR) and FR grains, exhibiting multiple nested-pattern heterostructure. The coarse-grained MEA annealed at 1200 ℃ (A1200) possesses a superior UE of ∼70% and an UTS higher than that of the as-cast sample, which can be rationalized by the interweaved stacking faults/nanoscale deformation-twins and the continuously generated twin boundaries. Moreover, a new parameter involving both UTS and UE is designed to unveil the salience of strength-ductility synergy. As compared with the reported MEAs within a similar yield strength range, A1200 MEA reveals the optimized , and can be considered as an outstanding candidate for further thermomechanical treatment.

中文翻译：

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通过简化的热机械处理调整再结晶以获得富镍中熵合金的最佳机械组合


为了获得 NiFeCoAl 中熵合金 (MEA) 的综合强度-延展性协同效应，采用了一种简化策略，通过一次冷轧 (∼80%) 和退火，无需预均匀化处理。在 800 ℃ 退火的 MEA (A800) 由无序面心立方 (FCC) 基体 (γ) 和有序 FCC 纳米级沉淀物 (γ' 和 γ') 组成，显示出 895MPa 的极限拉伸强度 (UTS) 以及均匀的伸长率（UE）为29%。发现纳米级γ'和γ'作为完全再结晶（FR）析出物在部分再结晶（PR）和FR晶粒内的选择性分布行为，表现出多重嵌套图案异质结构。在 1200 ℃ 退火的粗晶 MEA (A1200) 具有优于铸态样品的 70% 的 UE 和更高的 UTS，这可以通过交织的堆垛层错/纳米级变形孪晶和连续的变形来合理化。生成孪生边界。此外，设计了一个涉及 UTS 和 UE 的新参数，以揭示强度-延展性协同作用的显着性。与已报道的类似屈服强度范围内的 MEA 相比，A1200 MEA 显示出优化的 ，并且可以被认为是进一步热机械处理的杰出候选者。