Possibilities of enhancing mechanical properties of brittle intermetallic containing high entropy alloys (HEAs) using novel processing and microstructural design strategies were investigated in the present work. For this purpose, homogenized CoCrFeNi_2.1Nb_0.2 HEA consisting of FCC matrix and complex Laves phase particles was successfully processed by severe cold- or cryo-rolling to 90% reduction in thickness followed by annealing (800 °C/1 hour(h)). As compared to cold-rolling, cryo-rolling resulted in a finer lamellar nanostructure and decidedly greater fragmentation of the Laves phase. Upon annealing, the cold-rolled HEA showed a recrystallized FCC matrix dispersed with D0₁₉ structured ε nano-precipitates. In contrast, the finer nanostructure and greater driving force for accelerated precipitation of profuse nano-precipitates at the early stages of annealing inhibited recrystallization in the cryo-rolled HEA and resulted in the formation of heterogeneous microstructure consisting of retained deformed and recrystallized regions. The novel heterogeneous microstructure of the cryo-rolled and annealed HEA resulted in a remarkable enhancement in strength-ductility synergy. The present results indicated that cryo-rolling could be used as an innovative processing strategy for tailoring heterogeneous microstructure and achieving novel mechanical properties.

在本工作中，研究了使用新颖的加工方法和微结构设计策略来增强脆性含高熵合金的金属间化合物的机械性能的可能性。为此，通过严格的冷轧或冷轧至厚度减少90％，然后退火（800°C / 1小时（h）），成功地处理了由FCC基体和复杂的Laves相颗粒组成的均质CoCrFeNi _2.1 Nb _0.2 HEA。 。与冷轧相比，低温轧制可产生更细的层状纳米结构，并确定拉夫斯相的碎裂程度更大。退火后，冷轧的HEA显示出分散有D0 ₁₉的重结晶FCC基质结构化的ε纳米沉淀。相反，在退火的早期，大量纳米沉淀物的细小纳米结构和更大的驱动力加速沉淀，抑制了冷轧HEA中的再结晶，并导致形成了由保留的变形和再结晶区域组成的异质微观结构。低温轧制和退火的HEA的新型异质微观结构显着增强了强度-延展性的协同作用。目前的结果表明，低温轧制可以用作一种创新的加工策略，用于定制异质微观结构并实现新颖的机械性能。