Research progress on the mechanical properties of eutectic high-entropy alloys

High-entropy alloys (HEAs), an emerging class of multi-component metallic materials, offer a vast research domain for overcoming the conventional trade-off between strength and ductility in structural materials. Despite considerable advancements in the mechanical characteristics of HEAs, numerous unresolved questions persist regarding the interplay between processing, microstructure, and properties, especially in terms of optimizing performance through compositional and microstructural control. Recently, eutectic high-entropy alloys (EHEAs) have garnered significant attention due to their distinctive dual-phase layered structure, enabling a synergistic enhancement of strength and ductility by leveraging the high-entropy effect alongside the inherent attributes of eutectic alloys. For instance, the AlCoCrFeNi_2.1 EHEA demonstrates exceptional overall mechanical properties by capitalizing on the cooperative deformation mechanisms of the soft and hard phases, leading to a gradient distribution of dislocations during deformation. This review delves into the mechanisms underlying the strength-ductility trade-off in HEAs, with a specific focus on the compositional and microstructural aspects of EHEAs, outlining the current obstacles and future research directions in EHEA studies, and offering theoretical insights to steer the development of high-performance structural materials.