A novel nano-spaced coherent FCC1/FCC2 eutectic high entropy alloy

Nanostructured High Entropy Alloys as Structural and Functional Materials

“…Since the advent of the concept of eutectics, eutectic alloys have been developed as advanced materials, generating significant research interest due to their excellent castability and superior properties. − In comparison to single-phased HEAs, the development of eutectic high entropy alloys (EHEAs) offers possibilities for overcoming the strength-ductility trade-off by forming a multiphased microstructure in a composite manner . For the predominantly developed EHEAs with lamellar structures, their mechanical properties heavily rely on the interlamellar spacing (λ), which ranges from several nanometers to micrometers. ,− Lei et al conducted a study on a series of CrFeNiB x ( x = 0–0.3) EHEAs and observed that the compressive strength gradually increased while the value of λ decreased with an increase in B content . Similarly, Rahul et al investigated the effect of Nb addition in FeCoNiCuNb x ( x = 5, 7.5, 11.6) EHEAs and discovered that the value of λ decreased from 300 nm ( x = 5) to 200 nm ( x = 11.6) with an increase in compressive strength, indicating that the spacing λ and strength still adhered to the Hall-Petch relationship. , Additionally, the decreased λ also amplified the degree of heterogeneities, resulting in geometrically necessary dislocation (GND) pile-ups at multiple interfaces, leading to a stronger heterogeneous deformation induced (HDI) strengthening effect. − Wang et al prepared several EHEAs and found that the Al 19 Co 23 Fe 21 Ni 37 EHEA with a finer lamellar spacing of ∼780 nm exhibited higher strengthening rates and back stress compared to the Al 18 Co 27 Fe 20 Ni 35 EHEA with a coarser lamellar spacing exceeding 1.1 μm …”