Nanocrystalline Ni25Co20Cu10Fe25Mn20 High-Entropy Alloys Prepared by Mechanical Alloying

An Ni25Co20Cu10Fe25Mn20 high-entropy alloy (HEA) was produced using mechanical alloying. Similar to equiatomic NiCoCuFeMn alloy, a face-centered cubic single-phase nanocrystalline HEA was obtained after 28-h milling. The lattice parameter of this new HEA (0.360 nm) was slightly smaller than that of equiatomic alloy (0.361 nm). The crystallite size of the final product was 9 nm, significantly finer than the values reported for the equiatomic HEAs. According to the analysis of the HEA powder particles' deformation behavior, the system operated in a ductile-brittle mode. The thermal behavior of prepared alloy, characterized by differential thermal analysis, was similar from that of equiatomic NiCoCuFeMn alloy. Similar to the equiatomic NiCoCuFeMn, the sluggish diffusion effect was not true for the Ni25Co20Cu10Fe25Mn20 HEA. Studying the magnetic behavior of Ni25Co20Cu10Fe25Mn20 HEA, using vibrating sample magnetometry, confirmed a soft magnetic behavior for this material like an equiatomic alloy.