Effect of Alloying Elements on the Microstructure and Magnetic Properties of Mechanically Alloyed AlNiCo-Based High-Entropy Alloys

Herein, the effect of addition of Cu, Fe, and CuFe on microstructure and magnetic properties of equiatomic ternary AlNiCo alloy is reported. This addition of Cu, Fe, and CuFe to AlNiCo results in L12, B2, and mixed alpha + B2 phases, respectively, during the mechanical alloying (MA) and subsequent annealing process. The low-temperature magnetic properties show that the addition of nonmagnetic Cu to AlNiCo enhances the coercivity, while Fe enhances the saturation magnetization value. Further from the study of magnetic properties, it is suggested that the phase segregation effects are minimum in MA process compared to melt process. It is also shown that the disorder plays a significant role in controlling the magnetic properties. The observed anomalous magnetic behavior is discussed in terms of modifications in exchange interactions between constituent elements due to chemical and structural disorder. A comparative study of microstructure and magnetic properties of AlNiCo(Cu,Fe) high-entropy alloys is presented. Addition of Fe to weakly magnetic AlNiCo results in enhancement of magnetization values, while Cu addition leads to increase in coercivity value. It is demonstrated that in samples prepared by mechanical alloying process the phase segregation effects are minimum, which is reflected in magnetic properties.image (c) 2024 WILEY-VCH GmbH