Structure and Properties of Nanostructured Metallic Glass of the Fe–B–Co–Nb–Ni–Si High-Entropy Alloy System

Abstract

The new nanostructured Fe25B17.5Co21.35Nb3.65Ni25Si7.5 high-entropy metallic glass (HE-MG) was synthesized by a dint of splat quenching technique. The estimated cooling rate was ~106 K/s. The coherently scattering domain size (crystallite size) of Fe25B17.5Co21.35Nb3.65Ni25Si7.5 HE-MG estimated by the Scherrer formula was ~3 nm. The coercivity of the nanostructured films of the investigated high-entropy alloy was measured by a B–H curve tracer and was 40 A/m, while for the crystallized as-cast alloy, it was about 1200 A/m. Thus, in accordance with the measured values of coercivity, the nanostructured Fe25B17.5Co21.35Nb3.65Ni25Si7.5 film is a typical soft magnetic material. The low value of the coercive force of HE-MG with a high degree of structural homogeneity and amorphicity can be explained by the insignificant density of the pinning sites for domain walls. The Fe25B17.5Co21.35Nb3.65Ni25Si7.5 HE-MG demonstrates also a high value of saturation magnetization of 74 A · m2/kg, which was measured at room temperature by a vibrating sample magnetometer. Nanostructured films exhibit also a high value of microhardness ≥8000 MPa which indicates good mechanical properties.