Phase Evolution and Soft Magnetic Behavior of Mechanically Alloyed Fe–Co–Ni Medium Entropy Alloy at Different Disk Angular Velocity

Abstract

FeCoNi medium entropy alloy was mechanically alloyed at two angular velocities, i.e., 500 and 300 rpm, utilizing a high-energy planetary ball mill. The energy transfer criteria, phase, and microstructural evolution during the milling mechanism were described and analyzed by kinematics, X-ray diffraction, scanning electron microscope, and transmission electron microscopy. The results revealed that the total energy transferred during mechanical alloying was near ~ 4.635 times greater than FeCoNi-300 rpm. However, the structural analysis showed the γ-FCC phase in the case of FeCoNi-500 rpm and α-BCC + γ-FCC phases in case of FeCoNi-300 rpm. The magnetic properties were studied at 300 K and presented an excellent soft magnetic behavior with saturation magnetization of 124.86 emu/g and coercivity of 15.39 Oe in the case of FeCoNi-500 rpm. Furthermore, temperature-dependent magnetization measurements were also carried out and fitted with the modified Bloch model and Bloch and Curie–Weiss law-modified model. The results revealed that there is the existence of a significant ferromagnetic phase in the case of FeCoNi-300 rpm. © 2023, The Indian Institute of Metals - IIM.