Effect of Cr-Doping on the Structural and Magnetic Properties of Mechanically Alloyed FeCoNiAlMn1-x Cr x High-Entropy Alloy Powder

In this work, thenew compositions of FeCoNiAlMn1-x Cr x , (0.0 <= x <= 1.0), a high-entropy alloy powder (HEAP), areprepared by mechanical alloying (MA). The influence of Cr doping onthe phase structure, microstructure, and magnetic properties is thoroughlyinvestigated through X-ray diffraction (XRD), scanning electron microscopy(SEM), and vibrating sample magnetometry. It is found that this alloyhas formed a simple body-centered cubic structure with a minute face-centeredcubic structure for Mn to Cr replacement with heat treatment. Thelattice parameter, average crystallite size, and grain size decreaseby replacing Cr with Mn. The SEM analysis of FeCoNiAlMn showed nograin boundary formation, depicting a single-phase microstructureafter MA, similar to XRD. The saturation magnetization first increases(68 emu/g) up to x = 0.6 and then decreases withcomplete substitution of Cr. Magnetic properties are related to crystallitesize. FeCoNiAlMn0.4Cr0.6 HEAP has shown optimumresults with better saturation magnetization and coercivity as a softmagnet.