A systematic investigations on effect of annealing temperature on magnetic properties of a promising soft magnetic Co35Cr5Fe10Ni30Ti20 HEA

The present study investigates the effect of different annealing temperatures on phase formation, microstructure, and their correlation with magnetic properties of a promising soft magnetic Co35Cr5Fe10Ni30Ti20 High Entropy Alloy (HEA) design developed by our research group previously. We reproduced the Co35Cr5Fe10Ni30Ti20 HEA through the mechanical alloying and found the mixture of fcc and R-phase having M-s = 74.8 emu/g and H-c= 12.92 Oe. The different annealing temperature was decided based on the DTA analysis of the synthesized sample. The samples were annealed at 200, 500, 700, 790, 870, and 965 degrees C for 2 h to study the change in the phase evolution and magnetic behavior. Phase transformation was observed for 500 degrees C annealed HEA, and the value of M-s (82.38 emu/g) and H-c (41.49 Oe) increased after annealing at 500 C. Interestingly, the samples annealed at high temperatures (> 700 degrees C) have a high value of M-s and a significantly low value of H-c (< 2 Oe). Among annealed Co35Cr5Fe10Ni30Ti20 HEA, 790 degrees C annealed HEA has the highest value of M-s (90.79 emu/g) and the lowest H-c (1.66 Oe)of HEAs reported so far. The concluding reason behind the high value of M(s)for annealed HEAs area decrease in lattice parameter, i.e., improved magnetic interaction and a change in volume phase fraction of synthesized phases. However, the soft magnetic behavior of high-temperature annealed HEA is attributed to the synergetic effect of the decrease in magnetocrystalline anisotropy, particle size, and surface anisotropy. The value of M-s and H-c for the 790 degrees C annealed HEA is comparable to some commercial soft magnets, such as Supermalloy, Ni-Zn ferrite, and Mn-Zn ferrite. Thus, the designed and developed Co(35)Cr(5)Fe(10)Ni(30)Ti(20)HEA showed excellent soft magnetic characteristics even after annealing at high temperatures and may be further considered for industrial applications. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The present study investigates the effect of different annealing temperatures on phase formation, microstructure, and their correlation with magnetic properties of a promising soft magnetic Co35Cr5Fe10Ni30Ti20 High Entropy Alloy (HEA) design developed by our research group previously. The study found that annealing at different temperatures led to changes in the magnetic properties of the alloy, and annealing at 790 degrees C resulted in the highest magnetization and lowest coercivity, exhibiting excellent soft magnetic characteristics that make it suitable for industrial applications.