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 Co 35 Cr 5 Fe 10 Ni 30 Ti 20 High Entropy Alloy (HEA) design developed by our research group previously. We reproduced the Co 35 Cr 5 Fe 10 Ni 30 Ti 20 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 ͦ C for 2 h to study the change in the phase evolution and magnetic behavior. Phase transformation was observed for 500 ͦ 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 °C) have a high value of M s and a significantly low value of H c (<2 Oe). Among annealed Co 35 Cr 5 Fe 10 Ni 30 Ti 20 HEA, 790 ͦ 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 magneto-crystalline anisotropy, particle size, and surface anisotropy. The value of M s and H c for the 790 ̊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. • Co 35 Cr 5 Fe 10 Ni 30 Ti 20 high entropy alloy synthesized through mechanical alloying. • Effect of different annealing temperatures on Co 35 Cr 5 Fe 10 Ni 30 Ti 20 HEA was studied. • XRD and TEM analysis confirmed the formation of FCC (major) and intermetallic R-phase. • The Reported value of Hc for 790°C annealed HEA is second losed value for HEA. • 790 °C annealed HEA exhibited comparable magnetic behavior compared to commercial materials.