Investigation of phase transformation related magnetic properties of Ti addition to FeCoCuNiMn and FeCoCuNiAl high entropy alloys by vacuum arc melting

Abstract

The motivation for the present work is to explain the ferromagnetic properties of Cantor high entropy alloy by adding an alternative metal atom instead of Cr, which decomposes at high temperatures. With this motivation, MnTix and AlTix (x=0.0, 0.1, 0.3 and 0.5) were added to FeCoCuNi alloy to investigate the change in magnetic properties related to structural properties. The FeCoCuNiMn HEA showed similarities with the Cantor alloy, including an FCC phase. Replacing Mn with Al introduced B2 and BCC phases alongside FCC. Adding Ti to the FeCoCuNiMn alloy did not affect the phase structure but refined the microstructure. In contrast, Ti induced a transition from FCC to BCC in the FeCuCoNiAl alloy. For magnetic properties, FeCoCuNiMn had a saturation magnetization of 40.64 emu/g and a coercivity of 346 Oe, while FeCoCuNiAl exhibited 21.60 emu/g saturation magnetization and 38 Oe coercivity. The addition of Ti led to altered magnetic characteristics, converting FeCoCuNiAl from a soft magnetic alloy to a hard magnetic alloy. However, it negatively affected the saturation magnetization, with values of 17.11, 10.66, and 10.93 emu/g at Ti ratios of 0.1, 0.3, and 0.5, respectively.