A novel high-entropy alloy with an exceptional combination of soft magnetic properties and corrosion resistance

Abstract

The lack of corrosion resistance limits the application of most conventional soft magnetic materials (SMMs) in a corrosive environment, especially in seawater. Hence, enhancing the corrosion resistance of SMMs is critically important. However, a severe contradiction exists between magnetic properties and corrosion resistance as the main anticorrosion element Cr has strong anti-ferromagnetism that deteriorates the magnetism of alloys. This study aimed to report a novel single body-centered cubic high-entropy alloy (HEA) (Fe2.25Co1.25Cr)94Al6 with an optimal combination of soft magnetic properties, corrosion resistance, and mechanical properties. The saturation magnetization of the HEA was as high as 141.88 emu g−1 and the coercivity was only 2.9 Oe, which were superior to most of the reported magnetic HEAs and conventional alloys. The corrosion resistance of the HEA was better than that of the 304 stainless steel, all of soft magnetic HEAs, and most of the reported HEAs in simulated seawater medium. In addition, the novel HEA exhibited excellent mechanical properties with a yield strength of 1100 MPa, a compressive fracture strain of more than 33%, and an outstanding Vickers hardness value of 469 HV. Thus, this novel (Fe2.25Co1.25Cr)94Al6 HEA is a promising SMM for marine environment applications.