High-temperature strength-coercivity balance in a FeCo-based soft magnetic alloy via magnetic nanoprecipitates

Abstract

Precipitation strengthening is an effective approach to enhance the strength of soft magnetic alloys for applications at high temperatures, while inevitably results in deterioration in coercivity due to the pinning effect on the domain wall movement. Here, we realize a good combination of high-temperature strength and ductility (ultimate tensile strength of 564 MPa and elongation of ∼ 20 %, respectively) as well as low coercivity (6.97 Oe) of FeCo-2V-0.3Cr-0.2Mo soft magnetic alloy through introducing high-density magnetic nanoprecipitates. The magnetic nanoprecipitates are characterized by FeCo-based phase with disordered body-centered cubic structure, which enables the alloy to have a low coercivity. In addition, these nanoprecipitates can impede the dislocation motion and suppress the brittle fracture, which lead to a high tensile strength and ductility. This work provides a guideline to enhance strength and ductility while maintaining low coercivity in soft magnetic alloys via magnetic nanoprecipitates.