Tunable magnetic properties and heat-treatable bending ductility of Fe-Co-B-P-C amorphous alloys with a high saturated magnetization up to 1.79 T

A family of Fe85-xCoxB11P2C2 (x = 0, 5, 10, 15 and 20) amorphous alloys with high saturated magnetization (up to 1.79 T) and good bending ductility (foldable even after annealing at 600 K) were synthesized. The effects of the substitution of Co for Fe on glass formation, thermal stability and soft-magnetic properties were evaluated in details. The introduction of Co can significantly improve the saturated magnetization and the Curie temperature, while deteriorate the coercivity (Hc) in the resulting alloys. Applied tensile stress in the selected amorphous alloys can significantly decreases Hc from 13.7 A/m to 5.0 A/m as the tensile stress increases only from 0 to 25 MPa. The temperature window of annealing for bending ductility of these amorphous ribbons was also revealed. The optimal adjustment of both the alloy composition and applied stress provides a significant way to obtain advanced FeCo-based amorphous alloys with both excellent soft-magnetic properties and good bending ductility, which could be widely used in various engineering field, like high-speed electromotors.