Low core loss of Fe 85Si 2B 8P 4Cu 1 nanocrystalline alloys with high Bs and B800

Abstract

The Fe–Si–B–P–Cu nanocrystalline alloys exhibit high saturation magnetic flux density ( B s) as well as good soft magnetic properties such as low coercivity, high effective permeability and low magnetostriction after nanocrystallization. In this paper, the Fe 85Si 2B 8P 4Cu 1 alloy has been newly developed. On the viewpoint of magnetic softness, the Fe 85Si 2B 8P 4Cu 1 nanocrystalline alloy reveals low core loss ( W) at a commercially frequency of 50 Hz in the maximum induction ( B m) range of up to 1.75 T, and the W in the B m range of less than 1.8 T is smaller than that of the highest-graded oriented Si-steel due to high magnetic flux density at 800 A/m ( B 800) of above 1.8 T and excellent magnetic softness originated from much higher Fe content and uniform nanocrystalline structure with small magnetostriction. The electrical resistivity ( ρ) is relative higher than Si-steels. Thus the Fe–Si–B–P–Cu alloys are attractive for applying to magnetic parts such as motors, transducers, choke-coils and so-forth.