Novel Fe-C-B-P-Cu nanocrystalline alloys with superb magnetic properties and processability

Abstract

In this article, we present a new kind of Fe-C-B-P-Cu nanocrystalline alloys containing high P content with excellent comprehensive magnetic properties and processability. This kind of nanocrystalline alloys exhibits the high saturation magnetic flux density (Bs), low coercivity (Hc) and high effective permeability (μe) in the range of 1.73–1.84 T, 3.2–8.4 A/m and 6000–13000, respectively. It was found that increase of P content remarkably decreases the sensitivity of Hc to annealing temperature (Ta) and widen the optimum annealing temperature range to obtain a low Hc. With the increase of P content, the growth of α-Fe grains is retarded, but the nucleation of α-Fe grains is increased, resulting in reduced grain size and the intergranular amorphous layer, and precipitated high density of α-Fe nanocrystals. Based on the crystallization and structural features, the relationship between soft magnetic properties and microstructure for this kind nanocrystalline alloy was discussed in detail.