Copper-free nanocrystalline soft magnetic materials with high saturation magnetization comparable to that of Si steel

Abstract

The effect of rapid annealing on the structural and magnetic properties of melt-spun Fe-B based alloys has been investigated. The grain size of a Fe85B13Ni2 alloy after primary crystallization is reduced significantly by rapid annealing, and a low coercivity of 4.6 A/m and a high saturation magnetization of 1.90 T are obtained. This saturation magnetization is comparable to those of Si steels (1.8–2 T). The core losses of nanocrystalline Fe85B13Ni2 are lower by 60%–80% as compared with those of commercial Si steels. Rapid annealing is found to be effective in realizing a magnetically soft nanostructure without Cu addition, leading to an exceptionally low content of nonmagnetic additives (2.8 wt. %) and thus a high saturation magnetization in the nanostructure.

Rapid Annealing Optimizing Magnetic Softness and Thermal Stability of Mn-Substituted Fe-Based Nanocrystalline Alloys

“…However, their low B s of around 1.24 T is not conducive to the miniaturization and high power of electromagnetic devices. Many efforts have been devoted to improve the B s of Fe-based nanocrystalline alloys-e.g., increasing the Fe content [4][5][6], adding Co element to increase the magnetic exchange interaction [7][8][9], decreasing the amount non-magnetic and large-sized elements [10,11], and removing Cu element [12,13]. However, these alloys with high B s suffer from a low amorphous-forming ability and poor high-frequency magnetic softness, which is unable to meet the requirement for mass production and high-frequency applications.…”

Solid state amorphization in a thin Fe-Si-Mg-O surface film triggered by the reduction of elements from oxides in the temperature range of the α-γ transformation

“…The formation of the atomic structure and its effect on the properties of metallic glass have been studied by a number of researchers so far [3 -5]. Despite the substantial number of currently known chemical compositions of amorphous metallic glasses [6], the development of new ones [7] and the optimization of the known compositions [8] are still of considerable interest.…”

The Effect of Copper and Manganese on the Amorphization Process in a Thin Fe–Si–Mg–O Film

“…Despite the quite a large number of currently known chemical compositions of amorphous metal glasses, interest in developing new ones or optimizing the composition of known ones continues to grow [2][3][4][5][6]. It is important to emphasize that all technologies for producing amorphous materials imply ultrahigh cooling rates, for "freezing" atoms in a metastable structure that does not have a long-range order.…”