FeSiBPNbCu Bulk Nanocrystalline Alloys with High GFA and Excellent Soft-Magnetic Properties

Abstract

(Fe0.76Si0.09B0.1P0.05)99.3−xNbxCu0.7 (x = 0–1.5 at. %) bulk nanocrystalline alloys were prepared to investigate the alloying effects of Nb on glass forming ability, thermal stability, soft magnetic properties, and crystallization behavior. It was found that the amorphous forming ability was greatly improved with the addition of minor Nb. The thermal stability of Nb-containing alloy was significantly improved because the initial crystallization temperature and crystallization activation of the primary phase were obviously better than that of the Nb-free alloy. Further, the larger intervals of two-phase crystallization temperature and the significantly higher activation energy of crystallization of the second phase in the Nb-containing alloys favor the formation of a single α-Fe(Si) nanocrystalline structure. Moreover, Nb-containing alloys exhibit excellent soft magnetic properties, including high saturation magnetization of 1.42–1.49 T, low coercivity of around 1.0 A/m, and high permeability of about 18,000 at 1 kHz, which makes the alloys promising soft magnetic materials for industrial applications.

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.…”

Ab Initio Molecular Dynamics Study of the Structure and Properties of Nb-Doped Zr-Cu-Al Amorphous Alloys

“…Due to their formation and properties being very sensitive to the types and contents of constituent elements, some properties of ZrCu-based BMGs can be dramatically changed by doping Nb elements [8][9][10][11][12][13][14][15][16][17][18][19]. In the (Cu 50 Zr 43 Al 7 ) 100-x Nb x (x = 0, 1, 3, 6, 9 at.%) BMGs, the best room-temperature plasticity, and the highest fracture strength and glass transition temperature (T g ) are presented when x = 3 [1].…”