Effect of Cu and P on the Crystallization Behavior of Fe-Rich Hetero-Amorphous FeSiB Alloy

Abstract

The effect of simultaneously adding P and Cu on the crystallization behavior of hetero-amorphous FeSiB alloy was investigated. Thermal properties and microstructure evolution were studied by means of X-ray diffraction, transmission electron microscopy, differential scanning, and isothermal calorimetric methods. It is found that the addition of P and Cu to the FeSiB alloy changes its crystallization temperature as well as the apparent activation energy for crystallization. The crystallization process is mainly dominated by three-dimensional growth with various nucleation rates for the selected FeSiB(PCu) alloys. The phases formed during crystallization for the different alloys of Fe 84 Si 4 B 12 , Fe 83:3 Si 4 B 12 Cu 0:7 , and Fe 83:3 Si 4 B 8 P 4 Cu 0:7 are similar. The refinement effect of adding P and Cu to the FeSiB alloys is observed. The mean size of -Fe phases decreases from 200 nm to about 20 nm.

Structural, thermal and magnetic properties of Fe–Si–B–P–Cu melt-spun ribbons: Application of non-isothermal kinetics and the amorphous random anisotropy model

“…As shown in Fig. 4(a) and (b), the activation energies of both nucleation E x1 and growth E p1 of ␣-Fe nanocrystallites for the present alloy system are similar to that of the previous report [13]. Fig.…”

“…2(a)). The onset (T x1 ) and peak (T p1 ) crystallization temperatures of the first exothermic peak are associated with the nucleation and growth processes of ␣-Fe nanocrystallites, respectively [13,22,23]. The apparent activation energies of the nucleation (E x1 ) and growth (E p1 ) processes for melt-spun alloys can be calculated by the Kissinger's equation [24]:…”

“…Variable cooling rates alter the diffusion process of atoms during the rapid solidification process and thus affect the degree of amorphicity [7] and local short-medium range order [8] in melt-spun ribbons. As a consequence, the thickness, microstructure and the microstructure-dependent properties of the melt-spun ribbons exhibit a strong dependence on quenching wheel speed [7][8][9][10][11][12].From the viewpoint of kinetics, the activation energies of the nucleation and growth of nanocrystallites, which determines the nanocrystallizaiton process and the microstructure of the annealed nanocrystalline alloy [13][14][15][16][17], are intimately related to the microstructure of the melt-spun alloys. Thermal analysis can give the activation energy of the crystallization process from the viewpoint of non-isothermal kinetics.…”

Electrochemical Behavior of Annealed Soft-Magnetic Fe–Si–B–P–Cu Alloy

“…37) ) and optimizing the heat treatments. 4,5,79) Recently, Cu-added Fe-metalloid (B, C, Si, P) alloys, particularly for Fe 83.3 Si 4 B 8 P 4 Cu 0.7 alloy system, have exhibited low core loss, a saturation magnetic flux density, B s , as high as 1.88 T and a coercivity, H c , as low as 7 A m ¹1 , 1013) compared with the representative Fe 78 Si 9 B 13 amorphous alloys with a B s of about 1.54 T and a H c of 2.6 A m ¹1 . 10) The application of new-developed alloy systems as replacements of magnetic cores of the transformers and motors for the silicon-steel soft-magnetics is predicted to reduce the electric power loss substantially, more than 70%, 14,15) which make us believe in their bright future for the mass production.…”

Phase transition from fcc to bcc structure of the Cu-clusters during nanocrystallization of Fe85.2Si1B9P4Cu0.8 soft magnetic alloy

“…[10][11][12] Like as FINEMET the addition of a small amount of Cu in NANOMET effectively reduces grain size of precipitated bcc-Fe crystallites into a nanometer scale. 5,13,14 Therefore, it is expected that Cu in NANOMET plays a similar role as FINEMET. There are significantly different features, however, between NANOMET and FINEMET.…”