Unusual high Bs for Fe-based amorphous powders produced by a gas-atomization technique

Abstract

Fe-based alloy powders with a high Fe content of about 81 at.% were produced by a gas-atomization technique. Powders of Fe81Si1.9B5.7P11.4 (at.%) alloy showed a good glass forming ability and exhibited unusual high saturation magnetic flux density of 1.57 T. The core-loss property at a frequency of 100 kHz for the compacted core made of the Fe81Si1.9B5.7P11.4 powder is evaluated to be less than 500 kW/m3 under a maximum induction of 100 mT. Moreover, good DC-superposition characteristic of the core was also confirmed. These results suggest that the present Fe-based alloy powder is promising for low-loss magnetic-core materials and expected to contribute in miniaturization of electric parts in the near future.

Fabrication and Soft Magnetic Properties of Fe81.3Si4B10P4Cu0.7 Amorphous Powders by Using the Spinning-water Atomization Process

“…The amorphous forming ability of the aerosolized Fe76Si9B10P5 powders with low Fe content was close to 53 μm, while the Fe81.5Si0.5B4.5P11.0Cu0.5C2.0 powders prepared under the same processing conditions formed an amorphous state only when its particle size was below 10 μm [27]. Yoshida has prepared Fe81Si1.9B5.7P11.4 Febased amorphous powders with high Fe content by the combination of gas atomization and composition design, while Fe81Si3B6P10 and Fe81Si1.5B5P12.5 powders prepared by the same method have generated a large amount of Fe3B crystals in the preparation process, indicating that their thermal ability to maintain the amorphous state is very limited [17]. Although XRD results show that the powders are amorphous, XRD analysis cannot accurately distinguish the amorphous nanocrystalline alloy with grain size less than 7 nm [28].…”

“…The specific values are shown in Table 1. It is found that the sphericity of the powders prepared by the SWAP method was worse than gas-atomized powders [10,12,17,18]. This difference is mainly due to the different surface tension and water jet interaction modes during the solidification of the smelt droplets in different preparation processes [17,18].…”

“…This could be caused by the heat transfer and heat accumulation inside the center [5,9,17,18]. The FIB-SEM images (Fig.…”

Fe-Si-B-P-C-Cu nanocrystalline soft magnetic powders with high B s and low core loss

“…Gas-atomization may be one of proper techniques which can produced spherical powder particles, but this method has limitation in quenching rate compared to melt-spinning. 11 In this work, we reported investigation on magnetic properties of Fe-Si-B-P-Cu NANOMET powders produced by spinning-water atomization technique. This atomization method was reported to result in higher quenching rate than the conventional gas-atomization.…”