Development of novel Fe based nanocrystalline FeBNbPSi alloy powder with high B
                  s of 1.41T by forming stable single amorphous precursor

K. Yoshidome,M. Hosono,H. Kumaoka,A. Hasegawa,H. Matsumoto,Y. Kajiura,S. Mori

doi:10.1063/9.0000259

Abstract

The possibility of the powderization of precursor with a single amorphous phase was investigated in FeBNbP nanocrystalline alloy particles and FeBNbPSi nanocrystalline alloy powders. Fe90−xBxNb7P3 (x=9, 10), Fe79.5B9.5Nb7P3Si1 and Fe82−x B9Nb6P3Six (x=2, 3) powders were prepared by the gas atomization method using high pressure water for rapid quenching. The as-atomized particle as a precursor exhibiting low Hc of 141 A/m with a single amorphous phase was observed from a cross sectional image and SAED pattern in the Fe80B10Nb7P3 nanocrystalline alloy powder. In addition, the stability of amorphous phase in the FeBNbP nanocrystalline alloy was also significantly improved by the addition of Si. Therefore, the as-atomized Fe79B9Nb6P3Si3 nanocrystalline alloy powder with Si as a precursor powder of nanocrystalline alloy was achieved to exhibit excellent magnetic softness of low Hc of 53 A/m compared to the ordinary Fe73Si11B11Cr3C2 amorphous and Fe73.5Si13.5B9Nb3Cu1 nanocrystalline alloy powders. In addition, the Fe79B9Nb6P3Si3 powder after nanocrystallization at 873K achieved both high Bs of 1.41T and low Hc of 37 A/m compared to ordinary amorphous, and nanocrystalline alloys.

Highlights

Fe-based magnetic materials used as magnetic cores for inductors are categorized according to their respective microstructures such as crystalline structure and nonequilibrium structure
The as-atomized powder structures were examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM)
We concluded that the novel FeBNbPSi nanocrystalline alloy powder with both high Bs and low Hc was developed for the magnetic core of inductor products

Summary

INTRODUCTION

Inductors are required to have high specifications for IoT devices and automotive. Fe based soft magnetic materials are widely applied to inductors as magnetic core materials. Fe-based magnetic materials used as magnetic cores for inductors are categorized according to their respective microstructures such as crystalline structure and nonequilibrium structure. Representative metallic soft magnetic materials with crystalline structure are Fe-Si, Fe-Ni and Fe-Si-Al alloys. The FeSiB type amorphous alloy, the FePBNb glassy metal alloy, the FeNbB3–5 and the FeSiBPCu6–8 type nanocrystalline alloys are represented as metallic soft magnetic materials with the non-equilibrium structure. The Fe based nanocrystalline alloys with both high Bs and low Hc are expected among the Fe based soft magnetic materials. The powderization of Fe based nanocrystalline alloys with high Fe content of more than 75 at% is difficult because most Fe-based nanocrystalline alloys show low amorphous forming ability. We report on the novel Fe based Fe79.5B9.5Nb7P3Si1 and Fe82-xB9Nb6P3Six (x=2, 3) nanocrystalline alloys with Bs of over 1.4T and the powderization of these alloys in this paper

EXPERIMENTAL PROCEDURE

AND DISCUSSION

CONCLUSION