Fe-based amorphous powder cores with low core loss and high permeability fabricated using the core-shell structured magnetic flaky powders

Abstract

Fe-based amorphous powder cores based on the industrial flaky FeSiBCCr magnetic powders coated with high-quality inorganic (SiO2) insulating layer via a sol-gel method were successfully fabricated to improve the soft magnetic properties of powder cores. The core-shell structure of magnetic flaky powders was characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy analysis, and Fourier transform infrared spectroscopy. The influence of annealing temperature on the soft magnetic properties of the FeSiBCCr magnetic flaky powder cores (MFPCs) has been systematically investigated, and the comparisons were made with the conventional FeSiB and Finemet MFPCs at the same preparation conditions. It was found that the reasonable annealing temperature could enhance the permeability and reduce the core loss for the MFPCs. As compared to the conventional FeSiB MFPCs, the FeSiBCCr MFPCs annealed at 773 K for 0.5 h exhibits a higher permeability of 79.19, and lower core loss of 122.26 mW/m3 at 100 kHz for Bm = 0.05 T. Additionally, the FeSiBCCr MFPCs shows a better DC-bias property of 51.30%, and lower raw material cost than those of the Finemet MFPCs. The excellent comprehensive magnetic properties of the FeSiBCCr MFPCs are favorable for achieving the optimal design of powder cores toward practical applications.