Evaluation of microstructure and magnetic performance of Fe- 6.5 wt% Si soft magnetic powder core

This paper reports microstructure and magnetic performance of Fe-6.5wt% Si (Fe-Si) soft magnetic powder cores. Fe-Si powder core showed the extremely high saturation magnetization in the range from 186.1 to 192.2 emu/g depending on the annealing temperature. The permeability of the powder core at the frequency of 20 kHz gradually increased from 33.9 to 46.1 as the annealed temperature of the core was increased from 400 to 800 °C. The total core loss at the maximum magnetic flux density of 100 mT shows the increased tendency as function of frequencies in all annealed cores. In particular, the high saturation magnetization of 192.0 emu/g and lowest total core loss 267 kJ/m³ measured at 20 kHz and 100 mT were obtained for the annealed powder core at 800 °C, suggesting that it is one of the promising candidates for high frequency power electronic devices.