Magnetic properties of phosphoric acid passivated Fe-Si-B amorphous magnetic powder core
Yong Zhu, Cong Zhang, Xiansong Liu, Xucai Kan, Shuangjiu Feng, Qingrong Lv
Abstract
The magnetic properties of Fe-Si-B amorphous soft magnetic powder cores (SMCs) passivated by phosphoric acid are investigated in this work. Effects of phosphoric acid content and annealing temperature at different frequencies on permeability and magnetic loss of SMCs have been studied, too. Electronic microscope pictures and results of B-H analyzer show that the surface of Fe-Si-B SMCs is coated with a layer of dense phosphate. Experimental results show that Fe-Si-B SMCs with the best comprehensive magnetic properties ( μ e = 23.71; P cv = 470.6 mW•cm −3 measured at 1000 kHz, 20 mT) can be obtained by adding 0.8 wt% phosphoric acid at the annealing temperature of 480 °C.