Study of surface coating and magnetic properties of Fe-Si alloy powder cores

• 1、School of Optical and Electronic Information, Huazhong University of Science & Technology,Wuhan 430074
• 2、JPMF GUANGDONG CO., LTD,Jiangmen 529000

Abstract：Gas atomized Fe-6.5%Si alloy powders were surface-coated with various amounts of modified silica solution, and the effects of the coating on the magnetic properties of Fe-6.5%Si alloy powder cores have been investigated. It is founded that there exists uniform oxide compounds coating on the surfaces of the modified powders. The prepared magnetic cores exhibit stable permeability in the measured frequency range, showing good high-frequency characteristics. With the increasing amount of insulating solution, the magnetic permeability of the samples decreases while the DC-bias property substantially improves. However, the corresponding core loss indicates a different trend, i.e. decreasing at first and then increasing slightly. The sample withcorresponging to powders treated with 1.0 wt% of solution possesses a stable permeability of 78, a core loss of 170 mW/cm3 at the frequency of 50 kHz under the induction of 50mT, and 55% permeability at 10mT of DC-bias field. The results suggest that a proper coating on the powder surfaces can redound to achieve good performances for Fe-6.5%Si alloy powder cores.

Keywords： powder core Fe-6.5%Si alloy surface coating permeability DC-bias core loss