Effects of two silicone resin coatings on performance of FeSiAl magnetic powder cores

Two silicon resins with excellent thermal stability, JH1123 and JH7102, are used as the insulated agents and binders for the gas-atomized FeSiAl powder, and corresponding magnetic powder cores (MPCs) are fabricated. The insulation capability and application prospects of the two silicon resins are evaluated by comparing the magnetic properties of the coated powder and MPCs. The scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy results show that uniform insulation layers are both formed on the powder surfaces. JH1123 has stronger binding ability, and the JH1123-coated powder exhibits severe agglomeration, with d50 (average particle size) approximately twice that of the JH7102-coated powder. Both as-prepared MPCs exhibit outstanding soft magnetic properties. Wherein, the permeability of FeSiAl@JH1123 is up to 74.0, which is 35.5% higher than that of FeSiAl@JH7102 because JH1123 can further improve the density of the MPCs. As for FeSiAl@JH7102, it has better direct current bias and lower core loss of 716.9 mW cm-3 at 20 mT and 1000 kHz due to its lower coercivity and greater anti-magnetic saturation ability. A comprehensive comparison shows that FeSiAl@JH1123 is suitable for medium and high frequency applications, while FeSiAl@JH7102 is more suitable for high frequency applications. This indicates that the use of JH1123 and JH7102 silicon resins for binding and insulated coating not only simplifies the preparation process of MPCs, but also enables the controlled production of MPCs for different applications.

Automated summary

Two silicon resins, JH1123 and JH7102, were used as insulated agents and binders for the fabrication of magnetic powder cores (MPCs). The insulation capability and application prospects of these two resins were evaluated based on their effects on the magnetic properties of the coated powder and MPCs. It was found that both resins can form uniform insulation layers on the powder surfaces, with JH1123 exhibiting stronger binding ability and resulting in severe agglomeration.