Effect of resin types on magnetic properties and mechanical strength of FeSiBC amorphous magnetic powder cores

Four types of resins, P1-P4, are used as binders for FeSiBC amorphous powder, which are then press-molded and heat-treated to fabricate magnetic powder cores (MPCs). By testing the permeability, loss, density, and radial crush strength of MPCs, the effect of the binder on the magnetic properties of the cores is investigated and the best resin is found. The results show that the silicone resin P3 exhibits the best thermal stability, retaining 82.1% of its mass after heat treatment at 430 °C. This contributes to improving the insulation of MPCs and reducing the eddy current loss, which is 46.06 mW cm^-3 (150 kHz, 20 mT) with the mechanical strength of 11.13 MPa. The bonding of epoxy resin P4 is superior to that of other resins, which significantly improves the powder compactness and makes MPCs density reach 5.67 g cm^-3, and its permeability is as high as 28.7. The two types of resins have different advantages, and both lead to MPCs with excellent properties.