Design and Fabrication of FeSiCr@BN Soft Magnetic Composites with Improved Thermal Management and Core Loss Performance

The optimization of FeSiCr soft magnetic composites remains a critical research area in the development of integrated molded inductors. Constructing dense insulation layers and achieving the ordered alignment of flaky magnetic powders are effective strategies to enhance their overall performance. Inspired by the structural design of fried chicken steak, this study synthesizes FeSiCr@boron nitride (BN) soft magnetic composites. By modifying with two-dimensional BN and employing magnetic field–assisted directional molding, the composites achieve orderly particle alignment and efficient insulation coating. Experimental results indicate that the thiol-modified BN (BN-s) insulation layer chemically bonded to the FeSiCr matrix, combined with the ordered alignment of flaky particles induced by magnetic orientation, substantially improves core loss performance and thermal management. The FeSiCr@BN soft magnetic composites with the optimal BN-s content of 4   wt% show a core loss of 398.5   kW/m 3 (30 mT/300   kHz), a thermal conductivity of 30.01   W·m −1 ·K −1 , a reduced operating temperature rise of 119°C, and an impressive resistivity increase from 0.08 to 10.17 Ω·m. This work presents a design strategy for soft magnetic composites, highlighting the promising applications of the prepared composites in electronic devices, power electronic systems, and smart grids.