Soft magnetism enhancement and eddy current suppression in bioinspired Iron‐based nanocrystalline soft magnetic composites with nacre‐like structure

Bioinspired nacre-like structured high-density soft magnetic composites (SMCs) have been successfully constructed using flaky-Fe73.8Si13.5B8.7Cu1Nb3 powders in the supercooled liquid region (SCLR). These densely arranged particles with a consistent planar orientation significantly enhance the soft magnetic properties of SMCs, including high permeability and low magnetic losses. The internal structures of the composites and microstructure evolution of the flaky nanocrystalline particles during the hot-pressing process have been thoroughly studied. Moreover, systematic investigations into the effects of coatings and particle sizes on the maximum permeability and magnetic losses of the composites are conducted. The SMC prepared using the coated particles with a size of 0–100 μm exhibits a high maximum permeability of 2170 (at 1000 Hz) and low magnetic loss of 41.61 W kg–1 (at 1000 Hz and 1.0 T). The losses and permeability analysis reveal that the superior performance of these soft magnetic materials is attributed to their laminated structure, insulation coating, and the reduced planar demagnetizing factor. Compared to the traditional silicon steel, this novel SMCs exhibits high magnetic permeability and reduced magnetic losses at frequencies above 1000 Hz, which possess immense application potential within high-frequency electric machines.