High-permeability Fe-based soft magnetic composite comprising anisotropic Fe-Si chip fillers

Abstract

Here, we demonstrate a novel hybrid soft magnetic composite (SMC) comprising highly-ductile pure-Fe powders and anisotropic Fe-6.5wt%Si chips to capture both high density and soft magnetic properties including high permeability and low core loss. Thin Fe-6.5wt%Si chips with dimensions of 2 mm × 0.5 mm × 0.04 mm were continuously fabricated through melt spinning using grooved copper wheels, and uniform and dense SiO 2 surface insulation coatings on the Fe powders and Fe Si chips were achieved through solution-based sol-gel process. Then, the hybrid SMCs were fabricated through compaction molding of pure Fe powder and Fe Si mixtures with various mixing ratios. Degree of alignment of Fe Si chips and packing density of the hybrid SMCs depending on powder-to-chip mixing ratio were systematically investigated, and their effects on the soft magnetic properties were thoroughly evaluated. Finally, the hybrid SMC with optimum powder-to-chip mixing ratio of 6:4 showed highest permeability of 472 and core loss of 157.34 W/kg (at 1 T and 1 kHz), which are 22.25% higher, and 51.05% lower values than those of pure-Fe SMC, confirming the effectiveness of Fe Si chip fillers in the enhancement of soft magnetic properties of SMCs. • Novel Fe-based SMCs comprising anisotropic chips has been introduced. • High density (>95%) hybrid SMCs with various powder-to-chip ratio were demonstrated. • Fe Si chip fillers significantly lowers coercivity (by 59%) and increases permeability by 29% of the SMCs. • Hybrid SMCs showed 52% decreased core loss from that of the pure-Fe SMC.