Magnetic properties of soft magnetic composites prepared by gas-atomized glassy powders from a new Fe-based alloy with high glass-forming ability

Abstract

With a pressing need for high efficiency, low power consumption, and miniaturization of electronics, soft magnetic composites (SMCs) show great potential, especially for applications in key electronic component. However, core loss is still the focused issue for SMCs that hinders their sustainable development and widespread applications. In the present study, high-performance SMCs were fabricated by novel Fe₇₄B₇C₇P₇Si₃Mo₁Cr₁ powders with spherical shape and a fully glassy structure, which were successfully prepared by a gas atomization method. The microstructure and high-frequency magnetic properties of these SMCs were studied in detail. To enhance the soft ferromagnetism, the effects of annealing temperature (T_a) and powder size on their performance were clarified. Increasing T_a up to 703 K not only helps to effectively release internal stress in the powders, but also improves the integrity of the insulation layer structure, which is conducive to decreasing the core loss. In addition, reducing the powder size contributes to the overall performance enhancement. Prepared from the powders with the smallest mean particle size and annealed at 703 K, the SMC exhibits optimum property combination of a stable effective permeability of 26.2 up to 1 MHz, a total core loss of 883 kW m⁻³ (100 kHz, 100 mT), and a DC-Bias performance of 79.3% under 100 Oe field, which is even comparable to those of the most prominent SMCs reported so far. These results are meaningful for potentially stimulating the development and application of new low-loss SMCs.