FeSiBCrC amorphous magnetic powder fabricated by gas-water combined atomization

Abstract

Amorphous soft magnetic composites have been attracting attention because of its low core loss under high frequency application. It is demanded that the powder for fabricating amorphous soft magnetic composites has amorphous structure and nearly spherical shape, which facilitates the uniform coating of insulator on the surface of powder particles. In this paper, amorphous Fe73.5Si13B11Cr1C1.5 (at%) powder was produced by gas-water combined atomization process which takes advantages of both gas atomization and water atomization, and its properties was compared with powder produced by gas atomization and water atomization. Gas-water combined atomization powder with particle size of −60 μm were found to be amorphous with low coercivity, and the shape of particles was nearly spherical. The permeability of magnetic powder cores prepared with three kinds of powder first increased and then decreased with annealing temperature, and the core loss first decreased and then increased. The cores prepared with gas-water combined atomization powder showed the best overall properties, with an effective permeability of 26.9, a relative permeability of 83.3% under a superimposed DC magnetic field of 7.96 kA/m, a core loss of 258 mW/cm3 under a frequency of 100 kHz, and a magnetization intensity Bm of 0.05 T after annealing at 793 K in nitrogen gas.