Improvement of magnetic properties for FeSi/FeSiAl compound soft magnetic composites by introducing impact of powder size matching

摘要

Thirty-two kinds of FeSi/FeSiAl compound soft magnetic composites (SMCs) were orderly fabricated by interblending the FeSi and FeSiAl powders with each other under a consideration of particle size matching. SEM-EDS and FTIR were simultaneously employed to characterize the core-shell structure of the chemically coated powder. Loss contribution analysis for the corresponding compound SMCs was also carried out. As compared to the normal FeSi SMCs, the FeSi400↑/FeSiAl400↓(with mass ratio in 7∶3) compound SMCs possess excellent comprehensive magnetic properties of higher μ_e of 67.9 (increased by 12.6%), relatively high μ_e@7960 A/m of 42.7 (decayed by only 2.0%) and lower P_(cv) of 423.76 kW/m~3 (reduced by 17.5%) at 50 kHz, 0.1 T. Meanwhile, the FeSiAl600↑/FeSi600↓(within mass ratio of 7∶3) exhibit higher μ_e of 69.4 (increased by 3.4%), higher μ_e@7960 A/m of 35.1 (raised by 12.8%) and relatively low P_(cv) of 270.1 kW/m~3 (increased by only 3.2%) at 50 kHz, 0.1 T compared with these of the common FeSiAl SMCs. These results above indicated that the FeSi/FeSiAl compound SMCs with excellent comprehensive soft magnetic properties is conducive to the expansion of application scope in the power electronics field for the conventional FeSi and FeSiAl SMCs.