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

Abstract

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 μe of 67.9 (increased by 12.6%), relatively high μe@7960 A/m of 42.7 (decayed by only 2.0%) and lower Pcv of 423.76 kW/m3 (reduced by 17.5%) at 50 kHz, 0.1 T. Meanwhile, the FeSiAl600↑/FeSi600↓ (within mass ratio of 7:3) exhibit higher μe of 69.4 (increased by 3.4%), higher μe@7960 A/m of 35.1 (raised by 12.8%) and relatively low Pcv of 270.1 kW/m3 (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.