Soft magnetic properties regulation of FeSiBC amorphous powders/CIP magnetic powder core with single and double-layer core–shell structure

Abstract

In this study, an equal proportion of carbonyl iron powder (CIP) was added to the FeSiBC amorphous powders, then three kinds of composite powders, namely Powder@EP(epoxy resin) with a single-layer core–shell structure, Powder@SiO2(silica powder)@EP and Powder@SI(silicone resin)@EP with a double-layer core–shell structure, were synthesized and prepared into corresponding SMPCs (soft magnetic powder cores). The results show that the FeSiBC amorphous powders exhibit good sphericity, a high saturation magnetization (153.534 emu∙g−1), and a wide undercooled liquid region (△T = 51 K). When mixed with CIP, its saturation magnetization increased from 153.534 emu∙g−1 to 189.875 emu∙g−1, which is an ideal raw material for preparing SMPCs. The three SMPCs after insulation coating treatment have high permeability (29.3 ∼ 34.2), high DC bias performance (76.26 ∼ 84.11, 100 Oe), and low core loss (762.66 ∼ 902.69 mW·cm−3, 200 Gs, 1000 kHz), and excellent overall soft magnetic performance. Finally, the loss separation analysis of the magnetic core loss of SMPCs shows that the loss of Powder@SI@EP soft magnetic powder cores with a double-layer organic core–shell structure is only 762.66 mW·cm−3 at 200 Gs and 1 MHz, which is much lower than that of SMPCs with a single-layer core–shell structure (902.69 mW·cm−3, 200 Gs, 1000 kHz). At the same time, the permeability of SMPCs (31.0) is relatively high, and the comprehensive performance is good in the high-frequency range.