High-frequency soft magnetic composite fabricated by FeSiAl flakes via cold sintering process

Soft magnetic composites (SMCs) composed of insulating magnetic particles are essential for advancements in power electronics. Nonetheless, the high molding pressure associated with traditional cold-pressing methods compromise the integrity of insulating layers, thereby limiting their applicability in high-frequency applications. This study employs a cold sintering process to fabricate FeSiAl SMCs using FeSiAl flakes and ammonium molybdate tetrahydrate (AMT). The FeSiAl flakes are effectively consolidated, and a multi-layer insulation structure of Al 2 O 3 ·SiO 2 /Fe 2 (MoO 4 ) 3 can be formed in-between FeSiAl flakes, which endows the SMC with great high-frequency performance, characterized by a permeability of 60.7, a cut-off frequency of 38.7 MHz, a saturation magnetization of 121.4 emu/g, and a power loss of 2028.5 kW/m³ (at 10 MHz, 5 mT). This work highlights a new strategy for simultaneous consolidation and insulation of metallic magnetic particles at low pressure and low temperature, which shows great potential in fabricating high-frequency SMCs.