Multicomponent soft magnetic alloys for soft magnetic composites: A review

Soft magnetic multicomponent alloys (MCAs) are emerging materials, including amorphous, nanocrystalline, and high-entropy alloys, exhibit not only excellent soft magnetic properties but also high service performances such as high temperature stability, high corrosion resistance and high mechanical properties. They are promising candidates for the key materials of the components for power devices with high power density and high energy conversion efficiency at high frequency. However, despite the attractive properties of bulk soft magnetic MCAs, the soft magnetic composites (SMCs) based on the MCAs have not exhibited significant advantage in comparison to those based on the traditional alloys, which limits their wide applications. With urgent requirement in developing high-performance power inductors, understanding the fundamental behavior and underlying physics of soft magnetic MCAs is very important. In this review, the current status of soft magnetic MCAs and the SMCs based on MCAs is summarized. Novel preparation processes different from the conventional ones are discussed. The relationship among the preparation, properties and microstructure of the MCAs are also emphasized. The current status and existing challenges for the fabrication of SMCs based on soft magnetic MCAs are critically discussed. The potential solutions such as novel powdering techniques, forming methods, magnetic-thermal coupling processes and insulation coating approaches are proposed for future development.