AC Magnetic Properties of Fe-Based Composite Materials

We investigated the influence of resin content on ac magnetic properties of Fe-based composite material to extend possibilities for application of this kind of material at higher frequency. The samples of composite material with different content of phenol-formaldehyde resin acting as insulator were prepared by conventional powder metallurgy. The samples in the form of the ring were used for ac magnetic measurements and in the form of cylinder for specific resistivity measurements. The ac magnetic properties (sample in the form of ring) were measured at maximum flux density up to 0.4 T by MATS-2010SA loop tracer in a frequency range 1–150 kHz and obtained total power losses. The dc hysteresis loops were measured by a fluxmeter-based hysteresisgraph. The values of the specific resistivity measured by the van der Pauw method (sample in the form of cylinder) were used for calculation of eddy current losses. All magnetic properties of the composite rings were compared with the properties of the material prepared from the powder provided by HÖganÄs AB Sweden by the technology usually used by the producer.