Soft magnetic composites (SMCs), which are made of insulated magnetic powder via conventional PM compaction, offer several advantages over traditional laminated steel cores. One of the expected advantages is that the size and weight of magnetic parts can be reduced by designing three-dimensional magnetic circuit which utilizes the magnetic isotropy.
We have investigated the effect of particle size distribution, particle shape and inclusions on core loss and weve made efforts to develop raw iron powders of low core loss SMCs. Further improvement of core loss is required for the market expansion of SMCs. At low frequencies it is important to reduce the hysteresis loss which is achieved by heat treatment of SMCs. In this study, from the viewpoint of the strain and the crystal grain size the influence of heat treatment temperature on hysteresis loss is discussed.