Abstract
To decrease the hysteresis losses of soft magnetic composite (SMC) cores, it is effective that the coercivity of cores is reduced by the high temperature stress relieving annealing to the green compacts. It is reported about magnetic properties of SMC, which MgO system evaporation insulation coating on the surface of iron powders had greater heat-resistance than the conventional phosphate insulation coating. We found that it can be obtained new SMC core with lower iron loss made from iron powders with evaporated MgO insulation coating. The iron loss of them at 50 Hz for Bm = 1.5 T was lower 30% of the conventional SMC core and was almost the same with the laminated steel (50H600) core. It became clear that typical MgO insulating films had microcrystallines have the thickness of about 50 nm and enough heat resistance.
