Influence of annealing temperature and compaction pressure on the magnetic properties of dust cores composed of iron spherical particles and silicone

This paper reports the influence of the annealing temperatures and compaction pressures on statics and high-frequency magnetic properties of the cores composed of the spherical iron particles and silicone toward utilizing their dust cores as the soft magnetic materials of the reactors and motors of EVs. These properties markedly changed with the increase of annealing temperature. In particular, the real part of complex permeability became high and the core loss became the lowest for the core annealed at the temperature of 500 °C. In contrast, the compaction pressure between 981 and 1962 MPa has little influence on these properties owing to good malleability of the iron. On the basis of these results, it is revealed that the annealing temperature is one of the important dominant factors to improve the magnetic properties of cores composed of the iron particle and silicone. These results also suggest that the optimized annealing temperature may be approximately 500 °C.