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将不同粒径铁粉颗粒和适量高温硅树脂进行充分混合,在铁粉颗粒表面上均匀包覆一层硅树脂,采用粉末压实成型工艺将铁粉-硅树脂复合粉末制备成致密的铁基复合磁粉芯。系统研究铁粉粒径和硅树脂包覆量对磁粉芯密度及软磁性能的影响,探索最佳铁粉粒径大小和硅树脂包覆量。研究表明,在相同粒径下,磁粉芯的密度、涡流损耗和磁感应强度均随硅树脂包覆量增加而降低。在相同硅树脂包覆量下,磁粉芯的密度和涡流损耗随粒径增大而增加,磁滞损耗却随着粒径增大而降低。在平均粒径为120μm 的铁粉表面上均匀包覆0.5%硅树脂可制备出高密度、低损耗和较高磁感应强度的复合磁粉芯,在大功率条件下,较好软磁性能参数为 P s(B=1 T,f=400 Hz)=69 W/kg, B4k(H=4000 A/m)=0.96 T。

Fe-based magnetic powder cores by coating different size of pure iron particles with different content of silicon resin have been fabricated via powder compacting molding process.The Effects of particle size and content of silicon resin on density,DC and AC magnetic properties of magnetic powder cores were studied sys-tematically.The best particle size and content of silicon resin were searched in order to prepare high-perform-ance magnetic powder cores with high density,low loss and high magnetic induction.The investigation showed that,for coating the same particle size of the iron particles,the eddy loss of magnetic powder cores decreased with increasing the coating content of silicon resin.The density of the magnetic cores was also lower with the increasing content of silicon resin,which resulted in the decrease of saturation magnetic induction.With the same content of silicon resin,both the density and the eddy loss of magnetic powder cores increased accompa-nied by the increased particle size of pure iron particles.While the magnetic hysteresis loss decreased with in-creasing the particle size.The results revealed that high-performance magnetic powder cores with high density and good soft magnetic properties could be synthesized when coating the pure iron particles of the size for 120μm with the silicon resin content of 0.5wt%.High magnetization B4k(H=4 000 A/m) of 0.96 T and low loss P s(B=1 T,f=400 Hz) of 6 9 W/kg were obtained for Fe-based magnetic powder cores in this work.