Ultrasonic‐Assisted Preparation of FeSiBCr Soft Magnetic Powder Cores with Low Loss and High DC Bias Performance

To propel the development of electronic components toward high‐frequency and miniaturization, amorphous soft magnetic powder cores must possess low loss and excellent DC bias performance. Although employing nanoscale oxides for insulation coating is an effective means to reduce loss, ensuring the uniformity of insulation coating has emerged as a pressing technical challenge that requires urgent attention. Herein, ultrasonic technology is employed to successfully achieve a uniform dispersion of ZnO nanoparticles on the surface of amorphous powder, resulting in the fabrication of FeSiBCr/ZnO composite powder cores with low loss and high DC bias performance. Subsequently, the addition of epoxy resin further enhances the insulation coating effect. The specific impact of adjusting the time of ultrasonic treatment on coating effectiveness is thoroughly investigated, leading to the determination of the optimal coating process. Simultaneously, optimal insulation coating treatment is achieved through the controlled addition of ZnO nanoparticles, resulting in reduced losses. Finally, after ultrasonic treatment for 20 min, the FeSiBCr/1.0 wt% ZnO composite powder cores exhibit the best soft magnetic properties. Specifically, the loss is 254 mW cm −3 at 20 mT and 1000 kHz, and the DC bias performance reaches 83% at 100 Oe.