Inorganic-coated FeSiAl/TiO₂ soft magnetic composites with high DC bias and low loss

Abstract In this study, FeSiAl powder was mixed with nano-TiO 2 powder to prepare composite powder cores. The influence of different TiO 2 addition content (0–4 wt%) on the performance of FeSiAl soft magnetic powder cores was systematically investigated via scanning electron microscopy (SEM), B-H analyzer, and other characterization techniques. The experimental results show that the total loss of the coated composite powder core is greatly reduced. With increasing TiO 2 content, the total core loss initially decreased and then increased, reaching an optimal value at 3 wt% TiO 2 addition, where the lowest total core loss ( P cv = 557 mW cm −3 , at 20 mT,1000 kHz) and best coating effect were achieved. The DC bias performance was significantly enhanced with increasing TiO 2 coating content, demonstrating a 28.65% improvement in percentage permeability ( μ %) under a 100 Oe external field, and achieving a maximum μ % of 83.57% (4 wt%) under the same condition. This work provides valuable insights for reducing high-frequency losses and enhancing DC bias characteristics in FeSiAl-based soft magnetic materials, offering a promising reference for their application in high-frequency scenarios.