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

In this study, FeSiAl powder was mixed with nano-TiO₂ powder to prepare composite powder cores. The influence of different TiO₂ 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 TiO₂ content, the total core loss initially decreased and then increased, reaching an optimal value at 3 wt% TiO₂ addition, where the lowest total core loss (P cv = 557 mW/cm³，at 20mT， 1000kHz) and best coating effect were achieved. The DC bias performance was significantly enhanced with increasing TiO₂ coating content, demonstrating a 20.35% improvement in percentage permeability (μ%) under a 100 Oe external field, and achieving a maximum μ% of 86.92% 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.