Enhanced electromagnetic properties of Fe-Cr-Si alloy powders by sodium silicate treatment

The Fe-Si-Cr alloy powders were successfully modified by using the phosphatizing and sodium silicate coating processes. The optimized surface pre-treatment for Fe-Si-Cr powder was phosphatized in 2 wt.% phosphoric solution and further treated with 4 wt.% sodium silicate solution at 75 °C for 30 min. These treatments increased the high-frequency stability for Fe-Si-Cr alloy powders, and the annealed cores further showed the enhanced performance of permeability, impedance, quality factor and anti-corrosion ability. Comparing with the Fe-Si-Al alloy, the Fe-Si-Cr also showed a superior performance in density, moldability and saturated magnetic induction.