Electromagnetic properties of FeSiCr alloy powders modified with amorphous SiO2

Abstract The effects of amorphous SiO2 coating onto FeSiCr alloy powder on the electric and magnetic properties were investigated. FeSiCr alloy powder with an average particle size of 10 μm was coated with nano-sized silica powder to increase the resistivity and DC bias superposition characteristics. Inexpensive water glass (sodium silicate) was used as the raw material to form the amorphous silica layer onto the FeSiCr alloy powder surface acting as a binding and insulation layer. The amorphous silica layer thickness was about 20 nm to 50 nm. The thickness can be controlled by the amount of sodium silicate addition. The amorphous silica layer can significantly promote anti-oxidation, resistivity and DC bias superposition characteristic of the FeSiCr alloy.