Fe-based soft magnetic amorphous alloys with high saturation magnetization above 1.5Â T and high corrosion resistance

Fe-rich amorphous alloys with minor-addition of Cr and/or Nb were examined with the aim of developing Fe-based amorphous alloys exhibiting simultaneously high saturation magnetization above 1.5 T and good corrosion properties. Fe82Cr2B8P4Si3C and Fe82NbB9P4Si3C amorphous alloys were found to exhibit high saturation magnetizations of 1.49 T and 1.57 T, respectively, and rather good corrosion resistance in 3.5 mass% NaCl solution at 298 K. The minor-addition of Cr or Nb enables the formation of amorphous alloy particles without harmful oxide layer by water atomization process which makes these alloys suitable for applications as soft magnetic core materials. The addition of 1 at% Nb improved the corrosion resistance through the increase in Ecorr value, which makes easy to reach passive state, and the suppression of pitting corrosion. Besides, it has been proved that the simultaneous addition of Nb and Cr has an effect on forming protective passive film.