Fe-Co based Nanocrystalline alloy

Nanocrystalline FINEMET-type alloys (FeSiBCuNb ) having average grain diameter ~ 10 nm obtained by the devitrification of rapidly solidified (typically 20 mm thick ribbons) amorphous alloys are attractive for applications due to their excellent soft magnetic properties e. g. – high saturation magnetic induction comparable with Fe-based amorphous alloys and large permeability as observed in Co-based metallic glasses. In Finemet type alloys the presence of small amount of Cu enhances the nucleation rate while presence of Nb inhibits the grain growth resulting in nano-crystallization which proved to be key factor for obtaining the particular ultra fine grain structure.