Effect of Additional Cu Element on Structure and Crystallization Behavior of Amorphous Fe-Nb-Si-B Alloys

Abstract
The addition of Cu to an amorphous Fe74.5Nb3Si13.5B9 alloy was found to significantly change the crystallization process, resulting in the formation of a bcc solid solution containing a large amount of the solute elements with fine grains. It was further observed that the inhomogeneity of the amorphous structure increases upon the addition of Cu. The inhomogeneous amorphous structure was presumed to enhance the instability of the amorphous phase and the formation tendency of the bcc solid solution with soft magnetic properties.