Fabrication of Fe-based ribbon with controlled permeability by Joule heating under tensile stress

Abstract

We prepared an Fe-based ribbon with controlled permeability and low magnetic loss by continuous stress-annealing by joule heating (CSA-JH) method. The shortest annealing time necessary for the obtaining of the ribbons with completely developed anisotropy was 1 s, but in order to obtain the sufficiently crystallized ribbons with small saturation magnetostriction it is required to perform annealing longer than 2 s. A toroidal core was prepared from a long ribbon with controlled permeability and small saturation magnetostriction, and the magnetic loss and relative permeability of the core were evaluated in the frequency range of 0.1–3 MHz. The permeability was kept constant up to 2 MHz, and the magnetic loss is lower than that for other types of core with a similar permeability value. These results suggest that the CSA-JH method is a promising method for realizing an Fe-based core with excellent magnetic properties.