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

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 sec, but in order to obtain the sufficiently crystallized ribbons with small saturation magnetostriction it is required to perform annealing longer than 2 sec. 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. © 2008 Elsevier B.V. All rights reserved PACS: 51.60.+a; 75.30.Gw; 85.70.–w