AMORPHOUS GLASS-COVERED MAGNETIC WIRES FOR SENSING APPLICATIONS

Amorphous glass-covered magnetic wires consist of a cylindrical metall ic core with diameters of 3 to 25 mu m covered by a glass coating with a thickness of 2 to 15 mu m, such wires being obtained directly from the melt by the glass-coated melt spinning method. Amorphous glass-cov ered wires were introduced in 1974 and were studied up to the early 19 80s when they were disregarded; the appearance of in-rotating-water qu enched amorphous wires attracted much more interest. These wires have been practically reconsidered in the last two years since their many a pplication possibilities were not fully investigated during previous s tudies. In this paper we report the application related magnetic prope rties of the AGCMW from three important classes with respect to the si gn of their magnetostriction constant lambda:Fe-based (lambda > 0), Co -based (lambda < 0) and Co-based wires with a small amount of Fe (lamb da less than or equal to 0). We also present the tailoring possibiliti es for their magnetic properties, which are mainly determined for a gi ven composition by the influence of their dimensional characteristics (metallic core diameter, glass cover thickness, their ratio) on these properties, thus offering a more powerful tool for controlling their m agnetic behavior as compared to the case of in-rotating-water quenched wires. The advantages of using amorphous glass-covered wires in magne tic sensors and the basic operating principles of such sensors are als o presented. (C) 1997 Elsevier Science S.A.