THE EFFECT OF ANNEALING AND CRYSTALLIZATION ON THE MAGNETOELASTIC PROPERTIES OF FE-SI-B AMORPHOUS WIRE

The effect of furnace annealing on the magnetic and magnetoelastic properties of amorphous wire of composition Fe77.5Si7.5B15 has been investigated. The field dependence of Young's modulus and magnetization combined with x-ray analysis and scanning electron microscopy have been used to monitor the effects of annealing. The results indicate that progressive annealing leads first to relief of the radial casting stress with a corresponding reduction in angle between the average easy direction and the wire axis. Further annealing leads to surface crystallization for which it is suggested that the moments take up a circumferential orientation. Annealing still further leads to crystallization of the bulk material which greatly increases the anisotropy and greatly reduces the DELTAE effect.