Abstract: A method and apparatus of dynamic heat treating the ferromagnetic amorphous alloys by applying AC current or pulsed high current on the alloys in the form of a ribbon are disclosed. The amorphous ribbon is continuously passed through a pair of electrodes from which AC current is conducted on the amorphous ribbon to perform a Joule heating. A DC magnetic field is applied on the amorphous ribbon preferably along a length direction thereof to improve the soft magnetic properties of the amorphous alloys. The DC magnetic field can be applied on either the section of the amorphous ribbon between the pair of electrodes or the section that has already been heat treated. With the method and apparatus, ferromagnetic amorphous alloys with improved magnetic properties such as greater magnetic induction, lower coercivity and low hysteresis loss are resulted and the annealing embrittlement is avoided.

Abstract: A method of improving the magnetic properties of a ferromagnetic materials is disclosed. The method comprises a step of providing a specimen made of Fe, Ni or Co based amorphous alloys in a magnetizing field and a second step of applying an AC current or pulsed current on the specimen to improve its soft magnetic properties. The applied AC current has a frequency of 50 to 50K Hz, a wave form of either sine wave, triangular wave or square wave, and a current density of 10 to 500 A/cm.sup.2. The magnetic properties of the ferromagnetic materials are improved by a coercivity ratio less than 0.5, a magnetic induction ratio greater than 1 and a core loss ratio less than 0.3.