RAPID ANNEALING OF FE-SI-B AMORPHOUS TAPES BY JOULE HEATING - EFFECTS ON MAGNETIC AND MECHANICAL-PROPERTIES

We report a systematic study of relaxation effects in Fe-Si-B amorphous tapes rapidly annealed for short time at T approximately equals 800 K by Joule heating. It is found that this type of annealing in air can result in nearly the same degree of relaxation as obtained by two hours of conventional relaxation annealing in a furnace under inert gas or vacuum. The extent of relaxation as a function of current density and duration has been assessed by high precision calorimetric measurements and found to be highly reproducible. The effect of such rapid annealing on magnetic and mechanical properties are compared to those of conventional relaxation annealing for two hours at 655 K and found to be advantageous.