The influence of preannealing treatment on the exothermic behavior and magnetic properties of Fe73.5Cu1Nb3Si13.5B9 alloy

The preannealing process has been tried to resolve the overheating problem of the amorphous precursors Fe73.5Cu1Nb3Si13.5B9 ribbons when they are heat-treated under the optimum annealing process. The concentrating release of latent heat for the primary crystallization of Fe73.5Cu1Nb3Si13.5B9 ribbons can be reduced by fractional crystallization in the preannealing process. Quantitatively, a quarter of the latent heat can be released in advance at preannealing temperature 743 K for 30 min. The subsequent measurement of the soft magnetic properties indicates that the ribbons heat-treated first under the proper preannealing and then under the final annealing process (813 K for 60 min) still exhibit excellent soft magnetic properties. (C) 2000 Published by Elsevier Science B.V. All rights reserved.