Preparation and characterization of Fe-Nb-Cu-Si-B-based nanocrystalline soft magnetic materials

The nanocrystalline state of Fe73.5Nb3Cu1Si13.5B9 ribbons exhibit superior soft magnetic properties with low coercivity, high permeability and moderat e saturation induction value. However, due to the metastable nature of the materials, their properties depend very much on the preparation condition a nd heat treatment schedule. In the present work, the properties of the as-c ast ribbons prepared at different nozzle diameter and separation between th e quenching wheel and the nozzle were evaluated. The optimum conditions for getting continuous long ribbon from 150 g of ingot were established. The i nfluence of heat treatment to get nanostructure and superior soft magnetic properties for selected ribbons were also studied. The ribbon surface quali ty was improved by reducing air pockets at the ribbon surface which was in contact with the quenching wheel. (C) 2001 Elsevier Science B.V. All rights reserved.