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 moderate saturation induction value. However, due to the metastable nature of the materials, their properties depend very much on the preparation condition and heat treatment schedule. In the present work, the properties of the as-cast ribbons prepared at different nozzle diameter and separation between the quenching wheel and the nozzle were evaluated. The optimum conditions for getting continuous long ribbon from 150 g of ingot were established. The influence of heat treatment to get nanostructure and superior soft magnetic properties for selected ribbons were also studied. The ribbon surface quality was improved by reducing air pockets at the ribbon surface which was in contact with the quenching wheel.