effect of foil quality on the magnetic properties of fe-based amorphous cores

In the present research, amorphous Fe73.5Si13.5B9Nb3Cu1 Finemet foils, 22-28µm in thickness and 5mm in width, were prepared by Planar Flow Casting (PFC) process. The surface morphologyand the edge quality of the rapidly solidified foils were studied using an optical microscope. The structure of rapidly solidified foils was examined by X-ray diffractometry (XRD). Toroidal wound cores were prepared from the amorphous Finemet foils and their soft magnetic properties were measured using a dc B-H loop tracer. The comparison of measured foils thicknesses withthe calculated ones showed that the experimental data obtained in this research are in good agreement with the Fiedler equation. The study of magnetic properties of the amorphous wound cores revealed that the presence of holes in the amorphous foils can strongly degrade the soft magnetic properties. In other words, they cause an increase in coercivity and hysteresis loss as well as decrease in initial and maximum permeabilities.

Keywords:

Planar Flow Casting (PFC) Process , Rapidly Solidified Foils , Finemet