AC Iron Loss Prediction and Magnetic Properties of Fe-6.5 wt. % Si Ribbons Prepared by Melt-Spinning

Abstract

Ultra-thin Fe-6.5 wt. % Si ribbons of 35 μm in thickness were prepared by melt-spinning. The magnetic properties were investigated before and after annealing at 1000 °C. The DC properties and low-frequency (400 Hz~10 kHz) iron losses significantly improved after heat treatment. A simplified formula— P t = k t B m N —based on the Steinmetz law, which can be used to predict the AC iron loss, is presented. The symbols “kt” and “N” are defined as functions of microstructure and frequency. According to the tested results of iron loss, the values of “kt” and “N” can be fitted and therefore the simplified formula can be determined. The extent of AC iron losses can be predicted according to the formula. The results obtained from the formula predict AC iron loss to a good degree. The method developed in this work could be extended to other magnetic materials for predicting AC iron loss with greater ease.