High frequency iron loss of sendust thin ribbons made by a rapid quenching method

Sendust ribbons, about 20μm thick, 5.5∼6.5 mm wide and several meters long are made by a rapid quenching method. Ribbons obtained are so mechanically flexible that it is possible to wind them easily around a lod of 10 mm in diameter. The DC hysteresis loss changes with a flux density approximately as (B)^1.8. The iron loss increases with frequency as and with flux density as (B)^1.9. The eddy current loss increases with frequency as and with flux density as . The iron loss is lower than 19 × 10⁵W/m³in the composition range around 9.5% Si and 5.6∼6.2% Al at the frequency of 100 kHz and at the flux density of 400 mT.