Fe-Si-Al系噴霧粉を用いた圧粉磁芯の電磁気特性

概要

論文の詳細を見る
Powder compressed magnetic cores are widely used in smoothing choke coils of switching regulators. These cores are mostly made by cast-crushed Fe-Si-Al powder and there are little reports on the cores made by atomized powder. Magnetic properties of the cores were investigated with atomized Fe-Si-Al powder made under several conditions. High permeability was observed in the water-atomized powder cores , in which the effective demagnetizing factor N of the core might be decreased because of the contact between the powders of irregular shape. Resistivity of gas-atomized powder core was higher than that of water-atomized powder core. The reason was understood that electrical insulation between the powders was kept because of the smooth surface of the gas-atomized powder compared with the irregular shaped water-atomized powder. Furthermore core loss was almost constant above the critical resistivity of about 0.03 Ωm ,and it has large dependence below the resistivity. The critical resistivity was thought to be determined by change of the path of
電気製鋼研究会の論文