Magnetic properties of FeCuNbSiB nanocrystalline alloy powder cores produced from atomized powders by cold pressing

Abstract

Powder cores were produced from gas- and water-atomized powders by cold pressing at a pressure of 1.5 GPa. Structure, morphology and thermal stability analyses of the powders were carried out. The magnetic properties of the cores were examined at high frequency. Gas-atomized powder cores exhibit excellent high-frequency characteristics, which are a stable permeability up to 50 MHz, a quality factor of maximum value 95 at a frequency of 400 kHz and a core loss of 650 mW/cm(3) at f = 50 kHz and B-m = 0.1 T. It is considered that the excellent magnetic properties of FeCuNbSiB powder cores are due to the fact that atomized powders with nanocrystalline structure show good softness in magnetic properties and important fabrication conditions like an insulating layer and extremely high compacting pressure are well controlled.