Abstract
Amorphous Fe75Si12.5B12.5 powders were fabricated by spinning water atomization process (SWAP). The powders obtained exhibited good soft-magnetic properties up to particle size of about 200-300 μm. These amorphous particles were insulated by glass powder and pressed into toroidal and E shape cores by hot-pressing techniques at relatively high temperature conditions below crystallization temperature. The densities of the pressed cores were about 80-85%. The magnetic properties of toroidal samples 20 mm in diameter were measured after annealing. For the core pressed at 1.5 GPa, 465°C, the core loss at 100 kHz was 13 J/m3 = ( = 1.3 W/cc) for Bm = 0.1 T and the initial permeability was about 100 in the frequency range up to 1 MHz for Hm = 5 mOe, which were comparable to those of commercial Sendust compressed corse and Fe-based gapped amorphous ribbon cores for application to fly-back transformers or choking coils operating at frequencies above 100 kHz.
