On the amorphization and magnetic properties of Co-Fe-Si-B powders

The aim of this research is to present preparation techniques for Co68.25Fe 4.5Si12.25B15 amorphous powders using the following three techniques: commi nution of embrittled amorphous ribbons, gas, and gas-liquid atomization. Po wders with different fractions of amorphous material were obtained using th ese techniques and eve compared their structural and magnetic properties. B y gas atomization we obtained powders with 30% particles under 50 mu m and with 75% amorphous phase. By gas-liquid atomization we obtained about 35% a morphous particles with sizes <50 mu m. The magnetic measurements show that the magnetic properties of atomized powders are comparable to those of pow ders prepared by comminution of amorphous ribbons with the same composition . The atomized powders have the advantage that they can be prepared in a si ngle cycle. (C) 1999 Elsevier Science B.V. All rights reserved.