Preparation of Fe-based monodisperse spherical particles with fully glassy phase

Highlights: → We have successfully prepared monosized spherical particles of Fe-based metallic glass with diameters of several hundred micrometers by our developed atomization method. → All the monosized droplets were solidified through the quite same cooling history and thus given perfect glass formation alike by controlling the cooling rate. → We discussed about the critical cooling rate for the glass formation which was determined using the benefit of monodispersity. - Abstract: In this study, we prepared monodisperse spherical particles of a desired diameter using [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 alloy; the particles were prepared by using an atomization process developed by us. The particles have perfect sphericity and narrow size distribution along with a homogeneous composition. The phase transitions of particles from the fully glassy phase to the crystalline phase via mixed phase structures occurred as the particle diameter was increased; the particles produced in the fully glassy phase in an argon atmosphere had a diameter of less than 300 μm. This allowed the estimation of the intrinsic critical cooling rate for the particles with a fully glassy phase, Rc:Rc varied in the range of 700-900 K/s and depended only on the initial temperature of the alloy melt.