Influence of ribbon thickness on the formation and magnetic properties of melt-spun Fe-Co-Nd-Dy-B metallic glasses

The glass-forming ability, crystallized structure, and magnetic properties have been investigated for a Fe67Co9.5Nd3Dy0.5B20 glassy alloy with a large supercooled liquid region prepared by the melt-spinning technique. The glassy phase is formed in the wide ribbon thickness range below about 250 mum, and the volume fraction of the glassy phase decreases gradually with increasing ribbon thickness to above 250 mum. The crystallized nanocomposite structure consists of Nd2Fe14B, (Fe,Co)(3)B, and alpha-(Fe,Co), and the remanence B-r, coercivity H-i(c), and maximum energy product (BH)(max) are 1.24 T, 247 kA/m, and 105 kJ/m(3), respectively, for the ribbon of 250 mum in thickness annealed at 903 K for 600 s. The magnetic properties remain almost unchanged in the thickness range below 250 mum, and decrease gradually in the ribbons with thicknesses above 250 mum. (C) 2001 American Institute of Physics.