2001 Volume 42 Issue 10 Pages 2059-2063
The glass-forming ability, thermal stability and magnetic properties have been investigated for a Fe67Co9.5Nd3Dy0.5B20 glassy alloy with a large supercooled liquid region of 48 K prepared by the melt-spinning technique. The glassy phase is formed in the wide sheet thickness range from 20 to 250 \\micron. The glass transition temperature (Tg), crystallization temperature (Tx), supercooled liquid region (ΔTx=Tx−Tg) and heat of crystallization (ΔHc) remain almost unchanged in the thickness range below 250 \\micron, and then the ΔHc gradually decreases with further increasing sheet thickness. The crystallized nanocomposite structure consists of Fe3B, α-Fe, Nd2Fe14B and remaining glassy phase, and their average grain sizes are about 25 nm annealed at 903 K for 420 s. The remanence (Br), coercivity (iHc), and maximum energy product (BH)max are 1.26 T, 235 kA/m, and 104 kJ/m3, respectively, for the sheet of 250 \\micron in thickness annealed at 903 K for 420 s. The hard magnetic properties remain almost unchanged in the thickness range below 250 \\micron, and decrease gradually in the sheets with thicknesses above 250 \\micron.