Skip to Main Content
The melt-spun ribbons of Didymium12.5Fe68 Co10 Nb1V1Tb0.5B7 prepared at a wheel velocity of 17.5 m/s were crystallized by heat treatment. The optimum heat treatment condition was found to be at 600°C for 5 min. The values of (BH)max and HcJ amount to 103.6 kJ/m3 and 1628.0 kA/m, respectively. The temperature coefficients of Jr and HcJ for the crystallized ribbons were α (Jr)ave=-0.03%/°C (reversible) and α (HcJ)=-0.37%/°C (irreversible) for the temperature range 25 to 125°C. The compression molded Didymium12.5Fe68Co10Nb1V1Tb0.5B7 isotropic bonded magnet, prepared by using the ribbons annealed at 600°C for 5 min, achieve the (BH)max of 66.2 kJ/m3. The density amounts to 6.32 Mg/m3. At 150°C, irreversible losses of -2.5% result.