2001 年 25 巻 7 号 p. 1405-1409
Amorphous melt-spun ribbons of Didymium-Fe-Co-Nb-B alloys were prepared by the single-roller rapid-quenching method. The effects of the composition, wheel velocity, and heat treatment on the magnetic properties were investigated. Amorphous Didymium9-Fe76Co8Nb1B6 ribbons prepared at a wheel velocity of 20 m/s were crystallized by heat treatment, and the optimum heat treatment condition was found to be 625°C for 5 min, in which case the value of (BH)max was 147.3 kJ/m3. The temperature coefficients of Br and HcJ for ribbons of crystallized Didymium9-Fe76Co8Nb1B6 alloy were α(Br)= -0.087%/°C (reversible) and α(HcJ)= -0.416%/°C (irreversible), respectively. The value of (BH)max for a compression molded Didymium9-Fe76Co8-Nb1B6 isotropic bonded magnet prepared by using the ribbons annealed at 625°C for 5 min was 79.7 kJ/m3.