Abstract
Amorphous melt-spun ribbons of low rare-earth (Pr = 6 at.%) α-Fe/Pr2Fe14B-type Pr-Fe-Co-V-Nb-B system alloys were prepared by the single-roller liquid rapid-quenching method, and the effects of composition, substrate surface velocity, and annealing conditions on the magnetic properties were studied. The optimum preparation conditions and some of the properties were as follows: composition, Pr6Fe77Co8V1Nb1B7; substrate surface velocity, 40.0 m/s; annealing conditions, 575°C (heating rate: 575°C/min) for 5 min in Ar atmosphere; magnetic properties, (BH)max = 120.2 kJ/m3 (15.1 MGOe), HcJ = 360 kA/m (4.5 kOe), HcB = 300 kA/m, Jr = 1.2 T, recoil ratio = 75%, Hk/HcJ×100 = 25.3%, α(Jr) = −0.038%/°C, α(HcJ) = −0.37%/°C, Tc = 420°C. The value of (BH)max for a compression-molded Pr6Fe77Co8V1Nb1B7 isotropic bonded magnet prepared by using ribbons annealed at 575°C for 5 min was 56.0 kJ/m3 (7.0 MGOe) and the density was 5.70 Mg/m3.
