Magnetic properties of melt‐spun Pr(Nd)‐Fe‐Co‐Nb‐Cu‐Si‐B system ribbons and their bonded magnets

Melt‐spun ribbons of Pr‐Fe‐Co‐Nb‐Cu‐Si‐B system alloys were prepared by a single roller rapid‐quenching method. The effects of composition, wheel velocity, and heat treatment on their magnetic properties were investigated. The optimum preparation conditions of compounds were as follows: composition Pr 9 Fe 68.5 Co 10 Nb 1 Cu   0.5   −Si 0.5 B 10.5 ; wheel velocity 12.5 m/s; heat treatment 625 ° C for 5 min. The magnetic properties obtained were ( BH ) max =121.8kJ/m 3 , J r=0.90 T, H cJ=898.7kA/m, and H cB=509.0kA/m. The temperature coefficients of J r and H cJ of the ribbons of Pr 9 Fe 68.5 Co 10 Nb 1 Cu 0.5 Si 0.5 B 10.5 alloy were α( J r)ave=–0.034%/ ° C and α( H cJ)ave=–0.290%/ ° C, respectively. The value of ( BH ) max for isotropic Pr 9 Fe 68.5 Co 10 Nb 1 Cu 0.5 Si 0.5 B 10.5 bonded magnets prepared by using ribbons annealed at 625 ° C for 5 min was 84.4kJ/m 3 . The irreversible loss of the bonded magnets was –2.74% at 125 ° C. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(4): 1–7, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20638