Premium
Magnetic properties of melt‐spun Nd‐Pr‐Fe‐Co‐B‐V system alloys and their bonded magnets
Author(s) -
Yamamoto Hiroshi,
Kodama Iwao
Publication year - 1993
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.4391130105
Subject(s) - remanence , materials science , ribbon , melt spinning , magnet , annealing (glass) , amorphous solid , coercivity , analytical chemistry (journal) , alloy , metallurgy , composite material , nuclear magnetic resonance , magnetization , crystallography , condensed matter physics , magnetic field , chemistry , electrical engineering , physics , quantum mechanics , chromatography , fiber , engineering
Abstract Melt‐spun ribbons of Nd‐Pr‐Fe‐Co‐B‐V system alloys were prepared by the single‐roller rapidquenching method. The effects of composition, wheel velocity and heat treatment on the magnetic properties were investigated. The magnetic properties of their isotropic compression bonded magnets prepared from optimally annealed ribbons also were measured. Remanence (Br) was found to increase with decreasing rare‐earth content, and a maximum value of more than 1.0 T was obtained. A maximum energy product of 164.0 kJ/m 3 was obtained for (Nd 0.5 Pr 0.5 ) 9 Fe 4 Co 8 B 7.5 V 1.5 alloy ribbon prepared at a wheel velocity of 17.1 m/s. From TEM observation, the particle size of these ribbons was determined to be between 20 to 30 nm. It is conjectured that the high remanence is obtained by the interaction of these fine particles. The amorphous (Nd 0.5 Pr 0.5 ) 9 Fe 74 Co 8 B 7.5 V 1.5 ribbons prepared at a wheel velocity of 20.7 m/s were crystallized by heat treatment, and the optimum annealing condition was found to be at 650°C for 20 min. Its corresponding value of (BH) max was 146.2 kJ/m 3 . A maximum energy product of 86.4 kJ/m 3 was achieved with (Nd 0.5 Pr 0.5 ) 9 Fe 74 Co 8 B 7.5 V 1.5 bonded magnets made from the optimally prepared ribbons.