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Magnetic properties of melt‐spun Nd‐Fe‐Co‐B‐Cu‐Nb system alloys and their bonded magnets
Author(s) -
Yamamoto Hiroshi,
Katagiri Eito
Publication year - 1994
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.4391140102
Subject(s) - materials science , ribbon , remanence , melt spinning , annealing (glass) , amorphous solid , magnet , alloy , analytical chemistry (journal) , metallurgy , composite material , magnetization , crystallography , magnetic field , chemistry , physics , chromatography , quantum mechanics , fiber
Abstract Melt‐spun ribbons of Nd‐Fe‐Co‐B‐Cu‐Nb system alloys were prepared by the single roller rapid‐quenching method. The effects of composition, wheel velocity and heat‐treatment on the magnetic properties were investigated. The magnetic properties of bonded magnets prepared by compression molding of optimally annealed ribbons were also measured. A maximum energy product of 152.1 kJ/m 3 was obtained for the Nd 11 Fe 72 Co 8 B 7.5 Cu 0.5 Nb 1.0 alloy ribbon prepared at a wheel velocity of 17.1 m/s. From the TEM observation on the above Nd 11 Fe 72 Co 8 B 7.5 Cu 0.5 Nb 1.0 ribbon, the particle size of these ribbons was determined to be between 10 and 40 nm. It is conjectured that the high remanence is observed by the magnetic interaction of these fine particles, and it was found that these fine particles were achieved by Nd‐Fe‐Co‐B compound in addition with Nb and Cu at the same time. The amorphous Nd 11 Fe 72 Co 8 B 7.5 Cu 0.5 Nb 1.0 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 15 min. Its corresponding value of ( BH ) max is 144.5 kJ/m 3 . A maximum energy product of 88.1 kJ/m 3 was achieved with Nd 11 Fe 72 Co 8 B 7.5 Cu 0.5 Nb 1.0 bonded magnets made from the optimally prepared ribbons.