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Research on high‐performance NdFeB magnets
Author(s) -
Kaneko Yuji,
Tokuhara Koki,
Ishigaki Naoyuki,
Majima Kazuhiko
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.4391140501
Subject(s) - magnet , materials science , eutectic system , coercivity , phase (matter) , sintering , ternary operation , analytical chemistry (journal) , metallurgy , crystallography , alloy , chemistry , condensed matter physics , electrical engineering , physics , organic chemistry , chromatography , computer science , programming language , engineering
Abstract The effects of the constituent phase of Nd‐Fe‐B magnets on sintering behavior are investigated. In the case of Nd‐Fe‐B magnets, a liquid phase forms by ternary eutectic reaction of Nd 2 Fe 14 B, Nd 1.1 Fe 4 B 4 and Nd‐rich phase at 938 K. When the sintering temperature is raised above 1273 K, a remarkable shrinking occurs because of an increase in the amount of liquid phase which is supplied by the reaction between the Nd 2 Fe 14 B and the Nd 1.1 Fe 4 B 4 phase. The residual flux density ( B r ) of Nd‐Fe‐B magnets increases in proportion to the increase in the among of the Nd 2 Fe 14 B phase. By contrast, the intrinsic coercivity ( i H c ) declined because of a decrease in the amount of the Nd 1.1 Fe 4 B 4 and the Nd‐rich phase. As a result, new high‐performance Nd‐Fe‐B magnets with the maximum energy product of above 366 kJ/m 3 (46 mgOe) have been developed by means of controlling the component ratios of these phases in Nd‐Fe‐B magnets.