Sh. Pi et al., EFFECTS OF HEAT-TREATMENTS ON COERCIVITY AND MICROSTRUCTURE IN ND15FE77B8 SINTERED MAGNETS, Materials science & engineering. B, Solid-state materials for advanced technology, 32(1-2), 1995, pp. 89-91
The effects of psst-sintering heat treatments on the structure and pro
perties in sintered Nd15Fe77B8 magnets have been investigated. In the
as-sintered sample, the crystal structure of the Nd-rich phase was f.c
.c., while the Nd-rich phase transformed into a superlattice after hea
t treatment at 600 degrees C for 1 h. However, the structures of Nd2Fe
14B and B-rich (Nd1+epsilonFe4B4) phases did not change upon heat trea
tment. It is suggested that the formation of the superlattice enhances
the coercivity of the magnets.