A study of the effects of Cu-addition on the annealing behavior and microstructures of Nd-Fe-B type sintered magnets

Permanent magnets based on R-Fe-B and R-Fe-C alloys

“…The wettability of the grain boundary phase is also enhanced by the addition of small amounts of copper (Fidler and Bernardini 1991, Ragg and Harris 1993 due to the decrease of their melting temperature. Changes in the microstructure were shown.…”

Complete ductility in NdFeB-type alloys using the Hydrogen Ductilisation Process (HyDP)

“…To date the best magnetic properties have been for a Neomax-type alloy pressed at 5 t with a coercivity of 824 kAm -1 and a remanence of 770 mT. Although the coercivity is close to that expected for a M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 20 20 sintered magnet of a similar composition the remanence is significantly lower than that for a commercially produced sintered magnet based on the Neomax composition [10,11]. In order to achieve a significantly higher BH(max), the NdFe4B4 phase would have to be removed to reduce cracking, the cavitation would have to be eliminated and a higher level of deformation would have to be achieved.…”

“…There were some indications of alignment in the material, with an easy-axis in the z-direction (pressing direction); this direction can be seen again in Figure 6(a). In comparison, conventional sintered magnets with a similar composition to that used here have typically, a coercivity of 800-1000 kAm -1 and a remanence of 1200 mT [10,11].…”