Application of Magnetic Field in Fabrication Process of Anisotropic Bonded Nd-Fe-B Magnet

This work studied the application of the different magnetic field used in the compaction process for die fabrication of anisotropic Nd-Fe-B bonded magnet. The static field made from Nd-Fe-B permanent magnets was used in the blending process to separate the particles each other. The SEM observation gave intuitionistic results about it. The anisotropic Nd-Fe-B bonded magnets were fabricated with warm-compaction under the electromagnetic field about 2.5 T. It is known that magnetic field is necessary for anisotropic materials fabrication for alignment. And warm compaction was used to decrease the viscousness of binder, to enhance alignment magnetic particle while press, and to get high density materials. For coercivity of Nd-Fe-B magnets decrease largely with the temperature increasing, press in proper temperature and oriented field is benefit to the magnetic characteristics and the mechanical properties of the anisotropic bonded Nd-Fe-B magnets. Finally solidifying process was performed under the pulse field of 4 T. The increment for solidifying in the field was about 15% for maximum energy product of the bonded magnet. The magnetic properties of anisotropic bonded Nd-Fe-B magnets from d-HDDR powders compact at 90 °C in alignment field of 2.5 T were: B_r=8.55 kGs, _iH_c=12.0 kOe, (BH)_max=14.57 MGOe.