Bulk anisotropic Nd_2Fe_(14)B/α-Fe nanocomposite magnets prepared by hot-deformation processing of amorphous alloys

摘要

We succeeded in producing bulk anisotropic Nd_2Fe_(14)B/α-Fe nanocomposite magnets by hot-deformation processing of Nd-lean amorphous Nd_9Fe_(85)B_6. The bulk Nd_2Fe_(14)B/α-Fe nanocomposite magnets yielded at a uniaxial stress of 310 MPa at 700 ℃ for 2 min show a strong magnetic anisotropy and enhanced magnetic properties, e.g., an increase of ～51.4% in the maximum energy product along the stress direction as compared with the magnets produced by annealing amorphous Nd_9Fe_(85)B_6. A large uniaxial stress is favorable for the (001) texture development of Nd_2Fe_(14)B nanocrystals in the amorphous matrix, which may be attributed to a preferential nucleation and growth of Nd_2Fe_(14)B crystals at the stress. The present study provides a strategy to induce the texture for R_2Fe_(14)B phase in R-lean (R=rare earth) alloys and thus is of wide interest for yielding bulk anisotropic nanocomposite magnets with a high volume fraction of α-Fe phase.