A new method for the preparation of anisotropic Nd-Fe-B-based magnets

摘要

A new hot-forming process has been studied to produce anisotropic Nd-Fe-B-based magnets from melt-spun ribbons. The ribbon fragments were inserted in a Cu tube and hot-deformed together with one-stroke. At a height reduction ratio of 0.44, the melt-spun ribbons were densified into a magnet with a density of 7.14 g/cm/sup 3/, and showed a (BH)/sub max/ of 14.6 MGOe. With further deformation, the magnets were plastically deformed with Cu tubes in the lateral direction, and crystallographic anisotropy was introduced. The magnets with a height reduction ratio of 0.75 exhibited magnetic properties of (BH)/sub max/=32.1 MGOe, B/sub r/=11.7 kG, and /sub i/H/sub c/=10.6 kOe. This process shows the possibility that the conventional hot-pressing and subsequent die-upsetting for anisotropic magnets can be simplified into a one-step process.