EFFECT OF ND CONTENT ON INDUCED ANISOTROPY IN HOT DEFORMED FE-ND-B MAGNETS

The magnetic properties of die-upset forged Fe-Nd-B magnets with Nd content varying from 6 to 20 at% have been studied. It has been found that the crystallographic alignment is only possible for magnets containing more than 12 at% Nd, i.e. having a liquid grain boundary phase during deformation. This phase provides a fast diffusion path for atomic migration. The mechanism of texture formation is considered to be complex and comprise grain fracturing, dissolving of unfavourably oriented crystallites, growth of the grains with favourable orientation, as well as renucleation and growth of new grains from the saturated liquid boundary phase.