Enhanced texture in die-upset nanocomposite magnets by Nd-Cu grain boundary diffusion

Bulk anisotropic nanocomposite Nd2Fe14B/alpha-Fe magnets were prepared by hot pressing and die upsetting coupled with Nd-Cu grain boundary diffusion. The hot workability of nanocomposite magnets is enhanced dramatically by grain boundary diffusion of low melt point Nd-Cu alloy, resulting in a strong anisotropy by die upsetting. The microstructure of die-upset nanocomposite magnets is identical with that of the traditional die-upset rare earth-rich magnets. The coercivity, remanence, and squareness degree of demagnetization curves are optimized. The observation for microstructures and the analysis of magnetic properties suggest that the grain boundary diffusion mainly occurs in the hot deformation process. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793429]