Highly coercive milled and melt-spun (Pr, Nd)FeB-type magnets and their hot workability

Highly coercive isotropic (Pr1-xNdx)(2)Fe14B-type magnets (0 less than or e qual to x less than or equal to 1) have been processed using high energy ba ll milling and melt-spinning techniques, and an assessment of their hot def ormation behavior has been carried out. A very high coercivity of mu H-0(c) = 2.7 T and a remanence of J(r) = 0.72 T were found after annealing partly amorphous Pr15DyFe75.9B8Zr0.1 ribbons. Samples containing Dy (1at.%) and Z r (0.1at.%) exhibit an improved stability against grain growth with increas ing the annealing temperature. It has been found that the deformation force s necessary for texturing by hot deformation are the lowest for the as-mill ed Pr-containing alloys. As-milled Pr15Fe77B has been textured by die-upset ting at 750 degreesC obtaining magnetic properties as high as J(r) = 1.27 T , mu H-0(c) = 1.20T and (BH)(max) = 307 kJ/m(3).