Reproduction of Nd-Fe-B Sintered Magnet Scraps Using a Binary Alloy Blending Technique

Nd-Fe-B sintered magnet scraps were reproduced as the corresponding sintered magnets from the ground powders (mean particle ≤3μm) by using a binary alloy blending technique. Although the magnets re-sintered from the as-ground powders only provided poor magnetic properties, especially the observed coercivity values (∼20 kAm -1 ), the magnetic properties were considerably improved compared with the as-ground powders by adding an Nd-rich alloy (80 and 20 mass% for Nd and Fe, respectively) with the mass ratio of 90 (scrap powders) to 10 (Nd-rich alloy). Typical magnetic parameters of the recovered magnets were B r = ∼1.21 T, H cJ = ∼1.6 MAm -1 and (BH) max = ∼251 kJm -3 . It was found that the Nd-Fe-B sintered magnet scraps were reproduced as the practically usable magnets by the above process.