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

Abstract

Nd–Fe–B sintered magnet scraps were reproduced as the corresponding sintered magnets from the ground powders (mean particle ≤3 μm) 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 Br=∼1.21 T, HcJ=∼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.