Bimodal packing of NdFeB and SmFeN improves energy product

composite image
Calculated magnetic filling fraction as a function of fine particle (SmFeN) contents for different binder contents based on the Furnas principle; (b) magnetic hysteresis of NdFeB SmFeN PPS hybrid magnets; (c) powder X-ray diffraction patterns of the hybrid magnets; and (d) SEM image indicating the mixture of two different particle sizes. 

CMI researchers at Ames National Laboratory and Oak Ridge National Laboratory conducted the research for this highlight

Innovation
High performance magnets via combination of NeFeB and SmFeN powders of distinct sizes.

Achievement
Magfine anisotropic NdFeB (100 mm) and SmFeN (4 mm) powder packing in polyphenylene sulfide (PPS) polymer results in high performance (20 MG-Oe) bonded NdFeB magnets.

Significance and Impact 

  • Reduced cost, 40% reduced-Nd bonded magnet outperforms conventional NdFeB bonded magnets.
  • Calculations predict further improvement of BHmax by maximizing the filling fraction of coarse and fine magnetic powders.

Hub Target Addressed
Industrial adoption of CMI technologies.