Bimodal packing NdFeB and SmFeN improves energy product

multi-part diagram, (Top left) Scheme of bimodal packing particle to improve packing fraction; (top right) magnetic hysteresis of NdFeB SmFeN PPS hybrid magnets; Table with magnetic properties of NdFeB SmFeN hybrid magnets. 
(Top left) Scheme of bimodal packing particle to improve packing fraction; (top right) magnetic hysteresis of NdFeB SmFeN PPS hybrid magnets; Table with magnetic properties of NdFeB SmFeN hybrid magnets. 

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

Achievement
Magfine anisotropic NdFeB and SmFeN powder packing in polyphenylene sulfide (PPS) polymer results in high performance bonded NdFeB magnets. These findings demonstrate that additive manufacturing techniques can outperform conventional techniques.

Significance and impact

  • Correlation between the volumetric filling fractions of different magnetic powder particles and PPS polymer with magnetic properties have been studied.
  • 58% NdFeB (50-150 µm) and 42% SmFeN (3-5 µm) packing in 10% PPS yielded an energy product, (BH)max of 20 MGOe at 300 K and 24 MGOe at 250 K.
  • Theoretical calculations have been made to maximize the filling fraction of coarse and fine magnetic powders with binders towards further improving (BH)max. 

Details and next steps
Can be further optimize with AM NdFeB bonded magnets.

X.B. Liu, K. Gandha, H. Wang, K. Mungale, U.K. Vaidya, I.C. Nlebedim and M.P. Paranthaman, “Packing bimodal magnetic particles to fabricate highly dense anisotropic rare earth bonded permanent magnets,” RSC Adv., 2023, 13, 17097–17101 | 17097 DOI:10.1039/d3ra02349d