High-performance critical-element-free permanent magnets

X-ray diffraction patterns of precursor phases to L10 FeNi.
X-ray diffraction patterns of precursor phases to L10 FeNi.

CMI researchers at Ames Laboratory conducted the research for this highlight 

Achievement
Attained BHmax of 5.9 MGOe (pressed pellet) and 2.5 kOe coercivity (powder) via innovative yet simple, scalable, mechanochemical process (MP), while achieving reproducible 98+% yields of precursor t-FeNiN.

Significance and impact
High-performance, rare earth-free, low-cost material with the potential to quickly and broadly penetrate PM markets.

Next steps

  • Beneficiation (Fe/Ni ratio; doping with 1-2 at.% of transition; further refinements of microstructure)
  • Scale-up to 1-10 g quantities of L10-FeNi
  • IP disclosure drafted, under revision
  • Fabrication of magnets (grain alignment and compaction)
Hysteresis loops of loose powder (black) and pressed powder (red) samples of L10 FeNi, showing coercivities in excess of 2 kOe.
Hysteresis loops of loose powder (black) and pressed powder (red) samples of L10 FeNi, showing coercivities in excess of 2 kOe.