MM-FeCo-B magnet properties enhanced to 13.8 MGOe BHmax and 4.5 kOe coercivity

CMI researchers from Ames National Laboratory conducted the activity for this highlight

Innovation
Enhanced magnetic performance in magnet alloy with 90% less Nd than NdFeB magnets, using Dy-free grain boundary modifier.

Achievement
Increased Hcj of MM-FeCo-B magnets to 4.5 kOe and (BH)max to 13.8 MGOe by optimizing sintering conditions, amount of Nb doping, and addition of PrCuAl grain boundary modifier.

Significance and impact
By improving Hcj and BHmax, MM-FeCo-B magnets are well positioned as low-cost ‘gap magnet’ between Nd₂Fe₁₄B and ferrite magnets. Record-high Hcj for MM-FeCo-B proves effectiveness of combining grain boundary engineering and grain growth inhibitor Nb.

Hub Target Addressed
Accelerated magnet discovery and maturation.

graph shows MH curves of MM2.64Fe12-xNbxCo2Ga0.1B1.06 magnets, with 7.5% PrAlCu grain boundary modifier and indicated Nb additions. — MH curves of MM2.64Fe12-xNbxCo2Ga0.1B1.06 magnets, with 7.5% PrAlCu grain boundary modifier and indicated Nb additions.