Australia Materials: Takeaways from Discussion on Advances in Rare Earth Permanent Magnets

Research evidence excerpt

Australia Materials: Takeaways from Discussion on Advances in Rare Earth Permanent Magnets

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Continued

Heavy Rare Earth thrifting and technical limits: The expert expects significant change in

heavy rare earth use over the past five to ten years, with Dysprosium (Dy) and Terbium

(Tb) reductions already underway in the decade leading up to 2012, with prior levels at

around ~2%, now as low as ~0.5%, depending on application requirements. Further rare-

earth intensity reduction in sintered NdFeB magnets likely depends on coercivity gains

from grain refinement, lower defect density, and grain-boundary/microstructure

engineering. Conventional sintered NdFeB grains already sit in the low-single-digit micron

range leaving less room for grain-size reduction alone. Current materials still sit at roughly

only ~30% of theoretical coercivity in some calculations, suggesting additional headroom

if producers can further improve material quality.

Rare-earth-free substitution and application optimisation: Ferrite magnets are an

existing rare-earth-free option and price can drive substitution in some use cases.

However, the expert said high-performance, miniaturised and latest-technology

applications still require NdFeB. The expert cited 3.5-inch hard disk drives as an example

where room-temperature applications initially used meaningful Dy/Tb before

manufacturers realised those elements were unnecessary and removed them. The expert

said companies historically overestimated safety factors, creating room to allocate Dy/Tb

only where truly needed. Electric scooters were cited as an example where Neodymium-

Praseodymium (NdPr) is substituted with cerium and Dy/Tb content can be very low.

Application temperature drives rare earth intensity: The expert said rare earth reduction