Scientists develop high-performance permanent magnet without expensive heavy rare earth elements

The Nano Supplies Analysis Division on the Korea Institute of Supplies Science (KIMS), led by Dr. Tae-Hoon Kim and Dr. Jung-Goo Lee has efficiently developed a grain boundary diffusion course of that permits the fabrication of high-performance permanent magnets without the usage of expensive heavy rare earth elements. This pioneering expertise marks the world’s first achievement on this discipline.

The findings are revealed in Acta Materialia.

Permanent magnets are key parts in varied high-value-added merchandise, together with electrical car (EV) motors and robots. Nonetheless, standard permanent magnet manufacturing processes have been closely depending on heavy rare earth elements, that are solely produced by China, resulting in excessive useful resource dependency and manufacturing prices.

To beat these limitations, the analysis staff efficiently developed a high-end, high-performance permanent magnet without the usage of expensive heavy rare earth elements. The core of this breakthrough expertise lies in its two-step grain boundary diffusion course of.

The grain boundary diffusion course of is a key expertise designed to reinforce the efficiency of permanent magnets. On this course of, the heavy rare-earth supplies are coated to the floor of the magnet, adopted by high-temperature warmth therapy.

Throughout the heat-treatment, the heavy rare-earths diffuse into the magnet’s inside alongside the grain boundaries, enhancing the coercivity—the flexibility of the magnet to retain its magnetization.

The 2-step grain boundary diffusion course of developed by the analysis staff includes first thermally infiltrating a brand new high-melting-point metal-containing materials into the magnet at excessive temperatures, adopted by room-temperature cooling.

Within the second step, a low-cost mild rare earth (Praseodymium, Pr)-containing materials is re-infiltrated into the magnets at high-temperature. A key innovation of this expertise is its capability to suppress irregular grain coarsening, a singular phenomenon that occurred through the grain boundary diffusion course of. Such undesirable grain progress degrades the diffusion effectivity and magnetic efficiency.

The analysis staff efficiently managed this subject, which had been a significant limiting consider standard GBDP, thereby enhancing diffusion effectivity.

In consequence, the diffusion materials is quickly infiltrated into the magnet, considerably enhancing coercivity. This development allows the magnet to attain efficiency grades of 45SH to 40UH, equal to industrial magnets that comprise heavy rare earth elements (HREs), regardless of utilizing solely mild rare earth elements.

If this expertise is commercialized, it’s anticipated to scale back manufacturing prices whereas enhancing efficiency in high-value industries that require high-efficiency motors, comparable to electrical automobiles (EVs), drones, and flying automobiles.

Dr. Tae-Hoon Kim, the principal investigator of the examine, acknowledged, “Presently, the usage of expensive heavy rare earth elements in magnets for electrical car motors and high-end dwelling home equipment is inevitable.

“Nonetheless, because of the focus of heavy rare earth sources in particular areas and their excessive prices, researchers worldwide have been striving for years to develop applied sciences that may scale back or exchange heavy rare earths in magnets—but progress has remained stagnant.

“By introducing a novel idea, this expertise demonstrates the potential to interrupt free from heavy rare earth dependency in high-performance magnet manufacturing. Furthermore, it presents a brand new course for analysis on grain boundary diffusion processes, a core method within the permanent magnet trade.

“If commercialized, this expertise will mark the primary occasion of South Korea securing a dominant place in probably the most essential facet of permanent magnet expertise.”