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 everlasting magnets with out using costly heavy uncommon earth parts. This pioneering expertise marks the world’s first achievement on this area.

The findings are published in Acta Materialia.

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

To beat these limitations, the analysis workforce efficiently developed a high-end, high-performance everlasting magnet with out using costly heavy uncommon earth parts. 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 everlasting magnets. On this course of, the heavy rare-earth supplies are coated to the floor of the magnet, adopted by high-temperature warmth remedy.

In the course of the heat-treatment, the heavy rare-earths diffuse into the magnet’s inside alongside the grain boundaries, bettering the coercivity—the power of the magnet to retain its magnetization.

The 2-step grain boundary diffusion course of developed by the analysis workforce entails 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 uncommon 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 novel phenomenon that occurred in the course of the grain boundary diffusion course of. Such undesirable grain development degrades the diffusion effectivity and magnetic efficiency.

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

In consequence, the diffusion materials is quickly infiltrated into the magnet, considerably bettering coercivity. This development permits the magnet to realize efficiency grades of 45SH to 40UH, equal to business magnets that include heavy uncommon earth parts (HREs), regardless of utilizing solely mild uncommon earth parts.

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

Dr. Tae-Hoon Kim, the principal investigator of the research, acknowledged, “At present, using costly heavy uncommon earth parts in magnets for electrical car motors and high-end dwelling home equipment is inevitable.

“Nonetheless, because of the focus of heavy uncommon 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 uncommon earths in magnets—but progress has remained stagnant.

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

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