Spark plasma sintering and diffusion technology yield high-performance permanent magnets for green industries

A analysis staff has developed an modern manufacturing course of for permanent magnets that overcomes the restrictions of standard methods. The staff’s breakthrough considerably advances the diffusion technology, which is important for bettering magnetic efficiency, and creates new potentialities for making use of high-efficiency magnets in eco-friendly industries reminiscent of electrical automobiles, wind generators, and robotics.

The findings are published within the Journal of Alloys and Compounds.

The joint analysis staff from the Nano Technology Research Division at DGIST was led by Dr. Donghwan Kim and Dr. Jungmin Kim.

With the fast development of the electrical car and wind energy sectors, the demand for highly effective permanent magnets able to secure operation at high temperatures has soared. A significant instance is the neodymium (Nd-Fe-B) permanent magnet, extensively utilized in electrical car motors. However, these magnets expertise a decline in magnetic efficiency underneath extreme heat, requiring the addition of heavy rare-earth components reminiscent of terbium (Tb) and dysprosium (Dy) to take care of their energy. The problem is that these components are each uncommon and costly.

To handle this situation, the grain boundary diffusion course of has been extensively adopted. This method enhances magnetic efficiency by infiltrating a small quantity of heavy rare-earth materials into the magnet’s floor. However, diffusion on this course of is proscribed to the surface layer and doesn’t penetrate into the magnet’s inside, making it troublesome to use to thick magnets.

To overcome this limitation, the analysis staff mixed spark plasma sintering, a complicated manufacturing method, with the grain boundary diffusion course of. By pre-mixing the diffusion materials throughout the powder-based magnet fabrication stage, uniform diffusion was achieved all through the magnet. Consequently, the diffusion depth elevated markedly in contrast with that achieved by current strategies, permitting for the creation of a core–shell construction during which the magnet displays uniform and enhanced magnetic efficiency.

Remarkably, even with the identical quantity of rare-earth materials, the brand new course of achieved greater diffusion effectivity and considerably improved general efficiency. This development makes it attainable to provide magnets which can be smaller and lighter whereas sustaining robust magnetic energy. It is anticipated to contribute to the miniaturization, weight reduction, and improved vitality effectivity of electrical car motors. Additionally, the method reveals nice potential for utility to large-scale magnets.

Principal Researcher Dr. Donghwan Kim acknowledged, “This study presents a method that overcomes the limitations of the conventional grain boundary diffusion technology, enabling uniform performance throughout the magnet. It will make a significant contribution to the development of high-performance permanent magnets required in eco-friendly energy industries such as electric vehicles and wind power generation.”