The development of permanent magnets that demonstrate high-end performance without the need for expensive rare earth elements is expected to free us from dependence on rare resources.

The Korea Institute of Materials Science (KIMS, President Choi Chul-jin) announced on the 3rd that the research team of Dr. Tae-Hoon Kim and Dr. Jeong-Gu Lee of the Nanomaterials Research Division, in collaboration with the research team of Professor Woo-Young Lee of Yonsei University, has developed for the first time in the world a two-step grain boundary diffusion process that can produce high-performance permanent magnets without using expensive rare earth elements.

The permanent magnets developed through this research can be used as core components in various high value-added products such as electric vehicle motors and robots.

The existing permanent magnet manufacturing process had limitations in that it was highly dependent on resources and had high costs due to its dependence on rare earth elements exclusively produced in China.

On the other hand, through this research, we succeeded in developing a permanent magnet that achieves high-end powerful performance without expensive rare earth elements.

The second-stage grain boundary diffusion process is a technology for improving the performance of magnets. It involves applying a thin layer of the necessary material to the surface of the magnet and heat-treating it at high temperatures so that the material enters the magnet and improves performance, such as coercivity.

The process developed by the research team involves in the first step a new material containing a high-melting point metal that is infiltrated into the surface of a permanent magnet at high temperature and cooled to room temperature, and then in the second step, a low-cost light rare earth metal (Pr, praseodymium) is added.) is a method of re-applying the material and processing it at high temperatures.

This enabled the diffuser to quickly penetrate inside the magnet, enabling performance equivalent to that of commercial magnets using heavy rare earth elements, despite the use of light rare earth elements.

If this technology is commercialized, it is expected to both reduce manufacturing costs and improve performance of permanent magnets in high value-added industries such as electric vehicles, drones, and flying cars that require high-efficiency motors.

Senior Researcher Kim Tae-hoon, who is in charge of the research, explained, “Currently, expensive heavy rare earth elements are unavoidable for magnets used in motors for electric vehicles and high-end home appliances, but this technology introduces a new concept and shows the possibility of escaping dependence on heavy rare earth elements in the manufacturing of high-end magnets.” He added, “This study suggests a new direction for research on grain boundary diffusion processes, a core process in the field of permanent magnets.”

This study was conducted with the support of the Ministry of Science and ICT and the National Research Foundation of Korea-Nano and Materials Technology Development Project, and the results were published online on December 24 in the world-renowned academic journal 'Acta Materialia'.