»Development of complex shape multicomponent permanent magnets with the use of advanced 3D printing technology«
L2-1829 (C) (1.7.2019 – 30.06.2022)
Head: Spomenka Kobe
Participating partners: Josef Stefan Institute, Faculty of Mechanical Engineering UL (CEM), Kolektor d.o.o.
With the transfer to renewable energy and electric mobility, especially for motors of hybrid electric vehicles (HEV) and electric vehicles (EV), permanent magnets (PM), especially Nd-Fe-B magnets, are one of the most crucial raw materials necessary for modern Europe, as they are integral to energy conversion in electric motors and generators. Because of the demand for better efficiency, lower costs and the classification of the raw materials as critical for the EU, there is an ever-increasing industrial and scientific effort to design a new generation, in shape and composition, of Nd-Fe-B magnets. Today’s research is focused on finding new magnetic materials and magnetic materials with no heavy rare-earth elements, but still, no suitable replacement could be found for the Nd-Fe-B magnets with a high Dysprosium content. It was shown that changing the design of a magnet (“V” shape geometry) could increase the efficiency by 50% in a traction motor, but producing complex net shape parts by direct sintering is still not practically feasible, as it requires energy and resource intensive post-machining.
The objective of the proposed project is the development of a new type of magnet that will have a lower heavy rare-earth content and increased efficiency by applying design changes, like replacing “V-type” magnets by a single magnetic body of a curved shape, or introducing cooling structures and small laminations/segments to reduce eddy current losses. This will be achieved with the use of advanced 3D printing technology, which is a hot topic in today’s manufacturing process, but still have not been applied in the magnet production. Simulations will be developed to achieve the best design concepts for magnets in a traction motor. These new design concepts will be printed in a modified fused deposition modelling (FDM) printer. The printer will use specially made filaments, prepared in a modified extruder where the polymer/magnet powder mix will be extruded through a magnetic field, to achieve aligned particles, for highest magnetic properties. Different filaments will be prepared with different heavy rare-earth content and printed simultaneously to develop multicomponent magnets with high magnetic properties only in regions where the magnet feels the highest demagnetization load. To achieve good magnetic properties after printing, the polymer will be removed with a debinding step and the green body will be sintered to get a dense magnet. Because this has never been done on multicomponent magnets, special care has to be taken on the debinding and sintering step, because of the different sintering temperatures of the materials. A thorough LCA and LCC will be conducted to evaluate the economic and environmental aspect of the proposed production process compared to the classical sintering with post-machining.
The available high level of interdisciplinary scientific and technical expertise within the project group from JSI, CEM, and Kolektor d.o.o. offers unique opportunities to develop a full corpus of knowledge regarding opportunities, both in scientific excellence and exploitation, including advanced technologies that are the key to solving the strategically essential questions about critical raw materials. The development of a complex shape multicomponent permanent magnet could improve Kolektor’s strategic position on the global market as a producer of magnets with an increased material efficiency by at least 30% during manufacturing, and by reducing the need of heavy rare-earth elements below 1% used in electric mobility. On the short and medium time frame, the proposed new technology will increase the demand, production and the number of jobs in Kolektor d.o.o. This novel technology would, in general, protect Kolektor d.o.o., from unstable supplies, leading to stronger high-tech material sector within Slovenia and the EU.