Rare earths are one of the most strategically important raw materials for German industry because they are an important part of many high-tech products. To make more effective use of these valuable elements, the Fraunhofer Institute has developed a new solution in a joint project that has now been completed. These include optimized manufacturing processes, recycling methods and the development of new materials that can replace rare earths. Fraunhofer experts said demand for rare earths could be reduced to one-fifth of the current value of benchmark motors.
China has about 90% of the world's rare earth production, and then implemented export cessation, prices soared, and the vulnerability of German industry in the safety of these raw material supplies became apparent.
As a result, the researchers' goal is to use existing rare earths more wisely, looking for alternative materials, especially praseodymium and neodymium. For example, for magnets, such as those used in electric motors, these magnets are required. For reference, the Fraunhofer team chose two electric motors. Combined with all the options developed in the project to reduce or replace rare earths, the demand for praseodymium and neodymium in these engines can be reduced to 20% of the original required amount.
"Our goal is to halve the demand for rare earths for these benchmark engines." Professor Ralf B. Wehrspohn said: "Our performance is significantly better than combining different technical approaches." The head of the Structure Institute and a spokesman for the project emphasized the relevance of the example chosen: "In today's ordinary cars, there are dozens of these engines in moving windows, wipers or oil pumps. These engines Many of them work with permanent magnets containing rare earths. "
Fraunhofer researchers analyzed the global market for rare earths, while developing concepts for how to consider future reuse or recycling of rare earths in motor designs. They are also looking for ways to reduce waste in the magnet manufacturing process. This is possible, for example, by injection molding, in which the magnetic material is directly formed into the desired shape together with a plastic binder and then sintered. This also eliminates time for elaborate makeovers.
In another project, a method was developed to recycle permanent magnets, such as from electronics, wind turbines or cars that are no longer used. They are decomposed by pure hydrogen treatment, and the resulting particles are then poured back into or sintered. The capacity of the recirculating magnet reaches 96% of the capacity of the new magnet. By combining plasma sintering (SPS) and hot pressing, cesium is introduced into the grain boundary phase, resulting in the wide application of anisotropic magnets in electric motors.
The design of the reference motor is also optimized: if the motor does not become so hot during operation, a magnet with lower temperature stability can be used, which can use a lower proportion of cesium. Last but not least, we searched for some materials and found that these materials can also be used as magnets but do not contain rare earths. In high-throughput procedures, researchers have tested combinations of multiple materials and demonstrated new alloys that replace rare earths, among others, containing cesium. As flakes, these new compounds are already very magnetic. Analyze the current and expected supply safety of all identified alternative materials.