As part of the 40th Erfinderlabor, our research group participated with the outreach activity entitled “High Performance Materials and Recycling – A Contradiction?”. The motivation behind this study lies in the increasing demand for rare earth elements used in high-performance permanent magnets, which are essential for renewable energy technologies, electric mobility, and many everyday electronic devices. At the same time, the limited availability of these critical raw materials, their environmentally intensive mining processes, and their geopolitical supply risks highlights the urgent need for efficient and sustainable recycling strategies. Addressing these challenges is closely linked to climate change mitigation and the transition toward a circular economy. In this context, it is particularly important to introduce young scientists and future generations to sustainable materials research at an early stage.

During the laboratory visit, the students worked with real end-of-life Nd–Fe–B permanent magnets. They were guided through the recycling process, beginning with the disassembly of magnet-containing components, followed by surface cleaning. Following surface preparation, the magnets were melted then processed using hydrogen decrepitation, during which hydrogen absorption causes the Nd–Fe–B material to fracture along its grain boundaries, resulting in a coarse powder. This material was subsequently refined by jet milling to produce a fine and homogeneous magnet powder suitable for further processing. In the final step, the recycled powder was pressed under an applied magnetic field, allowing the particles to align and thereby restore the anisotropic magnetic properties required for high-performance permanent magnets.

The students successfully completed all laboratory steps and went beyond preparation, characterizing the recycled magnets using advanced techniques such as scanning electron microscopy (SEM) and physical property measurement (PPMS) to analyze their structure and magnetic properties. They then presented their study and results at Merck, gaining valuable experience in both experimental research and scientific communication.

See also the official news ticker by the Material Science department!