Formation and Stability of Hydrides During Hydrogenation of Ndfeb Magnets

Abstract

Demand for magnets has increased in the last decades due to their usage in the energy sector. One of the most common magnets used for applications such as electronic devices, wind turbines, etc. is Nd2Fe14B (NdFeB). Neodymium (Nd) is one of the critical elements listed by the EU, hence the efficient use and proper recycling of Nd-containing materials become of great interest. Hydrogen is commonly used during magnet production and some hydrogen-assisted recycling approaches were also reported. This study reports an analysis of formed hydrides during hydrogenation of NdFeB magnets at up to 400 degrees C. In addition to experimental results, thermochemical modeling was performed by using FactSage databases to discuss the effect of temperature and pressure on hydrogenation. The study showed that the stability of phases changes with the temperature and pressure which affects the hydrogen content of phases after hydrogenation.