Preparation of (Nd, Ce)-Fe-B Regenerated Magnets by In-Situ Restoration of Grain Boundary Structure Using Nascent Nd-Fe-B Powder

Abstract

Rare earth resource recycling is an important endeavor for environmental protection and resource utilization. This study explores the method of preparing regenerated magnets using waste magnets as raw materials based on existing processes. By utilizing existing Nd-Fe-B production equipment, various waste magnets are transformed into recycled powder. Next, nascent Nd-Fe-B powders with slightly higher rare earth content are selected as the repairing agent. The regenerated magnets are prepared by incorporating the nascent powder into the recycled powder. The focus lies in investigating the repairing effect of the nascent powder repairing agent on the microstructure of regenerated magnets and exploring the influence of sintering temperature and powder addition on the magnetic properties and microstructure of the regenerated magnets. The results showed that the nascent powder increased the proportion of grain boundary phases and effectively repaired the grain boundary structure of the regenerated magnets. In addition, the Pr element in the nascent powder replaces the Ce element in the recycled powder, which ultimately improves the magnetic properties of the regenerated magnet in a comprehensive manner. This study provides valuable insights and guidance for rare earth resource recycling and the preparation of regenerated magnets.