Field Assisted Sintering in the Direct Recycling of Hot Deformed Nd-Fe-B Magnet Scrap

Abstract

With the expanding use of high-performance permanent magnets, such as Nd-Fe-B, in green energy production and e-mobility, comes the need to further investigate contemporary production methods. Field assisted sintering technologies, such as spark plasma sintering and flash spark plasma sintering, have shown promising results with regards to anisotropic texturing, densification, and microstructural fine-tuning, even from non-ideal crushed anisotropic Nd-Fe-B scrap as a starting powder. Optimization of these processes could lead to magnetic performance that matches or exceeds standard commercial magnet production techniques, such as hot deformation. This is due to the fine parameter monitoring and control available with field assisted sintering devices. This study focuses on the optimization of field assisted sintering with commercial MQU-F to demonstrate net-shaping of anisotropic Nd-Fe-B magnets with an intention of transferring the parameters to the deformation of recycled magnet powder.