Recycled Sm-Co bonded magnet filaments for 3D printing of magnets

Abstract

Recycling of rare earth elements, such as Sm and Nd, is one technique towards mitigating long-term supply and cost concerns for materials and devices that depend on these elements. In this work recycled Sm-Co powder recovered from industrial grinding swarfs, or waste material from magnet processing, was investigated for use in preparation of filament for 3D printing of bonded magnets. Recycled Sm-Co powder recovered from swarfs was blended into polylactic acid (PLA). Up to 20 vol.% of the recycled Sm-Co in PLA was extruded at 160°C to produce a filament. It was demonstrated that no degradation of magnetic properties occurred due to the preparation or extrusion of the bonded magnet material. Good uniformity of the magnetic properties is exhibited throughout the filament, with the material first extruded being the exception. The material does exhibit some magnetic anisotropy, allowing for the possibility of the development of anisotropic filaments. This work provides a path forward for producing recycled magnetic filament for 3D printing of permanent magnets.

Magnetic Properties of SmCo5 + 10 wt% Fe Exchange-Coupled Nanocomposites Produced from Recycled SmCo5

“…The biggest promises of exchange-coupled nanocomposites are miniaturization (due to the increased (BH) max ) and sustainability by the reduction of the rare earth mass fraction (10–20% reduction) and efficiency increase. In this work, we explore the possibility of improving on the sustainability aspect by creating exchange-coupled nanocomposites from recycled SmCo 5 magnets [ 21 , 22 , 23 ] (90 wt%) and a cheap and available 3d metal (Fe, 10 wt%). While most of the recent work in this area is on Nd 2 Fe 14 B+Fe nanocomposites [ 24 , 25 , 26 , 27 , 28 ], the choice of recycled SmCo 5 was made due to the relative purity of these industrial magnets compared with other compositions [ 2 , 3 ].…”

Methodology for Shape Optimization of Magnetic Designs: Magnetic Spring Characteristic Tailored to Application Needs

“…These manufacturing techniques represent net shape methods which makes them very resource-efficient since no scrap is produced and no material is lost through, for example, a grinding process. Additionally, these methods open up the possibility to use recycled permanent magnet materials [17]. With increasing material in the global product cycles, this topic will further gain importance in the future.…”

Additive Manufacturing and Topology Optimization of Magnetic Materials for Electrical Machines—A Review

“…Research on additively manufactured SmCo magnets is still at the early stage, so far focusing on printing magnets made of recycled magnet powder. The authors in [64] shows the process on producing magnet filament, made of recycled SmCo magnet powder and polylactic acid (PLA) plastic, for 3D printing bonded magnet. The produced magnet filament, however, has low remanent flux density, below 0.1 T. This is due to the low volume percentage loading of the magnet powder (less than 20%), in the production of the magnet filament.…”