– a key goal in this segment is the development of clean manufacturing technologies that shorten the path between the initial design stages and finished products. We are dedicated to additive technologies (3D-printing), which enable rapid production of complex magnetic prototypes, both from fresh and recycled powders. In 2023, the EIT Manufacturing aProMag project (www.apromag.eu) was completed. The project aimed to develop innovative rotor prototyping processes for brushless DC motors and actuators using advanced 3D-printing of permanent magnets.
Key innovations included: i) integration of 3D-printing directly in the magnetic field to produce magnetically orientated magnets with improved magnetic properties, ii) use of powder from recycled Nd-Fe-B magnets and iii) cost/time savings through rapid prototyping. The breakthroughs we achieved are a developed sensor system for monitoring magnetic filaments and constructing a precision nozzle to produce magnetically orientated magnets of complex shapes.
Furthermore, in the framework of 3D-printing of permanent magnets we produced filaments based on SrFe12O19 with Polyphenylene Sulfide (PPS) with a filling factor of 70 wt. %. We subsequently printed this filament with a 3D-printer directly onto a permanent magnet. Upon printing in a magnetic field, we increased remanent magnetization by 61% due to improved magnetic orientation. The research entitled “Additive-manufactured anisotropic magnets for harsh environments” was published in the Journal of Magnetism and Magnetic Materials (https://doi.org/10.1016/j.jmmm.2023.171165).
Figure 3: Schematic of printing in a magnetic field (left). Demagnetization curves of the pure Sr-ferrite powder (100%-orange) and the 3D prints (70%-blue), with (solid line) and without (dashed line) an external magnetic field (right) (https://doi.org/10.1016/j.jmmm.2023.171165)
We continued our research on the M.ERA.NET Addmag project (https://www.m-era.net/materipedia/2021/addmag) investigating the additive manufacturing-based production of complex Nd-Fe-B magnets from recycled material. The first attempts to make magnets by 3D-printing and sintering showed that the carbon was not completely removed from the polymer and caused the formation of free iron. We are now optimizing the process to remove all the polymer and testing samples with lower polymer content and different polymers that are easier to remove from the sample.
