Effect of NdFeB particle size on the performance of 3D printed bonded magnets of polyamide‐based composites

Abstract Additive manufacturing has been widely used in the field of bonded magnets manufacturing. However, there are some key issues to be faced in order to obtain bonded magnets (BMs) with high performance. In this study, four different particle sizes of flake NdFeB powder (volume‐weighted mean diameter [VMD] of 5.60 μm, 19.21 μm, 33.25 μm, and 66.69 μm) were obtained by vibratory sieving. Flexible filaments for 3D printing BMs were produced using polyamide‐6 (PA6) as the substrate, and the production process is reported in this paper. Characterization of the performance of the 3D‐printed BMs revealed that the BMs with VMD less than 10 μm have excellent mechanical strength, but the ductility of the magnets decreases with decreasing VMD of NdFeB powder. As the NdFeB VMD decreases, the coercivity of the sample decreases and the remanence increases. This study provides a reference for the selection of filler particle size for 3D printing BMs, which can be used to develop 3D‐printed BMs with excellent performance.