Additive manufacturing of anisotropic hybrid NdFeB-SmFeN nylon composite bonded magnets

Abstract

In this work, we demonstrate a novel method of extrusion-based 3D printing additive manufacturing of bonded magnets comprising 65 vol% anisotropic composite powders of Dy-free magfine Nd-Fe-B and Sm-Fe-N in nylon. The 3D printing was performed using a big area additive manufacturing (BAAM) process. The effects of various post-printing alignment with different magnetic field intensities and temperatures on the properties of the anisotropic bonded Nd-Fe-B + Sm-Fe-N composite magnets were investigated. Remanence increases with alignment magnetic field leading to an increase in energy product, (BH)max. For anisotropic Nd-Fe-B + Sm-Fe-N composite bonded magnets with a 65 vol% loading fraction, (BH)max of up to 11.3 MGOe are obtained. In addition, the magnetic properties of the bonded magnets can be tuned through the post-printing alignment of anisotropic particles in different directions without impairing the original shape-changing effect. This technique shows great promise for producing anisotropic bonded magnets with enhanced magnetic properties.