Additive manufacturing of structural materials such as steels, Al-, Ni- and Ti-based alloys by laser powder bed fusion (LPBF) is established as a new production technology, which allows the fabrication of complex and individualized parts. It is a layer-by-layer additive manufacturing technique, which utilizes lasers to selectively melt metallic powders, which then fuse during solidification. The final product of this manufacturing technique is a dense metallic part. The LPBF process is characterized by local melting of a powder material, rapid cooling, directional heat transfer and several re-heating and re-melting. On the other side research on the additive manufacturing of functional materials like Nd-Fe-B based permanent magnets is still at the beginning and many aspects of the interplay between fabrication process, microstructure and resulting properties is still unknown. Furthermore, the search for materials modifications to improve the limited processability are of interest.

We present in our contribution a detailed analysis of the impact of the LPBF-process on the development of microstructural defects, mechanical and magnetic properties. A statistical based process model will be used to separate the effect of the major process parameter and their interactions on the magnetic performance. This approach allows to reproduce the magnetic hysteresis curve of LPBF-produced Nd-Fe-B magnets and can be used to identify potential for optimization of magnetic properties by adjusting the LPBF-process.

Furthermore, the effect of subsequent heat treatments on magnetic properties is linked to changes in the microstructure and show the potential for a further improvement of LPBF-produced Nd-Fe-B permanent magnets.