The importance of adjusting the processing parameters for the resulting material density of PBF‑LB AISI 316L lattice structures

Lattice structures are becoming more commonly used in the design of components for additive manufacturing. This is due to their ability to reduce the weight of manufactured parts, minimize material consumption, and achieve specific properties by modifying their geometry. As the applications of lattice structures continue to evolve, it is essential to determine whether the process parameters used in the PBF-LB (Laser Beam Powder Bed Fusion) process for manufacturing these structures should be the same as or different from those used for larger cross-sectional components. An analysis of the existing litera ture revealed insufficient data on this subject, which inspired this study. Experiments conducted using AISI 316L stainless steel showed that lattice structures can be produced with significantly lower volumetric energy density, while maintaining a high relative material density. In the experiment on lattice structures made of BCCZ and gyroid unit cells, a relative mate rial density of over 99.5% was achieved with a volumetric energy density of approximately 33 J/mm3. These findings are significant for the fabrication of lattice structures. The lower volumetric energy density typically allows for greater geometric accuracy and reduced internal stresses. Furthermore, it has been proven that the nodes of the structure are critical places exposed to porosity formation.