PSI - Issue 77

V. Kroužecký et al. / Procedia Structural Integrity 77 (2026) 161 – 169 Vít Kroužecký / Structural Integrity Procedia 00 (2026) 000 – 000

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Figure 6 Tensile graph (Default parameters – Blue line; modify parameters – red line)

Figure 7 Tensile graph (Default parameters – Blue line; modify parameters – red line) While both sets of samples reach comparable yield strength and ultimate tensile strength, the B samples demonstrate higher ductility and elastic modulus. 4. Conclusion The aim of this study was to reduce the surface roughness of downskin surfaces and to improve their topological uniformity by developing and testing modified processing parameters for LPBF. The proposed parameter set was further verified through mechanical testing. The feedstock material was recycled 316L stainless steel powder, which exhibited a significantly altered particle size distribution compared to virgin powder, characterized by an increased fraction of fine particles. Experimental results demonstrated a clear trend of decreasing surface roughness with increasing volumetric energy density (VED). More importantly, the modified parameters provided a more consistent surface topology compared to the default settings. These findings are particularly relevant for the manufacturing of components with overhanging features, such as internal cavities, where the use of support structures is not feasible due to inaccessibility or risk of damaging the final part. While this work focused primarily on manufacturability and surface quality, a broader range of mechanical tests will be necessary to confirm the applicability of the developed parameters. Future work will therefore include fatigue, hardness, and toughness testing to fully validate the performance of the optimized process conditions. Acknowledgements This research paper is co-financed from the state budget by the Technology agency of the Czech Republic under the Sigma Progamme. Applied research of unsupported metal additive manufacturing for complex-shaped parts intended for urgent services in key areas of the energy industry. TQ03000536. www.tacr.cz