A scan strategy for the manufacturing of support-free overhangs via Powder Bed Fusion of metals using a laser beam

Powder bed fusion of metals using a laser beam (PBF-LB/M) offers a high design freedom for the fabrication of complex geometries. However, the need for support structures limits a broad application of the process as it results in increased costs and post-processing efforts. This paper presents a scan strategy for PBF-LB/M that aims to enable the support-free manufacturing of parts with horizontal overhangs. The overhanging region was divided into four zones with tailored laser powers. The latter were varied in a design of experiments to assess the influence of this strategy on the surface roughness, the microstructure, and the dross formation. In contrast to the standard downskin parameters, this approach enabled the successful manufacturing of the specimens within a derived process window. A simulation-based methodology for the first-Time-right manufacturing in support-free PBF-LB/M was proposed, highlighting the need for further research.