Potential of contactless support structures for improving the part quality of AlSi10Mg PBF-LB parts

Abstract

Support structures are usually required to prevent thermally induced deformation of parts during the PBF-LB process, but also cause an increased effort for post-processing and an insufficient surface quality of the produced parts. An approach to overcome these limitations, suggested in the literature, is the use of contactless support structures (CSS), which should act as a heat sink to avoid thermally induced deformation. This approach was already successfully tested for electron beam melting (PBF-EB). Therefore, the aim of the present study is the experimental investigation of the application of CSS for the PBF-LB process. Different part and support geometries were built to investigate the potential of CSS to reduce thermally induced deformation during the PBF-LB process. Several use cases were covered, including increased overhang angles for thin features and maximized overhang thickness. The literature results for PBF-EB and Ti6Al4V could not be confirmed for PBF-LB using AlSi10Mg. The thermally induced deformation could not be reduced and the experimental results indicate that the use of CSS is accompanied by counterproductive process mechanisms.