Support structure removal in laser powder bed fusion of metals

Additive manufacturing enables the production of highly complex components. In laser powder bed fusion of metals, support structures play a crucial role in ensuring successful part manufacturing: they support overhanging features, fixate parts in space, and dissipate process-induced heat. However, since they do not belong to the functional part, supports need to be removed after manufacturing. Currently, this step relies on manual work, highlighting the need for innovation to further advance the manufacturing technology. In this study, the state of the art regarding support removal process innovation as well as support design optimization considering ease of removal is reviewed and discussed based on 66 publications. Scientific as well as commercial solutions are analyzed. The technical approaches are described and evaluated in terms of applicability and automation level, whereby it becomes apparent that technology transfer from the research sector to industrial application is not yet being given sufficient consideration. Additionally, the topic of support removal avoidance is touched upon. It has been shown that self-supporting part designs can reduce support structures, but cannot eliminate them entirely. In order to remove these support structures as well, mechanical and chemical solutions are proving to be the preferred options and currently offer the greatest potential for automation.