To Örebro University

Additive manufacturing (AM) is a newly developed technique for fabrication of parts with complexgeometries. Despite the fact that this technique has made it possible to fabricate near net shape and complexgeometries, there can be a mismatch between as-designed and as-fabricated geometries. These geometricalimperfections can hinder the structural response of fabricated structures by not fulfilling the strength theyare designed for. These mismatches, specifically surface morphology become even more important factorin case of manufacturing of thin-walled structures by AM. This is due to the fact that the surface regionwhich is mainly consist of partially melted powders does not necessarily contribute in strength. Thus, theeffect of surface morphology on mechanical properties in such structure should be investigated and takeninto account in the design stage. In this study high resolution X-ray computed tomography (micro-CT) hasbeen used for qualitative investigation of surface morphology of specimens made of AlSi10Mg. Flatspecimens with different thicknesses has been fabricated by selective laser melting (SLM). Using micro-CT it was possible to non-destructively measure the surface region in thin-walled builds. The measurementfrom micro-CT as well as result from optical profilometry showed the usefulness of micro-CT for thoroughinvestigation of AM parts. The study showed that micro-CT is a robust method for qualitative measurementof surface morphology of parts made of AlSi10Mg using SLM technique. It also gave an insight on wherethe geometrical mismatch specifically at micro scale become an important factor in design of such structuresfabricated using SLM technique. The result from this study lead to development in design stage of AMprocesses.