Most functional parts made with metal Additive Manufacturing (AM) undergo Hot Isostatic Pressing and machining to reduce porosity, surface defects, and to meet tight critical dimensions. However, metal AM applications that involve thin walls or struts, often cannot be accessed for machining with the same degree of precision possible for thick-section components. The requirement for machining also drives up cost, and importantly, it restricts the design freedom that often makes AM an attractive proposition to begin with.
For these reasons, this study focuses on as-built, thin wall structures made out of Inconel 718 using the Laser Powder Bed Fusion process. This study shows how morphological characteristics (porosity, surface finish, grain morphology) change as a function of size. As the thickness of components is reduced, changes in porosity distribution, dimensional accuracy, and surface finish are observed. The role of laser scan strategy in influencing these characteristics is also discussed.