Additive manufacturing process parameter influence on mechanical strength of adhesive joints, preliminary activities

The work illustrates how building parameters of the Additive Manufacturing process Fused Filament Fabrication can affect not only the mechanical properties but also the surface wettability and morphology. Wettability and morphology are relevant factors in bonded joints performance. Advantages of polymeric additive manufacturing are to allow a re-design of components with locally controlled properties and integrated functions. Major limitations are related to the lack of material testing standardization and constraints due to the build volume and to the object orientation for printability: the latter problems can be addressed with the use of bonded joints that allow to create bigger assemblies from smaller parts optimally designed to take advantage of material orthotropy and without the structural drawbacks. In this study, two materials are considered, acrylonitrile butadiene styrene and polylactideacid. Wettability, surface morphology and mechanical strength have been determined at different combinations of nozzle temperature, print speed and layer thickness.