Investigation of the Anisotropic Mechanical Behaviour of Short Carbon Fibre-Reinforced Polyamide 6 Fabricated via Fused Filament Fabrication

Short fibre-reinforced parts manufactured via fused filament fabrication (FFF) exhibit a pronounced anisotropic mechanical behaviour which can be attributed to the fibre reinforcement as well as to the printing process itself. In this work, both effects are briefly outlined to provide the information necessary for a better understanding of the experimental investigations carried out in this contribution. The fibre orientation, which determines the extent of anisotropy produced through the fibre reinforcement, is studied via micrographic imaging. Furthermore, the orientation measurements are combined with a parameter study to investigate the possibility of influencing the fibre orientation through the printing parameters. The printing process-induced anisotropy is attributed to interfaces forming between the polymer strands laid down during the printing process. Their mechanical properties are strongly dependent on the process temperature. This phenomenon is studied here via tensile testing of samples manufactured at varying process temperatures.