Analysis of fiber orientation, microstructure and mechanical properties of specimens made from fiber-reinforced ABS manufactured by Fused Filament Fabrication (FFF)

Fused filament fabrication (FFF) is a state-of-the-art process for manufacturing polymer-based components by 3D-printing. Unfortunately, conventional acrylonitrile-butadiene-styrene (ABS) materials used in FFF processes feature relatively low strength and hardness in comparison to materials used in injection molding. This contribution aims on the systematic, quantitative analysis of the fiber orientation in specimens manufactured from fiber-reinforced ABS by fused filament fabrication and its impact on the mechanical properties. ABS based compounds featuring different fiber contents have been compounded and subsequently processed by FFF. The microstructure of the composite materials have been analyzed regarding the fiber orientation using X-ray computed tomography. It could be stated, that the short fibers are oriented according to the printing paths and hence serve as markers for the analysis of the printing path course. To evaluate the mechanical properties, samples with different printing path course and therefore different fiber orientations have been manufactured. Bending tests and impact bending tests were carried out to compare the mechanical properties of reinforced samples in comparison to ABS materials without fibers. In general, an impact of fiber volume content and fiber orientation could be found for the specimens investigated.