Mechanical and SEM Characterisation of ABS Components obtained by Fused Deposition Modelling

New ABS for Fused Deposition Modelling (FDM) has been recently presented, characterized by high mechanical performances, finishing quality and high temperature strength. Both functional prototypes and rapid manufactured parts can thus be produced directly from the CAD representation. The great advantages, in terms of reduced times and costs for the product’s launching, can be properly exploited only through a deep knowledge concerning the parts’ performances as a function of the construction process. The present research is aimed at overcoming the trial-&-error approach diffused in industrial practice and filling a gap in existing literature. To this aim, specimens with different orientations in regard to filament deposition plane, have been manufactured and tested. Tensile tests, both at room temperature and at 70°C, have been used to determine the mechanical properties. As the extruded material has a tissutal structure, its anisotropic behaviour has been confirmed by experiments. The mechanical properties seem insensitive to the deposition direction (x, y, xy), while they worsen in the growth direction (z axis). This mechanical behaviour has been observed at both temperatures. An accurate SEM characterization has been carried out (1) to understand the effect of the manufacturing anisotropy on the mechanical performances, and (2) to comprehend how failure occurs and the way it is influenced by test temperature. Starting from the experimental results, an analytical material model has been developed, able to take into account the void percentage and, therefore, suitable to predict the mechanical behaviour of ABS components produced by means of the FDM technique.