Fracture surface analysis of 3D-printed tensile specimens of novel ABS-based materials

One of the most common materials utilized by material extrusion 3D printing is acrylonitrile butadiene styrene (ABS). The work presented in this research explored the effect of the addition of reinforcing materials on the mechanical properties of ABS in an effort to create materials with enhanced physical properties. A comparison was made between pure ABS, two ABS matrix composites, and one ABS/elastomer blend with the purpose of characterizing the effect of additives on the mechanical properties. Tensile test results of specimens built in different orientations showed that ABS reinforced with 5% by weight TiO 2 exhibited the highest ultimate tensile strength for specimens built in both horizontal and vertical directions with 32.2 and 18.4 MPa, respectively. The compounding of an elastomeric material with ABS improved the surface finish of parts as they were visibly smoother compared to those printed from the ABS baseline material, though there was an observable decrease in the ductility of tensile specimens. Analysis was performed on the fracture surface of the tensile specimens through the use of scanning electron microscopy. Fractography revealed different modes of failure related to the different additives. The effects of additives on the anisotropy associated with the mechanical properties of 3D-printed parts were also analyzed. © 2014 ASM International.