Effects of Build Orientation on Mechanical Properties of Fused Deposition Modeling Parts

Our aim was to further analyze the effect of print orientation on the mechanical properties of FDM parts and explore the failure modes of differently oriented printed parts using scanning electron microscopy. We compared 3D printed ABSplus (P430) FDM parts in tension, bending, and torsion printed in flat, edge, and vertical orientations to machined equivalent parts. Parts were printed on a Stratasys uPrint SE in orientations according to ISO/ASTM 52921:2013(E) and evaluated using ASTM standards. Tensile, torsion and bending results are reported. Printed part properties were in many cases significantly different from machined part properties. For example, when subjected to tensile testing, the edgewise print orientation produced both the highest elastic modulus and the highest ultimate tensile strength of the 3D printed parts. During flexural testing, the flatwise orientation produced the highest ultimate stress at 54.31 MPa, while the edgewise elongation at break was the highest at 8.7%. However, unlike what was observed in the tensile and flexural tests, torsion samples printed in the angled, vertical, and horizontal orientations did not fail at significantly different ultimate shear stress values. Scanning electron microscopy work revealed that fracture propagation and failure modes are significantly different between the various print orientations with fractures through filaments giving superior strength.