The impact of print orientation and raster pattern on fracture toughness in additively manufactured ABS

Fused deposition modeling (FDM) has been gaining industrial interest due to its potential to simplify and lower the cost of complex manufacturing. To better understand the mechanical response of these materials-due to potential integration of FDM parts into structural components-compact tension samples of acrylonitrile butadiene styrene (ABS) were printed in three orthogonal orientations to analyze how the fracture toughness varied with mesostructure. Furthermore, in each of these orientations the raster pattern was either an alternating +45/-45 degrees or a 0/90 degrees pattern. When the alignment of extruded filament layers changed from parallel to perpendicular with respect to the crack plane, a 54% increase in fracture toughness was observed. However, the raster pattern only had a significant effect in one of the print orientations; the fracture toughness decreased by 11% when a 0/90 degrees pattern was used in place of a +45/-45 degrees pattern in layers oriented perpendicularly to the crack plane. The orientation of individual tracks of deposited material with respect to the crack tip appeared to have the most pronounced role in altering the fracture toughness of FDM ABS. This research provides useful information and insight to future designers determining how processing affects the crack stability of these new materials used for space hardware. (C) 2017 Elsevier B.V. All rights reserved.