Characterizing the Influence of Print Parameters on Porosity and Resulting Density

Extrusion deposition additive manufacturing produces parts with inherent porosity, which typically manifests as easily accessible voids between beads. This open porosity can also be accompanied by voids within the beads themselves, and both types can impact a part’s desired performance. Porosity is influenced by a variety of factors, including infill percentage, layer height, nozzle diameter, print speed, and raster orientation. While their influence on mechanical properties and porosity have been studied previously, there has been minimal work connecting print parameters to porosity and subsequently to mechanical performance. This study investigates the relationships between print parameters, volumetric porosity, and mechanical performance. In addition, this study measures both open and closed porosity through use of a helium pycnometer rather than image analysis of a cross-section. Thus, this study will identify correlations between the volumetric density of parts and the resulting mechanical performance as a function of print parameters.