Application-oriented assessment of the interlayer tensile strength of additively manufactured polymers

Abstract

Extrusion-based additive manufacturing is often characterized with process-property-structure relationships, which lead to superimposed process-related effects. This study aims to separate superimposed effects, which occur due to the change of the process parameter layer height. The mechanical properties, in particular the interlayer tensile strength, are used to characterize the material capability in manufacturing direction z according to ASTM F2971. Different surface textures in the form of idealized, polished specimens and application-oriented, as built specimens complete the experimental design. The investigations highlight a decreasing primary surface profile and a higher material capability with decreasing layer height. The special design of experimental setup enables a retrospective data analysis that separates process-induced effects. Hence, the exact assignment of the proportions of process interactions is disclosed. The study results in a novel approach for characterizing extrusion-based additively manufactured polymer. The basic principle is to replace the common component testing by characterizing idealized material properties and calculating back to application-oriented conditions. The possibility of application-oriented correction factors based on idealized characterized material properties enables the change from component testing to material testing.