Effects of Microstructural Arrangement on the Mechanical Behavior of 3D Printed Polyamide

Abstract

This study aims to relate the microstructural arrangement, in particular the symmetry materialized by filament sequencing in the fused filament fabrication process, to the mechanical behavior of printed polyamide. Dog-bone structures were printed using various printing temperatures ranging from 250 °C to 280 °C, which were combined with part orientation including vertical, horizontal, and lateral configurations and raster angles (0°, 15°, 30°, and 45°) that represent the in-plane and out-of-plane symmetrical arrangement of the filament. Mechanical testing was conducted on both as-received filaments and printed structures to derive the effects of filament arrangement symmetry and process-generated defects on mechanical loss. In addition, a microstructural analysis using scanning electron microscopy was used to share more light on the filament arrangements and their consequence on the deformation mechanisms with respect to the printing conditions. The results showed that the 3D printed polyamide-based materials exhibited remarkable tensile performance with strain stiffening behavior and large elongation at break due to their particular filament layout. Among the considered printing conditions, the part orientation was found to have the largest influence on the tensile behavior, which modulates the behavior from complete restoration of the filament performance to mechanical loss.