Investigating the effect of printing conditions and annealing on the porosity and tensile behavior of 3D-printed polyetherimide material in Z-direction

Fused filament fabrication process presents drawbacks in mechanical properties observed when printing in the build direction (Z-direction). Such anisotropic properties will affect the part's performances and have to be minimized during fabrication. This study aims to evaluate the effects of nozzle temperature, printing speed and specimen state (annealed or as-printed) on porosity percentage and tensile properties for 3D printed polyetherimide (PEI) (ULTEM 1010) parts in Z-direction. The results demonstrated that print speed is the most influential process parameter that should be adjusted in consideration with the other printing parameters. The specimens' state did not reveal a noticeable influence, as the amorphous nature of PEI is considered less receptive to annealing. The optimization method to achieve the best results yielded values of 360°C and 30 mm s−1 as printing conditions, followed by heat treatment. This was confirmed by porosity measurements, tensile testing, and scanning electron microscopy observations. The best performances of PEI material were 3425.5 MPa, 102 MPa, and 4.30% for Young's modulus, tensile strength, and elongation at break, respectively.