Effects of build orientation on the mechanical and surface properties of polyetheretherketone fabricated with fused deposition modeling

PURPOSE: This study evaluated the effects of build orientation on the mechanical and surface properties of polyetheretherketone (PEEK) fabricated using fused deposition modeling (FDM). METHODS: Rectangular and six disc-shaped specimens were fabricated in three build orientations (0, 45, and 90°) using an FDM printer with a PEEK filament (PP) (n = 6 per group). Three-point bending tests were conducted on the rectangular specimens to assess the flexural strength (FS) and flexural modulus (FM), whereas Vickers hardness (HV) and surface roughness (Ra) tests were performed on the disc specimens. A scanning electron microscope (SEM) was employed to observe the cross-section of the deformed and undeformed parts of the rectangular specimen after a three-point bending test. The mean FS, FM, HV, and Ra of PP were analyzed using a one-way analysis of variance. Tukey's multiple comparison test was also performed (α = 0.05). RESULTS: The 90° PP had the highest FS and FM, followed by the 45° PP; the 0° PP had the lowest FS and FM. The surface of the 0° PP had no connecting surfaces between the layers, suggesting that its HV was the highest for the PP groups. For the 45° PP, the surface roughness may have increased because of the addition of a support structure to the specimen. CONCLUSIONS: Build orientation affects the mechanical and surface properties of the FDM-fabricated PEEK. Overall, the 90° PP demonstrated the most reasonable build orientation.