Experimental investigation on the effect of the Fused Deposition Modeling parameters on the processing of Polyether Ether Ketone

The use of Fused Deposition Modeling to produce high-performance polyether ether ketone is steadily increasing. However, the limited availability of in-depth studies on the process hampers its potential for industrial and scientific applications. This study investigates how nozzle temperature, nozzle speed, and layer thickness influence crucial product properties, including surface roughness, dimensional accuracy, and mechanical behavior, by means of Confocal and Scanning Electron Microscopy, X-ray Micro-Computed Tomography, Fourier-Transform Infrared Spectroscopy, Energy-Dispersive X-ray Spectroscopy, tensile and hardness tests. Selected samples were further analyzed in exceptional detail by synchrotron radiation, while degassing behavior in Ultra-High Vacuum conditions was explored for optimal configurations. The results highlight the critical influence of process parameters on the final properties of FDM-printed PEEK parts. Nozzle temperature proved to be the most significant factor in improving both mechanical performance and surface finish, while nozzle speed predominantly affected dimensional accuracy. Layer thickness had a secondary effect, mainly influencing surface roughness and contributing to internal defects and variability in mechanical properties. The combination of parameters that yielded the most balanced performance was identified as a nozzle temperature of 420 degrees C, nozzle speed of 40 mm/s, and layer thickness of 0.1 mm. Across all tested configurations, the maximum Ultimate Tensile Strength achieved was 84 MPa, while the highest recorded part density reached 99.8%. These outcomes enabled the successful manufacturing of components suitable for ultra-high vacuum environments. The process was validated through the fabrication of a benchmark part with complex geometries, demonstrating the capability of FDM to produce high-precision, high-performance components.