Investigation of process parameter influence on the mechanical properties of FDM-printed PEEK-carbon fiber composites using RSM and Taguchi methods

The mechanical performance of FDM-printed high-performance polymers like carbon fibre-reinforced PEEK remains sensitive to process parameters, limiting their reliability in structural applications. The present study addresses this challenge by investigating the influence of printing speed, layer thickness, and infill density on tensile, flexural, and compressive strengths. Using Response Surface Methodology (RSM) and Taguchi analysis, predictive models were developed and statistically validated through ANOVA. The models were highly reliable, with R2 values above 0.94 across all strength modes. Print speed and infill density had the greatest impact on tensile, flexural and compression strength, while layer thickness also played a significant role. Lower printing speeds and higher infill densities resulted in strength materials with better interlayer adhesion and fewer internal defects. The models can improve the mechanical performance of FDM printed parts by optimising process parameters across multiple objectives. This research has significant implications for aerospace, biomedical, and structural applications that require reliable and strong components.