Mechanical properties of AFP-manufactured CF/PEEK vs CF/LMPAEK ring coupons: Impact of process parameters on shear strength

Carbon fiber-reinforced thermoplastic composites such as CF/PEEK and CF/LM-PAEK are increasingly utilized in aerospace applications for their outstanding mechanical properties, including high strength-to-weight ratios and environmental resistance. To fully exploit these advantages in complex aerospace components, advanced manufacturing techniques such as Automated Fiber Placement (AFP) are employed, enabling precise control over fiber orientation and consolidation. However, achieving optimal shear strength requires precise control of automated fiber placement process parameters. This study investigates the mechanical performance of two-layer CFRTP coupons in-situ consolidated using hot gas torch AFP. A Design of Experiments approach was employed, systematically varying deposition rates, heat source settings and compaction pressures. Statistical analysis of the experimental results highlights the influence of these parameters on the single lap shear strength. Using experimental data, linear regression models were developed to analyze the relationships between the shear strength and key process parameters, including laydown speed, pressure, and temperature profiles. The results reveal distinct behaviors between CF/PEEK and CF/LM-PAEK, providing insights into optimizing AFP manufacturing processes.