Optimization of post-processing of PAEK composites based on automated placement technology

Poly（aryl ether ketone）（PAEK） thermoplastic composites exhibit exceptional impact resistance and possess significant application potential in the aerospace industry. To address mechanical performance limitations of PAEK composites fabricated through automated in-situ placement, this study systematically investigates the impacts of post-processing parameters-including temperature, pressure and time-on pore elimination and mechanical properties. Utilizing the automated fiber placement, PAEK prepregs are processed into laminates. A viscosity-pressure-time coupling model is formulated through differential scanning calorimetry（DSC）, rheological assessments and mechanical characterizations. The results demonstrate the model predicts reasonably pore elimination across varying process parameters and the critical post-processing temperature is identified as 340 ℃. The pore elimination is facilitated rapidly due to low and stable resin viscosity at 340-360 ℃. The post-processing pressure significantly influences pore removal efficiency, with a critical pressure of 0.7 MPa at 360 ℃ and requiring 60 min for complete pore elimination. Higher pressures lead to only marginal performance enhancements. The time dependency of material performance depends on pressure: at 0.7 MPa and 360 ℃, full pore elimination is achieved within 60 min, whereas at 1.6 MPa, the required time is reduced to 20 min. At 0.7 MPa, 360 ℃ and 60 min, the tensile strength, flexural strength and interlaminar shear strength are 2844, 1653 MPa and 103 MPa, respectively.