Ultrasonic welding of “PEEK–CF–fabric prepreg–PEEK” laminated composites

• Main Authors: Panin, S. V., Alexenko, V. O., Tian, D., Buslovich, D. G., Byakov, A. V.
• Format: Conference Proceeding
• Language: English
• Subjects: Binders (materials); Carbon fibers; Defects; Laminar composites; Melting; Optimization; Prepregs; Shear tests; Thickness; Ultrasonic welding
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0162779

In this study, the formation of laminated composites based on PEEK plates and prepregs from carbon fiber (CF) fabric and the PEEK binder were investigated. The varying parameters were the prepreg thickness (and the binder content as a result), as well as the ultrasonic welding (UW) duration. Their optimization enabled to obtain a uniform structure in the fusion zone without any damages of the CF-fabric, causing improved strength properties. It was shown that the prepreg thickness determined its ability to melt upon the investigated UW durations. In the case of the thinnest prepreg of 280 µm with the minimal binder content, the homogeneous low-defect interface had been formed. However, its fracture occurred by the tear mechanism. In the case of the thicker 460 µm prepreg, the UW joint was able to maintain its integrity in the shear tests at the high stress level, while the UW joint failure was along the interface between the UW joint and the base material. At the maximum studied UW duration, the prepreg had been melted and the CF-fabric had been damaged, as well as a significant number of defects (pores) had been formed at the interface. This had caused the increased withstand stresses in the shear test due to the interface reinforcement, but the formation of such a structure is unacceptable in real products. Finally, options for practical implementations of the obtained results were discussed.