Optimisation of ultrasonic welding process of carbon/epoxy composites using Nylon-based or PES thermoplastic interlayers

The aim of this study is to investigate ultrasonic welding in carbon fibre-reinforced thermosetting composites by optimizing process parameters, specifically sonotrode pressure and ultrasound application time. Joining is accomplished by incorporating electrospun veils, consisting of either polyether sulfone or nylon, into the outer layers of the composite laminates. Single lap shear tests were conducted to evaluate the mechanical strength of the joints and identify failure mechanisms. The results highlight a significant influence of the thermoplastic interlayer. Polyether Sulfone ensures consistently lower mechanical properties, while Nylon contributes to higher strength. In both scenarios, these joints show promising applications, particularly in sports automotive contexts where rapid and reliable part welding is crucial.