Ultrasonic welding of novel carbon/Elium® thermoplastic composites with flat and integrated energy directors : lap shear characterisation and fractographic investigation

The current research work presents a first attempt to investigate the welding attributes of Elium® thermoplastic resin and the fusion bonding using ultrafast ultrasonic welding technique. The integrated energy director (ED) polymer-matrix composites (PMCs) panel manufacturing was carried out using the Resin Transfer Moulding (RTM) technique and the scheme is deduced to manufacture a bubble-free panel. Integrated ED configurations and flat specimens with Elium® film of different thickness at the interface were investigated for ultrasonic welding optimization. Optimised weld time for integrated ED and flat Elium® panels with film (0.5 mm thick) configuration was found to be 1 s and 5.5 s, respectively. The ED integrated configuration showed the best welding results with a lap shear strength of 18.68 MPa. The morphological assessment has shown significant plastic deformation of Elium® resin and the shear cusps formation, which enhances the welding strength. This research has the potential to open up an excellent and automated way of joining Elium® composite parts in automotive, wind turbines, sports, and many other industrial applications.Published versionThe authors would like to acknowledge the financial support from the Institute for Sports Research, Nanyang Technological University, Singapore and ARKEMA, France. This research is part of the collaborative project between Nanyang Technological University, Singapore and ARKEMA, France under RCA-18/46 that focuses on the thermoplastic matrix used during resin transfer moulding of structural sports products in mass production