Joining hybrid metal–FRP tubes using ultrasonic welding for aerospace applications

Ultrasonic welding is an innovative and promising technique for aerospace applications, involving the joining of hybrid components in hydraulic systems, especially tubular metal–fiber reinforced polymer (FRP) hybrids. Hybrid structures are important for the aeronautical industry as they have the potential to significantly reduce aircraft weight and improve fuel efficiency.  Tubular metal–FRP hybrids, produced by an advanced type of ultrasonic metal welding, are investigated for the first time as part of the aeronautical research program (LuFo-V2) supported by the Federal Ministry for Economic Affairs and Energy (BMWi). The welding process will evolve in three stages for future applications in aircraft design. Suitable process parameters for tubular metal–FRP hybrid joining will be evaluated considering the mechanical and technological properties, as well as the microstructures of the hybrid interfacial area. Based on these results, the ultrasonic welding technique will be systematically prepared for prospective industrial use.