ZEus

Challenges in Future Aircraft Manufacturing

ZEus demonstrates the lightweight potential of thermoplastic fiber-reinforced composites as well as hybrid metal-fiber-reinforced composites in aviation by developing innovative joining methods for load-bearing aircraft structures. By directly creating material or form-fitting bonds between the joining partners, the use of mechanical fasteners such as rivets is completely eliminated.
 

CONTIjoin: Laser-Based Joining of Complexly Curved CFRP Fuselage Structures

The Fraunhofer IWS further developed the CONTIjoin technology for the deposition and welding of multi-layer CF-LM-PAEK laminate strips onto complex-curved fuselage segments. To this end, an adaptive consolidation tool and a sensor-based contour detection system with dynamic adjustment of the laser beam shaping were developed and tested. The proof-of-concept demonstrated nearly full-surface bonding on a multi-curved demonstrator panel. Material and strength tests confirmed that, with appropriate process control, the resulting welded joints can achieve performance characteristics on par with hot-pressed reference composites.
 

Direct Thermal Joining: Hybrid Titanium-CFRP Seat Rails

For hybrid seat rails made of titanium and CF-LM-PAEK, the IWS developed a continuous direct thermal joining process. The titanium surfaces were laser-structured to create a load-bearing form fit with the thermoplastic matrix. Coupon tests achieved more than 90% of the strength of the CFRP base material in shear tensile testing; failure occurred predominantly within the fiber composite and not at the joint interface. The demonstration of a continuously joined omega-hat seat rail confirmed the fundamental technical feasibility. Further development is needed regarding component tolerances, the heating of edge areas, and load-appropriate component design.
 

Adhesive-Free Joining Methods and High Automations Potential

For industry, both technologies offer potential for automated, continuous, and adhesive-free manufacturing processes. They can reduce assembly and material costs and are also relevant for applications in automotive engineering, hydrogen technology, and the construction industry.