FlexHyJoin | Flexible production cell for hybrid joining

Growing requirements in the transport industry with regard to safety, lightweight construction, fuel economy and functional integration can usually only be met by a mix of materials. The mantra is: "the right material in the right place". However, these hybrid material concepts can only be realized if the different components and materials are combinable respecting their individual properties. FlexHyJoin deals with the joining of metals and thermoplastic fibre reinforced polymer composites (TP-FRPC) by means of implementing two complementary joining technologies (laser and induction joining). The overall goal of the project is the construction of a fully automated production cell for joining metal with TP-FRPC including quality assurance for the automotive industry. The most important requirements to be fulfilled by the production cell are: weight neutrality, cost efficiency, time efficiency and bonding strength. With state of the art joining solutions, these requirements can only be partially met. Most joining methods such as adhesive, screw or bolt connections require additional weight. Adhesives are also expensive, while screw and bolt connections weaken the TP-FRPC structurally and cause an unfavourable load condition.

For this reason the FlexHyJoin project combines laser joining (LJ) for complex, smaller geometries and induction joining (IJ) for larger geometries in a single prototype production cell. The advantage of these joining processes is that components can be joined without need of additional material. This saves weight (weight neutrality) and costs (cost efficiency). With LJ and IJ, the components are heated in a single contactless process that goes easy on the material and joint to each other by use of a pressure device (time efficiency). By means of laser structuring of the metallic surface, high connection strength can be achieved. The key for the automation is an online process control and quality assurance. Non-destructive testing (NDT) shall ensure a 100% inspection of the joints and thus an automated and comprehensive quality assurance.

By providing an efficient joining process for hybrid material solutions, the FlexHyJoin project contributes to enable cost-effective, safe and climate-neutral mobility. In addition, the technologies developed in the project can be applied to a wide range of thermoplastic and metallic materials and transferred to many other applications and industries such as aviation, sports & recreation and energy sector.