Process Improvement of Continuous Induction Welding of Carbon Fiber-Reinforced Polymer Composites

Abstract Continuous induction welding is particularly suitable for joining carbon fiber-reinforced polymer composites (CFRPC) with thermoplastic matrix, as the energy required for melting the thermoplastic matrix is introduced without contact and leads to intrinsic volumetric heating of the adherends. However, the great potential of fast heating cannot be fully exploited. Therefore, a process improvement of continuous induction welding was carried out, which follows three complementary approaches. The first approach provides for the development of an adapted laminate structure. Compared to a conventional CFRPC laminate, the adapted laminate shows a heating in the joining zone that is approx. 16 K/s faster. The second approach intends to improve the currently used cooling system to cool the induction coil faced laminate surface. Spray cooling proved to be the most suitable method. Compared to pressurized air cooling, it was possible to achieve a temperature difference between the joining zone and the inductor faced laminate surface that was approximately twice as large. The third approach aims at the simulation-based improvement of the consolidation phase. This model can be used to determine the joining pressure and pressure time required to achieve intimate contact.