On the Assessment of Susceptor-Assisted Induction Curing of Adhesively Bonded Joints

The autoclave/oven curing process is known to be the current manufacturing technique that provides the best quality of composite laminates and bonded joints. However, this process implies high acquisition cost and a large ecological footprint. Furthermore, with the current complete aeroplane composite fuselages, it is infeasible to use autoclave/oven curing processes to assemble large sections of an aircraft. Therefore, new manufacturing solutions must be developed in order to make composites and composite bonding cost- attractive, energy- efficient and applicable to large-scale assemblies, while delivering at least the same product quality as the current autoclave/oven processes. This research addresses the challenge to explore an out- ofautoclave alternative curing process for bonded joints, based on induction heating. By exposing a material to an alternating electromagnetic field, heat is generated either by Jouleor hysteresis heating. The latter requires the material to be ferromagnetic for hysteresis losses to occur. In comparison with other heat transfer methods, the induction heating technique’s main advantages are high energy transfer intensity and low energy consumption [1, 2]. As common paste adhesives are neither conductive nor magnetic, strategies have to be developed in order to apply induction heating on adhesively bonded joints. If non-conductive adherends are used, such as Glass Fiber Reinforced Polymers, the adhesive must be modified in order to be able to generate heat by induction, so-called susceptor-assisted induction heating. Most of the available research focuses on the effect of different process- and material parameters on the induction heating process, and the achievable temperature at a certain set-up [3, 4]. However, little research has been done on assessing the effect of susceptor- assisted induction heating on the actual cure behaviour and mechanical performance of adhesively bonded joints. The purpose of this research is to develop additional insights in the field of susceptor-assisted, induction-heated adhesive bonding. The aim is to assess the impact of susceptor-assisted induction heating on the curing and mechanical performance of adhesively bonded joints.