Inductive Welding of CF-Thermoplastics

In contrast to the predominantly used thermosets, the application of thermoplastic polymers as matrix material in fibre reinforced plastics is beneficial in that the polymer can be remelted when heated. In addition to substituting labour-intensive rivet connections by material joints, the change of material allows for the manufacturing of large components by fusion welding of subcomponents that are easier to handle. The bonding of two components is achieved through the heating of the composite material above the melting point of the thermoplastic matrix while applying sufficient contact pressure.

The automated inductive welding of carbon fibre reinforced thermoplastics (CFRTP) is being researched at the DLR Center for Lightweight-Production-Technology in Stade in collaboration with COBES GmbH. Inductive welding utilises the electrical conductivity of carbon fibres. An applied alternating magnetic field induces eddy currents in the fibrous reinforcement of the composite, which results in local heating of the component. Since the heat develops directly inside the part, no heat transfer from the outside is necessary.

The goal is the determination of the process window and the automation of inductive welding for different carbon fibre reinforced high performance polymers, as well as the selection of suitable sensors, and the implementation of inline quality assurance for weld seams created in an automated process.

German Aerospace Center (DLR)

Institute of Composite Structures and Adaptive Systems

Niklas Menke · E-Mail: ·