Product Code: ICAL09_P132

Innovative Approach of Joining Hybrid Components
Authors:
Andreas Roesner, Fraunhofer ILT; Aachen Germany
Alexander Olowinsky, Fraunhofer Institute for Laser Technology; Aachen Germany
Arnold Gillner, Fraunhofer Institute for Laser Technology; Aachen Germany
Presented at ICALEO 2009

Joining of dissimilar materials is gaining importance especially in the automotive industry. The latest international initiatives concerning the average fleet CO2-emissions force the manufacturers to reduce the fuel consumption and the exhaust gas. This can mainly be achieved by the weight reduction of the vehicles. New methods for weight optimization are enabled by material selections adapted to the local strength requirements. While plastics are characterized by low density, small price, and literally unlimited shaping, metals can withstand distinct higher mechanical loads. Hybrid components combine the contradictory characteristics of plastics and metal and thus can lead to advantageous construction parts properties. As a result light and concomitant stiff components are realized. The need for joining these dissimilar materials without using additional material like adhesive or primer is the central challenge. A new approach to overcome the problems of state-of-the-art technologies is using laser radiation to ablate the metal surface in order to create microstructures with undercut grooves. By melting the above placed plastic with laser radiation, the material expands into these structures by the external clamping pressure and after setting the joining results by microcramping. In this paper the influence of different microstructure geometries and the process parameters of this innovative approach are presented and discussed in detail.