Thermal direct joining of metal of fiber reinforced thermoplastic components

In the field of lightweight construction load-capable mixing compounds with the material specific advantages of metal and thermoplastic become increasingly significant. For this efficient Process chains including adapted pre-treatment and joining processes in combination with process simulation tools are required. Post- or in-mold assembly processes, mechanical joining by screws or rivets and adhesive bonding are state-of-the-art techniques for joining dissimilar materials such as metal and thermoplastics[1, 2]. Specific restrictions can be found at the limited geometry flexibility, the use of additional material and comparable long joining times. Hence new joining solutions are needed. Within this presentation the use of thermal induced joining for metal - thermoplastic parts will be shown. These processes are characterized by short joining times and the substitution of glue, screws or rivets. The key technology to enable high joint strengths is the material adapted surface modification. As a research result the influence of physical and chemical pretreatment will be presented. It could be shown that metal ablation by high power lasers can efficiently generate a macroscopic surface structure, which enables mechanical fastening of the polymer at the metal surface. Depending on the materials to be joint different kind of heat input can be used. Within this presentation the joining by hotplates and by laser will be introduced. It will be shown, that an optimized surface pre-treatment enables joints with lap shear strengths of 20 N/mm² and more, depending on the material configuration.