Experimental Investigations of Thermal Joining of Polyamide Aluminum Hybrids Using a Combination of Mono- and Polychromatic Radiation

In recent years, the joining of plastics and metals for lightweight constructions has become more and more important for industrial applications. This paper presents experimental investigations of transmission joining of polyamide aluminum hybrids using a combination of mono- and polychromatic radiation. The used experimental setup consists of a diode laser, a laser processing head with additional infrared emitters, a robot and a clamping device for lap joints. With this setup, experiments are performed to determine a process window for the thermal joining of polyamide aluminum hybrids and to evaluate geometrical, material-related and process-related limits of the approach. For that, hybrid joints of aluminum with sheet thicknesses of 0.6 mm to 1.0 mm and 3mm thick unfilled polyamide 6 are used. To improve the mechanical interlocking between the polyamide and the aluminum surface a prior laser structuring of the metal is done by a ns-Nd:YAG-laser. Primarily,the influence of surface roughness and surface enlargement on the optical properties of aluminum and the mechanical properties of the joined specimens is investigated.