Behavior of adhesively bonded coated steel for automotive applications under impact loads

Novel manufacturing techniques and the application of new materials in the automotive industry increase the challenges in adhesive bonding. One of these is the bonding of coated materials such as high-strength steels with anti-cindering multi layers or painted components. In both cases, the entire build-up of the joint has to be taken into account to determine its strength.Based on common testing methods, i.e. lap-shear or butt-joint tests, this paper presents modifications and possible interpretations of these testing methods for the characterization of adhesive joints of coated materials under impact loading. Another aspect presented here is a laser-based approach for the removal of paint, to achieve higher bond strength. It has been found that the mechanical strength of the bond is influenced significantly by coatings and paints. Furthermore large dependence on the nature of the paint can be found. In general it can be noticed that the weakest layer within the entire joint is the coating or paint. Therefore, these additional layers have to be carefully considered during a product׳s development phase.