Projects

To obtain aluminum surfaces for reproducible and long-life bonded joints, commercially available aluminum sheets were processed with a solid state laser, and the emergent aluminum oxide layer was coated with polyamines as reactive polymers. As a result, uncontrolled adsorption of organic substances from the environment was repressed, on the one hand. On the other hand, at the surface, primary amino groups were fixed as reactive functional units that can chemically react with components in the adhesives within the subsequent bonding process.

The present research results demonstrate that the combination of laser processing and polyvinyl amine coating represents a simple and efficient pre-processing method resulting in higher strength bonded joints made of aluminum alloys with magnesium content. The bonding of the pre-processed joining parts can, as a result of this combination of pre-processing variants, be performed in a time-shifted manner. Thus, pre-processing of joints is feasible separate from the actual joining process, for instance at the site of the supplier, without any loss of strength.