Executing Organisation: Federal Ministry of Education and Research (BMBF), Project Management Karlsruhe (PTKA)
Currently, the automotive and aerospace industry is attempting to reduce weight by substitution of metal components with carbon fiber reinforced plastics (CFRP). The research project ELite aims for economic and resource efficient joining of CFRP and metals. The blz therefore investigates a robust process for pre-treatment of both materials in series production as well as an optimization of adhesion between CFRP samples and metals. Moreover a concept for insertion of metal components into CFRP is being tested and qualified for industrial application.
An increase in adhesion between metallic and CFRP components has to be realized by applying defined surface structures. Thereby, the potential of laser processes for pre-treatment is analyzed comprehensively. Accordingly, the impact of nano and micro structures on adhesion properties has to be merged to a model. Qualitative and quantitative analyses are done using different microscopy techniques as well as tensile-shear-strength tests. In addition, approaches about metal inserts that are placed inside the CFRP component during production process are taken, while the insert is welded to another metal component in a later process step.
By laser based pre-treatment of metal and CFRP microscopic and nanoscopic surface structures which lead to an increase of adhesion strength could be generated. Tensile-shear-strength tests of bonded metals show an improvement of adhesion of 40 % to 33 MPa. In case of joint concept with metal inserts a high composite liability could be achieved, which exceeds the tensile strength of the 300 µm thin metal insert and withstands a force of about 7 kN.
Laser based processed nano and micro structures for enhanced adhesion (aluminium, λ = 1.064 nm)