Scanning electron microscopy, atomic force microscopy and optical profilometry applied to adhesive bonding technologies

The use of scanning electron microscopy, atomic force microscopy, and optical profilometry is described as analyses techniques to obtaining information (topography, inter-valley distance and semi-quantitative chemical content) from the adherent surface on metals and carbon fibre composites. Surface inspection and post fracture analyses were performed on aluminium and carbon fibre, as adherends, to demonstrate that exist a strong relationship between the initial surface treatment, wettability and post fracture on the basis that the surface morphology is one of the most important factors to take into consideration when adhesive joining is performed. The microscopy observations permit to understand the crack growth in the adhesive bonding and show how it depends of the surface finishing quality and presence of surface
contaminants. Therefore, use of microscopy techniques are vital to predict if the failure mode will be cohesive, adhesive or a combination of both, and also their influence to correct the surface preparation procedure, thus improve adherence.