Effects of self-affine surface roughness on the adhesion of metal-polymer interfaces

This paper concentrates on a theoretical examination of the influence of roughness on the adhesive properties along metal-polymer interfaces. An algorithm has been designed to generate a self-affine surface roughness. It has been used to examine influence of the Hurst exponent on the interface strength during a pull-off test of metal-polymer laminates. The generated surfaces are implemented in a cohesive zone model representing the interface between a coated steel and polyethylene terephthalate (PET). From the model it can be concluded that a small increase in surface area is linear with the interface strength. This relation does not hold when the increase in surface area becomes larger than 150%. The deviation from the linear relationship increases with smaller Young’s moduli. This is caused by the reduced elastic energy storage in the polymer when local surface characteristics become more important.