Laser structured surfaces for metal-plastic hybrid joined by injection molding

The aim of this work is to investigate the influence of surface structures on the adhesion strength of metal-plastic hybrids. Aluminum substrates were structured with continuous wave and picosecond pulsed laser systems and overmolded with a thermoplastic polyamide material. The materials were examined in terms of structure topography, molding accuracy, and a tensile shear test. It was found that the surface pretreatment by laser structuring with continuous wave laser enhances the effective joining surface, creates a mechanical interlocking, and increases the adhesion strength of the hybrid compared to the untreated condition significantly. A shear strength of 11.9 MPa was achieved, which exploits 90% of the pure polyamide properties.