Evaluation of the properties of plastic-metal interfaces directly bonded via injection molding

Plastic and metal can be directly bonded via insert injection molding by creating surface porous structures with 30–50 nm sizes on metal surface. Molten polymers can be penetrated into the small pores created on metal surface in the short molding process, and strong joint can be obtained. The bonding mechanism of aluminum alloy (Al5052) and polyphenylene sulfide (PPS) with two different surface features of Al5052 was studied. Scanning transmission electron microscopy (STEM) was performed to investigate the interfacial structures in terms of elemental distributions and three-dimensional (3D) inter-connectivity of the pores on the Al5052, and the chemical reaction which takes place during the joint process was investigated by X-ray photon spectroscopy (XPS). The properties of the joint interfaces were evaluated to discuss the effect of interfacial structures on the joint properties.