Investigation of friction stir forming for mechanical interlocking high-performance polymers and aluminium sheets

Mass reduction and performance improvement have been resulting in manufacturing of components by new materials. The joint selection is a challenge, even more relevant if polymers and metals are combined. In literature, new solutions have been proposed to innovate various joining categories. Herein, the friction stir forming was employed to connect pure aluminium and PEEK sheets. Specifically, fasteners are formed on the metallic sheet plunging a rotating non-consumable tool into it. The process feasibility was achieved placing a thin layer of glass fibre reinforced polymer between the two plates shielding the plastic from thermal degradation. The effects of some process parameters, i.e. linear velocity and mandrel rotational speed, were analysed. The size and the shape of the extruded pins were evaluated and microscopic observations were performed to examine the morphology of the joined surfaces.