Characterization of friction stir spot welding between copper and poly-methyl-methacrylate (PMMA) sheet

In the present study, a novel approach has been used to create a metal-polymer weld. Copper and poly-methyl-methacrylate (PMMA), has been welded using friction stir spot welding (FSSW) process. The study aims to improve the tensile load carrying capacity of the weld by analyzing the effects of tool rotation speed, dwell time and tool pin length on the weld. It has been observed that tool rotation speed, tool pin length, tool rotation speed-tool pin length interaction and dwell time-tool pin length interaction have a significant effect on weld strength. Scanning electron microscopy (SEM) imaging of weld cross section shows that cracks are not present in the metal-polymer weld interface. Elemental area mapping analysis at the weld interface shaows that, a fine mixing of material is obtained. The optical imaging study exhibits the accumulation of polymer at the interface which provides strength to polymer for FSSW process. Electron backscatter diffraction shows that grains have been refined in copper material after the completion of the FSSW process.