Investigation of Friction Stir Welding (FSW) of Polymeric Materials

Friction Stir Welding (FSW) has emerged as a novel technique for joining polymers. Unlike traditional welding methods that involve melting and solidification, FSW operates in the solid-state, mitigating issues associated with thermal degradation, distortion, and residual stresses. Overall, FSW offers a promising solution for joining polymers, providing a combination of technical, practical, and environmental benefits. With ongoing research and development efforts aimed at optimizing process parameters, tool design, and material properties, the process is poised to become a widely adopted joining technique in various industries, ranging from automotive and aerospace to renewable energy and electronics. The work presented herein investigates the feasibility and effect of process parameters on polymer friction stir welded joints. Visual inspection of the welded joint and tension tests we conducted to validate the process. The joining process involved defined parameters such as feed rate and spindle speed. The materials investigated herein are polycarbonate, and nylon 6. Tests included joining samples made of similar materials. An attempt to expand the study to include joining dissimilar materials was carried out; however, unsuccessful. Samples that passed the visual inspection were tensile tested to examine the joint quality across the weld width. It was found that, for polycarbonate samples, the highest tensile strength was achieved at intermediate speeds with the highest feed rate. Lower speeds and feed rates produced successful welds but with lower strength. Increasing speed at constant feed rates generally reduced joint strength. For nylon samples, the highest tensile strengths were at the lowest testing parameters. Higher feed rates led to unsuccessful welds, and the highest speed and feed combination resulted in the lowest joint strengths. The findings of the study are expected to contribute to understanding the impact of process parameters on joint quality and material properties of similar and dissimilar polymeric materials.