Friction stir spot welding of pe material

Developments in the joining and welding technologies of plastic materials hold great significance for both industrial applications and academic research. In particular, Friction Stir Welding (FSW) and its derivative method, Friction Stir Spot Welding (FSSW), have come to the forefront due to their ability to perform welding without the need for external heating or adhesives, using non-consumable rotating tools. In today's industry, where lightweight structures are increasingly prioritized, the use of polymers instead of metals has become widespread, and thermoplastic materials such as polyethylene (PE) can be successfully joined using the FSSW method. In this thesis study, experiments were conducted on 4 mm thick PE sheets using various tool geometries and process parameters, and the optimum stirring time was determined. According to the results of the tensile tests, the first tool achieved a maximum tensile strength of 2412 N, corresponding to 91% of the reference specimen's 2650 N value. The second tool achieved 2176 N (82.12%), while the third reached 2356 N (88.9%). These findings clearly demonstrate the influence of tool geometry, rotational speed, plunge depth, and stirring time on weld performance. Furthermore, previous studies have also shown that these parameters directly affect joint quality, and that selecting the optimum combination allows for the formation of strong and homogeneous welds. In this study, fracture surfaces, failure zones, and cross-sections were examined in detail using an optical microscope, providing an in-depth analysis of the weld structure. As a result, it has once again been confirmed that the FSSW method is an effective, reliable, and high-performance technique for joining polymer materials. Keywords: Tensile Test, Parameter, Polyethylene, Friction Stir Spot Welding, Tool.