Evolution of temperature and microhardness in polymer plates welded by friction stir spot welding (fssw) using a welding tool without pin

The research paper focuses on the study of high-density polyethylene (HDPE) polymer material weldability using the friction stir spot welding (FSSW) technique. The study is a contribution, using microhardness, to a parametric analysis in order to optimise the welding temperature to evaluate its influence on the behaviour of the material. Experimental analysis helps to understand the welding temperature effect on weld quality during friction stir spot welding (FSSW). The results obtained allowed us to better understand certain phenomena resulting for example the heat flow effect on the mechanical property of weld spot during FSSW welding. Experimental tests have been carried out under various operational parameters such as the tool rotation speed and dwell time. The latter has been carried out to highlight the effect of the heat flow and operational parameters of the welding on the mechanical property of the friction stir spot welding of thermoplastic polymers. Microhardness tests at room temperature show that tool rotation speed and dwell time play a very important part. From this study we can say that welding by FSSW with operational parameters rotational speed 720 rpm and dwell time 40 s gives the best welding quality for the studied polymers.