Experimental Study of the Possibility of Butt Friction Stir Welding on Polyethylene Pipes

In Algeria, polyethylene (PE) pipes are commonly installed for the distribution of potable water and natural gas in urban and rural areas. They are used for economic reasons, in addition to perfect maintenance, compared to metal pipes. The experiences of these tube installations have shown technical advantages in operational safety aspects and structures lifespan with very interesting mechanical properties. The connection between the polyethylene pipes is done through couplings, which are considered expensive during their replacement due to frequent use, especially in the agricultural field. The main objective of the present experiment is to elicit the main parameters of friction stir welding on polyethylene pipes (butt welding) using a milling machine, especially the rotational speed of the clamped pipe sections called the rotational welding speed, which replaced the welding speed, with the highlighting of the clamping device to form a butt joint. In the present work, the process using the conventional tool is presented with the design and provision of a pipe assembly device intended for this research in order to weld these pipes together during the FSW process. The rotary device used in this experiment is mounted on a milling machine and rotates the tube sections attached to the rotating arms of the support. The spindle can rotate freely 360 ̊ with the tool's rotating speed of 1100 rpm. Two sections of high-density polyethylene pipes with an outer diameter of 125 mm, which are intended for natural gas distribution, were successfully welded to achieve the conventional friction stir welding (C-FSW) reliability of polyethylene pipes. This study makes it possible to highlight the parameters and the method, on which it is recommended to improve welded joints, in the context of research that will always be ongoing.