Mechanical and Microstructural Properties of HDPE Pipes Manufactured via Orbital Friction Stir Welding

Abstract

In recent decades, extensive research has been performed on the friction stir welding of flat-shaped materials while pipe welding, particularly polymer pipes, still encounters challenging issues. This work presents a feasible route for joining high-density polyethylene (HDPE) pipes using an orbital friction stir welding (OFSW) set-up properly designed with a retractable pin tool. Fully consolidated joints were achieved using a portable heating-assisted OFSW system suited for on-site pipeline welding. The obtained joined pipes were characterized by a high-quality weld surface and a lack of defects arising from the tool-pin hole. The samples welded with the optimum parameters presented comparable properties with the base materials and even a slight increase in the tensile strength. The highest tensile and impact strengths were 14.4 MPa and 2.45 kJ/m2, respectively, which is 105% and 89% of those of the base material. XRD, FTIR, and SEM were also applied to assess the property changes in the HDPE pipes after the FSW process. The morphological analysis evidenced that the crystalline structure of the welded sample was similar to that of the base material, proving the effectiveness of the proposed technology.

RETRACTED: The Effect of Intrinsic Mechanical Properties on Reducing the Friction-Induced Ripples of Hard-Filler-Modified HDPE

“…High-density polyethylene (HDPE), a frequently used engineering material with a simple molecular structure, is widely used as the pure matrix material for modification [ 28 , 29 , 30 ]. In addition, silicon nitride (Si 3 N 4 ), a hard filler, is chosen as the modifying filler because of its proven self-lubricating property in specific frictional conditions [ 31 , 32 , 33 ].…”

Manufacturing and Joining PP/NBR Blends in the Presence of Dual Compatibilizer and Halloysite Nanotubes

“…Heat sources are critical to the efficiency of the process, the final quality of components, and processing costs [ 25 , 26 ]. Friction stir welding (FSW) has significant advantages over other joining procedures since it avoids the production of porosity, solidification cracking, and residual thermal stress [ 27 , 28 , 29 , 30 ]. Tool-to-workpiece friction generates heat, so no melting of the workpieces is required in this method.…”