Evaluation of Mechanical Properties for Polyethylene Butt Welded Joint Formed by Friction Stir Welding

Friction stir welding is a solid state welding process suitable for producing joints, especially in lightweight materials, which are particularly interesting due to the weight saving potential. Thermoplastics have extensive applications in the present industry because they offer excellent physical and corrosion properties, high degree freedom of processing and design. The plunging of a specially designed non-consumable and rotating tool creates a connection between the sheets through frictional heat and plastic deformation. Minimum material loss is observed, and therefore a fully consolidated joint with flat surface is obtained. The aim of the present work is to investigate the mechanical properties of butt joints produced by friction stir welding (FSW) in high density polyethylene sheets of 7mm thickness. The determination of the welding parameters plays an important role for the weld strength. The tool rotational speed, tool plunge depth and dwell time were determined to be important in the joint formation and its strength. All the welding operations were done at the room temperature.