Friction stir welding of polyethylene sheets

Abstract

Polyethylene sheets 3 mm thick were friction stir welded with a cylindrical steel pin; two pin diameters and a combination of feed rates and rotational speeds of the pin were considered for the  experimentation. Moreover, a modification of the traditional friction stir welding process was investigated by adding a heating step of the pin and the samples to join. The quality of the joint was evaluated by means of tensile tests and thermal analysis. A correlation between mechanical properties and process parameters was found. Even if process optimization is required, the final performances of the joints are sufficient to assess that friction stir welding of polyethylene may be a valid alternative to conventional joining technologies.