Friction stir welding tooling for polymers: review and prospects

Friction stir welding (FSW) is a solid-state joining technique, which has been developed remarkably during the last decade. Due to its benefits over conventional welding techniques, along with growing industrial demands for lightweight design structures, FSW found its way into becoming one of the fascinating engineering subjects of today. FSW process is based on the generation of heat due to friction and material deformation under an axial force. Originally, this method was developed for welding metallic materials which were difficult to weld with conventional techniques. However, due to the significant increase in polymeric materials consumption in the industry, the possibility for implementing this technique in polymer welding received a considerable share of interest. Nevertheless, polymeric materials behave differently from metallic ones and, currently, there is still a limited number of research works in the literature concerning this specific topic. This article reviews previous studies, which were focused on welding polymers using the FSW technique. Development of FSW tools, welds strength and the most effective welding parameters for different polymeric materials are now analysed. New materials, configurations and test specifications are currently under research, including the possibility for dissimilar materials joining, taking FSW into a new phase in industrial applications.