Progress in Friction Stir Welding of Polymer and Aluminum Alloys

The heterogeneous structure of polymer and aluminum alloy is an effective way to meet the dual technical indicators of structural performance and lightweight design. Friction stir welding (FSW) is a solid-phase welding technology characterized by low temperature and large plastic deformation. It is basically not affected by the crystal structure and physical-chemical properties of materials and can realize polymer and aluminum alloy-specific materials quality connection. This paper presents a comprehensive review of the current advancements in FSW between polymers and aluminum alloys with a focus on optimizing welding parameters, joint formation, defect identification, and mitigation. The results showed that the most important details are that high rotation speed combined with low welding speed that is beneficial to increase welding heat input, improve joint forming and mechanical properties, and form aluminum riveting structure. Welding defects are the main reason for the low FSW performance of polymer and aluminum alloy heterogeneous structures. To improve the forming and load-bearing capacity of heterogeneous structures, welding tool structure design, surface pretreatment, and welding structure optimization can be utilized.