An Extensive Review on Effect of Weld line on Various Process Parameter of Friction Stir Welded Sheets

This study aims to review the effect of weld lines movement on the formability and mechanical behavior of Friction Stir Welded (FSW) joints between two different aluminum alloys using the Forming Limit Diagram (FLD) as a key evaluation tool. FSW is a solid-state joining process that provides an excellent mechanical properties compared to other fusion welding process, but the presence of weld lines can significantly influence the material's formability and performance under complex loading conditions. This research paper focused on evaluating the impact of weld line positioning, movement, microstructural variations, and mechanical heterogeneity on the forming limits of the dissimilar aluminum alloy joint. Various weld line positions, including center, offset, and perpendicular orientations relative to the strain. The FLD is generated for both the base materials and the welded joint, providing a comparative analysis of their formability. The study showed that use of optimizing input process parameters such as tool rotation speed, weld speed of tool, pin diameter, shoulder diameter, and tool's pin profile could effectively reduce the negative impact of weld line variation and play a vital role in better welding finished. It also showed that the optimized input parameters improved the microstructure, formability and mechanical properties of the welded blank, resulting in better forming limits and a higher resistance to deformation.