Investigation of Lazy S feature in self-reacting tool friction stir welds

Document Type

Conference Proceeding

Publication Date



Department of Materials Science and Engineering


The current research is an examination of the "Lazy S" feature found in self-reacting tool (SRT) friction stir welds. The research objectives are to characterize the feature using scanning electron and optical microscopy and determine its effect on the mechanical properties of the welded material. Welds were conducted in 2024-T4 aluminum. Welding parameters were varied in an attempt to influence the size and location of the feature. Tensile tests were performed on each weld and were correlated with the total length of the feature. Preliminary results indicate that there is a correlation between decreasing feature length and decreasing tensile strength.

Publication Title

TMS Annual Meeting