Effects of Vibration on Microstructure and Thermal Properties of Friction Stir Spot Welded (FSSW) Aluminum Alloy (Al5083)

Friction stir spot welding (FSSW) is a solid state joining technique with a simple concept. A non-consumable rotating tool with a specially designed pin and shoulder are inserted into the sheets or plates to be joined. In this study, the effect of vibration on microstructure and thermal properties of Al5083 weldment made by FSSW using rotation speed of 1500rpm and different dwelling times, namely 5 and 10s, was investigated. This new method was entitled FSSVW (friction-stir-spot-vibration welding). The experimental and numerical results, obtained using Abaqus software, were compared. In this work, the Johnson-Cook hardening condition was used for modeling of deformable metals. The results showed good comparability between experimental and FEM data. Also, metallography analyses indicated that the grain size decreased and the temperature increased as FSSVW method was applied. The results showed that vibration during FSSW leads to grain size decrease of about 30-50% in the weld region.