Mechanical Properties and Microstructure of Friction Stir Spot Welded 6082-T6 Aluminium Alloy Joint

Abstract

Friction stir spot welding (FSSW) can substitute resistance spot welding (RSW) to avoid the problem due to melting materials during welding. In this investigation, a friction stir spot welded 6082 T6 joint was made to study the effect of pin diameter and dwell time on mechanical properties and microstructure with variation of pin diameter and dwell time. In the stir zone, it is observed that the grain structure is fine equiaxed recrystallized grain whereas in the HAZ, it is coarse grain. The increase of pin diameter and dwell time lead to the increase of tensile shear load. The highest tensile-shear load obtained is 4987.1 N at the highest pin diameter of 7 mm and dwell time of 3 seconds, while the lowest one is 788.2 N that obtained at pin diameter pin of 3 mm and dwell time 3 second. The highest micro Vickers hardness obtained at stir zone of 96.2 VHN, while the lowest one is 42.1 VHN.