Friction stir spot welding (FSSW) is a powerful and superior alternative to resistance spot
welding and riveting for fabrication of aluminum sheet metal structures. The objective is to
study the variation of transient temperature in a friction stir spot welded plate of AA6061
Aluminum Alloy. Numerical and experimental investigations were performed to study the
temperature distribution during this process. Two thermocouples (type K) were placed at two
specified locations from the pin hole to measure the transient temperature during FSSW
welding process. Numerically, 3D finite element model was built using ANSYS workbench
Ver.15 to simulate the thermal model during welding. The torque and axial load were
measured experimentally to determine the coefficient of friction, which used with the other
parameters, to find the applied heat flux for the welding process. The temperature
distributions of the specimens welded by three tools with different pins; i.e. cylindrical,
tapered and triangular, at constant other FSSW parameters, were investigated and compared
with the experiment temperature measured using the thermocouples to validate the results.
The results show that the temperature produced from the welded specimen with cylindrical
pin shape has the highest temperature distributions due to high axial load and torque as
compared with other tool pin profiles. Also the results show good agreement between
numerical and experimental with a percentage error (-3.09 – 7.83) %.