Influence of Weld Process Parameters on Material Characterization of Friction Stir Welded Joints of Aluminium Alloy AA6061-T6

Friction stir welding, a solid state innovative joining technique, is widely being used to join aluminium alloys for aerospace, marine automotive and many other applications of commercial importance. FSW trials were carried out using a vertical machining centre (VMC) on AA6061 alloy. The main objective of the present work was to evaluate the weld processing parameter of friction stir weld (FSW) process for AA6061-T6 alloy and to determine the properties of the obtained joints with respect of welding speed. Experiments have been conducted by varying the welding speed of 55-70 mm/min and the rotating speed was fixed at 1700 rpm. Tensile properties, microstructure, microhardness, fractography, and corrosion resistance of FSW joints were investigated in this study. The result showed that there was a variation of grain size in each weld zone which depends upon the material and process parameters of FSW in the joint itself. The coarsest grain size was observed in heat affected zone (HAZ), followed by the thermomechanically affected zone (TMAZ) and the nugget zone (NZ). The maximum tensile strength of 184 MPa and highest joint efficiency of 49.32% were obtained on the joint fabricated at 55mm/min of welding speed.