Effect of FSW process parameters on mechanical properties and microstructure of dissimilar welded joints of AA2024 and AA6082

Abstract

The aluminum alloys AA2024 and AA6082 are the most common alloys used in the storage tank, pipelines, maritime frames, automobile and aerospace industries due to their high corrosion resistance and toughness.In the present work, these dissimilar aluminum alloys were successfully fabricated via friction stir welding (FSW) by varying input parameters (rotational tool speed (TRS) and welding speed). The great mixing of AA2024 and AA6082 was observed at a high rotational speed. The higher TRS enhanced the mechanical properties of the stir zone (SZ). The maximum ultimate tensile strength (UTS) of dissimilar alloys was observed 218.1 MPa at TRS of 1400 rpm with a welding speed of 30 mm/min caused by strain-free fine grains during the dynamic recrystallization (DRX) mechanism. The maximum hardness (93 HV) at SZ was observed at a TRS of 1200 rpm with a 30 mm/min welding speed. The fractured FSWed region at 1200 rpm shows the big and deep dimples, while equiaxed, fine dimples were observed at TRS of 1400 rpm.