Influence of surface enhanced treatment on microstructure and fatigue performance of 6005A aluminum alloy welded joint

Abstract The application of 6005A aluminum alloy in transportation is increasing, which puts forward higher requirements for the fatigue performance of welding process. In this study, friction stir welding (FSW) enhanced treatment was applied on the traditional metal inert gas (MIG) weld. The results show that the fatigue life of FSW plate is three times higher than that of original MIG welded plate at 140 MPa stress level. Under 107 cycles, the fatigue life limit was increased by 16 MPa compared with as-received MIG plate. The main reason of FSW leading to the increasing fatigue life are the reduction of porosity to reduce crack initiation and grain refinement to delay crack propagation.