Effect of arc voltage, welding current and welding speed on fatigue life, impact energy and bead penetration of AA6061 joints produced by robotic MIG welding

Abstract

Aluminum alloys forming to AA6061 have a wide range of desirable properties which are used in different industries such as aircraft industry and other aerospace structures. The effect of process parameters on fatigue life and impact energy of weld metal, and bead penetration in AA6061 joints produced by MIG robotic welding was studied in this paper. Different samples were produced by employing arc voltage of 20, 23, and 26 V, welding current of 110, 130, and 150 A, and welding speed of 50, 60, and 70 cm/min. After welding operations, the mechanical properties of the weld metal were evaluated by fatigue and impact testing at room temperature, and bead penetration was measured for geometrical specimens. Results were clearly illustrated when heat input increases, fatigue life of weld metal decreases whereas impact energy of weld metal increases in first and then drops significantly. A linear increase in bead penetration was observed with increasing welding current and arc voltage. The largest penetration in this study was observed for 60 cm/min welding speed. Keywords: MIG parameters; fatigue life; impact energy; bead penetration, welding.