Finite element simulation of tensile behavior of laser welded 5083 aluminum alloy joint with different filler wires

Abstract

5083 aluminum alloy (AA5083) is prone to produce pores and undercut defects during laser welding because of violent fluctuations and Mg alloy elements burning in a molten pool, which seriously affected the tensile properties of the welds. In this paper, the process of laser welding with filler wire was used to improve weld properties, and through experiments and finite element simulation (FES), the effects of welding wires (ER4047, 5356, and 5087) on joint properties and failure behavior were studied. The FES simulation results are very consistent with the digital image correlation (DIC) experiment measurements, which verifies the accuracy and reliability of the finite element model proposed in this work. With the FES, it was further found that the filler wire produced the weld reinforcement, which changed the stress and strain distribution around the weld. The location of the maximum strain of the weld is changed from the undercut of the no-filler wire weldment to the weld toe of the filler wire weldments. The stress concentration at the undercut of the weld is greatly reduced, and the load-carrying capacity of the filler wire welded joint is improved. Analysis shows that the high Mg content of ER5087 effectively suppressed the formation of porosity to obtain the highest tensile strength (285 MPa), reaching 85% of the base metal (BM) strength. The filling of the welding wire changed the fracture mode from ductile-brittle mixed fracture of no-filler wire to ductile fracture with filler wires.