Experiment Of 5083 Aluminum Alloy Laser Welding And Numerical Simulation Of Joint Tension Based On Filling Wire

5083 aluminum alloy（AA5083）is widely used in transportation industry because of its low density,excellent corrosion resistance and welding performance.However,due to high Mg content and good metal fluidity,it is easy to produce violent fluctuation of molten pool and burning loss of alloy elements in the process of laser welding,resulting in pores and undercut defects,which affect the tensile properties of the weld.In order to solve this problem,more molten metal is provided to the molten pool during laser welding to reduce undercut,make up for the burned alloy elements in the welding process and inhibit the generation of pores.Therefore,in this study,welding wire is filled during laser welding,so as to introduce alloy elements into the weld and improve the performance of the weld.In this paper,the effects of ER4047,ER5356 and ER5087 welding wires on the properties of AA5083 laser welded joint,the changes of joint stress-strain state and failure mechanism are studied through experiments and numerical simulation.On this basis,the weld shape is optimized by numerical analysis.The main contents are as follows:Firstly,the effect of welding wire on the microstructure and properties of welded joint is discussed.The results show that the elongation of wire filled weldments is higher than that of no wire filled weldments.The plasticity of ER5356 joint is the highest,and the elongation is as high as 10.8%.ER5356 and ER5087 contain high Mg,which increases the solid solution strengthening of Al₃Mg₂ phase and increases the joint strength.Because ER5087 also contains more Mn,which promotes grain refinement,the ER5087 joint has the highest tensile strength of 285MPa（85.5%of the base metal）and hardness.However,ER4047 welding wire reduces the joint strength because of its high porosity.At the same time,the micro characteristics of Weld Fracture show that the addition of welding wire makes the fracture mode of welded joint change from ductile brittle mixed fracture to ductile fracture.Then,the finite element simulation model of the welding specimen was established,and the tensile process was numerically simulated.The results show that the stress-strain curves of the test and simulation are basically consistent,which verifies the reliability of the finite element model.Secondly,through the simulation of the tensile process of four kinds of welding specimens,it was found that the addition of welding wire produces the weld reinforcement,which changed the stress-strain distribution around the weld during stretching,so that the maximum stress and strain of the weld were transferred from the weld to the weld toe.Finally,the welding seam shape of ER5087 is optimized by the optimization module of ABAQUS.Through the optimization analysis,the welding seam shape with relatively uniform stress distribution and better strength around the welding seam is obtained.