Study On Welding Process And Joint Properties Of 6082 Aluminum Alloy Laser Butt Welding

6082 aluminum alloy is a kind of high-quality aluminum alloy which is often used in automobile manufacturing.In the production practice,laser welding can effectively realize the high-quality combination of aluminum alloy joints.Through the use of aluminum alloy,joints on the body can effectively make vehicles more lightweight.Thus,aluminum alloy laser welded joints are widely used in the automotive industry.Therefore,the researches on the quality,especially the hardness,tensile strength and impact resistance of the aluminum alloy laser joint have a very important impact on the performance and safety of the vehicles.In this paper,the welding of 6082 aluminum alloy with laser butt welding was carried out in view of the actual needs of aluminum alloy welding joint in automobile manufacturing industry,The influence of 4 key technological parameters,laser power,welding speed,gas flow rate and defocusing distance,on weld formation was studied,through the optimization of welding parameters obtained sui Tab.for welding:welding power P=3.6k W and gas flow G=16L/min,v=14mm/s welding speed,defocusing amount was F=+1mm which was prepared with high quality welding joint.The performance test of the joint shows that the microhardness of the weld zone121HV was much higher than that of the base metal 75HV;The minimum tensile strength of welded joints was 210MPa,the maximum tensile strength was 246MPa,lower than the tensile strength of 6082 aluminum alloy base metal 340MPa;The impact absorption energy of weld zone was 28.2J,and the impact toughness was 30J/cm~2,higher than that of base metal.The impact absorption energy was 23.5J,and the impact toughness was25.2J/cm~2.The fracture characteristics of tensile and impact fracture were analyzed.This paper adopts GA-BP neural network to the laser power,welding speed,gas flow and defocus of these 4 parameters as input,simulation and prediction were studied by tensile strength and impact strength as the output,The results showed that the neural network constructed in this paper could predict the mechanical properties of joints accurately.The welding parameters were optimized by using the GA-BP neural network,and the optimum technological parameters are P=3.52kw,v=14.5mm/s,F=1.25mm,G=14.52mm.According to the optimized process parameters,the tensile strength of the joint was 255MPa,the impact strength was 24.5J/cm~2,and the quality was higher.