Design of MIG system for 7005 aluminum alloy main bridge section workstation and study on microstructure and properties of welded joints
As the rescue equipment that can play a great role in disaster relief,the emergency bridge should be as small as possible.The aluminum alloy itself has low density and light weight,and can solve this problem.But at present,the emergency bridge parts are still using hand welding.This method is of low production efficiency,and welding quality is not stable.In this study,the welding workstation is used to weld the main bridge section,the size,structure and weld position of the workpiece are analyzed,and the overall scheme is designed.The welding scheme of four robots with a single positioner is selected to complete the overall layout of the workstation.The mi-crostructure and properties of the welded joint of 7005 aluminum alloy,the main bridge material,were tested.The single wire MIG welding was used to complete the welding of 7005 aluminum alloy sample,and the mechanical properties of the sample were tested.The test shows that the average tensile strength of the weld is 290.74 MPa,and the fracture is in the heat-affected zone.The hardness of the weld zone is the lowest,with an average of 75HV;the weld center is slightly higher,with an average of 115HV;the base metal hardness is the highest,with an average of 165HV.By means of metallographic observation of the joint microstructure of the sample,it is found that the grain size of the heat affected zone is coarse,and the causes of porosity and softening of the weld heat af-fected zone are analyzed,and the solutions are put forward,which can be applied to the actual production.
main bridge section7005 aluminum alloyMIG weldingwelding robot workstationmicrostructure and properties of welded joint
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