Thin-walled Aluminum Alloy Tube Upsetting Forging Research

Sheet press forging forming can effectively improve the formability of sheets and has theadvantages of saving materials and reducing internal residual stress, thus plays an importantrole in the application of press forging process by expanding its applied range and determiningits technological limits.Firstly, this paper researches on the machanical properties of the material. Aluminumalloy sheet is welded by laser and metallographic structure of the weld zone is observed. Then,the weld zone is seperated out through wire-electrode cutting and goes through compressiontest, during which its compression performance is obtained. The forming limits of compressedweld zone can be estimated through the generation and extension of the cracks which areproduced at the time of compression failure and which can be observed from the side.Afterwards, standard tensile tests are conducted separately for laser-welded aluminum alloysheet and unwelded aluminum alloy sheet. The results are compared and the appearance of thefractures are observed separately through electron microscope, thus the fracture machanism isestimated. Then, this paper explores theoretically the upset forging forming properties of laser-welded5A06sheet.Secondly, through theoretical derivation of forming limits of the process, this paper putforwards a bend-recover model in upset forging forming process, and calculates the theoreticalforming limits of the model. For the above theoretical analysis, this paper implements a two-dimensional simulation of the upset forging process of thin-walled sheet by using ABAQUS,a software of finite element analysis. Through the simulation, this paper analyses the feasibilityof forming procedures and forming strains, and proves the reliability of theoretical analysisfrom the perspective of finite element. Afterwards, the simulation of the upset forging formingof welded thin-walled tube is finished by defining different material properties, and thefeasibility of upset forging forming of welded aluminum alloy thin-walled tube is analysed. At last, according to both the results of theoretical analysis and finite element simulation,the author designs a set of mould which can at the same time processing workpieces andverifying theoretical analysis. By setting the movements reasonably, this mould complete theprocessing of workpieces and verifies upset forging forming theory in the1000KN servopressure machine in State Key Laboratory Of Material Processing and Die&MouldTechnology.This paper, designs the upset forging process for thin-walled aluminum alloy tube;discovers the regular pattern of forming by probing into upset forging process from severalaspects such as material properties, process parameters and forming limits; and expand theapplied range of press forging by studying aluminum alloy thin-walled tube with weld joint.