Research On Tube Push-bending Process Of 5A02 Aluminum Alloy With Local Induction Heating

Aluminum alloy tube fittings is widely used in aircraft,aerospace and other broad as lightweight component,while having broad application prospects in automobile.The aluminum bending parts,whether as a finished part or forming process,the quality and accuracy of bending are significant.Bending pieces with CNC bending causes serious thinning on outside of bending,which is harmful to follow-up forming.Half-tube stamping with butt welding process is complex,while the existence of the welds will reduce the overall quality of parts.In this paper,bending process with local induction heating is used to bend the aluminum alloy tube,which could reduce the lateral thinning rate and improve the forming limit.The bending process of the rotary structure was researched by theoretical analysis.According to the static equilibrium equation,the force model of the tube was established.The stress and strain state of the high temperature deformation zone was analyzed in detail.Based on the Mises yield criterion and the total strain theory,the stress expression of the deformation zone was deduced.Based on plastic buckling model of the tube under axial loading,the factors of wrinkling inside during bending process were analyzed.Compared with steel tube,the temperature field distribution of 5A02 aluminum alloy with local induction heating was also researched.The bending process of 5A02 aluminum alloy tube with local induction heating was researched by finite element simulation software Abaqus6.14,and the principle of induction heating bending was verified according to stress and strain distribution.The influence of forming parameters on the bending process was analyzed by orthogonal design,and the 5A02 aluminum alloy pipe with diameter ratio of 31 was found that theoretical limit relative bending radius is 1.5.The bending experiments were carried out with induction heating devices.The actual temperature field distribution of 5A02 aluminum alloy with induction heating was measured.Because of slow heating speed and high thermal conductivity,the actual axial temperature distribution was flat.The thickness distribution of the bending parts was obtained by experiments and the influence of relative bending radius,heating temperature and width of the high temperature zone on the forming defects were also analyzed.The experimental results showed that the main defect in bending process of aluminum alloy with induction heating is the wrinkling inside.Increasing the relative bending radius or optimizing the heating-cooling system,obtaining a suitable temperature field can effectively eliminate wrinkling defect.