Study On Stamping Forming Properties Of Zirconium Alloy Sheet

Zirconium alloy has excellent corrosion resistance and excellent mechanical properties,and is often used in nuclear power and aerospace fields.The production of zirconium alloy strip components in the nuclear power industry requires a suitable stamping process to ensure the forming quality of the workpiece.Therefore,the research on the stamping properties of zirconium alloy sheet is very necessary.However,the method of pure experiment is time consuming and laborious,and the cost is very high.Therefore,in this paper,a combination of experiments and finite element simulation is used,taking 0.457 mm thick domestic and imported two different zirconium alloy materials as examples to explore the factors that affect the stamping properties of zirconium alloys.Firstly,the research status of zirconium alloy sheet stamping is introduced.The current research focuses on the microstructure of zirconium alloy or the heat treatment process of zirconium alloy.There are not many studies on the influencing factors of stamping.Subsequently,the tensile strain test,forming limit test(FLD),and electron backscatter diffraction(EBSD)experiments were used to obtain the stress-strain curve,forming limit curve,and microstructure of the zirconium alloy.Secondly,the constitutive model suitable for domestic and imported zirconium alloy materials is established,and the yield criterion most suitable for these two materials is explored.In the hardening model,a new model suitable for the hardening behavior of the two materials is established based on the hardening index n.The finite element simulation was used to study the influence of material properties on stamping forming performance.A stamping analysis model of zirconium alloy sheet was established.The research found that the anisotropy coefficient value and the hardening index value of thematerial have certain effects on the forming performance.When the material anisotropic parameter value is constant,with the increase of hardening index value,the wallthickness decreases less and the wall thickness distribution is more uniform.When the value of is constant,a sheet having a small plastic strain ratio anisotropy also has asmall tendency to crack when pressed.Therefore,controlling the hardening ability and anisotropic behavior of the sheet can improve the sheet punching performance.Finally,the response surface method was used to study the impact of stamping forming process parameters on forming performance.The effects of friction coefficient,blank holder force and punch speed and their interactions on the minimum wall thickness and maximum stress were studied,and optimized stamping process parameters were obtained.The results show that the interaction of friction coefficient,blank holder force and punch speed with minimum wall thickness and maximum stress is complicated,and it is difficult to determine the optimal parameter value by changing a single parameter calculation.The optimal combination of friction coefficient,blank holder force and punch speed was obtained through the response surface model,which provided a useful reference for the design of process parameters in actual production.