Study On Multi-pass Continuous Rolling Process And Quality Of Metal Chain Teeth

As a small metal component,metal zipper involves complicated production process.When a company produces metal zipper,it had the defect of low mechanical properties.After analysis,it was found that the mechanical property of the metal chain teeth was not good,causing the metal zipper to have poor mechanical properties.The occlusal force is not strong,and the pulling strength of metal zippers is not high."The root strength of the copper section is lower.Aiming at the phenomenon that the mechanical properties of the "Y"-shaped copper wire teeth are poor,the combination of the finite element method and the experimental method was used to analyze the process,and the optimal process scheme was obtained to improve the mechanical properties of the metal chain teeth.Firstly,the stress-strain curve was obtained through the room temperature compression experiment of H65 copper wire,and the material model was constructed.At the same time,the mesh optimization distribution and corresponding boundary constraints and contact processing were carried out on the copper wire model,and the finite element method of the multi-pass rolling forming process of H65 copper wire was established.Secondly,on the basis of the finite element model,the influence mechanism of the roll speed,the friction between the roll and the copper wire and the roll gap on the multi-pass rolling of the copper wire was studied,and the cross-sectional size and size of the copper wire during the rolling process were analyzed.Using the total equivalent effect variable of the copper wire section as an index of the hardening degree of the metal teeth,the mechanical properties distribution of the copper wire section after rolling was predicted,and the process parameters were optimized based on this as the optimization basis.Thirdly,on the basis of the optimization of the numerical simulation results,an experimental study was carried out on the roll gap,and the roll gap was adjusted in the first three passes to analyze its influence on the geometric size,cross-section microstructure distribution and streamline distribution of the "Y"-shaped copper material.The influence mechanism of hardness,the metal zipper production test was carried out under the optimal roll gap,and the corresponding mechanical property test was carried out to verify the rationality of the process plan.Finally,according to the numerical simulation and experimental results,it is shown that the relative error of the geometric dimensions of the "Y"-shaped copper cross-section obtained by the multi-pass rolling forming finite element numerical model of the H65 copper wire and the geometric dimensions obtained from the experiments under the same conditions is within 5%,the model had high reliability.The numerical simulation results showed that the mechanical properties of copper wire were most affected when the first three passes changed the roll gap.When the friction coefficient between the roll and the copper wire reached 0.3 and above,the deformation of the copper wire will cause deformity.When the rolling speed of the first pass was 13-22 rpm,it did not affect the quality of copper rolling,and when it was 25 rpm and above,the surface of the copper was wrinkled.In addition,through experiments on the optimal roll gap combination,it was found that the roll gap can greatly improve the hardening effect of H65 copper wire,and the increase rate was nearly 18.8%.At the same time,the mechanical test results of metal zippers had increased by 6% to 17%.The results of this research can provide technical support for improving the quality of metal chain teeth.