Study On Cold Rolling Deformation And Properties Of C19400 Copper Alloy Strip

With the development of 5G communication,C19400 copper alloy strips are widely used in VLSI circuits.In order to better integrate the structure and function of integrated circuits,higher requirements are imposed on C19400 copper alloy strips.Cold rolling is the most critical process in the processing of C19400 copper alloy strip,which determines the dimensional accuracy,surface quality and properties of the strip.Different rolling process parameters will have a greater impact on the rolling deformation law and performance.Therefore,it is urgent to carry out the cold rolling deformation rule and performance research of C19400 copper alloy strip.This article takes C19400 copper alloy strip as the research object.Based on the research method of combining finite element analysis and experiment,it conducts in-depth research on the cold rolling deformation law and performance.The research results provide a data basis for the optimization of cold rolling process parameters,the comprehensive performance of copper alloy plate and strip and further exploration of its application potential provide theoretical basis and reference.The main research contents and research results are as follows:1.The stress-strain relationship of C19400 copper alloy under different strain rates was obtained based on tensile experiments.The room temperature constitutive equation of C19400 copper alloy was established and the prediction accuracy of the constitutive equation was verified.Based on the Deform-3D finite element platform and the elastoplastic finite element method,a finite element model for cold rolling deformation of C19400 copper alloy strip was established.The rolling experiments were carried out under the same conditions,and the accuracy and reliability of the cold rolling deformation finite element model of C19400 copper alloy strip was verified.2.During the stable rolling stage,the magnitude and fluctuation of the rolling force increase with the increase of rolling passes;the rolling force increases with the increase of the friction coefficient.For every 0.05 increase in the friction coefficient,the rolling force increases by about 35 KN.Excessive coefficient increases the fluctuation of rolling force.Under different rolling pass matching conditions,the rolling force of each pass when the rolling pass match is 4 passes is much higher than that of other passes,that is,the change of the deformation of each pass will affect the rolling force.The roll speed has no obvious effect on the rolling force,but the increase of the roll speed of the roll will increase the fluctuation of the rolling force and shorten the rolling cycle.3.During the cold rolling deformation,the strain increases with the increase of the deformation.On the contact surface between the strip and the roll,the strain gradually increases from the center to the edge in the width direction;along the length direction,the strain at the end is greater than the strain at the middle,and the relatively uniform strain distribution in the middle,which explains the thinning of the strip edges.Strain increases with the increase of the friction coefficient,different passes matching have little effect on the final strain value,and the roll speed has almost no effect on the strain.4.The strip will rebound after each pass of cold rolling deformation.Taking the first pass as an example,the rebound values when the friction coefficients are 0.15,0.20,and 0.25 are 0.35,0.36,and 0.37,respectively.The rebound values gradually increase with the increase of the friction coefficient.When the rolling process is rolled in 4 passes,5 passes,and 6 passes,the total rebound values at point P1 are 0.94,1.19,and 1.55,respectively.Comparing the friction coefficient and the roll speed,the rolling pass matching has a greater impact on the rebound value;the roll speed has no significant effect on the rebound value,but it can shorten the rebound time.5.The residual stress of the strip gradually increases with the increase of the deformation,and the distribution of the middle part tends to be uniform.The edges and ends of the strip are liable to form residual stress accumulation.The residual stress increases with the increase of the friction coefficient;The influence of roll speed on the maximum value of residual stress is very small,and the distribution of residual stress is more uniform at 21 r/min;compared with other passes,the residual stress of the strip after 5 passes is small and the distribution is relatively uniform.6.Based on the analysis of rolling force,strain,residual stress,and rebound with different friction coefficients,roll speeds,and rolling passes,when the friction coefficient is 0.15,the roll speed is 21 r/min,and the rolling passes are 5 passes,it is a more reasonable cold rolling process parameter of C19400 copper alloy strip.7.Based on the cold rolling deformation test of C19400 copper alloy strip,the performance parameters at different deformation amounts were obtained.Its electrical conductivity and elongation gradually decrease with increasing deformation,and its hardness and tensile strength gradually increase with increasing deformation.When the amount of cold deformation is 82.5%,the conductivity decreases by 21.4%,the elongation decreases by 79.4%,the hardness increases by 21.9%,and the tensile strength increases by 55.3%.The formula of conductivity,hardness,tensile strength,elongation and deformation rate are fitted respectively,and the R~2 value of each formula is very close to 1,which confirms the accuracy of the fitting formula,and establishes the prediction model of cold rolling deformation performance.