Research On Compatible Deformation And Transverse Bonding Performance Of Cold-rolled Cu/Al Clad Strip

Cu/Al clad strip not only has the advantages of high conductivity and good thermal conductivity,but also has the strengths of light weight and low price.The compatible deformation of Cu/Al clad strip during cold rolling affects the bonding performance and the thickness ratio of the clad strip.The research on compatible deformation and transverse bonding performance of Cu/Al clad strip is helpful to the application in practical production.In this paper,the cold rolling process of Cu/Al clad strip is studied.Based on the cold rolling experiment,the finite element model is established to study the compatible deformation and the transverse bonding performance of the interface.The specific research contents are as follows:Firstly,the roll-bonding experiment of Cu/Al strip was carried out,and the finite element model was established according to the experimental data.Based on the uniaxial tensile test data of Cu and Al materials with different reduction rates after rolling,the metal model under large strain is established;the friction coefficient of roll is calculated by using the rolling force data with different reduction rates;then the finite element model is built and tested,the change trend of rolling force simulation data and experimental data of Cu strip,Al strip and Cu/Al clad strip with different reduction rates is basically the same,and the error is controlled within 10%.It can basically meet the needs of engineering analysis.Secondly,the finite element model is used to analyze the mechanism of compatible deformation of roll-bonding Cu/Al strip.After the stress of Cu/Al strip's compatible deformation is analyzed,the influence of different rolling process conditions on the thickness ratio of Cu to Al is analyzed,and the experimental thickness ratio data is compared with the simulated thickness ratio data.The results show that the thickness ratio will be affected by reduction rate,friction coefficient between clad strip interface,friction coefficient of roll and roll radius.It is known that the main reason for the nonconforming deformation of Cu and Al is caused by the different plasticity properties of Cu and Al,but the stress and boundary conditions of the clad strip and the interaction between Cu/Al strip play a major role in the rolling deformation,so that the deformation of the two metals with large plastic differences is very little different.Finally,the finite element model is used to analyze the transverse bonding performance of Cu/Al clad strip.The influence of transverse compressive stress field,equivalent strain field,velocity field and the combination of each field on the bonding properties of Cu/Al interface in rolling deformation zone under different spread and different reduction rate was analyzed.The results show that: when the rolling width of Cu/Al clad strip is less than 40 mm at 0.5 reduction rate,the transverse bonding performance from the center of plate width to the edge gradually decreases;when the rolling width of Cu/Al clad strip is greater than 60 mm,the transverse bonding performance from the center of plate width to the edge increases slowly and then decreases rapidly;the bonding performance is poor in the area 5?10mm from the edge of the plate.when the reduction ratio is increased from 0.2 to 0.6 rolling 60mm-wide Cu/Al clad strip,the transverse bonding performance is improved as a whole,and the bonding performance from the center of plate width to the edge still increases slowly and then decreases rapidly.