Bond Rolling Principles Of Laminated Precision Alloy Materials

The emergence and development of the state-of-the-art technology andindustry is calling for better and better material properties, which is hard tomeet by only one kind of component. The last several decades havewitnessed growing interest in the production, research and use of laminatedmaterials. Laminated materials are made of several layers of dissimilarmaterials. By careful preparation and reasonable material design, optimumintegrated properties such as strength, corrosion resistance, electricalconductivity, thermal conductivity and magnetic conductivity can beobtained for special service conditions. Up to now, laminated materialshave been widely used in the fields of space flight, aviation, oil, machinery,chemistry, light industry, automobile industry, ship building, construction,electric power, electronic industry and nuclear energy.Bond rolling is one of the ways capable of joining a large number ofdissimilar plates and sheets. The past research of laminated materialsfocused on replacements, decoration and transition materials, in which thewave range of thickness and thickness ratio is broad. With the rapiddevelopment of electric power, electronic industry and computer in recentyears, the proportion of laminated materials used in wiring, instrumentsand electronic chipsets is notably increasing. The demands for theprecision and stabilization of the material properties is also becoming moreand more strict, thus need accurate control of the individual thickness andthickness ratio of the laminated materials. In conclusion, the study on therolling principles of laminated precision materials is very important for notonly the practical control of bond process, but also the basic theory of bondrolling.In this paper, the effect of temperature and tensile force on thethickness ratio after bond was mainly studied under the condition ofcontrol atmosphere process. First, the basic experimental research of bondrolling was carried out. Then, with the help of the control atmosphere bondexperiment, the law of control atmosphere bond was investigated in detail.At last, based on rigid-plastic finite element method (FEM) theory, thesimulation of bond rolling process was accomplished, the characteristic ofit was discussed. By means of elastic-plastic finite element method (FEM)simulation, the residual stress in the work piece is analyzed. Detailedcontents are illustrated as follows:(1) Based on the whole factor orthogonal experiment of bondrolling with brass H68 and pure Aluminum L2, the effect of initialthickness, initial thickness ratio and reduction on the thickness ratioafter bond was discussed. It shows that, if other factors are constant, thethickness ratio after bond will go up with the rising of initial thickness,initial thickness ratio and reduction.(2) There are many factors related to the thickness ratio afterbond, and the relationship among them is complicated. So in this paper,in order to accurately describe the change of the thickness ratio duringbond, MATLAB language tool kit of B-P structure artificial neuralnetwork (ANN) was applied to the training of experimental data. UsingANN model obtained from this training, the predicted error relative tonon-sample test results is within 7%. By the help of experience andtryout, the optimum ANN structure of 3-9-10-1 was chosen. Somefactors such as the number of test samples, ANN structure and theunison of experimental data were discussed(3) By cooperating with a some factory, the process of controlatmosphere bond was carefully studied. It is for the first time that theeffect of temperature and tensile force on the threshold deformation andthe thickness ratio after bond was studied. The test results show that,front and rear tensile force will decrease the threshold deformationobviously, which will weaken with the rising of the temperature. Thecontrol of temperature will adjust the thickness ratio to a relative largeextent, while the control of tensile force will adjust the thickness ratiowithin a small extent.(4) Based on rigid-plastic finite element method (FEM) theory,through the secondary development on DEFORM 2D simulationplatform, it is for the first time that the FEM simulation of bimetal bondand sandwich bond was carried out with the similar condition ofpractical manufacturing. According to the contours of stress, strain,strain rate and nodal velocity, the characteristic of bond process wasdiscussed in detail. Compared with 9 group of test results, the FEMsimulation error of the thickness ratio is within 10%. Based onelastic-plastic finite element method (FEM) theory, through thesecondary development on DEFORM 2D simulation platform, it is forthe first time that the elastic-plastic simulation of bimetal bond wascarried out. According to the contours of stress, the characteristic ofresidual stress was discussed. Compared with the simulation resultwithout tensile force, bond rolling with tensile force will improve theuneven distribution of residual stress.