Research On Laser Shock Line Adhesive-Cinching Of Foils

With the vigorous development and rapid change of modern industry,how to realize the joining of lightweight materials such as aluminum alloy and high-strength steel has become a key concern in the process of component design and manufacturing.Laser shock line clinching is a plastic forming technology used in the field of sheet metal joining.Specifically,it refers to the use of the shock wave of the laser-induced explosive plasma as the driving force for deformation,which cooperates with a specific mold to produce the desired plastic deformation of the multi-layer similar or dissimilar sheets to form a stable interlocking structure.Adhesive bonding is also an important way to realize material joining,using the mechanical bonding force,physical adsorption and chemical bonding force generated on the joint surface to connect the two boards.In this paper,a novel laser shock line adhesiveclinching technology is proposed,which is an advanced joining technology that combines the laser shock clinching and the chemical adhesive bonding to achieve an incremental line joining for metal foils.It has unique technical advantages and broad potential applications in the field of micro-manufacturing.The main work and conclusions are as follows:(1)The laser shock wave pressure loading model was established,the Johnson-Cook material constitutive model and the adhesive elastic-plastic bifold line constitutive model were adopted.Through finite element analysis and process experiments,the material flow and structural evolution during the adhesive-clinching were systematically studied.The influence of process parameters such as forming height,laser energy,and laser spot overlap ratio on the line adhesive-clinching is revealed.(2)By the three-pass-six-point laser shock adhesive-clinching technique,the effective joining between the double-layer metal foil and the key-shaped perforated stainless steel sheet was realized,and obtained fine adhesive-clinching joints for double-layer aluminum foils,and double-layer copper foils.The material flow and deformation mechanism of each pass and each point of each pass are analyzed through the cross-sectional view.The laser energyforming height process window of aluminum foil and copper foil was established,and according to the final deformation of the material,the process window was divided into nonclinching structure area,adhesive-clinching joining area and failure area.(3)The mechanical properties of the line adhesive-clinching joints were tested.It was found that the joining strength of the samples was significantly improved compared with the pure clinching.According to the vertical shear force-displacement curve and the parallel shear force-displacement curve of the specimen under the three clamping methods,it was found that the strength of the adhesive-clinching joint is closely related to the tensile direction.Under the same clamping method,when the load direction is perpendicular to the length direction of the line clinching,the tensile force threshold that it can withstand is higher.(4)The possibility of laser shock line adhesive-clinching with different key-shaped hole length and width combinations was explored.Finite element models with different keyshaped hole sizes are established.By observing the simulated stress distribution,it was found that as the length of the key-shaped hole increases,the formability of the material in the forming area is better,and the overall distribution is more uniform.Under the guidance of the simulation results,the experimental study of the multi-size laser shock line adhesive-clinching was carried out,which confirmed the multi-scenario applicability of the process.