An experimental and numerical study on laser shock clinching for joining copper foil and perforated stainless steel sheet

This paper presents an experimental and numerical study on laser shock clinching (LSC) for joining copper foil and perforated stainless steel sheet. The deformation evolution of an interlock was discussed by analyzing the cross sections and thickness distribution of the specimens. Failure modes and failure mechanism in the joining process were discussed to obtain a better understanding of the process. Fracture of copper foil commonly takes place at the hole edge and the base of clinch, meanwhile, the region with large strain concentration was more likely to generate fracture. The effect of main process parameters on the joining conditions has been investigated and process windows have been made based on a series of experiments. The results show that good joining can only be obtained under the combination of moderate laser energy and forming height. Clinched joints produced in the LSC process can absorb both radial and axial force, while shearing strength was far larger than peeling strength of the clinched joints produced under the same experimental parameters. What's more, the LSC process has then been simulated by finite element method (FEM). FEM results agree well with the experimental results, which implies that numerical simulation can be effectively used to analyze the deformation and the failure mechanism in the LSC process.