Making interlock by laser shock forming

A novel processing technology for interlocking and joining three sheets of two copper foils and a perforated stainless steel sheet by laser shock forming is presented in this paper. In this forming process, two layers of ductile copper foils are positioned above a perforated stainless steel sheet, a shock pressure induced by pulsed laser is applied on the upper foil, both foils are indented downwards through the hole of the perforated sheet, and impact on the rigid bottom support, then spread radially to produce a double interlock, thus to join the three sheets together. Finite element analysis as well as practical experiments were conducted to verify the feasibility of making interlocks by laser shock forming. The numerical simulation reveals the deformation mechanism of interlocks based on the analysis of plastic flow and shape evolution during the process. These results point to the practicality of clinching and joining three sheets by laser induced plastic deformation, namely laser shock joining or laser shock clinching.