A study on super-speed forming of metal sheet by laser shock waves

In this paper, the authors explore a dynamic super-speed forming method driven by laser shock waves. The initial exploration of laser shock forming (LSF) is done through bulge testing with specimens of 430 sheet metal, using a neodymium–glass laser of pulse energy 10–30 J and duration 20 ns (FWHM). The investigation revealed that the plastic deformation during the LSF is characterized as ultra-high strain rate, and it is indicated that the plastic deformation increases non-linearly with the increase of the energy density of the laser. By investigating the hardness and residual stress of the surfaces, it is conclude that LSF is a combination technique of laser shock strengthening and metal forming for introducing strain hardening and a compressive residual stress on the surface of the workpiece. This technique can achieve forming with or without a mold.