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

摘要

In this article, we work on a dynamic super-speed forming method driven by laserrnshock waves. The initial observation of the laser shock forming is done through a bugle testingrnwith specimens of 430 sheet metal , using a neodymium-glass laser of pulse energy 10～30J andrnduration of 20ns(FWHM). The investigation revealed that the plastic deformation during thernlaser shock forming is characterized as ultrahigh strain rate. We indicate that plastic deformationrnincreases nonlinearly when the energy density of the laser varies. By investigating the hardnessrnand residual stress of the surfaces, we conclude that laser shock forming is a combinationrntechnique of laser shock strengthening and metal forming for introducing a strain harden and arncompressive residual stress on the surface of the work-piece. This technique can achieve formingrnwith or without mould.