Laser shock forming on coated metal sheets characterized by ultrahigh-strain-rate plastic deformation

Abstract

We report on a dynamic ultrahigh-strain-rate forming method driven by laser impact. This investigation reveals that laser shock forming is a mechanical, not a thermal process, and the strain rate can go up to 107–109 s−1, two or more orders higher than that of all the existing forming methods. By investigating the hardness and residual stress of the surfaces, we conclude that laser shock forming is a technique with combining laser shock strengthening and metal forming, which introduces strain hardening and compressive residual stresses. We also discover some nonlinear plastic deformation characters in laser shock forming.