Effects of Temperature on Laser Shock Induced Plastic Deformation: The Case of Copper

Abstract

Laser shock induced plastic deformation has been used widely, such as laser shock peening (LSP), laser dynamic forming (LDF), and laser peen forming. These processes have been extensively studied both numerically and experimentally at room temperature. Recently, it is found that at elevated temperature, laser shock induced plastic deformation can generate better formability in LDF and enhanced mechanical properties in LSP. For example, warm laser shock peening leads to improved residual stress stability and better fatigue performance in aluminum alloys. There is a need to investigate the effects of elevated temperature on deformation behavior of metallic materials during shock induced high strain rate deformation. In this study, LSP of copper are selected to systematically study the effects of elevated temperature in shock induced high strain rate deformation. Finite element modeling (FEM) is used to predict the deformation behavior. The FEM simulation results of surface profile and residual stress distribution after LSP are validated by experimental results. The validated FEM simulation is used to study the effects of temperature on the plastic deformation behaviors during LSP, such as plastic affected zone, stress/strain distribution, and energy absorption.