Laser shock processing: a review of the physics and applications

Developed since the beginning of the 1970s in the United States (Battelle, Columbus), laser shock processing (LSP) is being extensively studied in France in order to improve the mechanical properties of metallic surfaces of dense or porous materials. This paper reviews the considerable data on LSP which has been obtained in recent years and provides an exhaustive account of current trends concerning the physics, the mechanics and the applications involved. After presenting some general and specific data regarding the physical principles of laser shock (laser system, plasma physics, pressure generation, physical limits) and mechanical effects induced (experimental and theoretical) on different materials, the efficiency of the process is illustrated through two potential industrial applications linked with modifications of surface states: fatigue and wear resistance of metals. Experience with LSP applications shows that, because it uses safe surface geometries and provides greater affected depths, LSP is about to emerge as a real alternative to classical treatments.