Abstract:
Laser shock processing (LSP) is a new and efficient type of laser surface treatment technologies. Compared with the traditional surface modification technologies, laser shock processing can form a deeper residual stress layer to the material and make surface grain refinement or even appear nano-crystalline, meanwhile significantly improving the fatigue life of the material. When the high-energy laser irradiates at the confinement layer (black paint, black tape or aluminum foil), the material of the confinement layer is instantaneously melted and gasified to produce a high-temperature and high-pressure plasma. The plasma shock wave is a detonation wave that can be used to calculate the peak pressure of the shock wave by the C-J model. The plasma propagates to the interior of the material under the constraint of the confinement layer (water or optical glass). The pressure of the shock wave far exceeds the elastic yield limit of the material. Therefore, the material undergoes elastic-plastic deformation and eventually forms a stable residual stress field and a slight plastic deformation. The development of the technology research process is also introduced. On this basis, the development direction of the technology is forecasted.