Control of Shock Wave Driven by Nanosecond Laser and Its Application to Machining

Abstract

With the recent development in the output power of lasers, processing using high power lasers has come to be used instead of conventional techniques. This article introduces nanosecond laser peening mechanisms. Compared with the prior technique, laser peening has the feature of being able to add a deep residual stress field to the material in spite of less surface deformation, which can be explained by a dislocation density model using a microscopic local stress field due to shock waves. Since the microscopic local stress field shows a strong correlation with the shock wave, the interference of the spatial shock wave affects the residual stress field distribution. This article clarifies such physical properties and describes the possibility of peening using a high-power laser.