Recent progress in laser shock peening: Mechanism, laser systems and development prospects

Laser shock peening (LSP) is a novel laser surface treatment technology that is rapidly being developed and widely exploited in various industries, including aerospace, nuclear, and biomedical. In the last few decades, there have been a large number of theoretical and experimental studies of LSPs. The demand for LSP technology in laser processing is steadily increasing. There is a growing aspiration to achieve a more uniform residual stress layer and to broaden its influence across a wider range. Simultaneously, efforts are underway to overcome constraints associated with peripheral equipment, such as absorption and constraint layers, aiming to expand its application domains. Laser, as a direct processing tool, requires in-depth research into the specific impact of laser parameters on different materials, which is considered crucial for enhancing material performance. This paper provides a systematic review of the mechanisms of LSP grain refinement in materials with different structures. Moreover, the influence mechanisms of typical laser system parameters are analyzed, and implementable optimization methods are presented. Finally, the development directions of LSP are currently being summarized. This study actively investigates the specific impact of laser parameters on LSP, aiming to achieve precise control of the intensity and propagation characteristics of laser-induced shock waves. The study scrutinizes the specific influence of laser parameters on LSP to optimize material properties post-treatment and enhance the engineering practicality of LSP technology through highly controllable laser techniques.