Dislocation density-based study of grain refinement induced by laser shock peening

摘要： Laser shock peening (LSP) is an innovative surface processing technique. Grain re?nement induced by LSP has been proved to be feasible to improve the surface properties of materials and prolong the service life of metallic components. The three-dimensional ?nite element model, which incorporates a dislocation density-based constitutive model and the temporal-spatial distribution of laser shock wave, was adopted to simulate the process of grain re?nement induced by LSP. The predicted dislocation cell sizes, dimple fabrications induced by the repetitive LSP of copper are in good agreement with experimental results, which con?rms the validity of the dislocation density-based three-dimensional ?nite element model. The e?ects of laser spot overlap ratio and laser power density (peak laser shock wave pressure) on LSP-induced grain re?nement were investigated in detail based on the numerical simulations of multiple LSP of copper and CP-Ti.