研究目的

To simulate the process of grain re?nement induced by laser shock peening (LSP) and investigate the effects of laser spot overlap ratio and laser power density on LSP-induced grain re?nement.

研究成果

The three-dimensional ?nite element model, incorporating the dislocation density-based constitutive model and the temporal-spatial distribution of laser shock wave pressure, is capable of simulating the process of grain re?nement induced by LSP. The model was validated by comparing the predicted dislocation cell sizes and dimple fabrications with experimental results. The study found that increasing the laser spot overlap ratio and laser power density leads to more uniform and smaller dislocation cell sizes, indicating improved grain re?nement.

研究不足

The study is limited by the assumptions of the dislocation density-based material constitutive model and the temporal-spatial distribution of laser shock wave pressure. The model does not account for twinning and stacking-fault bundles, which are principal defect structures at higher laser shock wave pressures.