Laser shock peening was an innovative surface treatment technique applied to improve the mechanical properties and surface microstructures of metallic components. This paper was concerned with prediction of the microstructural evolution of metallic components subjected to single or multiple laser shock peening impacts. A numerical framework was developed to model the evolution of dislocation density and dislocation cell size using a dislocation density-based material model. It was shown that the developed model captures the essential features of the material mechanical behaviours and predicts that the total dislocation density reaches the order of 1014/m2 and a minimum dislocation cell size was below 250nm for laser shock peening of monocrystalline coppers using the laser energy density on the order of 500GW/cm2. It was further shown that the model was able to predict material strengthening in terms of residual stress and microhardness of the LY2 aluminium alloy due to grain refinement in a laser shock peening process with less laser energy densities on the order of several GW/cm2.

Dislocation Density-Based Modeling of Subsurface Grain Refinement with Laser-Induced Shock Compression. H.Ding, Y.C.Shin: Computational Materials Science, 2012, 53[1], 79-88