Laser shock processing: Modeling of evaporation and pressure field developed in the laser-produced cavity

Laser shock processing during high-intensity beam ablation of the metallic surface is examined. The phase change due to evaporation and melting is modeled using an energy method. The vapor front expansion and pressure build-up in the laser-produced cavity are obtained numerically using a control volume approach. Elasto-plastic response of the substrate material due to mechanical loading of pressure field developed in the cavity is modeled and predicted using a finite element method. It is found that a high-pressure region is developed in the vicinity of the cavity edge, which, in turn, results in excessive stresses and plastic strain in this region. The depth of the plastic region in the order of a few micrometers below the surface is predicted.