Modeling and Simulation Improvement in Laser Shock Processing

Previous work has reported numerical and experimental results pertaining micro-scale laser shock processing, which imparts compressive residual stresses in metallic targets with higher spatial resolution. In this paper, the more detailed physical process of laser-liquid-solid interaction is considered to achieve more accurate simulation results of shock pressure and to provide values for coefficients which otherwise need to be arbitrarily chosen. The expansion of plasma is modeled as one-dimensional laser supported combustion wave. The 1D results are then modified to consider radial and axial expansion effects. The influence of pulse duration and beam size is also considered. Three-dimensional simulation of shock pressure-solid interaction is carried out as opposed to axisymmetric simulation reported previously. Finite extent of target geometry is also considered as opposed to the semi-infinite geometry assumed previously. The model and simulation improvement is experimentally validated.