Correlation between particle removal and shock-wave dynamics in the laser shock cleaning process

Abstract

It has been shown that the laser shock cleaning (LSC) method is effective for eliminating micron- and submicron-scale particulates from solid surfaces. In the LSC process, a high-power laser pulse induces optical breakdown of the ambient gas close to the solid surface to be cleaned and the subsequently-created shock wave followed by a high-speed flow stream detaches the particles. Therefore, there should be a strong correlation between the dynamics of the shock wave and the cleaning performance. In this work, experimental analyses are conducted to measure the cleaning performance using micron-sized alumina particles attached to a silicon surface. The experimental data showing the particle-removal performance are compared with the results of the dynamics of the laser-induced shock waves, leading to a simple model for particle removal by the LSC scheme in the continuum-flow regime.