Thermo-mechanical simulation and experimental investigations of fused silica with microsecond-pulsed CO2 laser cleaning

Laser cleaning is widely used to remove surface contaminants and defects due to its low cost, high efficiency, and environmental protection. However, residual thermal stress caused by huge temperature gradient significantly induces thermal distortion and cracks. Due to the lack of understanding of the coupling interaction between laser and fused silica, it is still challenging to reveal the mechanism of thermal stress formation, severely restricting the further development of laser cleaning. In this article, we built a three-dimensional thermo-mechanical model to obtain the stress value and distribution of thermal stress and reveal the evolution mechanism of stress in different times and spaces. Moreover, laser cleaning experiments under different processing parameters were carried out to validate the simulated results, and theoretical simulations fit well with experimental results, which proves the effectiveness of the multi-physics model. This research provides new insights into thermal stress evolution, which can promote further development in laser cleaning technology.