Simulation of Bi-Material Nano-Second Laser Ablation
In the field of laser applications, surface treatment is highly studied. Two process categories are commonly used. First processes use very short pulses (femto or pico seconds) known to avoid thermal effects and to have high spatial resolutions. Second processes have higher interaction times (nanoseconds) leading to higher treatment rates and thus, more suitable for industry.
The current study concerns nanoseconds laser technology and more precisely, the simulation of ablation phenomenon. This process, close to drilling but with very small aspect ratios, is based on total or partial vaporization of an oxide layer to be treated. As the characteristic times still very smalls, experimental studies are quite difficult and mainly done at large scale (lot of pulses).
The supposed ablation phenomena are phase explosion, mechanical fracturing and vaporization. Authors propose a numerical study that aims to identify the most likely phenomenon leading to a micrometer oxide layer removal.
To do this, a simulation is done including COMSOL Multiphysics® Heat Transfers, Two-Phase Flow, Moving Mesh and Transport of Diluted Species interfaces.
The simulations results were compared to experiment in terms of residual ablated shapes and total ablated mass. As the results are quite similar, the computed thermal field is used to propose an explanation of the current ablation case.
