Nd: YAG laser ablation of aluminum alloy 6061 before and after silicon dioxide coating

In this work, the process of laser ablation of aluminum alloy 6061 (AA 6061) before and after silicon dioxide (SiO₂) coating was studied both experimentally and by numerical simulation. Four different laser fluences (0.5 J/cm², 1 J/cm², 1.5 J/cm² and 2 J/cm²) were applied to investigate laser ablation of AA 6061 before and after coated by SiO₂ film. It was founded that the thermal diffusion and ablation depth of AA 6061 had been directly influenced by both laser fluence and SiO₂ coating. At relatively low laser fluence (0.5 J/cm²), ablation deformation and damage of AA 6061 were not observed. While the laser fluence reached to 1 J/cm², vaporization took place in AA 6061. With increased laser fluence, the ablation range and depth expanded. The vaporization of SiO₂ films happened in the first laser fluence, however, the area of the zone affected were much less than AA 6061, that demonstrates the SiO₂ film has a positive effect on AA 6061. A 3-dimensional computational model was used to compute the temperature variation in a solid material over time. The results of the model (depth to width ratio versus laser ablation) exhibited well with the experimental results in some ways.