## 3 Results and Discussion
### Solid-Liquid Mixture of Media on the Cleaning Effect of  
Building upon the results obtained from aqueous media and SiO\({}_{2}\) processing, we contemplated the outcomes of combining the two. Given that the water layer did not yield the desired cleaning effect at a height of 0.5 mm, a unique surface emerged, to which SiO\({}_{2}\) was subsequently added for comparative analysis to investigate the efficacy of laser cleaning following their mixture. Due to the inherent physical properties of SiO\({}_{2}\), it is not readily soluble in water and can only be suspended in water. Consequently, varying proportions of the mixture were employed as an auxiliary medium for laser cleaning, with different amounts of SiO\({}_{2}\) added to the suspension. These proportions are expressed as percentages and solely indicate the ratio of SiO\({}_{2}\) within the mixture. The microscopic morphology of laser cleaning after solid-liquid mixing is shown in Figure 19. Upon further examination of the above results with the aqueous medium as an auxiliary, it was observed that the addition of SiO\({}_{2}\) enhanced the cleaning effect. Specifically, when the proportion of SiO\({}_{2}\) was set at 0.5% (Figure 19b), the surface exhibited pits after ablation, indicating that SiO\({}_{2}\)'s addition promoted the cleaning process. As the proportion of SiO\({}_{2}\) increased to 1% (Figure 19c), the surface morphology underwent a transformation, with the region becoming smoother but also with the emergence of some pits. Additionally, the shadow traces still hinted at the presence of the rust layer, which had not been fully removed. At a SiO\({}_{2}\) proportion of 2% (Figure 19d), the surface appeared flat, with regions of over-ablation, and some rust remained. As the proportion of SiO\({}_{2}\) continued to rise, the  
Figure 17: Relationship between SiO\({}_{2}\) height and cleaning depth. Figure 18: SiO\({}_{2}\) environment medium cleaning comparison chart. cleaning effect deteriorated, as seen in Figure 19f, where at 10% SiO\({}_{2}\), there was a more pronounced presence of rust that had not been removed. The mixture of SiO\({}_{2}\) and H\({}_{2}\)O, at certain proportions, can enhance laser cleaning and is conducive to the cleaning process. The three-dimensional morphology of laser cleaning after solid-liquid mixing is shown in Figure 20. Under cleaning in the mixture, the three-dimensional morphology did not show significant noticeable changes; from the addition of 0.5% of SiO\({}_{2}\), some surface bulging appeared, and the overall height difference increased from 15 \(\upmu\)m to 25 \(\upmu\)m. The bulging part of the surface corresponds to the ablation area, which also corresponds to the addition of SiO\({}_{2}\) to promote the cleaning of the underwater medium; when reaching the addition of SiO\({}_{2}\) to 1%, the surface begins to flatten again, compared with the maximum value of 20 \(\upmu\)m, which is shown in Figure 20c. That is, in Figure 20c, the surface begins to be flat again, and the maximum height difference comes to 20 \(\upmu\)m, which is 5 \(\upmu\)m less than that in Figure 20b, and the protruding area is reduced; furthermore, with the addition of SiO\({}_{2}\), when it comes to Figure 20d, the maximum height difference of the surface reaches 12 \(\upmu\)m, which is the most minor height difference of the surface in this stage; subsequently, with the increase in the added amount of SiO\({}_{2}\), the height difference of the surface increases, and the height difference of the surface reaches 10%, which corresponds to the ablation area, and it also corresponds to the promotion effect of adding SiO\({}_{2}\) on underwater media cleaning; at this time, it also corresponds to the promotion effect of adding SiO\({}_{2}\) to the underwater media cleaning. When the proportion of SiO\({}_{2}\) is 10%, the height difference reaches 45 \(\upmu\)m. The addition of SiO\({}_{2}\) to the aqueous solution first decreases the difference and then increases it.