In order to reveal the mechanism of nanosecond pulsed laser cleaning of the anodic oxide film on the surface of aluminium alloy and its interaction characteristics, a combination of Comsol simulation and cleaning experiments was used to study the changing law of the oxide film on the surface of aluminium alloy cleaned by single-pulse and multi-pulse laser under four kinds of laser actions with powers of 20 W, 35 W, 50 W and 65 W. The results showed that the single pulse experimental cleaning area under the four power conditions was larger than the area of ablation simulation; when P=20 W, the oxide film was not destroyed, and its surface contamination carbon was removed, the remaining three power conditions under the cleaning of the surface ablation, but the experimental ablation area was smaller than that of ablation simulation. Under the thermal stress generated by the coupling of the ablation and plasma shock, the oxide film cracking and local chipping occurred. In the multi-pulse laser cleaning process, there were superposition areas caused by plasma shock and ablation, and the cleaning area and depth were larger than those of the single-pulse experimental. This study points out that there are three cleaning mechanisms in the laser cleaning process of oxide film, namely, ablation, plasma shock and thermal stress. The plasma shock area includes laser spot irradiated area and non-irradiated area, and in irradiated area, the three cleaning mechanisms work together, while in the non-irradiated area, both the plasma shock and the thermal stress are interactively coupled. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.
