Surface integrity control of laser cleaning of an aluminum alloy surface paint layer

Removal of a paint layer of 2024 aluminum alloy was studied using a nanosecond fiber pulsed laser with a maximum power of 30 W and the influence of laser cleaning energy density on the surface integrity of the substrate was explored. The cleaning energy density threshold of the paint layer is 17.69J/cm² and the damage energy density threshold is 24.77J/cm². The optimum cleanliness and surface integrity of laser cleaning were obtained when the energy density was 21.23J/cm². Microhardness and Young's modulus of the surface after laser cleaning were improved by 6% and 25%, respectively. The mechanical properties of the surface of the substrate after laser cleaning were significantly improved, which is an advantage for this high-quality non-destructive cleaning technology of the aircraft skin surface paint layer.