Fig. 1. Surface morphology comparison of sample before and after painting. (a) Before painting; (b) after painting

Fig. 2. Nanosecond pulsed laser cleaning equipment. (a) Pulsed fiber laser; (b) laser cleaning head

Fig. 3. Schematic of scanning path of laser cleaning

Fig. 4. Online detection mechanism of laser cleaning surface

Fig. 5. Macroscopic appearances of sample surface cleaned by laser with different powers. (a) 70 W; (b) 150 W; (c) 200 W; (d) 240 W

Fig. 6. Height cloud images of surface microstructure after laser cleaning at different powers (frequency is 30 kHz). (a) 150 W; (b) 180 W; (c) 200 W; (d) 240 W

Fig. 7. Evolution of laser cleaning surface microstructures with laser power. (a) 150 W; (b) 160 W; (c) 180 W; (d) 200 W

Fig. 8. Surface micro-morphologies. (a) 150 W; (b) 160 W; (c) 170 W; (d) 180 W; (e) 190 W; (f) 200 W

Fig. 9. Surface composition analysis. (a) 150160 W laser power; (b) 170200 W laser power; (c) region AC; (d) region DH

Fig. 10. Typical cleaning state images at different laser powers. (a) 150 W; (b) 160 W; (c) 180 W; (d) 200 W

Fig. 11. Binary processing results of laser cleaning images. (a) 150 W; (b) 160 W; (c) 180 W; (d) 200 W

Fig. 12. Changes in the number of black and white pixels in each cleaning state