Fig. 1. Morphologies of anodized film of 5083 aluminum alloy. (a) SEM morphology; (b) enlarged pore morphology; (c) metallographic micrograph; (d) oxide film thickness

Fig. 2. Laser cleaning system. (a) Schematic; (b) laser scanning track

Fig. 3. Two dimensional morphologies after laser cleaning under different single pulse energies. (a) 84 mJ; (b) 86 mJ; (c) 88 mJ; (d) 90 mJ; (e) 92 mJ; (f) 94 mJ; (g) 96 mJ; (h) 98 mJ; (i) 100 mJ

Fig. 4. Three dimensional morphologies after laser cleaning under different single pulse energies. (a) 84 mJ; (b) 86 mJ; (c) 88 mJ; (d) 90 mJ; (e) 92 mJ; (f) 94 mJ; (g) 96 mJ; (h) 98 mJ; (i) 100 mJ

Fig. 5. Surface roughnesses after laser cleaning under different single pulse energies

Fig. 6. Two dimensional morphologies after laser cleaning under different pulse frequencies. (a) 3.71 kHz; (b) 6.35 kHz; (c) 7.67 kHz; (d) 8.33 kHz; (e) 8.67 kHz; (f) 9.00 kHz; (g) 9.33 kHz; (h) 9.67 kHz; (i) 10.00 kHz

Fig. 7. Schematic of spot overlap

Fig. 8. Three dimensional morphologies after laser cleaning under different pulse frequencies. (a) 3.71 kHz; (b) 6.35 kHz; (c) 7.67 kHz; (d) 8.33 kHz; (e) 8.67 kHz; (f) 9.00 kHz; (g) 9.33 kHz; (h) 9.67 kHz; (i) 10.00 kHz

Fig. 9. Surface roughnesses after laser cleaning under different pulse frequencies

Fig. 10. Two dimensional morphologies after laser cleaning at different laser travel speeds. (a) 1.0 mm/s; (b) 3.0 mm/s; (c) 6.5 mm/s; (d) 7.0 mm/s; (e) 7.5 mm/s; (f) 12.5 mm/s

Fig. 11. Running track of laser spot

Fig. 12. Three dimensional morphologies after laser cleaning at different laser travel speeds. (a) 1.0 mm/s; (b) 3.0 mm/s; (c) 6.5mm/s;(d) 7.0 mm/s; (e) 7.5 mm/s; (f) 12.5 mm/s

Fig. 13. Surface roughnesses after laser cleaning under different laser travel speeds

Fig. 14. Comparison of three dimensional surface morphologies before and after mechanical polishing. (a) Before mechanical polishing;(b) after mechanical polishing

Fig. 15. SEM morphologies after laser cleaning under different single pulse energies. (a) 84 mJ; (b) 86 mJ; (c) 88 mJ; (d) 90 mJ; (e) 92 mJ; (f) 94 mJ; (g) 96 mJ; (h) 98 mJ; (i) 100 mJ

Fig. 16. EDS detection results corresponding to SEM morphologies in Fig. 15

Fig. 17. SEM morphologies after laser cleaning under different pulse frequencies. (a) 3.71 kHz; (b) 6.35 kHz; (c) 7.67 kHz; (d) 8.33 kHz; (e) 8.67 kHz; (f) 9.00 kHz; (g) 9.33 kHz; (h) 9.67 kHz; (i) 10.00 kHz

Fig. 18. EDS detection results corresponding to SEM morphologies in Fig. 17

Fig. 19. SEM morphologies after laser cleaning at different laser travel speeds. (a) 1.0 mm/s; (b) 3.0 mm/s; (c) 6.5 mm/s; (d) 7.0 mm/s; (e) 7.5 mm/s; (f) 12.5 mm/s

Fig. 20. EDS detection results corresponding to SEM morphologies in Fig. 19

Fig. 21. Element contents (mass fractions) of laser cleaned surface and substrate surface

Fig. 22. Mechanisms of laser removal of anodized film. (a) Hole blasting mechanism; (b) elastic vibration stripping mechanism; (c) thermal ablation mechanism; (d) flow forming morphology of molten pool at position ① in Fig. 22(c)