Fig. 1. Cross-section morphology and surface morphology of 2219 aluminum alloy. (a) Cross-section morphology; (b) surface morphology

Fig. 2. Schematic of laser cleaning device

Fig. 3. Surface of sample cleaned at different speeds

Fig. 4. SEM morphology of sample surface cleaned at different speeds. (a) 800 mm·min-1; (b) 1000 mm·min-1; (c)1400 mm·min-1; (d) 1800 mm·min-1

Fig. 5. Component analysis of area A

Fig. 6. Components analysis of area B

Fig. 7. Schematic of spot scanning track in laser cleaning process

Fig. 8. Schematic of spots effective overlap in clean direction

Fig. 9. SEM morphology of sample surface cleaned at different speeds near threshold. (a) 1000 mm·min-1; (b) 1200 mm·min-1

Fig. 10. Appearance of welded joints

Fig. 11. X-ray analysis of welded joints

Fig. 12. Surface topography of sample after laser cleaning

Fig. 13. The areas exist the mechanism of elastic vibration stripping. (a) Area without spot overlap; (b) cleaning area edge

Fig. 14. Principle of laser removing anodic oxide film