Fig. 1. Schematic of laser-arc hybrid welding

Fig. 2. Schematic of weld appreance

Fig. 3. Effect of arc voltage on weld appearance. (a) Weld width; (b) reinforcement

Fig. 4. Effect of laser power on weld appearance. (a) Laser-leading; (b) arc-leading

Fig. 5. Total area of weld at different heat source postions

Fig. 6. Effect of metal vapor on droplet transfer at different heat source positions. (a) Laser-leading; (b) arc-leading

Fig. 7. Schematic of various forces on droplet at different heat source positions. (a) Laser-leading; (b) arc-leading

Fig. 8. Characteristics of keyhole at different heat source positions. (a)-(d) Laser-leading; (e)-(g) arc-leading

Fig. 9. Difference between high-speed welding of thin plates and low-speed welding of thick plates. (a) Thick plates; (b) thin plates

Fig. 10. Microhardness distributions of cross-sectional weld at different heat source positions

Fig. 11. Weld line scan results. (a) Arc-leading; (b) laser-leading

Fig. 12. Component analysis results of bottom area (laser area) of weld at different heat source positions. (a) Arc-leading, electron image; (b) arc-leading, energy spectrum; (c) laser-leading, electron image; (d) laser-leading, energy spectrum

Fig. 13. Tensile samples. (a) Fracture at base metal; (b) fracture at weld

Fig. 14. Tensile strength of weld sample at different heat source positions