Fig. 1. Laser-MAG hybrid welding equipment and schematic of edge joint. (a) Equipment; (b) edge joint

Fig. 2. Laser-MAG hybrid welding process of edge joint. (a) Arcing; (b) short circuit; (c) arc striking

Fig. 3. Schematics of different welding modes. (a) Laser leading; (b) arc leading

Fig. 4. Metallographs of weld cross-section obtained at different welding modes. (a) Laser leading; (b) arc leading

Fig. 5. Radiographs of weld obtained at different welding modes. (a) Laser leading; (b) arc leading

Fig. 6. Droplet transfer process for arc leading. (a) T+0 ms; (b) T+2.2 ms; (c) T+4.8 ms; (d) T+8.4 ms

Fig. 7. Droplet transfer process for laser leading. (a) T+0 ms; (b) T+0.8 ms; (c) T+5.2 ms; (d) T+13.8 ms

Fig. 8. Image brightness curves at different welding modes. (a) Laser leading; (b) arc leading

Fig. 9. Effect of laser-wire distance on porosity. (a) -1 mm; (b) 0 mm; (c) 1 mm; (d) 2 mm

Fig. 10. Effects of laser-wire distance on droplet transfer period and weld penetration

Fig. 11. Droplet transfer process when laser-wire distance is -1 mm. (a) T+0 ms; (b) T+29.6 ms; (c) T+87.2 ms; (d) T+104 ms

Fig. 12. Droplet transfer characteristics at different laser-wire distances. (a) -1 mm; (b) 0 mm; (c) 1 mm; (d) 2 mm

Fig. 13. Porosity in weld obtained at different laser powers. (a) 2000 W; (b) 2500 W; (c) 3000 W

Fig. 14. Droplet and keyhole shapes at different laser powers. (a) 2000 W; (b) 3000 W