Fig. 1. Pictures of laser control cabinet and robot. (a) Control cabinet of 4000 W laser device；(b) ABB robot

Fig. 2. Schematic of laser beam deflection angles. (a) (c) Angle 1; (b) (d) angle 2

Fig. 3. Weld tissue distribution under different deflection angles. (a) Angle 1; (b) angle 2

Fig. 4. Weld micro-tissue of angle 2 sample. (a) Massive tissue; (b) spherical tissue

Fig. 5. Elemental scanning results of angle 1 sample along the middle position of weld

Fig. 6. Elemental scanning results of angle 2 sample along the middle position of weld

Fig. 7. Weld interface in copper side under different deflection angles. (a) Angle 1; (b) angle 2

Fig. 8. Weld micro-hardness under different deflection angles. (a) Angle 1; (b) angle 2

Fig. 9. Weld fracture under different deflection angles. (a) Angle 1; (b) angle 2