Fig. 1. Schematic of laser cladding assisted by directional Lorentz force

Fig. 2. Powder morphology. (a) Powder microstructure; (b) internal hollow structure

Fig. 3. Schematic of bubble force analysis

Fig. 4. Schematic of computation grids

Fig. 5. Lorentz force distributions in molten pool under different conditions. (a) Magnetic field strength of 0.6 T, current density of 5×106 A·m-2, upward Lorentz force; (b) magnetic field strength of 0.6 T, current density of 5×106 A·m-2, downward Lorentz force

Fig. 6. Flow field distributions in molten pool under different conditions. (a) Magnetic field strength of 0 T; (b) magnetic field strength of 0.6 T, current density of 5×106 A·m-2, Lorentz force is upward; (c) magnetic field strength of 0.6 T, current density of 5×106 A·m-2, Lorentz force is downward

Fig. 7. Trajectory map of bubbles with different diameters at different positions. (a) Front position; (b) middle position; (c) rear position; (d) statistical diagram of bubble park position

Fig. 8. Trajectory map of bubbles at different positions and under different Lorentz forces. (a) Point A position; (b) point B position; (c) point C position; (d) speed map along Y direction of bubble at point A

Fig. 9. Final park positions of bubble at different positions and under different Lorentz forces. (a) Point A position; (b) point B position; (c) point C position

Fig. 10. Distributions of pores in cladding layers under different conditions. (a) B=0 T; (b) B=0.3 T, upward Lorentz force; (c) B=0.6 T, upward Lorentz force; (d) B=0.3 T, downward Lorentz force; (e) B=0.6 T, downward Lorentz force