Fig. 1. Powder bed model

Fig. 2. Polyhedral mesh model in fluid dynamics simulation

Fig. 3. Morphology of the molten pool during the molten channel forming process at 200 W and 1.0 m·s^-1. (a)(b)(c)(d) Top view; (e)(f)(g)(h)cross-sectional view

Fig. 4. Recoil pressure during forming

Fig. 5. Morphology of the single-channel formed at different scanning speeds

Fig. 6. Average width of molten channel and standard deviation

Fig. 7. Variation of molten channel width and its coefficient of standard deviation with scanning speed

Fig. 8. Simulation and experimental results of forming single-channel at different scanning speeds. (a)(b)(c) Top view;(d)(e)(f) cross-sectional view

Fig. 9. Molten pool size at different scanning speeds

Fig. 10. Morphology of the single-channel formed at each laser power

Fig. 11. Molten channel width and its coefficient of standard deviation at each laser power

Fig. 12. Simulation and experimental results of forming single-channel at each laser power. (a)(b)(c) Top view;(d)(e)(f) cross-sectional view

Fig. 13. Molten pool size at each laser power

Fig. 14. Molten channel width and its coefficient of standard deviation at each line energy density

Fig. 15. Distribution of molten channel width and its coefficient of standard deviation at different laser powers and scanning speeds. (a) Distribution ofmolten channel width; (b) distribution ofcoefficient of standard deviation of molten channel width

Fig. 16. Cross-section of molded parts under different process parameters and schematic diagram of cross-section profile. (a)(b)(c) Cross-section of the molded parts; (d) schematic diagram of cross-section profile

Fig. 17. Curve of the molten channel cross-section profile. (a) Realistic profile; (b) calculated profile

Fig. 18. Ideal single-channel model

Fig. 19. Surface morphology of the single-layer multi-channel. (a) Three-dimensional reconstruction result; (b) simulation result; (c) experimental result