Fig. 1. Schematic of coaxial cladding nozzle

Fig. 2. Flow channel model of coaxial cladding nozzle

Fig. 3. Contours of mass fraction of argon. (a) Streamline chart of shielding gas based on contour of mass fraction; (b) mass distribution of shielding gas above substrate

Fig. 4. Effects of shielding gas inlet numbers on mass fraction of argon

Fig. 5. Effects of shielding gas inlet numbers on effective protection length

Fig. 6. Effect of flow rate of shielding gas on effective protection domain

Fig. 7. Exterior of single cladding layers of Ti-6Al-4V alloy under different flow rates of shielding gas. (a) 20 L·min-1; (b) 40 L·min-1; (c) 30 L·min-1; (d) 10 L·min-1

Fig. 8. Morphologies of multi-track-overlapped cladding layers of Ti-6Al-4V alloy. (a) Multi-track and single layer; (b) single-track and multilayer

Fig. 9. Cross-section morphology of single-track cladding layer

Fig. 10. Curve of temperature variation at one point in scanning direction