Fig. 1. Experimental materials and method. (a) Morphology of DD6 alloy powder; (b) substrate; (c) deposited sample; (d) sample area division and quantitative size

Fig. 2. Cross-sectional microstructures in single-channel single-layer laser deposition under different laser powers. (a) 400 W; (b) 600 W; (c) 800 W; (d)1000 W; (e) 1200 W; (f) 1400 W

Fig. 3. Cross-sectional microstructures of samples when laser power is 800 W. (a) Scanning speed is 5 mm/s and powder feeding rate is 5 g/min; (b) scanning speed is 10 mm/s and powder feeding rate is 10 g/min; (c) scanning speed is 15 mm/s and powder feeding rate is 15 g/min; (d)(e)(f) local microstructures

Fig. 4. Cross-sectional microstructures of samples when laser power is 1000 W. (a) Scanning speed is 5 mm/s and powder feeding rate is 15 g/min; (b) scanning speed is 10 mm/s and powder feeding rate is 5 g/min; (c) scanning speed is 15 mm/s and powder feeding rate is 10 g/min; (d)(e)(f) local microstructures

Fig. 5. Cross-sectional microstructures of samples when laser power is 1200 W. (a) Scanning speed is 5 mm/s and powder feeding rate is 10 g/min; (b) scanning speed is 10 mm/s and powder feeding rate is 15 g/min; (c) scanning speed is 15 mm/s and powder feeding rate is 15 g/min; (d)(e)(f) local microstructures

Fig. 6. Microstructures of single-channel 30-layer sample when laser power is 1000 W, scanning speed is 15 mm/s, and powder feeding rate is 10 g/min under continuous deposition strategy. (a) Overall cross-section microstructure; (b) top microstructure; (c) center microstructure; (d) bottom microstructure

Fig. 7. Microstructures of 4-channel 10-layer sample when laser power is 1000 W, scanning speed is 15 mm/s, and powder feeding rate is 10 g/min under continuous deposition strategy. (a) Overall cross-section microstructure; (b) top microstructure; (c) center microstructure; (d) deflection columnar crystal; (e) bottom microstructure

Fig. 8. Element distributions of multi-channel multi-layer sample when laser power is 1000 W, scanning speed is 15 mm/s, and powder feeding rate is 10 g/min under continuous deposition strategy. (a) Top element spectrum obtained by surface scanning; (b) bottom element spectrum obtained by surface scanning; (c) distribution of each element at top; (d) distribution of each element at bottom

Fig. 9. Microstructure and crystal orientation distributions of single-channel multi-layer sample when laser power is 1000 W, scanning speed is 15 mm/s, and powder feeding rate is 10 g/min under intermittent deposition strategy. (a) Microstructure of sedimentary area; (b) top crystal orientation distribution; (c) bottom crystal orientation distribution; (d) bottom pole diagram

Fig. 10. Microstructure and crystal orientation distributions of multi-channel multi-layer sample when laser power is 1000 W, scanning speed is 15 mm/s, and powder feeding rate is 10 g/min under intermittent deposition strategy. (a) Microstructure of sedimentary area; (b) top microstructure; (c) center microstructure; (d) bottom microstructure; (e) top crystal orientation distribution; (f) bottom crystal orientation distribution; (g) bottom pole diagram

Fig. 11. Distributions and statistical results of crystal orientation differences at bottom of deposition areas of single-channel multi-layer and multi-channel multi-layer samples under intermittent deposition strategy. (a) Distribution of crystal orientation difference at bottom of deposition area of single-channel multi-layer sample; (b) distribution of crystal orientation difference at bottom of deposition area of multi-channel multi-layer sample; (c) statistical result of crystal orientation difference at bottom of deposition area of single-channel multi-layer sample; (d) statistical result of crystal orientation difference at bottom of deposition area of multi-channel multi-layer sample