Fig. 1. Experimental setup for ultrasonic-assisted laser melt injection

Fig. 2. Morphology, particle size and phase composition of WC particles. (a) Morphology and size distribution of WC particles; (b) XRD test result of WC particles

Fig. 3. Longitudinal section morphology and WC particle size distribution on longitudinal section of laser melt injection layer with a powder feeding rate of 8 g/min. (a) Without ultrasound; (b) with ultrasound

Fig. 4. Cross section morphology and cell division of laser melt injection layer with powder feeding rate of 8 g/min. (a) Without ultrasound; (b) with ultrasound

Fig. 5. Number density of WC particles in different cells with a powder feeding rate of 8 g/min. (a) Without ultrasound; (b) with ultrasound

Fig. 6. Construction process for Voronoi diagram of laser melt injection layer

Fig. 7. Voronoi cell area of laser melt injection layer without ultrasound. (a) Powder feeding rate of 2 g/min; (b) powder feeding rate of 4 g/min; (c) powder feeding rate of 6 g/min; (d) powder feeding rate of 8 g/min

Fig. 8. Voronoi cell area of laser melt injection layer with ultrasound. (a) Powder feeding rate of 2 g/min; (b) powder feeding rate of 4 g/min; (c) powder feeding rate of 6 g/min; (d) powder feeding rate of 8 g/min

Fig. 9. Fitting lognormal curve of Voronoi cell area

Fig. 10. Coefficient of variability of Voronoi cell area of laser melt injection layer

Fig. 11. Flaw detection of laser melt injection layer with and without ultrasound

Fig. 12. Distribution and morphology of crack in laser melt injection layer. (a) Longitudinal section; (b) cross section