Fig. 1. Schematic of repair experiment. (a) V-groove; (b) simulated repairing path

Fig. 2. Size of tensile specimen

Fig. 3. Cross-sectional metallograph of repaired sample

Fig. 4. Microstructure of as-cast K452. (a) Typical phase distribution; (b) γ'phase on grain boundaries; (c) γ'phase inside grains

Fig. 5. Characteristics of liquid film in heat affected zone. (a) Low-melting eutectic liquation crack; (b) component liquation crack

Fig. 6. Cross sections of samples under different laser energy densities. (a) 30 J/mm2; (b) 35 J/mm2; (c) 40 J/mm2; (d) 30 J/mm2; (e) 35 J/mm2; (f) 40 J/mm2

Fig. 7. Microstructures under different laser modes. (a) Continuous laser; (b) pulsed laser

Fig. 8. Cross sections of samples under different laser energy densities. (a) 30 J/mm2; (b) 35 J/mm2

Fig. 9. Microhardness of repaired sample. (a) Cross section; (b) longitudinal section

Fig. 10. Microstructure characteristics of HAZ. (a) microstructure of HAZ; (b) γ'phase at position 1; (c) γ' phase at position 2 ; (d) γ' phase at position 3

Fig. 11. Microstructure of RZ. (a) Microstructure at bottom of RZ; (b) microstructure at top of RZ