Fig. 1. Schematic of laser-directed energy deposition as well as powder morphology and statistical size. (a) Schematic showing laser-directed energy deposition of GH4169 on a CuCrZr substrate; (b) morphology and statistical size of GH4169 alloy powder

Fig. 2. Partial CuCrZr substrate plates with surface treatment. (a) Surface treatment schematics; (b)(c) thermal spraying; (d) cold spraying; (e) physical vapor deposition (PVD); (f) electroplating; (g) surface powder spreading (pre-grooved)

Fig. 3. Laser coaxial powder delivery additive manufacturing. (a) CuCrZr/GH4169 dissimilar metals block specimen; (b) sampling diagram of specimens for tensile test and microstructure observation; (c) dimension of tensile specimen; (d) physical diagram of tensile specimen

Fig. 4. Coatings with different thicknesses prepared by different surface pre-treatment processes. (a)‒(c) Thermal spraying; (d)‒(f) cold spraying; (g)‒(i) electroplating; (j)‒(k) PVD; (l) surface powder spreading

Fig. 5. Comparison chart of the designed and actual coating thickness for different surface pre-treatment processes

Fig. 6. Metallographic images showing cross-sections of the specimens obtained by single-pass deposition with three processes on thermal-spraying pretreated CuCrZr substrate

Fig. 7. Metallographic images showing cross-sections of the specimens obtained by single-pass deposition with three processes on cold-spraying pretreated CuCrZr substrate

Fig. 8. Metallographic images showing cross-sections of the specimens obtained by single-pass deposition with three processes on CuCrZr substrate pretreated by electroplating, PVD, and surface powder spreading

Fig. 9. Cross-section parameters of single-pass cladding samples. (a) Schematic diagram of the cross-section parameters; (b) radar chart of the cross-section parameters

Fig. 10. CuCrZr/GH4169 dissimilar metals additive manufacturing block specimens and their nondestructive testing results. (a) Actual photograph; (b) cross-sectional view; (c)(d) nondestructive testing results

Fig. 11. Microstructure at the interface of CuCrZr/GH4169 dissimilar metals specimen. (a) Metallographic image; (b) SEM image; (c)‒(g) EDS elemental mapping images of Cu, Cr, Zr, Ni, Nb; (h) metallographic image of the transition zone; (i) sampling diagram in transition zone for EDS analysis; (j) SEM image of GH4169 zone

Fig. 12. Tensile test results of CuCrZr/GH4169 dissimilar alloy additive manufacturing specimens. (a) Tensile curves and residual specimen images; (b) subsurface image of the tensile fracture; (c) SEM image of the tensile fracture surface