Fig. 1. XRD results of Al2O3/CoNiCrAlY coating at different energy densities

Fig. 2. Microstructures of coating before oxidation. (a) Bottom of E1 coating; (b) top of E1 coating; (c) Al₂O₃ distribution in E1 coating; (d) bottom of E2 coating; (e) top of E2 coating; (f) Al₂O₃ distribution in E2 coating; (g) bottom of E3 coating; (h) top of E3 coating; (i) Al₂O₃ distribution in E3 coating

Fig. 3. Oxidation kinetics curves of Al₂O₃/CoNiCrAlY coating at different energy densities. (a) Isothermal oxidation weight gain curves; (b) relationship curves between ΔW² and oxidation time

Fig. 4. XRD results of Al₂O₃/CoNiCrAlY coating at different energy densities after oxidation

Fig. 5. Microstructures of coating after oxidation. (a) Surface of E1 coating; (b) enlarged view of region I in Fig. (a); (c) enlarged view of region Ⅱ in Fig. (a); (d) surface of E2 coating; (e) enlarged view of region ix in Fig. (d); (f) enlarged view of region vi in Fig. (d); (g) surface of E3 coating; (h) enlarged view of region ii in Fig. (g); (i) enlarged view of region vii in Fig. (g)

Fig. 6. Microstructures of cross section of coating after oxidation. (a)(b) Coating of E1 sample; (c)(d) coating of E2 sample; (e)(f) coating of E3 sample

Fig. 7. Coating oxidation models. (a) Initial stage of oxidation; (b) after some time oxidation

Table 1. Chemical compositions of cladding material CoNiCrAlY

Table 2. Process parameters of laser cladding

Table 3. EDS analysis results of white particles

Table 4. EDS results of Al₂O₃/CoNiCrAlY coating shown in Fig. 5

Table 5. EDS results of Al₂O₃/CoNiCrAlY coating shown in Fig. 6