Thermal Properties of Plasma-Sprayed (La 0.4 Sm 0.5 Yb 0.1 ) 2 -Zr 2 O 7 Coatings on NiCrCoAlY Bond Coats

(La0.4Sm0.5Yb0.1)2Zr2O7 (LSYZO) coating was prepared by atmospheric plasma spray. Sm2Zr2O7 (SZO) coating was also prepared in the same conditions as a contrast. Microstructures and phases of LSYZO coatings were investigated by scanning electrical microscopy (SEM) and X-ray diffraction (XRD), respectively. The thermal conductivities of the two coatings were measured. The results show that the phase composition of LSYZO coating has no change after plasma spraying. The adhesion strength of LSYZO coating is 22 MPa, which is comparable with that of SZO coating. And LSYZO coating has lifetime of about 40 cycles. The thermal conductivity of LSYZO coating is lower than that of SZO coating, which mainly depends on the complex structure of LSYZO ceramic.