Morphology and thermal conductivity of La2(Ce0.3Zr0.7)2O7-3wt.%Y2O3 coatings

Abstract

Abstract The La 2 (Ce 0.3 Zr 0.7 ) 2 O 7 -3 wt%Y 2 O 3 coating was deposited by electron beam physical vapor deposition (EB-PVD). In order to reveal the structure evolution of the coating with the deposition parameter, the selected rotation rates of the substrate were 0 rpm, 5, 15 and 25 rpm, while the substrate temperature was fixed at 870 °C based on the structure zone model of 0.3 sub /T mp direction. The tips of the ‘roof top’ or the pyramids were covered by four {111} planes. During rotation deposition, the columnar crystal grew along the direction. If one assumes that the pore fraction has little effect on the thermal conductivity, the ‘C’ shaped Type I pores reduced the thermal conductivity, the straight Type I pores increased the thermal conductivity, the lamellar Type II pores significantly reduced the thermal conductivity. The minimum thermal conductivity was 0.761 W/(m K) at the rotation rate of 15 rpm. This gives an approach to optimize the structure of the La 2 (Ce 0.3 Zr 0.7 ) 2 O 7 -3 wt%Y 2 O 3 coatings.