Thermal and mechanical properties of ZrO2-CeO2 plasma-sprayed coatings

The thermal and mechanical properties of ZrO2-CeO2 plasma-sprayed coatings were evaluated to examine their potential as a thermal barrier coating, ZrO2-CeO2 solid-solution powders containing up to 70 mol% CeO2 are successfully plasma sprayed, but cerium content decreases during spraying due to the vaporization of cerium oxide, Hardness is greatest at 30 mol% CeO2. With increased CeO2 content, the thermal conductivity decreases to 0.5 W/m . K and the thermal expansion coefficient increases to 12.5 x 10(-6)/K. Increased torch input power causes both the relative density and the hardness to increase monotonically, while the thermal conductivity and the thermal expansion coefficient are not significantly affected, When heated above 1300 K, the coating shrinks considerably due to sintering and its thermal conductivity increases abruptly.