The relationship between the life-time & the structure properties of CeO2 stabilized zirconia TBCs

摘要

Coatings of zirconia alloyed with 25wt% ceria and2.5wt% yttria or 8wt% yttria were prepared using the air plasmaspray(APS) process. For each of these coatings thermal shockresistance and thermal expansion parallel to the substrate under the1300°C high temperature environment were measured toinvestigate the phase transformation behavior of ceramic topcoating and thermal expansion mismatch stress. Microhardness testwas also used to compare ZrO2-25CeO2-2.5Y203 with ZrO2-8Y203coating in the light of mechanical property. These results werediscussed in conjunction with the phase stability of the specimens,as determined by X-ray diffraction. The ZrO2-CeO2-Y203 coatingwas found to have more stable thermal properties than ZrO2-Y203coating. The thermal shocked ZrO2-Y203 coating exhibited a non-linear thermal expansion curve which was probably due to areversible tetragonal-monoclinic transformation.