Preparation and High-temperature Properties of Nanostructured CeO_2/ZrO_2-Y_2O_3 Thermal Barrier Coating

The nanosized ZrO_2-8wt%Y_2O_3(YSZ) and CeO_2/ZrO_2-8wt%Y_2O_3(CYZ) particles were agglomerated as powder feedstocks.Thermal barrier coatings were prepared on the GH30 high temperature alloy surface by atmospheric plasma spray.The microstructures of the agglomerated powders doped with 25wt%CeO_2 particles and the coating were characterized using scanning electron microscope(SEM),transmission electron microscope(TEM) and X-ray diffraction(XRD) technology.The thermal shocks resistance of the ZrO_2-8wt%Y_2O_3(YSZ) and CeO_2/ZrO_2-8wt%Y_2O_3(CYZ) coatings were tested at 900℃,1100℃and 1300℃.The oxidation resistance testing of coatings were tested at 1050℃for 100h.The results show that the nano-powder by agglomerated treatment is porous spherical.The phase compositons of the nano-CYZ coating are relatively stable t phase(t-ZrO_2, t-Zr_(0.82)Y_(0.81)O_(1.91),t-Zr_(0.82)Ce_(0.18)O_2) and c phase(c-CeO_2).The average grain size of the CYZ coating is about 45nm. The nanostnictured CeO_2/ZrO_2-Y_2O_3 coating exhibit higher thermal-shock and oxidation resistances than those of the nano-YSZ coating.