Study on High-Temperature Properties of (La0.5Eu0.25Y0.25)2Zr2O7 Ceramic Coating

In this work, rare-earth elements Eu and Y were added to La 2 Zr 2 O 7 (LZ) as doping elements, and the ceramic coating of (La 0.5 Eu 0.25 Y 0.25 ) 2 Zr 2 O 7 (LEYZ) was prepared. The evolution of the sintering resistance, thermal shock resistance, and thermal insulation properties of the multi-element rare-earth co-doped modified coatings under long-term and high-temperature conditions was studied. The results showed that the sintering resistance of the doped coating was significantly improved, and the coating still does not fall off after 200 h at 1100 °C. The thermal shock life of the coating at 1000 °C is increased by 47% compared with that of the undoped modified LZ coating. The length of the vertical cracks in LEYZ ceramic layer is obviously shorter than that in LZ coating, which will be more beneficial to preventing the coating from peeling off. Compared with LZ coating, the insulation temperature of the LEYZ ceramic coating is increased by 24, 26 and 34% in the range of 900 ~ 1100 °C, respectively. The coating has the best thermal insulation effect, which is consistent with theoretical calculation results. The results demonstrate that the modified lanthanum zirconate coatings doped with Europium and Yttrium has great potential in high-temperature performance.