等离子喷涂CeO2改性La2Zr2O7纳米热障涂层高温性能研究

研究了不同Ce掺杂量对La2Zr2O7相结构稳定性的影响,确定了Ce原子掺杂量为5.45％的CeO2改性La2Zr2O7涂层（CLZ）.研究了采用大气等离子喷涂制备的涂层与原始粉末化学成分计量比偏离情况.经共沉淀制粉、喷雾干燥团聚造粒、大气等离子喷涂制备了Ce原子掺杂量为5.45％的新型纳米CLZ热障涂层,研究了涂层的长期组织结构稳定性、抗热震性以及失效机制.结果表明,CLZ涂层具有良好的长期组织结构稳定性,涂层在1150℃下热震循环寿命达到26次.涂层失效主要以层状撕裂为主.陶瓷层和粘结层热膨胀不匹配、粘结层发生氧化可能是导致CLZ涂层热震失效的主要原因.

Study on High-temperature Properties of Nano-scaled CeO2 Modified La2Zr2O7 Thermal Barrier Coatings

The effects of Ce on the structural stability of La2Zr207 were studied. The CeO2 modified La2Zr207 coating with Ce doping amount of 5.45% （CLZ） was designed. The composition deviations between the coating and the powder were analysised. Then the nano-CLZ thermal barrier coatings were prepared through co- precipitation, spray drying and atmospheric plasma spraying processes. The structural stability of the coating after long-term thermal exposure, thermal shock resistance and failure mechanism were studied. The experimental results show that the CLZ coating has excellent long-term structural stability, and the cycle life reached 26 times in the thermal shock experiments at 1150 ℃ . The coating failure was mainly caused by lamellar tearing in the ceramic layer. The thermal expansion mismatch between ceramic layer and the bonding layer, bond coat oxidation may be responsible for the thermal shock failure of CLZ coating.