纳米氧化锆热障涂层高温性能演变研究

摘要

Nanostructured yttria-stabilized zirconia (YSZ) coatings were deposited by atmospheric plasma spraying method, and the microstructure and phase composition of coatings were analyzed by FESEM, XRD and Raman spectra techniques in order to research the evolution of high-temperature properties of coating. The microstructure results show that a special "nano-micro" double-state structure always kept in the nano YSZ coatings, and the grain size gradually increased along with the rise of working temperature and time but still maintained nano size. The results of phase composition show that the metastable tetragonal phase is the unique phase in nano YSZ coatings and doesn't change with the working environment. While the changes of raman peak shape and position revealed that the condition of high temperature made the structure defects of coating decrease and the phonon scattering depress, which caused the rise of thermal conductivity ofnano YSZ coatings.%采用大气等离子喷涂技术制备了纳米氧化锆热障涂层。利用FESEM、XRD和拉曼光谱开展了纳米氧化锆热障涂层的微观组织和物相组成的高温演变研究。微观组织分析结果表明，纳米氧化锆热障涂层始终保持着独特的“纳米-微米”双态结构，而其中纳米晶粒大小随着服役温度和服役时间的增加而增大，但仍保持纳米结构；物相分析结果表明，纳米氧化锆热障涂层主要由非平衡四方相组成，并不随服役环境的变化而变化；而拉曼峰形状及位置的变化则进一步揭示了高温服役环境会造成涂层组织缺陷减少和声子散射降低，从而导致热导率的上升。