摘要
为研究硅酸锆陶瓷作为航空发动机高温(>1200℃)热障/热防护涂层的可能性,采用大气等离子喷涂技术制备了硅酸锆涂层。用原位高温X射线衍射技术研究了涂层在25～1400℃循环升降温过程中的物相变化行为,以及分别在1000,1200℃和1400℃恒温不同时间后的物相转变;用扫描和透射电镜观察粉体及涂层的形貌。结果表明:硅酸锆粉体在等离子喷涂后分解成为四方相和单斜相的ZrO2以及非晶态的SiO2;由于ZrO2和SiO2两相界面上Si—O—Zr键的作用,涂层中的SiO2对ZrO2在高温下的相变产生了阻滞作用。在温度高于1200℃热处理后涂层中ZrO2和SiO2能够重新生成稳定的硅酸锆涂层。
In order to study the possibility of using ZrSiO4 as a thermal barrier coating or thermal protection coating at high temperatures （above 1 200 ℃）, ZrSiO4 coatings were fabricated by an atmosphere plasma spraying technique. The phase-transformation behavior of the coatings during temperature circulation from 25 ℃ to 1 400 ℃and isothermal phase-transformation process at 1 000, 1 200 ℃ and 1 400 ℃ for different time were investigated by the in-situ high-temperature X-ray diffraction method. The microstructures of ZrSiO4 powders and coatings were observed by scanning electronic microscopy and transmission electronic microscopy. The results show that ZrSiO4 was decomposed into t-ZrO2, m-ZrO2 and amorphous SiO2 during plasma spraying. The transformation from t-ZrO2 to m-ZrO2 during heat treatment is retarded due to the formation of strong Si-O-Zr bonds on the interface between ZrO2 and SiO2. It was also found that the decomposed ZrO2 and SiO2 can recombine rapidly into zircon at heat treatment temperatures above 1 200 ℃.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2008年第8期1103-1108,共6页
Journal of The Chinese Ceramic Society
关键词
等离子喷涂
硅酸锆
氧化锆
相变
plasma spraying
zircon silicate
zirconia
phase transformation
