PS-PVD用CeO2掺杂8YSZ团聚粉末及其涂层

在纳米ZrO₂-8%Y₂O₃(摩尔分数)(8YSZ)粉末中掺杂20%(质量分数)微米级CeO₂粉末,并通过喷雾干燥合成CeO₂-8YSZ(CYSZ)复合团聚粉体。借助激光粒度仪和扫描电镜(SEM)及附带能谱仪(EDS)考察羧甲基纤维素黏结剂(carboxymethyl cellulose,CMC)质量分数对复合团聚粉体性能影响。采用PS-PVD制备具有柱状结构的CYSZ热障涂层,对涂层截面和表面进行EDS分析。采用X射线衍射(XRD)和X射线光电子能谱(XPS)分析涂层物相。结果表明:黏结剂质量分数达到2%时可获得球形度高、粒度分布均匀的团聚粉体;制备的涂层中Ce元素呈均匀分布;涂层物相基本为t-相结构,其中Ce⁴⁺取代Zr⁴⁺进入ZrO₂晶格形成类质同象的固溶体结构,显示出CeO₂掺杂对t-相向m-相转变的抑制作用;所制备CYSZ涂层在1100℃,水冷循环100次后仍保持完整,展现出较高的抗热冲击性能。

Preparation of CeO2-doped 8YSZ agglomerated powder for PS-PVD and its coating

CeO2-8YSZ (CYSZ) composite agglomerated powder was synthesized by spray drying of 20% micron-scale CeO2 powder doped with nano-ZrO2-8 mol% Y2O3 (8YSZ) powder. The effect of the binder (carboxymethyl cellulose, CMC) ratio on the properties of the composite agglomerated powder was investigated with the aid of a laser particle size tester, scanning electron microscopy (SEM) and incidental energy spectrometry (EDS). A CYSZ thermal barrier coating with a columnar structure was prepared by PS-PVD, and EDS analysis of the coating cross-section and surface was carried out. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyze the physical phases of the coating. The results show that agglomerated powder with high sphericity, good flowability and uniform particle size distribution can be obtained with a binder ratio of 2%, the prepared coating has a uniform distribution of Ce element, and the coating phase is basically a t-phase structure, in which Ce4+ replaces Zr4+ and enters into the ZrO2 lattice to form a homogeneous solid solution structure, showing the inhibition of the transition from t-phase to m-phase by CeO2 doping. In addition, the prepared CYSZ coating remained intact after 100 cycles of water cooling at 1100 °C, showing high thermal shock resistance.