PS-PVD用CeO_(2)掺杂8YSZ团聚粉末及其涂层

Preparation of CeO_(2)-doped 8YSZ agglomerated powder for PS-PVD and its coating

在纳米ZrO_(2)-8%Y_(2)O_(3)(摩尔分数)(8YSZ)粉末中掺杂20%(质量分数)微米级CeO_(2)粉末,并通过喷雾干燥合成CeO_(2)-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Ce^(4+)取代Zr^(4+)进入ZrO_(2)晶格形成类质同象的固溶体结构,显示出CeO_(2)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。

CeO_(2)-8YSZ(CYSZ)composite agglomerated powder was synthesized by spray drying of 20%micron-scale CeO_(2) powder doped with nano-ZrO_(2)-8 mol%Y_(2)O_(3)(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 Ce^(4+)replaces Zr^(4+)and enters into the ZrO_(2) lattice to form a homogeneous solid solution structure,showing the inhibition of the transition from t-phase to m-phase by CeO_(2) doping.In addition,the prepared CYSZ coating remained intact after 100 cycles of water cooling at 1100°C,showing high thermal shock resistance.