CeO_2-Y_2O_3-ZrO_2热障涂层的组织结构及隔热性能

Microstructures and Thermal Insulation Capability of CeO_2-Y_2O_3-ZrO_2 Thermal Barrier Coatings

为获得孔隙率高、隔热性能好的热障涂层CeO2-Y2O3-ZrO2(CYSZ),采用低温超音速火焰喷涂(LT-HVOF)和大气等离子喷涂(APS)工艺在K4169镍基高温合金表面分别沉积NiCoCrAlYTa粘结层和CeO2、Y2O3共同稳定的ZrO2空心粉CYSZ陶瓷层。通过扫描电子显微镜(SEM)和X射线衍射仪(XRD)对不同喷涂电流(500,600和700A)制备的CYSZ热障涂层和采用传统Y2O3稳定的ZrO2团聚粉7YSZ为陶瓷面层的热障涂层的组织结构进行观察分析,并测定其隔热性能。结果表明:与传统的7YSZ类似,CYSZ涂层主要组成相为四方t相,涂层呈典型层状结构,但相对于7YSZ,空心粉CYSZ涂层存在更多孔隙和微裂纹;在1 150℃时,随着喷涂电流的增大,隔热性能呈降低趋势,CYSZ涂层隔热性能比传统7YSZ涂层隔热性能好。

To obtain CeO2-Y2 O3-ZrO2 thermal barrier coatings with more pores and better thermal insulation capability, this research prepared NiCoCrA1YTa alloy bonding coatings on the K4169 superalloy surface by low temperature high velocity oxygen fuel （LT-HVOF） and hollow powders ceria-yttria stabilized zirconia （CYSZ） top coatings by an atmos- pheric plasma spray （APS） process. The thermal barrier coatings with more pores and great thermal insulation capability were deposited by the APS process using hollow powders CYSZ. The morphology and microstructures of CYSZ coatings sprayed by different currents （500, 600, and 700 A） were characterized using SEM and XRD. Thermal insulation properties of the CYSZ coatings and traditional agglomerated powders yttria stabilized zirconia 7YSZ coatings sprayed by different currents were examined. The results show that similar to traditional 7YSZ coatings, a relatively stable t-phase （t- ZrO2 ） formed in CYSZ coatings. The CYSZ coatings show a typical lamellar structure with more closed pores and microc- racks. Moreover, at the temperature of 1 150℃, the thermal insulation property performs worse with the sprayed current increasing, and accordingly, the thermal insulation property of CYSZ coatings are better than 7YSZ coatings.