CeO_2/ZrO_2-Y_2O_3纳米热障涂层高温熔盐腐蚀性能及失效机理

Molten salt corrosion resistance and failure mechanism of nanostructured CeO_2/ZrO_2-Y_2O_3 thermal barrier coating

采用两种热障涂层材料分别是纳米8%Y_2O3-ZrO_2(以下简称为YSZ)和在8%Y_2O_3-ZrO_2中掺杂25%的纳米CeO_2(以下简称为CSZ),应用大气等离子喷涂技术在GH30高温合金钢表面上制备了YSZ和CSZ隔热涂层,测试了两种涂层在950℃时耐Na_2SO4熔盐腐蚀的能力,使用SEM、XRD和EDS技术对涂层的失效机理进行了分析,结果表明:腐蚀60h后,YSZ涂层大面积脱落并且出现了t-ZrO_2→m-ZrO_2转变,而CSZ涂层基本无脱落,保持t-ZrO_2。CSZ阻止腐蚀介质进去涂层的能力强于YSZ,抗高温熔盐腐蚀性能优于YSZ。

Nanosized 8% Y2O3-Zr O2（ YSZ） and nanosized 8% Y2O3-Zr O2 doped with 25% of nanometer Ce O2（ CSZ） were used as two kinds of thermal barrier coating materials,and the YSZ and CSZ powders were deposited on GH30 superalloy surface using air plasma spraying（ APS）,respectively. Corrosion resistance of the coatings in molten Na2SO4 salt were tested at 950 ℃ for 60 h. The failure mechanism of the coatings was analyzed by SEM,XRD and EDS technique. The results show that large area spallation and the transformation from t-Zr O2 to m-Zr O2 occurr in the YSZ coating after corrosion for 60 h,however,less area spallation and no phase transformation of t-Zr O2 to m-Zr O2 is observed in the CSZ coating. Compared with the YSZ coating,CSZ coating has better ability to stop Na and S elements into the coating,and exhibits better corrosion resistance than YSZ coating.