LI Renwei ¹, GONG Wenbiao ²
(1. Engineering Training Center, Northeast Dianli University, Jilin 132012, Jilin, China; 2. Key Laboratory of Advanced Structural
Materials of Ministry of Education, Changchun University of Technology, Changchun 130012, Jilin, China)

Abstract: The nanosized 8%Y₂O₃-ZrO₂ (YSZ) was used to prepare a thermal barrier coating material on GH₃0 superalloy surface by air plasma spraying. The failing process of coating was followed during the thermal shock test at 900 ℃. Meanwhile, the microstructures, phase stability and cross-section of the failed coatings were analyzed by FESEM, EDS and XRD. The results showed that with the increase of the number of thermal shock test cycles, the grain size of the ceramic coating grew obviously, and there was less phase transformation from t-ZrO₂ to m-ZrO₂ of coating. A large amount of thermally grown oxide (TGO) was found between ceramic layer and bond layer.
Key words:  nanostructured 8%ZrO₂-Y2O₃; thermal barrier coating; grain growth; TGO; failure mechanism