Effect of sample rotation speed on microstructure and thermal cycling behaviour of (Gd0.8Yb0.2)2Zr2O7/YSZ dual-layer thermal barrier coatings prepared by EB-PVD

• Published in: Ceramics international Vol. 49; no. 9; pp. 13559 - 13569
• Main Authors: Wang, Bo, Jiang, Chengyang, Guo, Hongbo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2023
• Subjects: Degradation and failure; EB-PVD; Sample rotation speed; Thermal barrier coatings (TBCs); Thermal cycling test; EB-PVD; Sample rotation speed; Thermal cycling test; Thermal barrier coatings (TBCs); Degradation and failure
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2022.12.232

A (Gd0.8Yb0.2)2Zr2O7/YSZ double ceramic layer thermal barrier coating (TBC) system prepared by electron-beam physical vapor deposition (EB-PVD) is a promising choice for protecting hot-section parts of areo-plane gas-turbine engines at ultra-high temperature. The microstructure and further thermal cycling lifespan are strongly dependent on the EB-PVD process parameters (sample rotational speed, deposition temperature, chamber pressure, etc.). In the current study, three kinds of (Gd0.8Yb0.2)2Zr2O7/YSZ double ceramic layer TBCs were manufactured with different sample rotation speeds by EB-PVD. The thermal cycling behaviour of the three TBCs with different microstructures was investigated at 1150°C in comparison with the single YSZ-TBC. The results showed that TBCs prepared with low sample rotation speed were made of small and irregular columnar grains and exhibited the best thermal cycling behaviour among all the tested TBCs. The effect of sample rotation speed during deposition on microstructure and further thermal cycling behaviour, including crack evolution and TGO growth were discussed.