Microstructure and high-temperature oxidation behavior of plasma-sprayed Si/Yb2SiO5 environmental barrier coatings
| Autor: | Jingchen Li, Jie Xiao, Hongbo Guo, Xu Hui-Bin, Qiaomu Liu |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0209 industrial biotechnology
Materials science Silicon Annealing (metallurgy) Mechanical Engineering Aerospace Engineering chemistry.chemical_element Atmospheric-pressure plasma TL1-4050 02 engineering and technology engineering.material Ceramic matrix composite Microstructure 01 natural sciences Thermal expansion 010305 fluids & plasmas 020901 industrial engineering & automation Coating chemistry 0103 physical sciences engineering Composite material Eutectic system Motor vehicles. Aeronautics. Astronautics |
| Zdroj: | Chinese Journal of Aeronautics, Vol 32, Iss 8, Pp 1994-1999 (2019) |
| ISSN: | 1000-9361 |
| Popis: | An environmental barrier coating (EBC) consisting of a silicon bond coat and an Yb2SiO5 top-coat was sprayed on a carbon fibers reinforced SiC ceramic matrix composite (CMC) by atmospheric plasma spray (APS). The microstructure of the coating annealed at 1300 °C and its high-temperature oxidation behavior at 1350 °C were investigated. The significant mass loss of silica during the plasma spray process led to the formation of Yb2SiO5 and Yb2O3 binary phases in the top-coat. Eutectics of Yb2SiO5 and Yb2O3 were precipitated in the top-coat, and channel cracks were formed in the top-coat after 20 h annealing because of the mismatch between the coefficients of thermal expansion (CTEs) of Yb2SiO5 and the SiC substrate. The EBC effectively improved the oxidation resistance of the CMC substrate. The channel cracks in the Yb2SiO5 top-coat provided inward diffusion channels for oxygen and led to the formation of oxidation delamination cracks in the bond coat, finally resulting in spallation failure of the coating after 80 h oxidation. Keywords: Ceramic matrix composite (CMC), Environmental barrier coatings (EBCs), High-temperature oxidation, Plasma spray, Ytterbium silicate |
| Databáze: | OpenAIRE |
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