Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7898465 | Journal of the European Ceramic Society | 2018 | 13 Pages |
Abstract
Long time oxidation protection at ultra-high temperatures or ablation protection has been a choke point for C/C composites. In this study, long time ablation protection of different-La2O3-content (5-30 vol.%) modified ZrC coating for SiC-coated carbon/carbon (C/C) composites was investigated. Results showed that ZrC coating with 15 vol.% La2O3 had good ablation resistance and could protect C/C composites for at least 700âs at 2160 °C. A high-thermal-stability and low-oxygen-diffusivity oxide scale containing m-ZrO2 particles and molten phases with La0.1Zr0.9O1.95 and La2Zr2O7 was formed during ablation, offering the ablation protection. La could erode grain boundaries of ZrO2 to refine ZrO2 by short-circuit diffusion and m-ZrO2 particles were retained due to less bulk diffusion than grain-boundary diffusion of La into ZrO2. The erosion resulted in the formation of molten phases containing fine nano-ZrO2, which served as viscous binder among m-ZrO2 particles and crack sealer for the oxide scale.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Yujun Jia, Hejun Li, Xiyuan Yao, Jiajia Sun, Zhigang Zhao,