摘要
To improve the corrosion resistance of Cf/SiC composites in a water vapor oxygen coupled environment,the bilayer Yb_(2)Si_(2)O_(7)/SiC and tri-layer Yb2Si2O7/(SiCw-Mullite,SM)/SiC environment barrier coatings were designed and prepared on the surface of Cf/SiC composites by chemical vapor deposition and sol-gel method united with air spraying.Results show that the mass loss of bi-layer Yb_(2)Si_(2)O_(7)/SiC coating coated samples was 17.24×10^(-3) g cm^(-2) after 200 h oxidation at 1673 K,and the average compression strength retention rate was only 79.44% due to the formation of wide penetrating cracks.Comparatively,SiC whiskers in SM middle coating can not only increase the crack propagation resistance of mullite middle coating,but also alleviate the difference of coefficient of thermal expansion between Yb_(2)Si_(2)O_(7) outer coating and mullite middle coating.Therefore,the mass loss of trilayer Yb_(2)Si_(2)O_(7)/SM/SiC coating coated samples was only 2.93×10^(-3) g cm^(-2) after 200 h oxidation at 1673 K,and the average compression strength retention rate was up to 98.79%.
基金
This work was funded by the National Natural Science Foundation of China(Grant No.52102122 and 52075555)
Natural Science Foundation of Hunan Province(Grant No.2021JJ10057 and Grant No.2020JJ4116)
the National Defense Basic Scientific Research Program of China(fund from National Key Laboratory of Science and Technology on Highstrength Structural Materials,Central South University,Changsha 410083,China)。
作者简介
Corresponding author:Zhuan Li,E-mail addresses:lizhuan@csu.edu.cn;Corresponding author:Yang Li,E-mail addresses:liyang_csu@126.com。
