Water vapor corrosion behavior and failure mechanism of air sprayed bi-layer Yb_(2)Si_(2)O_(7)/SiC and tri-layer Yb_(2)Si_(2)O_(7)/(SiCw-Mullite)/SiC environmental barrier coating  

作　　者：Pengju Chen Peng Xiao Zhuan Li Yichen Wang Xian Tang Yang Li 

机构地区：[1]School of Nuclear Science and Technology,University of South China,Hengyang 421001,China [2]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [3]National Key Laboratory of Science and Technology on High-strength Structural Materials,Central South University,Changsha 410083,China [4]School of Engineering and Materials Science,Queen Mary University of London,London E14NS,UK

出　　处：《Advanced Powder Materials》2023年第1期15-24,共10页先进粉体材料（英文）

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)。

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%.

关 键 词：Yb_(2)Si_(2)O_(7)/SM/SiC EBCs Water Corrosion Mechanism 

分 类 号：TG1[金属学及工艺—金属学]