Design of Ti_(2)AlC/YSZ TBCs for more efficient in resisting CMAS attack  

作　　者：Lei Guo Yanyan Li Guang Li 

机构地区：[1]School of Materials Science and Engineering,Tianjin University,Tianjin 300072,China [2]Tianjin Key Laboratory of Advanced Joining Technology,Key Lab of Advanced Ceramics and Machining Technology,Ministry of Education,Tianjin 300072,China [3]Shanghai Institute of Space Power-Sources,Shanghai 200240,China

出　　处：《Journal of Advanced Ceramics》2023年第9期1712-1730,共19页先进陶瓷（英文）

基　　金：sponsored by the National Natural Science Foundation of China(Grant No.51971156).

摘　　要：Ti_(2)AlC has been demonstrated as the promising protective layer material for thermal barrier coatings(TBCs)against calcium-magnesium-alumina-silicate(CMAS)attack.In this study,the reliability of Ti_(2)AlC coatings against the CMAS corrosion was explored,and new Ti_(2)AlC/YSZ TBCs more efficiently resistant to CMAS were designed.The fabricated Ti_(2)AlC coatings inevitably contain some impurity phases(TiC and Al2Ti3),the contents of which were minimized by optimizing the spraying distance.Corrosion tests revealed that Ti_(2)AlC/YSZ TBCs yielded higher resistance to the CMAS attack than YSZ TBCs,but with long-term exposure to CMAS,the Ti_(2)AlC protective coating exhibited microstructure degradation due to the presence of the impurity phases,which caused the formation of a layer mixed with Al_(2)O_(3)and TiO_(2)rather than a continuous compact Al_(2)O_(3)layer on the surface.Pre-oxidation schemes were designed in air or with a controlled oxygen partial pressure,which revealed that the pre-oxidation at an oxygen partial pressure of~630 Pa could promote a continuous Al_(2)O_(3)layer formed on the Ti_(2)AlC protective coating surface.Furthermore,a vacuum heat treatment at 867℃for 10 h before pre-oxidation was beneficial for the formation of the compact Al_(2)O_(3)layer.Through the above scheme design,new Ti_(2)AlC/YSZ TBCs were obtained,which had reduced impurity phase contents and a pre-oxide layer with an ideal structure on the surface.New TBCs exhibit higher microstructure stability exposed to CMAS and more efficient CMAS resistance.

关 键 词：thermal barrier coatings(TBCs) calcium-magnesium-alumina-silicate(CMAS) Ti_(2)AlC/YSZ pre-oxidation design corrosion resistance mechanisms 

分 类 号：V263[航空宇航科学与技术—航空宇航制造工程] TG174.4[金属学及工艺—金属表面处理]