摘要
稀土硅酸盐环境障涂层(EBCs)是应用于新一代高推重比航空发动机热端部件的重要材料,但在服役过程中,稀土硅酸盐面层易产生纵向裂纹,为腐蚀性介质进入EBCs体系内部提供通道,使硅黏结层发生氧化并产生裂纹,最终导致EBCs失效。二硅化钼(MoSi_(2))具有优异的高温性能,有望改善稀土硅酸盐EBCs体系的高温稳定性。本工作采用MoSi_(2)改性Yb_(2)SiO_(5)面层,通过真空等离子喷涂技术(VPS)分别制备了以Yb2SiO5、Yb_(2)SiO_(5)-5%MoSi_(2)(体积分数,下同)和Yb_(2)SiO_(5)-10%MoSi_(2)作为面层,以Yb_(2)Si_(2)O_(7)作为中间层,以Si作为黏结层的三种环境障涂层体系,利用场发射扫描电子显微镜表征了涂层在1350℃热震前后的形貌变化。结果表明:掺杂MoSi_(2)不仅能改善涂层的损伤容限,还可消耗氧化性介质,减少其向涂层体系内部的扩散,使黏结层上TGO层厚度分别降低83%和88%,从而有效改善涂层体系的高温稳定性。
Rare-earth silicate environmental barrier coatings(EBCs)are important materials for the application in hot end components of new generation high thrust-to-weight ratio aero engines.However,the rare-earth silicate top layer is prone to form longitudinal cracks,which provides a channel for corrosive media to enter the interior of the EBC system,causing oxidation and cracking of the silicon bond layer,ultimately leads to the failure of EBCs under high temperature service environment.MoSi2 has excellent high-temperature properties and is expected to improve the high-temperature stability of rare-earth silicate EBC systems.In this work,three kinds of EBCs with Yb_(2)SiO_(5),Yb_(2)SiO_(5)-5%MoSi_(2)(Volume fraction,the same below)and Yb2SiO5-10%MoSi_(2) as the top layer,Yb_(2)Si_(2)O_(7) as the intermediate layer and Si as the binder layer were prepared by vacuum plasma spraying(VPS)technique respectively.The morphological changes of the coating before and after thermal shock at 1350℃were characterized by field emission scanning electron microscopy.The doping of MoSi_(2) not only improves the damage tolerance of the Yb_(2)SiO_(5) coating,but also consumes the oxidizing medium and reduces its diffusion into the interior of the coating system,which reduces the thickness of the TGO layer on the bonded layer by 83% and 88% and effectively improves the high-temperature stability of the coating system.
作者
梁锐辉
钟鑫
洪督
黄利平
吴一鸣
赵芳霞
牛亚然
张振忠
郑学斌
LIANG Ruihui;ZHONG Xin;HONG Du;HUANG Liping;WU Yiming;ZHAO Fangxia;NIU Yaran;ZHANG Zhenzhong;ZHENG Xuebin(Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;College of Materials Science and Engineering,Nanjing Tech University,Nanjing 211816,China)
出处
《航空材料学报》
CAS
CSCD
北大核心
2023年第4期37-44,共8页
Journal of Aeronautical Materials
基金
国家自然科学基金(52202075)
上海市科学技术委员会科学基金(20ZR1465700)。
关键词
环境障碍涂层
硅酸镱
MoSi_(2)
热震
真空等离子喷涂
environmental barrier coatings
ytterbium silicate
MoSi_(2)
thermal shock
vacuum plasma spraying
