期刊
CERAMICS INTERNATIONAL
卷 48, 期 17, 页码 25528-25537出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.ceramint.2022.05.232
关键词
Environmental barrier coatings; Water vapor attack; YbDS corrosion; Volume shrinkage; Porosity
资金
- Aero Engine Corporation of China Industry-University-Research Cooperation Project [HFZL2019CXY015]
This study investigates the stress characteristics of YbDS environmental barrier coatings (EBCs) under the coupling effect of YbDS corrosion and thermal cycling. The results emphasize the importance of corrosion-induced stress changes and the influence of volume shrinkage and increased porosity on the EBC stress field.
Ytterbium disilicate (Yb2Si2O7, YbDS), with good thermal matching ability, is a promising candidate for environmental barrier coatings (EBCs). Nevertheless, cracking and delamination of the YbDS topcoat may occur in a flowing steam environment due to the corrosion transformation from YbDS to ytterbium monosilicate (Yb2SiO5, YbMS). In this work, a scanning electron microscope (SEM)-based thermo-mechanical model, involving such corrosion transformation, is established to explore the stress characteristics in EBCs under the coupling effect of YbDS corrosion and thermal cycling. The main factors resulting in EBC failure during YbDS corrosion were also investigated. The results showed that compressive stress acted on the YbDS topcoat without a water vapor attack. However, the tensile stress occurred in the corroded YbDS coating after steam cycling. A large stress led to premature cracking of the EBC, thus providing channels for corrosive medium penetration. Volume shrinkage during YbDS corrosion dominated the stress magnitude in the corrosion zone. Furthermore, the increasing porosity caused a decrease in the Young's modulus and shrinkage strain of the corrosion zone, significantly affecting the EBC stress field. These findings not only enhance the comprehensive understanding of coupled stress characteristics in YbDS-EBCs, but also provide theoretical guidance for extending the EBC lifetime.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据