期刊
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
卷 76, 期 4, 页码 -出版社
ASME
DOI: 10.1115/1.3086590
关键词
boundary layers; crack-edge stress field analysis; delamination; heat transfer; thermal barrier coatings; yttrium compounds; zirconium compounds
类别
Delamination of coatings initiated by small cracks paralleling the free surface is investigated under conditions of high thermal flux associated with a through-thickness temperature gradient. A crack disrupts the heat flow thereby inducing crack tip stress intensities that can become critical. A complete parametric dependence of the energy release rate and mode mix is presented in terms of the ratio of the crack length to its depth below the surface and coefficients characterizing heat transfer across the crack and across the gaseous boundary layer between the surface and the hot gas. Proximity to the surface elevates the local temperature, which in turn, may significantly increase the crack driving force. A detailed assessment reveals that the energy release rates induced by high heat flux are capable of extending subsurface delaminations in thermal barrier coatings, but only when the modulus has been elevated by either calcium-magnesium-alumino-silicate (CMAS) penetration or sintering. Otherwise, the energy release rate remains well below the toughness.
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