...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Key Engineering Materials >Modelling of Crack Growth Near the Metallic-Ceramic Interface During Thermal Cycling of Air Plasma Sprayed Thermal Barrier Coatings
【24h】

Modelling of Crack Growth Near the Metallic-Ceramic Interface During Thermal Cycling of Air Plasma Sprayed Thermal Barrier Coatings

机译：空气等离子体喷涂热障涂层热循环过程中金属-陶瓷界面附近裂纹扩展的建模

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The lifetime under thermal cycling of a system consisting of an air plasma sprayed thermal barrier coating (TBC) deposited on a metallic bondcoat (BC) is determined by the sub-critical growth of micro-cracks near the interface between both coatings. This growth mainly occurs during the cooling down phase, as shown by the acoustic emission monitoring during the thermal cycling. The factors controlling the stress level leading to the crack growth are the local curvature of the metallic-ceramic interface, the growth of an oxide scale (TGO) at such interface and the sintering of the TBC, the two last processes occurring during the high temperature cycle phase. Implementing all these factors, a model based on Finite Element Method (FEM) calculations is presented where growing cracks are incorporated by assigning soft properties to the FEM cells occupied by the cracks. Determining the growth direction for the maximum energy release rate at every cooling down step, the current crack extension during the cycling is tracked until it reaches a characteristic length corresponding to the TBC failure. The influence by the metallic-ceramic interface roughness and by the temperature gradient across the TBC is discussed.
机译：由沉积在金属粘结层（BC）上的空气等离子喷涂热障涂层（TBC）组成的系统在热循环下的寿命由两个涂层之间界面附近微裂纹的亚临界生长决定。这种增长主要发生在冷却阶段，如热循环过程中的声发射监测所示。控制导致裂纹扩展的应力水平的因素是金属-陶瓷界面的局部曲率，该界面处的氧化皮（TGO）的生长以及TBC的烧结，这是高温期间的最后两个过程循环阶段。实现所有这些因素后，提出了一个基于有限元方法（FEM）计算的模型，其中通过为裂缝所占的FEM单元分配软属性来合并正在扩展的裂缝。在每个冷却步骤中确定最大能量释放速率的增长方向，跟踪循环过程中的当前裂纹扩展，直到达到对应于TBC失效的特征长度。讨论了金属陶瓷界面粗糙度和整个TBC上温度梯度的影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号