Thermomechanical fatigue life of a TBC-comparison of computed and measured behaviour of delamination cracks
Abstract Thermal barrier coatings (TBCs) are used in hot parts of gas-turbine engines in order to increase gas temperatures and improve thermal efficiency.A TBC consists of a metallic bond coat (BC) and a ceramic top coat (TC).During high-temperature service,thermally grown oxide will form in the BC/TC interface.This together with the general difference in mechanical and thermal expansion properties leads to a tendency of spalling damage,by which areas of the coating will flake off during thermomechanical cycling.The modelling of this damage process is rather difficult,but the authors have managed to set up a fracture-mechanically based model,which takes thermal cycling,mechanical cycling and oxide growth into account.The model has been tested and verified under controlled laboratory conditions,using thermal cycling furnaces and continuous inspection of damage development.It has also been used in an FEM computation environment for prediction of TBC spalling in real gas-turbine components.In this article,the model is described,computations are shown of the development of a typical delamination crack in the BC/TC interface,and the computed results are compared with actual delamination crack behaviour seen in the corresponding testing.
TBC fracture-mechanical model experimental FEM interface crack
S(o)ren Sj(o)str(o)m H(a)kan Brodin Magnus Jinnestrand
Department of Management and Engineering,Link(o)ping University,SE-58183 Link(o)ping,Sweden Department of Management and Engineering,Link(o)ping University,SE-58183 Link(o)ping,Sweden;Siemens
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）