Evaluation of delamination on thermal barrier coatings by stress measurement and addition of strengthening mechanism

热障涂层系统（TBC）已被广泛用于提高燃气涡轮机叶片和轮叶中的热段部件的操作温度。热障涂层通常由外层氧化物陶瓷涂层（TC）和内层金属间化合物粘结涂层（BC）组成，以保护镍基高温合金免受高温和氧化的影响。在使用过程中，TGO形成，并且这种形成增加了涂层的残余应力。TGO/BC界面由于残余应力的增加而发生分层，最终TC层从TBCs上剥落。本研究利用威尔金森方法计算局部应力分量，其中应力由EBSD图的畸变决定。此外，高韧性的热障涂层形成通过使用的应力耗散的BC层由于低屈服应力通过热处理。

Thermal barrier coating systems (TBCs) have been widely used to increase the operating temperature of hot section components in gas turbines blades and vanes. TBCs usually consists of outer oxide ceramics top coat (TC) layer and inner intermetallic bond coat (BC) layer in order to protect the Ni-base superalloy from high temperature and oxidation. During the service, TGO forms and this formation increases the residual stress of the coating. Delamination of TGO/BC interface occurs because of the increasing residual stress and finally TC layer spall off from the TBCs. In this research, local stress components were evaluated by Wilkinson method where the stresses were decided by the distortion of the EBSD pattern. Further, high toughened TBCs were formed by using the stress dissipation of the BC layer due to the low yield stress by heat treatment.