The growth of thermally grown oxide (TGO) is often regarded as a key factor causing failures of thermal barrier coatings (TBCs) because it leads to thermal cycling and growth stresses. However, the delamination mechanism of TBCs induced by the growth process of TGO is still unclear. Here, a finite element method (FEM) considering both thermal cycling and growth stresses is developed. The accumulation of damage and crack nucleation, propagation, and coalescence are obtained using a phase field damage model. The results indicate that there is a critical TGO thickness of 8–10 μm, which may result in delamination of the TBCs. Both thermal cycling and growth stresses induce the premature failure of TBCs. The delamination mechanism induced by thermal cycling and growth stresses is obtained. When the interface roughness is A/L ≥ 1/4, the cracks pass through the TGO/TC interface and propagate in the TC layer. When the interface roughness is A/L ≤ 1/8, the cracks propagate along the vicinity of the TGO and will not pass through the TC/TGO interface. When the interface roughness is 1/8 < A/L less than 1/4, the cracks bifurcate at the vicinity of TGO interface, and one branch propagates in the TC and the other propagates along the vicinity of the TGO.

通常将热生长氧化物（TGO）的生长视为导致热障涂层（TBC）失效的关键因素，因为它会导致热循环和生长应力。然而，由TGO的生长过程引起的TBC的分层机制仍不清楚。在这里，开发了一种同时考虑热循环和生长应力的有限元方法（FEM）。使用相场损伤模型可以获得损伤的累积以及裂纹的成核，扩展和合并。结果表明，临界TGO厚度为8-10μm，这可能导致TBC分层。热循环和生长应力都会引起TBC的过早失效。获得了由热循环和生长应力引起的分层机理。界面粗糙度为A时/大号 ≥1/4，裂纹穿过TGO / TC接口和繁殖在TC层。当界面粗糙度甲/大号 ≤1/8，裂纹沿着TGO附近传播，并且不会通过TC / TGO接口。当界面粗糙度为1/8 <  A / L 小于1/4时，裂纹在TGO界面附近分叉，一个分支在TC中传播，另一个分支在TGO附近传播。