Thermal cycling is able to cause interface undulation and interface delamination in the MCrAlY coating system. A generalized plane strain finite element model was built in this work to analyze interface undulation and interface delamination. Increasing thermally grown oxide (TGO) thickness facilitates interface undulation. The possible reason for this is that increase in TGO thickness causes the TGO film to be subjected to larger bending moments. Nonetheless, interface undulation can be suppressed in the case of the existence of the top-coat. Simultaneously, the incorporation of the top-coat leads to an obvious reduction in the maximum tensile stresses within the bond-coat/TGO interface. Furthermore, whether the top-coat is incorporated into the coating system model or not, the bond-coat/TGO interface is subjected to compressive stresses, at its concave region and tensile stresses, at its convex region. Therefore, the convex region is thought to be the most likely place where cracks nucleate at the bond-coat/TGO interface. Additionally, the TGO thickness has a significant influence on the in-plane strain energy stored within the TGO film, and the in-plane strain energy is also thought to be one of the mechanisms for the interface delamination.

中文翻译：

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热循环下MCrAlY涂层系统界面起伏和界面分层的有限元分析：考虑氧化物厚度和面漆效应

热循环能够导致 MCrAlY 涂层系统中的界面起伏和界面分层。本文建立了广义平面应变有限元模型，对界面起伏和界面分层进行了分析。增加热生长氧化物 (TGO) 厚度有利于界面起伏。造成这种情况的可能原因是 TGO 厚度的增加导致 TGO 薄膜受到更大的弯矩。尽管如此，在存在面漆的情况下可以抑制界面起伏。同时，面漆的加入导致粘合层/TGO 界面内的最大拉伸应力明显降低。此外，无论面漆是否包含在涂层系统模型中，粘合层/TGO 界面都会受到压应力，在其凹区和拉伸应力，在其凸区。因此，凸面区域被认为是最有可能在粘合涂层/TGO 界面处产生裂纹的地方。此外，TGO 厚度对 TGO 薄膜中存储的面内应变能有显着影响，面内应变能也被认为是界面分层的机制之一。