Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 2021

Идентификатор DOI: 10.1016/j.engfailanal.2021.105320

Ключевые слова: failure mechanisms, fem, interface, ni-based superalloy, tbc system

Аннотация: In the present work, microstructural analysis and finite element modelling are employed to study interface cracking behaviour in a thermal barrier coating (TBC) on a single-crystal Ni-based superalloy. The cohesive zone elements are implemented in the model to simulate interfacial debonding between the top-coat (TC), thermally grown oxide (TGO) and bond-coat (BC). To evaluate the effect of the interface geometry on the residual stress state and cracking behaviour, two units of the TGO profile are analysed: a regular sinusoidal undulation with constant thickness and an irregular (unevenly thick) TGO layer with symmetrical penetrations into the TC and BC layers. It has been found that the morphology of the TGO layer influences not only the magnitude and distribution of residual stresses but also governs the mechanisms of interfacial failure. For the regular TGO shape, the debonding cracks form at the peak of TGO/BC interface and at the valley of TC/TGO interface. Whereas only the TC/TGO interfacial debonding is observed in case of the irregular TGO profile. The debondings induce the stress redistribution in TBC layers that depends on which interface and to what extent is damaged. The TBC system with the regular TGO layer appears to be a more prone to interface failure than that one with the irregular TGO shape. However, much higher compressive stresses in the TGO layer are observed in the latter case. Possible scenarios of the TBC failure in terms of further cracks propagation are discussed. © 2021 Elsevier Ltd

Журнал: Engineering Failure Analysis

Выпуск журнала: Vol. 123

Номера страниц: 105320

ISSN журнала: 13506307

Издатель: Elsevier Ltd

• Burov Andrey (Fed Res Ctr Informat & Computat Technol, Krasnoyarsk Branch, Krasnoyarsk 660049, Russia)
• Fedorova Elena (Fed Res Ctr Informat & Computat Technol, Krasnoyarsk Branch, Krasnoyarsk 660049, Russia; Siberian Fed Univ, Polytech Inst, Krasnoyarsk 660041, Russia)

• Scopus
• Web of Science Core Collection
• Ядро РИНЦ (eLIBRARY.RU)