Crack propagation modeling on the interfaces of thermal barrier coating system with different thickness of the oxide layer and different interface morphologies

A finite element model (FEM) is developed to simulate the crack development in a typical plasma sprayed thermal barrier coatings system in consequence of the stresses induced by thermal cycling, the growth of the oxide layer and different interface morphologies. The thermo-mechanical model is designed to takes into account a non-homogenous temperature distribution and the effects of the residual stress generated during coating process. Crack propagation at the top-coat/oxide and oxide/bond-coat interfaces is simulated thanks to the contact tool “Debond” present in the ABAQUS finite element code. Simulations are performed with a geometry corresponding to identical or dissimilar amplitude of asperity and for different thickness of oxide layer. The results show a significant difference between the case with and without presence of crack propagation and an important damage on the interfaces due to the growth of the oxide layer very close to the height of the interface asperities.