Versagensmechanismen eines Modellsystems von Wärmedämmschichten (Failure mechanisms of a model system of thermal insulation layers)

In the present work the failure mechanisms of thermal barrier coating systems are examined. These layer systems are used on highly stressed components in gas turbines to protect the substrate materials. The failure mechanisms of the thermal barrier coating systems could not be fully elucidated due to the complex interactions of different phenomena (e.g. creep, sintering, differential thermal expansion, diffusion and oxidation processes). For this reason, a simplified model system is presented, which offers the possibility to investigate two essential aspects of layer failure, the influence of the creep properties and the interface roughness.

In the present work finite element simulations of the model system are varied on the micro and mesoscale according to experimental test series. The crack initiation and the crack propagation are analyzed, from which a failure scenario of the model system is derived