Fatigue and fracture behavior of ceramic thermal barrier coating systems applied on Ni-based super alloys

Abstract

Ceramic thermal barrier coatings are used for thermal protection of components, which are heated on one side and cooled at the back side. One common application is on gas turbine blades made from nickel based super alloys. The coated components are subjected to thermal and mechanical fatigue with typical material temperatures up to 1200°C at the heated and about 900°C at the cooled surface under quasi-stationary conditions. Thus, the service conditions are complex and it is difficult to perform realistic and meaningful laboratory experiments for evaluation of damage behavior of the coating systems. In the manuscript a short overview over testing and evaluation methods will be given. Strategies, how to achieve data for lifetime prognosis of TBS-systems used for airfoils in gas turbines are discussed by means of examples the authors are working on.