June 22-27, 2014
A lifing model has been developed based on lab testing to describe the time-temperature-dependence of TBC spallation. An extensive parameter study, using serial parts and coating processes, was done to investigate the affect of manufacturing scatter on TBC life as well as on thermal loading. The impacts of several parameters have been quantified. The transfer to part level has to consider the overall boundary conditions, i.e. increased TBC thickness will reduce on one hand the bondcoat temperature and the risk of spallation, but on the other hand, the increased thickness will increase the stresses within the TBC and the risk of spallation. The overall impact of TBC thickness can be positive or negative. It depends on the other parameters responsible for heat flux and temperatures.
Hans Peter Bossmann and Gregoire Witz, "Probabilistic lifetime prediction of TBC coated parts considering design, operation and manufacturing + Thermal barrier coatings ageing mechanisms in land-based gas turbines" in "Thermal Barrier Coatings IV", U. Schulz, German Aerospace Center; M. Maloney, Pratt & Whitney; R. Darolia, GE Aviation (retired) Eds, ECI Symposium Series, (2015). http://dc.engconfintl.org/thermal_barrier_iv/32