Failure mechanisms of thermal barrier coatings for high temperature gas turbine components under cyclic thermal loading [Elektronische Ressource] / vorgelegt von Vitalii Postolenko

Failure Mechanisms of Thermal Barrier Coatings for High Temperature Gas Turbine Components under Cyclic Thermal Loading  Von der Fakultät für Georessourcen und Materialtechnik der Rheinisch -Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Ingenieurwissenschaften genehmigte Dissertation vorgelegt von Dipl.-Ing. Vitalii Postolenko aus Kiew, Ukraine Berichter: Univ.-Prof. Jochen M. Schneider, Ph.D. Univ.-Prof. Dr.-Ing. Lorenz Singheiser Tag der mündlichen Prüfung: 21. November 2008 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar Abstract The mechanical behavior of PYSZ TBCs, deposited by EB-PVD and APS techniques, has been studied under thermal cyclic and isothermal loading. Two types of bond coats were chosen for the different multilayer systems: a single phase (Ni,Pt)-aluminide and a NiCoCrAlY overlay layer in the case of the EB-PVD and APS TBC respectively. The degradation of APS TBCs, i.e. crack evolution and oxidation kinetics during isothermal and thermal cyclic loading were systematically monitored and analyzed by means of scanning electron microscopy. Finally the life time results were summarized and compared with similar experiments previously described in literature. It was found out that isothermal and cyclic oxidation result similar damage mechanisms and oxide growth kinetics.