Influence of composition and processing on the oxidation behavior of MCrAlY-coatings for TBC applications [Elektronische Ressource] / vorgelegt von Juan Pablo Toscano Alvarez

Influence of Composition and Processing on the Oxidation Behavior of MCrAlY-coatings for TBC Applications Von der Fakultät für Maschinenwesen der Rheinisch-Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Ingenieurwissenschaften, genehmigte Dissertation vorgelegt von JUAN PABLO TOSCANO ALVAREZ aus Valencia, Venezuela Berichter: Univ.-Prof. L. Singheiser Univ.-Prof. T. Beck Tag der mündlichen Prüfung: 4. Juni 2008 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar. Summary The adherence of the thermally grown oxide (TGO) to the bond coat is recognized to be crucial for the lifetime of thermal barrier coatings (TBC) in aircraft engine and gas turbine blades. The stability of the system has to be guaranteed over extended service times (around 25000h) at high operation temperatures. With this aim, it is necessary that the TGO is slow-growing and adherent. This work studies the influence of different parameters in the oxidation behavior and scale adherence on MCrAlY-bond coats. For this purpose, three MCrAlY-coatings were selected and subjected to oxidation tests at high temperature in the form of TBC systems, overlay coatings and free-standing coatings. The first part of the work treats the influence of the chemical composition on the oxidation behavior of the bond coat.