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7404 |
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Thursday, May 05, 2022, Hall D 12:20 PM Industrial Gas Turbines |
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Optimization of segmented thermal barrier coatings (s-TBCs) for high temperature applications |
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Behiye Aybike Yalcinyüz* / Technische Universität Berlin, Germany Franz Kamutzki / TU Berlin / Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF), Fachgebiet Beschichtungstechnik, Germany Prof. Dr.-Ing. habil. Christian Rupprecht/ TU Berlin / Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF), Fachgebiet Beschichtungstechnik, Germany Dr.-Ing. Georg Thomas/ TU Berlin / Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF), Fachgebiet Beschichtungstechnik, Germany Prof. Dr. Aleksander Gurlo/ TU Berlin / Institut für Werkstoffwissenschaften und -technologien, Fachgebiet Keramische Werkstoffe, Germany Roy Patgunarajah/ Siemens Energy Global GmbH, Germany Alessandro Casu/ Siemens AG, Germany Christoffer Dama/ Siemens Energy Global GmbH, Germany |
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Hot section components of stationary gas turbines such as turbine blades are coated with thermal barrier coatings (TBCs) to increase the high thermal strain tolerance thereby the improvement of the performance for the gas turbines. TBCs represent high-performance ceramics and are mostly composed of yttria stabilized zirconia (YSZ) in order to fulfill the function of the thermal insulation. The microstructure of conventional TBCs should be porous to decrease the heat conduction. Besides porous TBCs, the recently developed vertically segmented thermal barrier coatings (s-TBCs) feature an outstanding thermal durability. In this work, process parameters development for atmospheric plasma spraying (APS) of s-TBCs are presented. Within the experiments, relevant process parameters such as spraying distance, powder feed rate, surface speed and pathway strategy have been optimized. The aim of this work is to achieve a combination of low internal residual stress and high adhesive tensile strength for s-TBCs. For the formation of vertical cracks, the heat input into the powder feedstock material and the substrate have to be controlled precisely. Additionally, the effect of pre- and post-heat treatment as well as mechanical treatment are discussed. Key Words: Segmented thermal barrier coatings (s-TBCs), Atmospheric plasma spraying (APS), Gas turbines, mechanical treatment, ceramic coatings |