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3950 |
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Wednesday, May 21, 2014, Hall H3 2:00 PM Power Generation - Industrial Gas Turbines 1 |
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Engineered multi-layered thermal barrier coatings for enhanced durability |
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Vaishak Viswanathan / Stony Brook University, NY Gopal Dwivedi / Stony Brook University, USA Michael Flynn/ Stony Brook University, USA Michael Miller/ Stony Brook University, USA Sanjay Sampath*/ Stony Brook University, USA |
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The durability of plasma sprayed thermal barrier coatings has been of significant interest ever since their inception in gas turbine engine components. Although several novel materials are being developed, 7-8 % YSZ continues to serve as the industry standard. One of the major reasons being the penalty of lower fracture toughness that is associated with these novel TBC materials. While toughness is an essential component in determining the spallation life of coatings, the elastic energy present in the coating is almost equally critical. Since the failure of typical APS coatings occur at the interface of the bond coat and topcoat due to the strains associated with TGO growth, the toughness is most critical at that particular interface. We experimentally demonstrate that by functionally optimizing the location specific needs of toughness and modulus via a multi layered TBC architecture, the furnace cyclic life of coatings can be significantly improved. Thus by leveraging the benefits of process science we present a durability strategy for APS YSZ coatings. |