| Abstract |
| In order to improve efficiency, performance and lifetime of hot components of gas turbine at high temperature, thermal barrier coating (TBC) systems on the superalloy are widely used. TBC systems mainly consist of superalloy substrate, MCrAlY bond coat(BC) and yttria stabilized zirconia top coat(TC). Thermally grown oxide (TGO), mainly α-Al2O3, is formed and grown at BC/TC interface during gas turbine operation and/or fabrication. Stable growth of TGO, especially α-Al2O3, is very important for the lifetime of TBC systems because the formation of α-Al2O3 at the interface increases the adherence of TBC and BC. In order to improve the high temperature stability of TBC systems, a small amount of Pt was added at the interface between BC and TBC. TBC systems, which were coated with only NiCoCrAlY (with or without a Pt layer) BC and both BC and TC (with or without a Pt layer) on Co-Base Superalloy ECY768, were prepared by air plasma spraying process (APS). Isothermal and cyclic oxidation tests were performed at 1100℃ in air, respectively. TBC systems with a Pt layer, showed the formation of more stable TGO and then longer lifetime than TBC systems without a Pt layer. We might conclude that the addition of a Pt layer in TBC systems, consisted with Cobased ECY768 substrate, NiCoCrAlY BC and YSZ was effective to enhance the durabilitsy of TBC system at high temperature. |
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| Key Words |
| thermal barrier coating, NiCoCrAlY, Pt, Air plasma spray, thermally grown oxide |
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