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2008 |
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Tuesday, May 04, 2010, Sophia Room 3:40 PM Gas Turbines 2 |
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On the oxidation behavior of a thermal barrier coating with cold gas dynamic spray CoNiCrAlY bond coat |
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Eric Irissou / National Research Council Canada
- Industrial Materials Institute, CANADA Weijie R. Chen/ National Research Council Canada/Institute for Aerospace Research, Canada Jean-Gabriel Legoux/ National Research Council Canada/Industrial Materials Institute, Canada Xijia Wu/ National Research Council Canada/Institute for Aerospace Research, Canada Basil R. Marple*/ National Research Council Canada/Industrial Materials Institute, Canada |
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Cold gas dynamic spray (CGDS) utilizes a supersonic gas jet to accelerate solid fine powders above a critical velocity at which particles impact, deform plastically, and bond to the substrate material in a low temperature, open-air environment. This process is intuitively promising for thermal barrier coating (TBC) bond coat deposition, because oxidation of the feedstock powders is not expected to occur at the deposition temperature. Therefore, in contrast to what is often observed with commonly employed thermal spray technologies such as air plasma spray, the bond coat composition is expected to be the same as the feedstock powders. This paper presents the oxidation behaviour of a TBC with CGDS-produced CoNiCrAlY bond coat, and compares it to the TBC with a commercial APS-CoNiCrAlY bond coat. Oxidation behaviour of the TBCs was evaluated by examining the microstructural evolution of the TBCs, growth kinetics of the thermally-grown-oxide (TGO) layers, as well as cracking behaviour during thermal exposure at 1050°C. |