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2195 |
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Tuesday, May 04, 2010, Sophia Room 5:00 PM Gas Turbines 2 |
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Challenges for plasma spray deposition of decomposition prone perovskite coatings |
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Maria Ophelia Jarligo* / Institut für Energie- und Klimaforschung IEK-1, Forschungszentrum Jülich GmbH, Germany Georg Mauer/ Institut für Energieforschung (IEF-1), Forschungszentrum Jülich GmbH, Germany Daniel Mack/ Institut für Energieforschung (IEF-1), Forschungszentrum Jülich GmbH, Germany Robert Vaßen/ Institut für Energieforschung (IEF-1), Forschungszentrum Jülich GmbH, Germany Detlev Stöver/ Institut für Energieforschung (IEF-1), Forschungszentrum Jülich GmbH, Germany |
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Processing of powder feedstock materials often influences the deposition behavior and ultimately, the properties of the atmospheric plasma spray (APS) deposited coatings. The necessity of materials design and the control of deposition parameters are therefore, of high importance. Feedstocks from promising ceramic thermal barrier coating materials with Ba(Mg1/3Ta2/3)O3 and La(Al1/4Mg1/2T1/4)O3 perovskite structures (thermal conductivity ~ 2 W/m-K and coefficient of thermal expansion~11x10-6 /K at 1473 K) were prepared through solid state and conventional spray drying techniques. The powders were then deposited on metallic substrates by APS process. Monitoring of in-flight particle characteristics and splat formation as well as characterization of deposited coatings, were conducted. It was found that these types of perovskite materials tend to loose constituents during deposition by atmospheric plasma spraying. This paper reports on the challenges of powder feedstock design and the control of critical deposition parameters to prevent or minimize the non-stoichiometric deposition of decomposition-prone perovskite coatings by APS process. |