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3834 |
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Friday, May 23, 2014, Hall H1 11:00 AM Corrosion Protection |
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UHTC by plasma spraying for oxidation protection: ZrB2-based coatings produced with different precursors |
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Charlotte Barre* / CEA Le Ripault, France Aurélie Quet / CEA Le Ripault, France Luc Bianchi/ CEA Le Ripault, France Anne Sauveroche/ Herakles Groupe SAFRAN, France |
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Due to the constant increase of working temperatures, the use of protection against oxidation for composite materials is a real need today in aerospace field. The coating which going to be used as a protection must be resistant to oxidation at very high temperatures (>2000°C), but it has also to be chemically and physically stable, and of course compatible with the covered substrate, particularly in terms of adhesion and thermal shock resistance. Considering all these points, refractory borides such as ZrB2 or HfB2, which belong to Ultra High Temperature Ceramics (UHTC), combined with silicon carbide or other elements, appear to be good candidates for aerospace applications. Dealing with the assumption that coating microstructure can significantly influence the kinetic of oxidation of the coatings, the aim of this work is to create ZrB2-based coatings using plasma spraying technology by varying these microstructures. Therefore, the nature of the precursor feedstock and the spraying conditions using both standard plasma spraying and SPS are studied. The morphology and the composition of coatings are investigated. Then, microstructures of the obtained deposit will be related to their behavior at very high temperatures under an oxidative atmosphere. |