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8010 |
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Monday, April 29, 2024, Blue 1 11:10 AM Aviation Industry I |
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A novel NiAl/hBN abradable coating for high-pressure compressor efficiency in aerospace gas turbine engines |
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Gregory Szyndelman* / Oerlikon Metco, Schweiz Scott Wilson / Oerlikon Metco AG, Switzerland |
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This paper introduces an innovative composite powder composed of hexagonal boron nitride encapsulated by a nickel-aluminum alloy (NiAl/hBN), specifically designed for use as an abradable coating material. The primary emphasis of this research lies in its potential application for clearance control purposes within the high-pressure compressor section of aerospace gas turbine engines. These engines, driven by the imperative for increased efficiency, require coatings that can function effectively under increased pressure conditions and elevated service temperatures up to 800°C. In response to this requirement, a NiAl/hBN abradable powder material has been developed. This coating material demonstrates exceptional resistance to oxidation and exhibits favorable abradability when in contact with Nickel superalloy blades at these elevated temperatures. The primary goal of these coatings is to reduce wear on the rotating components while simultaneously optimizing gas path efficiency by offering precise clearance control in critical seal areas. The NiAl/hBN coatings, discussed in this study, display remarkable resistance to oxidation, making them suitable for service temperatures ranging from 450°C to 800°C (840°F to 1470°F). The research findings highlight that NiAl/hBN coatings can be applied efficiently using atmospheric plasma spray technology, offering a good balance between resistance to oxidation, resistance to solid particle erosion, and abradability. These coatings can be easily cut by bare untipped nickel alloy blade components. In scenarios that demand harder and more erosion-resistant coatings, the study recommends employing hard-tipped mating blades to minimize the risk of blade damage resulting from contact with the coating. The NiAl/hBN coatings will be benchmarked against alternative solutions, such as CoNiCrAlY-hBN and NiCrAl-Bentonite abradable coatings, with the aim of comprehensively understanding the failure mechanisms and performance differentials. This research significantly contributes to the development of advanced materials and coatings for aerospace applications, with a particular focus on enhancing engine efficiency and prolonging the lifespan of engine components. |