A Study of Hot Corrosion Behaviour of NiAl Coatings in an Aggressive Environment

Abstract:

The microstructure and corrosion behaviour was studied for a diffusion β-NiAl and Si modified β-NiAl coatings formed on the superalloy MAR-M 247. First type, β-NiAl coating was applied with the help of method “out-of-pack”. Second type, Si modified β-NiAl coating was applied by method “pack-cementation”. Diffusion coatings created protective, heat-activated layer which separated superalloy from aggressive environment. Corrosive environment was created by tablets Na₂SO₄ at 900°C. Technique of scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDS) was used to characterize the corrosion products. Experiment confirmed the advantages relating to the application of diffusion coating in aggressive environment which imitated environmental condition during operation of turbine engine. This experiment was made in cooperation with company PBS Velká Bíteš a. s., Velká Bíteš, Czech Republic and The Silesian University of Technology, Faculty of Materials Science and Metallurgy, Katowice, Poland.

• Periodical: Solid State Phenomena (Volume 226)
• Pages: 177-182
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.226.177
• Online since: January 2015
• Authors: Marta Kianicová, Jan Kafrik*
• Keywords: Diffusion Aluminide Coatings, Hot Corrosion, Out-of-Pack, Pack-Cementation, Superalloy

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