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Internal surface protection of gas turbine blade by Si-aluminide coating / A. Firouzi in Materials and corrosion, Vol. 62 N° 7 (Juillet 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 7 (Juillet 2011) . - pp. 681–686 Titre : Internal surface protection of gas turbine blade by Si-aluminide coating Type de document : texte imprimé Auteurs : A. Firouzi, Auteur ; K. Shirvani, Auteur Année de publication : 2011 Article en page(s) : pp. 681–686 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aluminide  coating  Blade  Cooling  passages  Silicon  Slurry Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A laboratory-scale slurry silicoaluminizing process has been developed to apply coating into cooling passageways of a first-stage gas turbine blade. Analytical techniques for characterizing the coatings comprised optical microscopy, SEM, EDS, and XRD. The results of metallographic examinations demonstrated that acceptable coatings had been formed in almost all of the passageways. The amounts of Al and Si in the topcoat were found to be in the ranges of 24–26 wt% and 4.5–6 wt%, respectively. The heat treated coating consisted largely of β-NiAl phase as the coating matrix with uniform distribution of <2 µm-size precipitates. In addition, oxidation and hot corrosion performance of the coatings were investigated by cyclic exposure to 1100 °C and the furnace method using a mixture of sodium sulfate-40 wt% sodium vanadate-10 wt% sodium chloride at 780 °C, respectively. It was found that the presence of Si in the coating improves both oxidation and hot corrosion Type II properties. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005854/abstract [article] Internal surface protection of gas turbine blade by Si-aluminide coating [texte imprimé] / A. Firouzi, Auteur ; K. Shirvani, Auteur . - 2011 . - pp. 681–686. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 7 (Juillet 2011) . - pp. 681–686 Mots-clés : Aluminide  coating  Blade  Cooling  passages  Silicon  Slurry Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A laboratory-scale slurry silicoaluminizing process has been developed to apply coating into cooling passageways of a first-stage gas turbine blade. Analytical techniques for characterizing the coatings comprised optical microscopy, SEM, EDS, and XRD. The results of metallographic examinations demonstrated that acceptable coatings had been formed in almost all of the passageways. The amounts of Al and Si in the topcoat were found to be in the ranges of 24–26 wt% and 4.5–6 wt%, respectively. The heat treated coating consisted largely of β-NiAl phase as the coating matrix with uniform distribution of <2 µm-size precipitates. In addition, oxidation and hot corrosion performance of the coatings were investigated by cyclic exposure to 1100 °C and the furnace method using a mixture of sodium sulfate-40 wt% sodium vanadate-10 wt% sodium chloride at 780 °C, respectively. It was found that the presence of Si in the coating improves both oxidation and hot corrosion Type II properties. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005854/abstract