Abstract
A composite coating of aluminide-yttrium has shown excellent corrosion resistance in a cyclic high-temperature hot-corrosion environment. To understand the effect of yttrium on the stability of the composite coating, the specimens were prepared with various coating parameters of Y thickness, sequence of post heat treatment and surface condition before Y-ion plating. Performance of the composite coating was evaluated by isothermal oxidation and cyclic high-temperature hot corrosion. Isothermal-oxidation-test results show that the Y in the composite coating helps to form a thick and dense Al2O3 scale which is ductile and resistant to thermal stress. The Y in Al2O3 may act as a donor which leads to an increase in concentration of interstitial oxygen and, thus, increases in oxidation rate. The presence of Y2O3 and (Y, Al) O-type compounds in grain boundaries of Al2O3 and boundaries between the Al2O3 and NiAl effectively prohibits the fast diffusion of oxidants (such as O and S) and Al along grain boundaries. Consequently, it may induce slow diffusion through the matrix, and thus the corrosion resistance of the composite coating under cyclic hot corrosion increases substantially.
Similar content being viewed by others
References
E. Lang,The Role of Active Elements in the Oxidation Behavior of High Temperature Metals and Alloys (Elsevier, London, 1989).
W. E. King,The Reactive Element Effect on High Temperature Oxidation after Fifty Years. Materials Science Forum, Vol. 43 (Trasns Tech Pub., Switzerland, 1989).
S. Shankar, D. E. Koenig, and L. E. Dardi,J. Metallogr. 33, 13 (1981).
T. A. Taylor, M. P. Overs, B. J. Gill, and R. C. Tucker, Jr.,J. Vac. Sci. Technol. A 3, 2526 (1985).
R. Streiff, J. Stringer, R. C. Krutenat, and M. Caillet (ed.), Proc. 1st Int. Symp. High Temperature Corrosion of Materials and Coatings for Energy Systems and Turboengines, Univ. Provence, Marseille, France, 1986.
T. A. Ramanarayanan, M. Raghavan, and R. Petkovic-Luton,J. Electrochm. Soc. 131, 923 (1984).
D. C. Tu, C. C. Lin, S. J. Liao, and J. C. Chou,J. Vac. Sci. Technol. A 4, 2601 (1986).
A. Takei, A. Ishida, K. Nii, and M. Yamazaki, Proc. 9th ICMC, Toronto, 1984, p 86.
F. Wang, H. Lou, L. Bai, and W. Wu,Proc. 2nd Int. Symp. High Temperature Corrosion of Advanced Materials and Coatings, R. Streiff, J. Stringer, R. C. Krutenat and M. Caillet, eds. (Les Embiez, France, 1989), p. 87.
K. Y. Kim, J. H. Jun, and H. G. Jung, Oxid. Met.40, 321 (1993).
G. Beranger, F. Armanet, and M. Lambertin, in Ref. 1.).
J. E. Restall and C. Hayman, UK Patent GB 2167773A (1986).
G. Gauje and R. Morbioli, inHigh Temperature Protective Coatings (Atlanta, GA, 1983).
W. Sun, H. J. Lin, and M. Hon,Met. Trans. A 17, 215 (1986).
M. M. Al-Aiat and F. A. Kroger,J. Am. Ceram. Soc. 63, 280 (1980).
N. Birks and G. H. Meier,Introduction to High Temperature Oxidation of Metals (Edward Arnold, London, 1983), p. 107.
J. G. Smeggil,Mater. Sci. Eng. 87, 261 (1987).
J. C. Pivin, C. Roques-Carmes, J. Chaumont, and H. Bernas,Corros. Sci. 20, 947 (1980).
P. Choquet, C. Indrigo, and R. Mevrel,Mater. Sci. Eng. 88, 97 (1987).
W. Y. Wu, A. Rhamel, and R. Schorr,Oxid. Met. 22, 59 (1984).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kim, K.Y., Kim, S.H., Kwon, K.W. et al. Effect of yttrium on the stability of aluminide-yttrium composite coatings in a cyclic high-temperature hot-corrosion environment. Oxid Met 41, 179–201 (1994). https://doi.org/10.1007/BF01080780
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01080780