Abstract
The early stages of TiAl oxidation at 900°C and 1000°C in air have been investigated by transmission electron microscopy (TEM). The investigations revealed that at the beginning of oxidation, i.e., after 4 min, TiO2 and Al2O3 grow in a preferential orientation on the γ-TiAl substrate. After 4 h of oxidation an oxide scale structure can already be found similar to that known from long-term oxidation. In addition, besides α-Al2O3, the formation of a second aluminum oxide phase and of titanium nitrides is observed. The processes at the metal-oxide interface of oxidation in the early stages, consisting of a repeated cycle of Al2O3 formation, Al2O3 dissolution, outward migration of Al through the scale, and reprecipitation of Al2O3 in the outer scale, are described by a model. The four stages observed in the kinetics of TiAl oxidation are explained on the basis of the results obtained and the structure of the oxide scale.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
G. H. Meier, D. Appolonia, R. H. Perkins, and K. T. Chiang, inOxidation of High Temperature Intermetallics (The Minerals, Metals and Materials Society, Warrendale, 1989), p. 185.
N. S. Choudhury, H. C. Graham, and J. W. Hinze, inProperties of High Temperature Alloys with Emphasis on Environmental Effects, Z. A. Foroulis and F. S. Pettit, eds. (The Electrochemical Society, Princeton, 1977), p. 668.
G. Welsch and A. J. Kahveci, inOxidation of High Temperature Intermetallics (The Minerals, Metals and Materials Society, Warrendale, 1989), p. 207.
S. Becker, A. Rahmel, M. Schorr, and M. Schütze,Oxid. Met. 38, 425 (1992).
Y. Shida and H. Anada,Corros. Sci. 35, 945 (1993).
R. A. Perkins and K. T. Chiang,Scripta Metall. 21, 1505 (1987).
A. Gil, H. Hoven, E. Wallura, and W. J. Quadakkers,Corros. Sci. 34, 615 (1993).
A. Rahmel, W. J. Quadakkers, and M. Schütze,Mater. Corros. 46, 271 (1995).
G. H. Meier, F. S. Pettit, and S. Hu,J. Phys. IV 3, 395 (1993).
U. Figge, A. Elschner, N. Zheng, H. Schuster, and W. J. Quadakkers,Fresenius J. Anal. Chem. 346, 75 (1993).
A. Strecker, U. Salzberger, and J. Mayer,Praktische Metall. 30, 482 (1993).
J. Doychak,J. Electron Microsc. Tech. 11, 180 (1989).
J. Doychak and M. Rühle,Oxid. Met. 31, 431 (1989).
I. Küppenbender and M. Schütze,Oxid. Met. 42, 109 (1994).
G. Thomas and M. J. Goringe,Transmission Electron Microscopy of Materials (Wiley, New York, 1979).
Joint Committee on Powder Diffraction Standards, Powder Diffraction Files.
P. Hirsch, A. Howie, R. B. Nicholson, D. W. Pashley, and M. J. Whelan,Electron Microscopy of Thin Crystals (Krieger, 1977).
J. W. Edington,Practical Electron Microscopy in Materials Science Vol.2: Electron Diffraction in the Electron Microscope (Macmillan, London, 1975).
U. Herold-Schmidt, B. Opolka, and S. Schwantes, Sonderband Praktische Metallographie,23 (1992).
E. U. Lee and J. Waldmann,Scripta Metall. 22, 1389 (1988).
W. T. Donlon and W. E. Dowling,Mat. Res. Soc. Proc. 288, 629 (1993).
W. E. Dowling and W. T. Donlon,Scripta Metall. Mater. 27, 1663 (1992).
A. Rahmel and P. J. Spencer,Oxid. Met. 35 (1991).
G. Welsch, S. L. Friedmann, and A. J. Kahveci, inMicroscopy of Oxidation, M. J. Bennett and G. W. Lorimer, eds. (The Institute of Metals, London), p. 193.
A. Petzold,Aluminiumoxid (Deutscher Verlag für Grundstoffindustrie, Leipzig, 1991).
G. Chen, Z. Sun, and X. Zhou,Corrosion 48, 939 (1992).
F. Dettenwanger, E. Schumann, M. Rühle, J. Rakowski, and G. H. Meier, Proc. MRS Fall Meeting, 1994.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lang, C., Schütze, M. TEM investigations of the early stages of TiAl oxidation. Oxid Met 46, 255–285 (1996). https://doi.org/10.1007/BF01050799
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01050799