Abstract
The oxidation behavior of the titanium aluminides Ti-50Al and Ti-48Al-5Nb has been investigated in Ar+20%O2 and in air at 900°C. Thermogravimetric studies in combination with structural analyses using optical metallography, SEM/EDX and X-ray diffraction show a marked influence of nitrogen on the composition and growth rate of the oxide scales. For a more detailed study concerning the effect of nitrogen on the scale-growth kinetics, thermogravimetrical analyses were carried out during which the gas atmosphere was changed from air to Ar−O2, and vice versa, without intermediate cooling of the specimen. The results show, that nitrogen adversely affects the formation of the initially formed alumina scale and that it enhances the growth rate of the rapidly growing Ti-rich oxide. This effect was observed in both alloys investigated, although the thermogravimetric results at first sight indicated an opposite effect for the Nb-containing alloy. This apparent contradiction is caused by internal oxidation which occurs in this alloy during exposure in Ar−O2.
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References
M. Yamaguchi,High Temperature Intermetallics, 30 April-1 May 1991 (Proceedings, The Royal Society, London), p. 15.
A. Rahmel and P. J. Spencer,Oxid. Met. 35, 53 (1991).
S. M. L. Sastry and H. A. Lipsitt,Proc. 4th Int. Conf. Titanium, H. Kimura and O. Izumi, eds. (Kyoto, 1980), p. 1231.
N. S. Choudhury, H. C. Graham, and J. W. Hinze,Properties of High Temperature Alloys, Z. A. Foroulis and F. S. Pettit, eds. (The Electrochemical Society, 1976), p. 668.
G. H. Meier, F. S. Pettit, and S. Hu,High Temperature Corrosion (Les Embiez, France, 1992),Proc. J. Phys. IV3, 395 (1993).
S. Becker, A. Rahmel, M. Schorr, and M. Schütze,Oxid. Met. 38, 425 (1992).
J. Rakowski, D. Monccau, F. S. Pettit, and G. H. Meier,Proc. 2nd Int. Conf. Microscopy of Oxidation, S. B. Newcomb and M. J. Bennett, eds. (Institute of Metals, London), p. 476.
A. Gil, H. Hoven, E. Wallura, and W. J. Quadakkers,Corros. Sci. 34(4), 615 (1993).
U. Figge, A. Elschner, N. Zheng, H. Schuster, and W. J. Quadakkers, Arbeitstagung “Angewandte Oberflächenanalytik”, 22–25 June 1992, Jülich, FRG, Proceedings inFresenius J. Anal. Chem. 346, 75 (1993).
W. J. Quadakkers, A. Elschner, N. Zheng, H. Schuster, and H. Nickel,2nd Int. Conf. Microscopy of Oxidation, M. Bennett and S. Newcomb, eds. (The Institute of Materials, London), p. 488.
A. Kästner, XTEM Untersuchungen an oxidierten Titan-Aluminiden, Diploma thesis, University Hamburg, FRG, 1992.
B. K. Kad and B. F. Oliver,Scripta Metall. Mater.,26, 1809 (1992).
S. R. Shuon and A. P. Druschitz,J. Met.,May, 36 (1987).
R. W. Beye and R. Gronsky,Acta Metall. Mater. 42, 1373 (1994).
A. Rahmel, W. J. Quadakkers, and M. Schütze,Materials and Corrosion 46, 271 (1995).
X. L. Li, R. Hillel, F. Teyssandier, S. K. Choi, and F. J. van Loo,Acta Metall. Mater. 40, 3149 (1992).
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Zheng, N., Quadakkers, W.J., Gil, A. et al. Studies concerning the effect of nitrogen on the oxidation behavior of TiAl-based intermetallics at 900°C. Oxid Met 44, 477–499 (1995). https://doi.org/10.1007/BF01051039
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DOI: https://doi.org/10.1007/BF01051039