Abstract
The oxidation behaviour of γ-TiAl based alloys with different Nb contents (2–10 At.%) was investigated in air and in argon-20% oxygen at 900 °C using thermogravimetric analysis. The oxide scales were characterized by a combination of optical microscopy, SEM/EDX and X-ray diffraction analyses. Although in all studied cases the presence of niobium improves the oxidation resistance of γ-TiAl, the oxidation kinetics, scale morphology and composition in air differed strongly from that in argon-oxygen. In air the oxidation resistance increases with increasing niobium-content. In Ar/O2 the niobium dependence is far more complex because internal oxidation occurs which is favoured by the presence of niobium. SNMS analysis revealed that the differences in behaviour in the two atmospheres are related to the formation of Ti-rich nitride at the scale/alloy interface during air oxidation. The positive effect of niobium on the oxidation resistance of γ-TiAl is mainly caused by a decrease of the transport processes in the heterogeneous TiO2/Al2O3-surface scale. Nitride formation and/or niobium enrichment at the scale/alloy interface also affect the oxidation behaviour, however these factors are believed to be the result of the decreased transport processes rather than the main reason for the niobium effect.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
M. Yamaguchi, in:Proceedings High Temperature Intermetallics, London, 30 April–1 May 1991, The Royal Society, p. 15.
A. K. Misra,Metal. Trans. 1991,22A, 715.
M. Khobaib, F. Vahldiek,2nd Int. SAMPE Metals Conference, Dayton, Ohio, Society for the Advancement of Materials and Process Eng., August 2–4, 1988, Proc. p. 262.
S. Becker, A. Rahmel, M. Schorr, M. Schütze,Oxid. Met.,1992,38, 425.
S. M. L. Sastry, H. A. Lipsitt, O. Izumi, H. Kimura, in:Proc. 4th Int. Conf. Titanium Kyoto 1980, p. 1231.
H. A. Lipsitt,Mat. Res. Soc. Symp. Proc. 1985,39, 351.
Y.-W. Kim,JOM,1989,41, 24.
N. S. Choudhury, H. C. Graham, J. W. Hinze, in:Properties of High Temperature Alloys (Z. A. Foroulis, F. S. Petit, eds.), The Electrochem. Soc., 1976, p. 668.
N. Zheng, H. Nickel, W. J. Quadakkers,Oxid. Met.
S. N. Basu, J. W. Halloran,Oxid. Met. 1987, 27.
W. J. Quadakkers, A. Elschner, W. Speier, H. Nickel,Appl. Surface Sci. 1991,52, 271.
U. Figge, A. Elschner, N. Zheng, H. Schuster, W. J. Quadakkers,Fresenius J. Anal. Chem. 1993,346, 75.
A. Gil, H. Hoven, E. Wallura, W. J. Quadakkers,Corr. Sci. 1993,34, 615.
G. H. Meier, F. S. Pettit,High Temperature Intermetallics, London, 30 April–1 May 1991, The Royal Society, p. 66.
W. J. Quadakkers, A. Elschner, N. Zheng, H. Nickel,12th International Corr. Congress Vol. 5B, 19–24 September, 1993, Houston, USA, NACE, p. 3842.
G. H. Meier, F. S. Pettit, S. Hu,J. Physique 1993,IV, 395.
P. Kofstad,High, Temperature Corrosion, Elsevier, London, 1988, p. 323.
U. Figge, W. J. Quadakkers, H. Schuster, F. Schubert, in:Proceedings EUROCORR ‘92’ Espoo, Finland, 31 May–4 June 1992, Vol. 1, p. 591.
K. Przybylski, A. J. Garratt-Reed, B. A. Pint, E. P. Katz, G. J. Yurek,J. Electrochem. Soc. 1987,134, 3207.
B. A. Pint, J. R. Martin, L. W. Hobbs,Oxid. Met.,1993,39, 167.
R. A. Versaci, D. Clemens, R. Hussey, W. J. Quadakkers,Solid State Ionics 1993,59, 235.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nickel, H., Zheng, N., Elschner, A. et al. The oxidation behaviour of niobium containing γ-TiAl based intermetallics in air and argon/oxygen. Mikrochim Acta 119, 23–39 (1995). https://doi.org/10.1007/BF01244851
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01244851