Hostname: page-component-76fb5796d-5g6vh Total loading time: 0 Render date: 2024-04-25T16:24:55.118Z Has data issue: false hasContentIssue false
  • English
  • Français

Microstructure and Oxidation Resistance of Cr-Ta-Si alloys

Published online by Cambridge University Press:  18 January 2011

Ayan Bhowmik ,
Hon Tong Pang ,
Steffen Neumeier ,
Howard J. Stone  and
Ian Edmonds
Ayan Bhowmik
Affiliation:
Rolls-Royce UTP, Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, United Kingdom
Hon Tong Pang
Affiliation:
Rolls-Royce UTP, Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, United Kingdom
Steffen Neumeier
Affiliation:
Rolls-Royce UTP, Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, United Kingdom
Howard J. Stone
Affiliation:
Rolls-Royce UTP, Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, United Kingdom
Ian Edmonds
Affiliation:
Rolls-Royce plc, P.O.Box 31, Derby, DE24 8BJ, United Kingdom
Get access

Abstract

The phase equilibria and oxidation resistance of alloys lying near the Cr-rich end of the Cr- Ta-Si system have been investigated. Samples were prepared by arc-melting and homogenized at 1300°C for 500hrs. Identification of the phases present and their compositions were carried out using x-ray diffraction and electron probe micro-analysis and the ternary phase diagram on the Cr-rich end was plotted. A three-phase equilibria was found to exist between an A2 Cr-solid solution, a hexagonal Laves phase and the A15 Cr3Si intermetallic phase for alloys with higher contents of Si.Thermo-gravimetric analysis of the alloys at 1100°C demonstrated an improvement in the oxidation resistance of the ternary alloys with increasing Si-content. The microstructures of the oxidized samples revealed the formation of a thick chromia layer on top of a Cr,Ta-mixed oxide layer and an internal oxidation zone for all the alloys. A protective silica layer was not observed to form in any of the alloys tested.

Keywords

phase equilibriaoxidationthermogravimetric analysis (TGA)
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1295: Symposium N – Intermetallic-Based Alloys for Structural and Functional Applications , 2011 , mrsf10-1295-n06-05
Copyright
Copyright © Materials Research Society 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Fleischer, R. L., Taub, A. L., J. Metals 41, 8 (1989).Google Scholar
2. Anton, D. L., Shah, D. M., Duhl, D. N., Giamei, A. F., J. Metals 41, 12 (1989).Google Scholar
3. Anton, D. L., Shah, D. M., Mater. Sci and Engg. A 153, 410 (1992).Google Scholar
4. Fleischer, R. L., J. Metals 22, 2281 (1987).Google Scholar
5. Thoma, D., Perepezko, J., Mater. Sci Engg A 156, 97 (1992).Google Scholar
6. Takeyama, M., Liu, C., Mater. Sci Engg A 132, 61 (1991).Google Scholar
7. Kumar, K. S., Pang, L., Horton, J. A., Liu, C. T., Intermetallics 11, 677 (2003).Google Scholar
8. Kumar, K. S., Miracle, D., Intermetallics 2, 257 (1994).Google Scholar
9. Chen, K., Allen, C., Livingston, J., J. Mater Res 12, 1472 (1997).Google Scholar
10. Bhowmik, A., Stone, H. J., under preparation (2010).Google Scholar
11. Kumar, K. S., Pang, L., Liu, C. T., Horton, J. A., Kenik, E. A., Acta Mater. 48, 911 (2000).Google Scholar
12. Mittal, R. C., Si, S. K., Gupta, K. P., Journal of the Less Common Metals 60, 75 (1978).Google Scholar
13. Brady, M. P., Tortorelli, P. F., Payzant, E. A., Walker, L. R., Oxidation of Metals 61, 379 (2004).Google Scholar