Hostname: page-component-745bb68f8f-b6zl4 Total loading time: 0 Render date: 2025-01-28T14:12:37.351Z Has data issue: false hasContentIssue false
  • English
  • Français

Deformation Mechanisms Responsible for the Creep Resistance of Ti-Al Alloys

Published online by Cambridge University Press:  15 February 2011

M. A. Morris  and
T. Lipe
M. A. Morris
Affiliation:
Institute of Structural Metallurgy, University of Neuchâtel, Av. Bellevaux 51, 2000 Neuchâtel, SWITZERLAND.
T. Lipe
Affiliation:
Institute of Structural Metallurgy, University of Neuchâtel, Av. Bellevaux 51, 2000 Neuchâtel, SWITZERLAND.
Get access

Abstract

Two γ-based Ti-Al alloys with similar grain sizes and, respectively, lamellar and duplex microstructures have been creep tested at 700°C and constant stresses ranging between 280 and 430 MPa. TEM observations have confirmed that the duplex alloy deforms by extensive mechanical twinning whose density increases with applied stress and increasing strain. The new twin interfaces subdivide the γ grains throughout the primary stage of creep. At the onset of the minimum creep rate, the twin interfaces in the duplex alloy behave in the same way as the γ/γ or the α2/γ interfaces in the lamellar alloy. However, single dislocations were also present and it appears that in both alloys the deformation process is controlled by the accumulation and emission of dislocations from the different interfaces.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 460: Symposium Z – High-Temperature Ordered Intermetallic Alloys VII , 1996 , 275
Copyright
Copyright © Materials Research Society 1997

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. Takahashi, T., Nagai, H. and Oikawa, H., Mat. Trans., JIM, 30, 1044, (1989).Google Scholar
2. Hayes, R.W. and London, B., Acta Metall. Mat., 40, 2167, (1992).Google Scholar
3. Es-Souni, M., Bartels, A. and Wagner, R., Acta Metall. Mat., 43, 153, (1995).Google Scholar
4. Wheeler, D. A., London, B. and Larsen, D.E. Jr, Scripta Metall. Mat., 26, 934, (1995).Google Scholar
5. Beddoes, J., Wallace, W. and Zhao, L., Int. Mat. Rev., 40, 197, (1995).Google Scholar
6. Bartholomeus, M. F., Yang, Q. and Wert, J.A.: Scripta Metall., 29, 389, (1993).Google Scholar
7. Huang, S.-C. and Shih, D.S., in Properties and Microstructures of High Temperature Materials, ed. Kim, Y.-W. and Boyer, R.r., TMS, PA, USA, 105, (1991).Google Scholar
8. Bartholomeusz, M. F. and Wert, J.A.:, Met. Mat. Trans., 25A, 2161, (1994).Google Scholar
9. Seo, D.Y., An, S.U., Bieler, T.R., Larsen, D.E., Bhowal, P. and Merrick, H., in Gamma Titanium Aluminides ed. by Kim, Y.-W., Wagner, R. and Yamaguchi, M., TMS, 745, (1995).Google Scholar
10. Feng, C.R., Smith, H.h., Michel, D.J. and Crowe, C.R., in Intermetallic Matrix Composites, ed. Anton, D.L. et al. MRS, Pittsburgh, USA, 194, 219, (1990).Google Scholar
11. Morris, M.A., Phil. Mag A, 68, 237, (1993).Google Scholar
12. Morris, M.A., Phil. Mag A, 69, 129, (1994).Google Scholar
13. Morris, M.A., Intermetallics, 4, 417, (1996)Google Scholar
14. Morris, M.A. and Lipe, T., Intermetallics, in press.Google Scholar
15. Luster, J. and Morris, M.A., Metall. Mat. Trans. 26A, 1745, (1995)Google Scholar
16. Farenc, S., Coujou, A. and Couret, A., Phil. Mag., A67, 127, (1993).Google Scholar
17. Jin, Z. and Bieler, T.R., Phil. Mag., 71A, 925, (1995).Google Scholar
18. Hayes, R. W. and Martin, P.L., Acta Metall. Mat., 40, 2761, (1995)Google Scholar
19. Morris, M.A. and Martin, J.L., Acta Metall., 32, 549, (1984)Google Scholar