Hostname: page-component-745bb68f8f-v2bm5 Total loading time: 0 Render date: 2025-01-25T06:27:33.068Z Has data issue: false hasContentIssue false
  • English
  • Français

Quantitative Observations in Dislocation Mechanisms in Gamma TiAl

Published online by Cambridge University Press:  22 February 2011

B. Viguier ,
M. Cieslar ,
K. J. Hemker  and
J. L. Martin
B. Viguier
Affiliation:
Institut Genie Atomique, EPFL, CH-1015 Lausanne, Switzerland
M. Cieslar
Affiliation:
Institut Genie Atomique, EPFL, CH-1015 Lausanne, Switzerland
K. J. Hemker
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD
J. L. Martin
Affiliation:
Institut Genie Atomique, EPFL, CH-1015 Lausanne, Switzerland
Get access

Abstract

Quantitative TEM observations have been made on a series of gamma Ti47Al51Mn2 polycrystals that were deformed at different temperatures. Special attention has been given to determining the statistical variation of defect densities that occur at the different temperatures. The results, which are in good agreement with mechanical testing [J], indicate that three different mechanisms control deformation in this alloy: lattice friction and the formation of faulted dipoles at low temperatures, the pinning of ordinary dislocations at intermediate temperatures, and the bowing and looping of dislocations at high temperatures. The anomalous flow strength of this alloy has been found to be related to the intrinsic pinning of ordinary dislocations. Details of this pinning and subsequent unzipping process, which are the basis for the new local-pinning-unzipping (LPU) models[2-4], are outlined within.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 364: Symposium L – High-Temperature Ordered Intermetallic Alloys–VI , 1994 , 653
Copyright
Copyright © Materials Research Society 1995

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

1. Viguier, B., Bonneville, J., Hemker, K.J., Martin, J.L., MRS Symp. Proc., this volume, (1994).Google Scholar
2. Louchet, F. and Viguier, B., Scripta Metall. et Mater., 31, 369, (1994).Google Scholar
3. Louchet, F. and Viguier, B., Phil. Mag. A, in press, (1994).Google Scholar
4. Louchet, F. and Viguier, B., MRS Symp. Proc., this volume, (1994).Google Scholar
5. Hug, G., Loiseau, A. and Lasalmonie, A., Phil. Mag. A, 54, 47, (1986).Google Scholar
6. Schäublin, R. and Stadelmann, P., Mat. Sci and Eng. A, 164, 373, (1993).Google Scholar
7. Viguier, B., Hemker, K.J. and Vanderschaeve, G., Phil. Mag. A., 69, 19, (1994).Google Scholar
8. Shechtman, D., Blackburn, M.J. and Lipsitt, H.A., Met. Trans. A, 5, 1373, (1974).Google Scholar
9. Whang, S.H. and Hahn, Y.D., Scripta Metall. et Mater., 24, 485, (1990).Google Scholar
10. Morris, M.A., Phil. Mag. A, 69, 129, (1994).Google Scholar
11. Furubayashi, E., J. of Phys. Soc. of Japan, 27, 130, (1969).Google Scholar
12. Viguier, B., Hemker, K.J., Bonneville, J., Louchet, F. and Martin, J.L, Phil. Mag. A, in press, (1994).Google Scholar
13. Rao, S.I. and Dimiduk, D.M., MRS Symp. Proc., this volume, (1994).Google Scholar
14. Kad, B.K. and Fraser, H.L., Phil. Mag. A, 69, 689, (1994).Google Scholar
15. Hemker, K.J., Viguier, B. and Mills, M.J., Mater. Sci. and Eng. A, 164, 391, (1993).Google Scholar