Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-29T07:24:24.890Z Has data issue: false hasContentIssue false
  • English
  • Français

Dislocation Dynamics in Intermetallic and Oxide Dispersion Strengthened (ODS) Alloys

Published online by Cambridge University Press:  21 March 2011

Ulrich Messerschmidta ,
Susanne Gudera ,
Dietrich Häusslera  and
Martin Bartscha
Ulrich Messerschmidta
Affiliation:
Max Planck Institute of Microstructure Physics, Halle/Saale, D-06120, Germany
Susanne Gudera
Affiliation:
Max Planck Institute of Microstructure Physics, Halle/Saale, D-06120, Germany
Dietrich Häusslera
Affiliation:
Max Planck Institute of Microstructure Physics, Halle/Saale, D-06120, Germany Institute of Materials Science, University of Erlangen/Nürnberg, Erlangen, D-91058, Germany
Martin Bartscha
Affiliation:
Max Planck Institute of Microstructure Physics, Halle/Saale, D-06120, Germany
Get access

Abstract

In situ straining experiments in a high-voltage electron microscope allow the observation of the dynamic behaviour of individual dislocations. Such experiments have been performed on the intermetallic alloys NiAl, NiAl containing 0.2 at% Ta, α-TiAl, and MoSi2, and the oxide dispersion strengthened (ODS) alloys INCOLOY MA956 and INCONEL MA754 in a wide range of temperatures. There are many similarities in the dynamic behaviour of dislocations in the different materials. In the intermetallic alloys, a transition occurs between low temperature mechanisms and a viscous motion in the temperature range of the flow stress anomaly. The viscous motion at high temperatures can be explained by diffusion processes in the dislocation cores, whichcan be described by the theory of the Cottrell effect. The diffusing species can be quite different, alloying components or intrinsic point defects like vacancies and antisite defects existing in the lattice or only in the dislocation cores. If the dislocations are straight and crystallographically oriented during their motion, they may be dissociated and move by a succession of glide and conservative climb between the partial dislocations. In the ODS alloys, the dislocations move between the oxide particles again in a viscous way. The relation between the dislocation dynamics and the strain rate sensitivity of the flow stress is discussed for thedifferent materials.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 652: Symposium Y – Influences of Interface & Dislocation Behavior on Microstructure Evolution , 2000 , Y11.6
Copyright
Copyright © Materials Research Society 2001

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. Messerschmidt, U. and Bartsch, M., Ultramicroscopy 56, 163 (1994).Google Scholar
2. Messerschmidt, U., Guder, S., Häussler, D., and Bartsch, M., Int. Conf. on Processing and Manufacturing of Advanced Materials, THERMEC 2000, LasVegas, 4.-8.12.2000, to be published in J. Mater. Proc. Technol. Google Scholar
3. Messerschmidt, U., Hausählter, R. and Bartsch, M., Mater. Sci. Eng. A 234–236, 822 (1997).Google Scholar
4. Messerschmidt, U., äHussler, D., Bartsch, M. and Sauthoff, G., Intermetallics 7, 455 (1999).Google Scholar
5. Srinivasan, R., Savage, M.F., Noebe, R.D. and Mills, M.J., MRS Proc. 552, KK 9.10.1 (1999).Google Scholar
6. Häussler, D., Bartsch, M., Aindow, M., Jones, I.P. and Messerschmidt, U., Phil. Mag. A 79, 1045 (1999).Google Scholar
7. Guder, S., Bartsch, M., Yamaguchi, M., and Messerschmidt, U., Mater. Sci. Eng. A 261, 138 (1999).Google Scholar
8. Messerschmidt, U., Guder, S., Junker, L., Bartsch, M. and Yamaguchi, M., to be publ. in Mater. Sci. Eng. AGoogle Scholar
9. Guder, S., Bartsch, M. and Messerschmidt, U., submitted to Phil. Mag. AGoogle Scholar
10. Messerschmidt, U., Bartsch, M., Guder, S., ählter, D. Häuä, and Yamaguchi, M., Intermetallics 6, 729 (1998).Google Scholar
11. Messerschmidt, U., Bartsch, M., Guder, S., and Häussler, D., MRS Proc. 552, KK 10.9.1 (1999).Google Scholar
12. Hirth, J.P., Lothe, J., Theory of Dislocations, Wiley, New York, 1982.Google Scholar
13. Christoph, U. and Appel, F., Materials Research Society Fall Meeting 2000, Abstract N7.1Google Scholar
14. Mills, M.J., Srinivasan, R. and Daw, M.S., Phil. Mag. A 77, 801 (1998).Google Scholar
15. Srinivasan, R., Daw, M.S., Noebe, R.D. and Mills, M.J., to bepublished in Phil. Mag. AGoogle Scholar
16. Ito, K., Inui, H., Shirai, Y. and Yamaguchi, M., Phil. Mag. A 72, 1075 (1995).Google Scholar
17. Rösler, J. and Arzt, E., Acta Metall. 38, 671 (1990).Google Scholar
18. Bartsch, M., Wasilkowska, A., Czyrska-Filemonowicz, A., and Messerschmidt, U., Mater. Sci. Eng. A 272, 152 (1999).Google Scholar
19. Häussler, D., Reppich, B., Bartsch, M., and Messerschmidt, U., to be published in Mater. Sci. Eng. AGoogle Scholar