Hostname: page-component-848d4c4894-pjpqr Total loading time: 0 Render date: 2024-07-03T11:50:03.140Z Has data issue: false hasContentIssue false

Thermally Activated Unpinning of Screw Dislocations in the Anomalous Regime in L12 Compounds

Published online by Cambridge University Press:  01 January 1992

M. Khantha
Affiliation:
Department of Materials Science and EngineeringUniversity of PennsylvaniaPhiladelphia, PA 19104-6272.
J. Cserti
Affiliation:
Department of Materials Science and EngineeringUniversity of PennsylvaniaPhiladelphia, PA 19104-6272.
V. Vitek
Affiliation:
Department of Materials Science and EngineeringUniversity of PennsylvaniaPhiladelphia, PA 19104-6272.
Get access

Abstract

We present a model for the anomalous increase of the yield stress exhibited by many L12 compounds. It is based on two thermally activated processes that describe respectively the pinning and unpinning of [101] screw dislocations in the (111) plane. The model explains all the important characteristic features observed in the anomalous regime. We discuss the applications of the model to Ni3Ga and Ni3(Al,Ta).

Type
Research Article
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

REFERENCES

1. Takeuchi, S. and Kuramoto, E., Acta Metall. 21, 415 (1973).Google Scholar
2. Pope, D. P. and Ezz, S. S., Int. Met. Rev. 25, 233 (1984).Google Scholar
3. Heredia, F. E. and Pope, D. P., Acta Metall. Mater. 39, 2027 (1991).Google Scholar
4. Thornton, P. H., Davies, R. G. and Johnston, T. L., Metall. Trans. A 1, 207 (1970).Google Scholar
5. Bonneville, J., Baluc, N. and Martin, J. L., Int. Symp. on Intermetallic Compounds - S tructure and Mechanical Properties - (JIMIS-6). edited by Izumi, O. (Sendai, Japan, The Japan Institute of Metals), Vol. p. 323330, (1991).Google Scholar
6. Paidar, V., Pope, D. P. and Vitek, V., Acta Metall. 32, 435 (1984).Google Scholar
7. Hirsch, P. B., Journal de Physique III 1, 989 (1991).Google Scholar
8. Vitek, V. and Sodani, Y., Scripta. Metall. Mater. 25, 939 (1991).Google Scholar
9. Hirsch, P. B., Philos. Mag. A 65, 569612 (1992).Google Scholar
10. Khantha, M., Cserti, J. and Vitek, V., Scripta. Metall. Mater. 27, 481486 (1992).Google Scholar
11. Khantha, M., Cserti, J. and Vitek, V., Scripta. Metall. Mater. 27, 487492 (1992).Google Scholar
12. Hirsch, P. B., to appear in High-Temperature Ordered Intermetallic Alloys V. edited by (Pittsburgh, Materials Research Society), (1993).Google Scholar
13. Teutonico, L. J., Granato, A. V. and Lücke, K., J. Appl. Phys. 35, 220 (1964).Google Scholar
14. Teutonico, L. J., Lücke, K., Heuser, F. W. and Granato, A. V., Journal of the Acoustical Society of America 45, 1401 (1969).Google Scholar
15. Blair, D. G., Hutchinson, T. S. and Rogers, D. H., J. Appl. Phys. 40, 97 (1969).Google Scholar
16. Haberman, R., Mathematical Models. (Prentice Hall Inc., Englewood Cliffs, 1977).Google Scholar
17. Baluc, N., Karnthaler, H. P. and Mills, M. J., Philos. Mag. A 64, 137150 (1991).Google Scholar
18. Heredia, F. H., Ph.D. Thesis, University of Pennsylvania, (1990).Google Scholar
19. Leibfried, G., Z. Phys. 127, 344 (1950).Google Scholar
20. Ezz, S. S., Pope, D. P. and Vitek, V., Acta Metall. 35, 1879 (1987).Google Scholar