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Mesoscopic Simulation of Dislocation Activity at Crack Tips

Published online by Cambridge University Press:  15 February 2011

A. Hartmaier
Affiliation:
Max-Planck-Institut für Metallforschung, Stuttgart (hartmaie@finix.mpi-stuttgart.mpg.de)
P. Gumbsch
Affiliation:
Max-Planck-Institut für Metallforschung, Stuttgart
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Abstract

Discrete dislocation dynamics simulations have been performed to study dislocation activity in the vicinity of a crack tip and to get a better understanding of the decisive mechanisms of the brittle-to-ductile transition (BDT). The comparison of these simulations with fracture experiments on tungsten single crystals leads to a preliminary model for the BDT of this material. Many features predicted by this model are also found in other materials. Dislocation nucleation and the availability of active sources are shown to be limiting plasticity at low temperatures and partly in the semi-brittle regime. At elevated temperatures dislocation nucleation occurs easily, such that plasticity in this regime and the BDT itself, must be viewed as a thermally activated processes, which are controlled by dislocation mobility.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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References

1. Rice, J. R. and Thomson, R., Phil. Mag. A 29, 73 (1974).Google Scholar
2. Khantha, M., Vitek, V., and Pope, D. P., Key Eng. Mat. 103, 227 (1995).Google Scholar
3. Hirsch, P. B., Roberts, S. G., and Samuels, J., Proc. R. Soc. Lond. A421, 25 (1989).Google Scholar
4. Nitzsche, V. R. and Hsia, K. J., Mat. Sci. and Eng. A176, 155 (1994).Google Scholar
5. Roberts, S. G., in Computer Simulations in Materials Science, edited by Kirchner, H. O., Kubin, L. P., and Pontikis, V. (Kluwer Academic Publishers, Dordrecht, 1996), 308, pp 409433.Google Scholar
6. Hartmaier, A. and Gumbsch, P., phys. stat. sol. (b) 202 R1 (1997).Google Scholar
7. Gumbsch, P., Riedle, J., Hartmaier, A., and Fischmeister, H. F., Science 282 1293 (1998).Google Scholar
8. Abraham, F. F., Schneider, D., Land, B., Lifka, D., Skovira, J., Gerner, J., and Rosendrantz, M., J. Mech. Phys. Solids 45 1461 (1997).Google Scholar
9. Schoeck, G., Phil. Mag. A 63 111 (1991).Google Scholar
10. Zhou, S. J. and Thomson, R., J. Mater. Res. 6 639 (1991).Google Scholar
11. Xu, G., Argon, A. S., and Ortiz, M., Phil. Mag. A 72 415 (1995).Google Scholar
12. Lin, I.-H. and Thomson, R., Acta metall. 34 187 (1986).Google Scholar
13. Thomson, R., in Solid State Physics, edited by Ehrenreich, H. and Turnbull, D., (Academic Press, New York, 1986) 39, pp. 1129.Google Scholar
14. Riedle, J., Gumbsch, P., and Fischmeister, H. F., Phys. Rev. Lett. 76 3594 (1996).Google Scholar
15. Kocks, U. F., Argon, A. S., and Ashby, M. F., in Progress in Materials Science, edited by Chalmers, B., Christian, J. W., and Massalski, T. B. (Pergammon Press Ltd., Oxford, England, 1975) 19, chap. 3.Google Scholar
16. Samuels, J. and Roberts, S. G., Proc. R. Soc. Lond. A 421 1 (1989).Google Scholar
17. Serbena, F. C. and Roberts, S. G., Acta metall. mater. 42 2505 (1994).Google Scholar
18. Schadler, H. W., Acta metall. 12 861 (1964).Google Scholar
19. Prekel, H. L., Lawly, A., and Conrad, H., Acta metall. 16 337 (1968).Google Scholar
20. Ziebart, U., PhD thesis, Universitiit Stuttgart, 1986.Google Scholar
21. Brunner, D., presented at the UHPM-98, Sevrier Annecy Lake, France, 1998 (unpublished).Google Scholar
22. Argon, A. S., and Maloof, S. R., Acta metall. 14 1449 (1966).Google Scholar
23. Bucki, M., Novák, V., Savitsky, Y. M., Burkhanov, G. S., and Kirillova, V. M., in Strength of Metals and Alloys, 1, pp. 145150, 1979.Google Scholar
24. Devincre, B., and Roberts, S. G., Acta mater. 44 2891 (1996).Google Scholar
25. Riedle, J., PhD thesis, Universität Stuttgart, 1995.Google Scholar
26. Riedle, J., Gumbsch, P., Fischmeister, H. F., Glebovsky, V. G., and Semenov, V. N., Mat. Letters 20 311 (1994).Google Scholar
27. Zhou, S. J., and Thomson, R., J. Mater. Res. 6 1763 (1991).Google Scholar
28. Warren, P. D., Scripta metall. 23 637 (1989).Google Scholar
29. Ebrahimi, F. and Shrivastava, S., Acta mater. 46 1493 (1998).Google Scholar
30. Booth, A. S. and Roberts, S. G., Acta mater. 45 1045 (1997).Google Scholar
31. Bergmann, G. and Vehoff, H., Mat. Sci. and Eng. A192/193 309 (1995).Google Scholar
32. Michot, G., presented at the 2do Congresso Internacional de Technologia Metalurgica e de Materiais (ABM), Sao Paulo, Brasil, 1997 (unpublished).Google Scholar
33. Gumbsch, P., J. Mat. Sci. 10 2897 (1995).Google Scholar