Hostname: page-component-76fb5796d-x4r87 Total loading time: 0 Render date: 2024-04-25T15:41:00.332Z Has data issue: false hasContentIssue false
  • English
  • Français

Nonlocal effects of existing dislocations on crack-tip emission and cleavage

Published online by Cambridge University Press:  03 March 2011

Vijay Shastry ,
Peter M. Anderson  and
Robb Thomson
Vijay Shastry
Affiliation:
Department of Materials Science and Engineering, The Ohio State University, 116 West 19th Avenue, Columbus, Ohio 43210-1179
Peter M. Anderson
Affiliation:
Department of Materials Science and Engineering, The Ohio State University, 116 West 19th Avenue, Columbus, Ohio 43210-1179
Robb Thomson
Affiliation:
Laboratory for Materials Science and Engineering, National Institute of Standards and Technology, Building 223, Room B309, Gaithersburg, Maryland 20899
Get access

Abstract

This paper investigates the criterion for a ductile-to-brittle transition in materials, due to nonlocal shielding effects at the crack tip when the dislocation free zone (DFZ) size is small. It is found that both cleavage and emission criteria are altered by nonlocal shielding, but that the emission shift is dominant, and is always in the direction to increase the local critical stress intensity for emission, kIIe. The nonlocal shift varies with the sum, Σ(γusdj)−3/2, over each dislocation (j), where γus is the unstable stacking fault energy, and dj is the distance from each dislocation to the crack tip. When there is a pileup of many shielding dislocations against a barrier near the crack tip, the total shift for the pileup varies as (γusd)−1. The most likely candidates for a brittle transition induced by the nonlocal shift are materials where barriers to dislocation motion exist within 10–100 nanometers of the crack tip, such as in thin films, multilayers, or ultrafine grain materials.

Type
Articles
Information
Journal of Materials Research , Volume 9 , Issue 3 , March 1994 , pp. 812 - 827
Copyright
Copyright © Materials Research Society 1994

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

1Ohr, S. M., Mater. Sci. Eng. 72, 1 (1985).CrossRefGoogle Scholar
2Anderson, P. M. and Rice, J. R., Scripta Metall. 20, 1467 (1986).Google Scholar
3Lin, I-H. and Thomson, R., Acta Metall. 34, 187 (1986).Google Scholar
4Lin, I-H. and Thomson, R., Scripta Metall. 17, 1031 (1983).Google Scholar
5Clarke, D. R. and Cooke, R. F., Inst. Phys. Conf. Ser. No. 104: Chap. 4, 397 (1989).Google Scholar
6Gerberich, W., Huang, H., Zielinski, W., and Marsh, P. G., Metall. Trans. 24A, 535 (1993).CrossRefGoogle Scholar
7Chang, S-J. and Ohr, S. M., J. Appl. Phys. 52 (12), 7174 (1981).CrossRefGoogle Scholar
8Chang, S-J. and Ohr, S.M., Int. J. Fracture 23, 83 (1983).Google Scholar
9Lashmore, D. S. and Thomson, R., J. Mater. Res. 7, 2379 (1992).Google Scholar
10Li, C. and Anderson, P. M., in Thin Films: Stresses and Mechanical Properties IV, edited by Townsend, P. H., Sanchez, J., Li, C-Y., and Weihs, T. P. (Mater. Res. Soc. Symp. Proc. 308, Pittsburgh, PA, 1993), p. 731.Google Scholar
11Rice, J. R., J. Mech. Phys. Sol. 40, 239 (1992).Google Scholar
12Zhou, S. J., Carlsson, A., and Thomson, R., Phys. Rev. B 47, 7710 (1993).CrossRefGoogle Scholar
13Beltz, G. and Rice, J. R., in Modeling the Deformation of Crystalline Solids, edited by Lowe, T. C., Rollett, A. D., Follansbee, P. S., and Daehn, G. S. (The Minerals, Metals and Materials Society, Warrendale, PA, 1991), p. 457.Google Scholar
14Argon, A., Acta Metall. 35, 185 (1987).Google Scholar
15Thomson, R., Zhou, S. J., Carlsson, A., and Tewary, V., Phys. Rev. B 46, 10613 (1992).Google Scholar
16Rose, J. H., Smith, J. R., and Feranti, J., Phys. Rev. 28, 1835 (1983).CrossRefGoogle Scholar
17Bilby, B. A., Cottrell, A. H., and Swinden, K. H., Proc. R. Soc. A 272, 304 (1963)Google Scholar
18Lin, I-H., Mater. Sci. Eng. 81, 325 (1986).CrossRefGoogle Scholar
19Majumdar, B. S. and Burns, S. J., Int. J. Fracture 21, 229 (1983).Google Scholar
20Bird, P. F. and Friedman, M. D., Handbook of Elliptic Integrals for Engineers and Scientists (Springer, New York, 1971).CrossRefGoogle Scholar
21Hirth, J. P. and Lothe, J., Theory of Dislocations, 2nd ed. (John Wiley, New York, 1982).Google Scholar