Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-29T08:11:09.459Z Has data issue: false hasContentIssue false

Computer Simulation of ao<110> Screw Dislocations in Ni3Al

Published online by Cambridge University Press:  26 February 2011

T.A. Parthasarathy
Affiliation:
Universal Energy Systems Inc., Dayton, OH, 45432.
D.M. Dimiduk
Affiliation:
Wright Research and Development Center, WRDC/MLLM, WPAFB, OH, 45433–6533.
C. Woodward
Affiliation:
Universal Energy Systems Inc., Dayton, OH, 45432.
D. Diller
Affiliation:
Wright Research and Development Center, WRDC/MLLM, WPAFB, OH, 45433–6533.
Get access

Abstract

Dissociation of the ao<110> screw dislocation in Ni3Al was studied using the embedded atom method of computer simulation. The dissociation occurred predominantly along the {111} plane, however, a {001}-plane step occurred in the APB at the center of the configuration. When a pair of ao/2<110> superpartials initially separated in the {111} plane was relaxed, the step formed once again but with a reduced height. When the pair was relaxed from larger distances the step was not formed. The results indicate that the elastic interaction “torque” due to elastic anisotropy is responsible for the formation of the {001} APB step. When a stress was applied to these dislocation configurations by simulation, results confirmed that the step in the APB and the octahedral cross-slipped-core dissociations can be significant barriers to glide of the screw dislocation.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

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) Vitek, V., Crystal Lattice Defects, v5 (1974) p1.Google Scholar
2) Greenberg, B.A., Ivanov, M.A., Gornostirev, Yu.N., Karkina, L.E., Phys.Stat. Sol.(A), 38 (1976) p653.Google Scholar
3) Grinberg, B.A., Ivanov, M.A., Gornostirev, Yu N., Yakovenko, L.I., Phys. Met. Metall., 39 (1978) p 117.Google Scholar
4) Gornostyrev, Yu N., Grinberg, B.A., Yakovenkova, L.I., Phys. Met. Metall.,51 (1981) p 170.Google Scholar
5) Grinberg, B.A., Indenbaum, V.N., Gornostyrev, Yu N., Phys. Met. Metall. 63 (1987) p 60.Google Scholar
6) Yamaguchi, M., Paidar, V., Pope, D.P., Vitek, V., Phil. Mag. A,45(5) (1982)p 867.Google Scholar
7) Paidar, V., Pope, D.P., Vitek, V., Acta Metall., 32 (3) (1984) p 435.Google Scholar
8) Foiles, S.M., Daw, M.S., J. Mater. Res., 2 (1987) p 5.Google Scholar
9) Voter, A.F., Chen, S.P., MRS Symp. Proc., 82 (1987) p 175.Google Scholar
10) Yoo, M.H., Daw, M.S., Baskes, M.I., in “Atomistic Simulation of Materials”, Ed. Vitek, V., Srolovitz, D.J., Plenum Press, N.Y., p 401.Google Scholar
11) Farkas, D., Savino, E.J., Scr. Metall., 22 (1988) p 557.Google Scholar
12) Pasianot, R., Farkas, Diana, Savino, E.J., “Dislocation Core Structure in Ordered Intermetallic Alloys”, Jol de Physique 1ll, special issue “Mechanisms of Deformation and Strength of Advanced Materials”, (1990) in press.Google Scholar
13) Dimiduk, D.M., “Dislocation Structures and Anamolous Flow in L12 Compounds”,“Dislocation Core Structure in Ordered Intermetallic Alloys”, Jol de Physique 1ll, special issue “Mechanisms of Deformation and Strength of Advanced Materials”Google Scholar
14) Timoshenko, S., Goodier, J.N., “Theory of Elasticity”, McGraw-Hill, New York, (1951), p 39.Google Scholar
15) Yoo, M.H., Scr. Metall., v20 (1986) p 915.CrossRefGoogle Scholar
16) Paidar, V., Yamaguchi, M., Pope, D.P. and Vitek, V., Phil. Mag.,A, v45, No5 (1982) pp 883894.Google Scholar
17) Tichy, G., Vitek, V. and Pope, D.P., Phil. Mag. A, v53, No.4 (1986) pp 467484 Google Scholar
18) Takeuchi, S., Phil. Mag. A, v41, No.4 (1980) pp 541553.Google Scholar
19) Clement, N., Caillard, D., Lours, P., Coujou, A., Scr. Metall., v23, (1989) p 563.Google Scholar