Abstract
We present computer simulation results for the planar faults involved in core spreading of 〈100〉 and 〈111〉 dislocations. Seven γ surfaces were computed for different crystallographic planes ({110}, {112}, {123}, {210}, {100}, {111}, and {122}). Stable APB’s are observed in the {110} and {112} planes, but they are deviated from the exact 1/2a〈111〉 position. No other stable planar fault was observed. The fact that a stable minimum is observed deviated from the 1/2〈111〉 position suggests the possibility of different dissociation reactions for the 〈111〉 screw dislocation in the {110} and {112} planes. The fact that no other stable minima were observed in the γ surfaces indicates that no true core dissociation is expected for the 〈100〉 dislocations. We propose that dislocation core spreading in various planes can be understood in terms of the directions of lowest restoring forces observed for the corresponding γ surfaces.
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References
I. Baker and P. Munroe, in High Temperature Aluminides and Intermetallics, edited by S. H. Whang, C. T. Liu, D. P. Pope, and J. O. Stiegler (TMS, Warrrendale, PA, 1990), p. 425.
R. Pasianot, D. Farkas, and E. J. Savino, J. Phys. III 1, 997 (1991).
D. Farkas, R. Pasianot, D.B. Miracle, and E.J. Savino, in High Temperature Ordered Intermetallic Alloys TV, edited by L.A. Johnson, D. P. Pope, and J. O. Stiegler (Mater. Res. Soc. Symp. Proc. 213, Pittsburgh, PA, 1991), p. 217.
V. Vitek, Philos. Mag. 18, 773 (1968).
V. Vitek, Crystal Lattice Defects 5, 1 (1974).
A. F. Voter and S. P. Chen, in Characterization of Defects in Materials, edited by R. W. Siegel, J. R. Weertman, and R. Sinclair (Mater. Res. Soc. Symp. Proc. 82, Pittsburgh, PA, 1987), p. 175.
M.J. Norgett, R. C. Perrin, and E.J. Savino, J. Phys. F2, L73 (1972).
M. Yamaguchi, D.P. Pope, and V. Vitek, Philos. Mag. A 43, 1265 (1981).
M. Yamaguchi and Y. Umakoshi, in The Structure and Properties of Crystal Defects, edited by V. Paidar and L. Lejček (Elsevier, Amsterdam, 1983), p. 131.
T. Parthasarathy, S.I. Rao, and D. Dimiduk, Philos. Mag. (1993, in press).
S.C. Tonn, Y. Zhang, and M.A. Crimp, Mater. Sci. Eng. (1993, in press).
J. T. Kim and R. Gibala, in High Temperature Ordered Intermetallic Alloys IV, edited by L. A. Johnson, D. P. Pope, and J. O. Stiegler (Mater. Res. Soc. Symp. Proc. 213, Pittsburgh, PA, 1991), p. 261.
M.J. Mills and D.B. Miracle, Acta Metall. Mater. 41, 85 (1993).
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Farkas, D., Vailhe, C. Planar fault energies and dislocation core spreading in B2 NiAl. Journal of Materials Research 8, 3050–3058 (1993). https://doi.org/10.1557/JMR.1993.3050
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DOI: https://doi.org/10.1557/JMR.1993.3050