Edge dislocation dipoles

The appearance of a (5-7-7-5) defect can be interpreted as the nucleation of a degenerate dislocation loop in the planar hexagonal network of the graphite sheet. The configuration of this primary dipole is a (5-7) core attached to an inverted (7-5) core. The (5-7) defect behaves thus as a single edge dislocation in the graphitic plane. Once... 

Fig. 3.72 Dislocations in MgAl204 spinel deformed at 1800 °C, a 2 % strain, showing mostly edge dislocations and dipoles produced by glide, and b 3 % strain, showing uniform 3-dimensional network of dislocations produced by glide and climb [38]. With kind permission of John Wiley and Sons...

Fig. 6.9 MV electron micrograph of a one percent creep strain specimen (031) lamella the edge dipole seen In A Is enlarged note an as-grown sub-boundary on the right and numerous long edge dislocations parallel to [100] [45]. With kind permission. Permissions Dept., EDP Sciences by Dr. Corinne Griffon and Professor Escaig...

Figure 6.18 Dislocation structure in sapphire deformed 4% by basal glide at 1400°C, consisting of A) glide dislocations, B) edge dipoles, C) faulted dipoles and D, E) dislocation loops. Basal foil, 650 kV. (Micrograph from B. J. Pletka and T. E. Mitchell, Case Western Reserve University, reproduced courtesy of The American Ceramic Society, Westerville, OH.)...

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