Question

Show how a pure edge dislocation loop can develop screw segments by gliding into a new shape. Hence show that it is geometrically possible for an edge dislocation loop to become a source for glide on any plane containing its Burgers vector.

Answer 1

Now, From the above diagram we can conclude that a dislocation L-shaped on the slip plane can have one segment in the edge orientation and the perpendicular segment in the screw orientation. Essesntially the helicoidal layer of the screw terminates along the slip plane becoming the extra half plane of the edge segement. If there were an extended curved connection between the edge and screw segments, i would be a mixed segment. (If horizontal floors were constructed above the helicoidal garage) the edge of the parking ramp represents the horizontal edge dislocation.

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