Answer:
A full detail of the edge and screw dislocation and motion is attached in a picture format, attached here.
Explanation:
Edge and Screw Dislocations
• In an edge dislocation, localized lattice distortion exists along the
end of an extra half-plane of atoms.
• A screw dislocation results from shear distortion.
• Many dislocations in crystalline materials have both edge and
screws components; these are mixed dislocations.
• An edge dislocation moves in response to a shear
stress applied in a direction perpendicular to its line.
• Extra half-plane at A is forced to the right; this
pushes the top halves of planes B, C, D in the same
direction.
• By discrete steps, the extra 1/2-plane moves from L
to R by successive breaking of bonds and shifting of
upper 1/2-planes.
• A step forms on the surface of the crystal as the
extra 1/2-plane exits.
Dislocation Motion
