Affordable Access

Publisher Website

Experimental lower bounds on geometrically necessary dislocation density

Authors
Journal
International Journal of Plasticity
0749-6419
Publisher
Elsevier
Publication Date
Volume
26
Issue
8
Identifiers
DOI: 10.1016/j.ijplas.2010.03.009
Keywords
  • Single Crystal
  • Geometrically Necessary Dislocation (Gnd) Density
  • Lattice Rotation
  • Electron Backscatter Diffraction (Ebsd)
  • Orientation Imaging Microscopy (Oim)

Abstract

Abstract A single nickel crystal is indented with a wedge indenter such that a two-dimensional deformation state with three effective plane strain slip systems is induced. The in-plane lattice rotation of the crystal lattice is measured with a three micrometer spatial resolution using Orientation Imaging Microscopy (OIM). All non-zero components of the Nye dislocation density tensor are calculated from the lattice rotation field. A rigorous analytical expression is derived for the lower bound of the total Geometrically Necessary Dislocation (GND) density. Existence and uniqueness of the lower bound are demonstrated, and the apportionment of the total GND density onto the effective individual slip systems is determined. The lower bound solution reduces to the exact solution under circumstances in which only one or two of the effective slip systems are known to have been activated. The results give insight into the active slip systems as well as the dislocation structures formed in the nickel crystal as a result of the wedge indentation.

There are no comments yet on this publication. Be the first to share your thoughts.