Dislocation structure during nano-indentation and surface topographic maps

Dislocation structure evolution during nano-indentation is investigated using a three-dimensional multi-scale discrete dislocation plasticity model. This model combines two length scales, discrete dislocation dynamics and continuum finite element analysis. The multiplication, growth and movement of dislocations on different slip planes in the vicinity of the nano-indentation site is studied. Moreover, topographical maps of the nano-indented surface are generated to observe the patterns formed by exiting dislocations. Different initial configurations of dislocation sources are employed in the study. It is observed that the dislocation activity in general and cross-slip activity in particular significantly depends upon the initial configuration of the dislocation sources. Secondly, the orientation of the crystal influences the topography of the nano-indented surface.