In addition, it has been demonstrated that the microstructures of Si after indentation with a spherical indenter depends on the maximum indentation load [9], loading/unloading rate [22] and, number of applied stress cycles [23].
where Ap is the projected contact area between the indenter and the sample surface at the maximum indentation load, Pmax.
Figure 5 Sequence of instantaneous defect evolution versus indentation penetration depth.
Figure 2b shows the tip at its maximum indentation depth.
Figure 3d illustrates atomic configuration at the maximum indentation depth.
At a slightly larger indentation penetration depth, the indentation loads are much smaller than those of the pristine single-crystal copper surface.
Figure 4 Loading-unloading-reloading process with the maximum indentation depth smaller than the critical indentation depth.
In dry indentation, the maximum indentation force increases from 468.0 to 549.7 eV/Å as the indentation speed increases from 10too 100 m/s.
In wet indentation, the maximum indentation force increases from 423.2 to 565.6 eV/Å with the same increase of speed.
where Pmax is the maximum indentation load and Ac is the projected contact area of the indentation.
