Publication Type
Journal
Journal Name
Materials Science and Technology
Publication Date
Page Numbers
1055 to 1059
Volume
28
Issue
9-10
Abstract
The elastic-plastic transition of crystals at small length scales can be quantitatively evaluated by the sudden discontinuities (“pop-ins”) on nanoindentation load-displacement curves. For defect-free crystals under nano-contacts, pop-in stress fluctuations result purely from the thermally activated process of homogeneous dislocation nucleation, while at intermediate contact sizes fluctuations can arise from the spatial statistics of pre-existing defects. Their convolution exhibits a distinct dependence on the stressed volume; the transition between these two is found to depend on dislocation density and crystallography.
