|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Mechanical Behavior at the Nanoscale III
||On the Relationship among Lattice Misorientation Field, Strain Gradient Effects, and Indentation Size Effects
||Yanfei Gao, Lucia Nicola, Bennett Larson, George Pharr
|On-Site Speaker (Planned)
Strain gradient effects are commonly modeled as the origin of the indentation size effects, but studies on the microstructural comparisons of experiments and theories are limited. From a strain gradient crystal plasticity model to simulate the lattice rotation field of Cu single crystals under spherical indentation, we found that the forming of distinct sectors of positive and negative angles in the lattice rotation field is governed primarily by the slip geometry and crystallographic orientations, depending only weakly on strain gradient effects, although hardness depends strongly on strain gradients. These predictions agree well with micron-resolution, three-dimensional X-ray microscopy (3DXM) measurements of the lattice rotation fields on variously oriented Cu single crystals. Two-dimensional discrete dislocation simulation results suggest that the hardness in the nanocontact regime is governed synergistically by a combination of strain gradients and source-limited plasticity, but the lattice rotation field is insensitive to these two factors.
||Planned: A print-only volume