Post-deformation microstructure analyses of copper oligocrystals using EBSD and crystal plasticity simulation.

Oligocrystals are millimeter-sized grains, which are conveniently used to draw a better correlation between deformation and microstructure than polycrystals. They usually do not contain an underlying grain, which could affect the deformation of grains that are visible on the specimen surface. The out-of-plane displacements commonly seen at/near grain boundaries in oligocrystals demand the use of stereovision-based Digital Image Correlation (stereo DIC). Recently, tensile deformation of a copper oligocrystal specimen was reported in [1] using high-resolution stereo DIC. In the present work, we perform post-deformation microstructure analyses of that specimen using EBSD and compare the results with a crystal plasticity simulation based on full-constraint Taylor theory. There is little agreement between the EBSD measurements and the crystal plasticity simulations with respect to the extent of grain rotation and the grain orientation spread. Nevertheless, the EBSD measurements reveal a qualitative agreement among the spatial distribution of kernel average misorientation, norm of Nye's dislocation density tensor, and the DIC strain gradients. In addition to showing an excellent agreement between the post-deformation microstructure analyses performed in this work and the published DIC results, we clearly bring out the discrepancies of the crystal plasticity simulation based on Taylor model. [ABSTRACT FROM AUTHOR]