Inhomogeneous deformation of {111}<uvw> grain in cold rolled tantalum

The microstructures of {111} grain were characterized in detailed and systematically investigated with the aid of electron backscatter diffraction (EBSD) and transmission electron microscope (TEM). The stored energy in different regions in the grain was evaluated by the band contrast values collected from EBSD. The results show that the distribution of energy is inhomogeneous through the grain. Especially, the regions containing the least and the largest energy were extracted from the EBSD data, and then quantitatively analyzed based on the misorientation and Schmid factor. Many peaks with large misorientation appeared in the region containing larger energy, and these peaks represent the existences of micro-bands and micro-shear bands in {111} grain. The results of Schmid factor suggest that the region containing larger energy is prone to deforming ahead of the region with less stored energy, implying the more serious subdivision of the microstructure of region with larger stored energy.