Simulations of texture evolution in heavily deformed bulk nanocrystalline nickel

The texture evolution in cold-rolled coarse-grained (CG) and nanocrystalline (NC) Ni sheets is simulated by the viscoplastic self-consistent and Taylor-type dislocation-based plasticity models, respectively. The simulated three-dimensional crystal orientation distributions are directly compared with the X-ray diffraction experimental measurements. Both models capture very well the texture development in the CG Ni, although the simulated brass texture component, i.e., {100}< 112 >, is slightly weaker than the experimental value. In the simulations of the texture evolution for the NC Ni, we add a shearing-strain component epsilon(13) to the total velocity gradient tensor and reduce the number of active {111}< 110 > slip systems from 12 to 8. The new constrained conditions retard the development of the brass component and lead to the enhancement in the initial cube orientation, i.e., {100}< 001 >, in agreement with the experimental observations in the cold-rolled NC Ni sheets. The present investigations suggest that the dislocation-based plasticity mechanism is still the dominant one in affecting the deformation behavior of NC Ni with an initial grain size of similar to 28 nm. (c) 2007 Elsevier B.V. All rights reserved.