New misorientation scheme for a visco-plastic self-consistent model: Equal channel angular pressing of magnesium single crystals

A visco-plastic self-consistent model has been used to model the equal channel angular pressing of magnesium single crystals. A new misorientation scheme is included in the model to reproduce texture, grain misorientation distribution and coincident site lattice distribution. The proposed misorientation scheme is based on the possible interactions between dislocations belonging to different slip systems. It produces specific grain misorientations depending on the relative activity of the slip systems. The results are compared to experimental data measured by the electron backscatter diffraction of magnesium single crystals with different initial orientations processed by ECAP at 503 K. A comparison is also made with predictions of the visco-plastic self-consistent model without grain interactions and considering a co-rotation scheme. It is shown that the approach proposed in this paper reproduces the texture and misorientation angle distribution and the distribution of coincidence site lattice boundaries much better. Qualitative agreement is also obtained for misorientation axes distributions, which allows for the prediction of the distribution of coincidence site lattice boundaries.