Heterogeneity of deformation texture in equal channel angular extrusion of copper

Texture evolution and heterogeneity during equal channel angular extrusion (ECAE) of an annealed pure copper billet are investigated using a combined finite element-polycrystal modeling approach. For the first ECAE pass, texture predictions at several locations across the billet using either the visco-plastic self consistent (VPSC) or Taylor model are compared against orientation imaging microscopy (OIM) texture measurements. The results show significant spatial variation in texture, in good agreement with the OIM measurements, and indicate a better performance of the VPSC model than the Taylor model. The study was extended for routes A and C up to 16 passes. For route A the textures at the top and middle regions are similar, remain much stronger than that in the bottom region, and strengthen with the number of passes. In route C, the textures at the top and bottom positions become similar after the second pass, but are quite different from the textures in the middle; the texture heterogeneity is smaller for odd-numbered passes than for even-numbered passes.