Texture formation during equal channel angular extrusion of fcc and bcc materials: comparison with simple shear

Abstract

The texture formation in one pass of equal channel angular extrusion (ECAE) is investigated in comparison with that after simple shear deformation. The orientation of the die's intersection plane and the deviation of deformation from simple shear along this plane are the two main factors that together contribute to differences in measured ECAE textures from simple shear. With this in mind, an appropriate method for analysis of ECAE textures is developed. Using an idealized simple shear model for ECAE deformation, the ideal orientations and fiber textures for ECAE of both fcc and bcc materials are derived for any die angle. To demonstrate this method, two popular polycrystal models, finite element simulation, and orientation imaging microscopy texture measurements of copper are used to quantify the individual contributions of these two factors in actual ECAE deformation. The importance of comparing ECAE textures with the negative rather than positive shear texture is emphasized, otherwise interpretations of the ECAE experimental and simulated data can be misleading.