TEXTURE EVOLUTION DURING MULTI-PASS EQUAL CHANNEL ANGULAR EXTRUSION OF BERYLLIUM

摘要

Equal channel angular extrusion (ECAE) is applied to refine grains in beryllium (Be), using die angles of 90° and 120° via route B_C. Comparison of the experimental textures measured by neutron diffraction and the ideal orientations predicted by crystal plasticity simulations suggests that the main deformation mechanisms during ECAE of this material are =type dislocation glide and tensile twinning. The effect of die angle is seen as the rotation of texture about the axis normal to the flow plane. For both cases the main texture components are located at orientations with the crystallographic shear plane parallel to the macroscopic shear plane or crystallographic shear direction parallel to the macroscopic shear direction. Since the textures after ECAE become much stronger that of the initial material, other processing routes should be sought to obtain weakly-textured Be materials that are ideal for potential capsule applications.