Texture evolution maps for upset deformation of body-centered cubic metals

Texture evolution maps are used as a tool to visualize texture development during upset deformation in body-centered cubic metals. These maps reveal initial grain orientations that tend toward normal direction (ND)||〈1 1 1〉 versus ND||〈1 0 0〉. To produce these maps, a finite element analysis (FEA) with a rate-dependent crystal plasticity constitutive relation for tantalum is used. A reference case having zero workpiece/die friction shows that ∼64% of randomly oriented grains rotate toward ND||〈1 1 1〉 and ∼36% rotate toward ND||〈1 0 0〉. The maps show well-established trends that increasing strain rate sensitivity and decreasing latent-to-self hardening ratio reduce both 〈1 1 1〉 and 〈1 0 0〉 percentages, leading to more diffuse textures. Reducing operative slip systems from both {1 1 0}/〈1 1 1〉 and {1 1 2}/〈1 1 1〉 to just {1 1 0}/〈1 1 1〉 has a mixed effect: it increases the 〈1 1 1〉 percentage but decreases the 〈1 0 0〉 percentage. Reducing the number of slip systems and increasing the number of FEA integration points per grain strengthen 〈1 1 1〉–〈1 0 0〉 texture bands that are observed experimentally.