Stress accommodation in rhenium at room temperature

Polycrystalline rhenium is an undeformed metal at room temperature, while in the monocrystalline state rhenium demonstrates considerable plasticity due to the basal slip and the prismatic slip. Such deformation schemes as rolling, bending, shearing, and high-pressure torsion having a different percentage of tensile stress, are considered. Analysis of the dislocation structure of rhenium based on ab initio calculations of its lattice properties is carried out. The type of mechanical behavior of polycrystalline rhenium depends on the share of tensile stress in the deformation scheme. It behaves like a brittle solid under bending, while its behavior is ductile under high-pressure torsion. The cause of its poor plasticity under rolling and bending is the fact that dislocation slip does not activate inside the grains. Possible stress accommodation mechanisms in refractory HCP-metal rhenium at room temperature are discussed.