Ideal mechanical properties of vanadium by a first-principles computational tensile test

We employ first-principles total energy method based on the density functional theory with the generalized gradient approximation to investigate the ideal tensile strengths of a bcc vanadium (V) single crystal systemically. The ideal tensile strengths are calculated to be 19.1, 32.8 and 31.0 GPa for bcc V in the [1 0 0], [1 1 0] and [1 1 1] directions, respectively. We show that the [0 0 1] direction is the weakest direction due to the occurrence of structure transition at the lower strain and the [1 1 0] direction is strongest because of the stronger interaction of atoms between the (1 1 0) planes in comparison with the (0 0 1) and (1 1 1) planes. We derive the Young’s modulus formula V single crystal in different tensile directions and give detailed analysis. According to the elastic constants of V single crystal, we have estimated some mechanical quantities of polycrystalline V, which are the bulk modulus of B, the shear modulus of G, Young’s modulus of E and the Poisson’s ratio of ν. The results might provide a useful reference for V as a candidate structural material in the fusion Tokamak.