The effect of vanadium impurity on Nickel Σ5(012) grain boundary

We report first-principle density functional theory investigation on the effect of vanadium impurity in the nickel Σ5(012) symmetrical tilt grain boundary (GB) using Norm-conserving pseudopotentials. We first calculate segregation energies for interstitial and different substitutional sites in order to determine site preference and the segregation properties of V in the Ni GB. It is found that vanadium atoms prefer to segregate in the substantial sites of the GB. Furthermore, the calculations of tensile strength for different V positions in Ni Σ5(012) GB show an enhancement of the maximum tensile strength σMax up to 17%, indicating that vanadium acts as a strengthening element in Ni GB, which is in agreement with experimental observations.