Vanadium Effects on a BCC Iron Sigma 3 Grain Boundary Strength

Kim, S., Kim, S., & Horstemeyer, M. (2011). Vanadium Effects on a BCC Iron Sigma 3 Grain Boundary Strength. Proceedings of the 2011 TMS Annual Meeting & Exhibition. San Diego, CA.

Abstract

The effects of micro-alloying element, vanadium, on a BCC Fe sigma 3 (111)[1-10] symmetric tilt grain boundary strength are studied using Density Functional Theory calculations. The lowest energy configuration of the grain boundary structure are obtained from the first-principles calculations. The substitutional and interstitial point defect formation energies of vanadium in the grain boundary are compared. The substitutional defect is prefered to interstitial one. The segregation energies of vanadium onto the grain boundary and its fractured surfaces are computed. The cohesive energy calculation of the grain boundary with and without vanadium show that vanadium strengthen the BCC iron grain boundary. The tensile and shear tests on the grain boundary with and without vanadium segregation are carried out to study the vanadium effect on the grain boundary.