The effects of Vanadium on the strength of a bcc Fe \Sigma 3(111)[1-10] grain boundary

TL;DR

This study uses density functional theory to investigate how vanadium micro-alloying affects the strength of a specific bcc iron grain boundary, revealing that vanadium enhances boundary cohesion.

Contribution

It provides first-principles insights into vanadium's role in strengthening bcc Fe grain boundaries, including defect energies and segregation behavior.

Findings

Vanadium prefers substitutional sites in the grain boundary.

Vanadium segregation increases grain boundary cohesion.

Vanadium strengthens the grain boundary structure.

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 \Sigma 3(111)[1-10] grain boundary.