Grain boundary segregation of C, N and O in hcp titanium from first-principles

Abstract

It is believed that grain boundary segregation of light interstitials can serve as possible mechanism of thermal stability in commercially pure nanostructured titanium alloys. In this paper, using first-principles calculations, we show that independent segregation of C, N and O atoms at Σ7 high angle grain boundary in α-Ti is energetically unfavourable. The presence of interstitial elements near and at the grain boundary interface results in the increase of the grain boundary width and specific formation energy.