The segregation effects of Co and Cr on the bcc Fe Σ3 [1¯10](111) grain boundary cohesion were investigated based upon the Rice–Wang thermodynamics model by the first-principles DMol method within the framework of density functional theory. The electronic properties were studied for Co/Fe and Cr/Fe systems. The calculated segregation energy difference between the grain boundary and the corresponding free surface was 0.25eV for solute Co and −0.43eV for solute Cr, which indicated that Co could weaken and Cr enhance the grain boundary cohesion in bcc Fe. In these systems the chemical effect induced by Co and Cr had crucial effects, but the geometry effect could be neglected. In addition, an anti-parallel spin island was formed around the central of GB.

Effects of Co and Cr on BCC Fe Grain Boundaries Cohesion from First-Principles Study. J.X.Shang, X.D.Zhao, F.H.Wang, C.Y.Wang, H.B.Xu: Computational Materials Science, 2006, 38[1], 217-22