First-principles density functional theory calculations were used to determine decohesion properties of Σ = 5 (012) grain boundary of Ni with dopants B, C, S, Cr and Hf. The relative stability of sites was evaluated and cleavage energies were calculated. Electronic structure was used to understand these properties in terms of changes in bonding with addition of dopants. It was found that strengthening of the Ni grain boundary resulted from Hf, B and Cr doping. In contrast, the grain boundary weakened with S and C doping. These results were expected to be useful in the design of next-generation nanostructured Ni-based alloys with improved mechanical behavior.

Effect of Dopants on Grain Boundary Decohesion of Ni - a First-Principles Study. S.Sanyal, U.V.Waghmare, P.R.Subramanian, M.F.X.Gigliotti: Applied Physics Letters, 2008, 93[22], 223113