The stability and interfacial bonding of coincidence tilt and twist grain boundaries in Al and Cu were examined by using the projector-augmented wave method within the density-functional theory. For the {221} Σ = 9 tilt boundary, glide models were more stable than mirror models for Al and Cu, and the {001} Σ = 5 twist boundary was more stable than the Σ = 9 tilt boundary for Al and Cu, due to smaller structural distortions. There was a tendency that the boundary energies in Al were substantially smaller than those in Cu. This could be explained by the electronic and atomic behavior of bond reconstruction at the interfaces in Al, due to the covalent nature of Al as observed in the charge density distribution, in contrast to rather simple metallic bonding at Cu grain boundaries.

First-Principles Study of the Stability and Interfacial Bonding of Tilt and Twist Grain Boundaries in Al and Cu. R.Z.Wang, M.Kohyama, S.Tanaka, T.Tamura, S.Ishibashi: Materials Transactions, 2009, 50[1], 11-8