The segregation of Cu atoms at [110] S = 11 and [001] S = 5 tilt boundaries was studied. The Cu atoms were found to segregate to asymmetrical sites at the S = 11 boundary, and to form zig-zag planar aggregates at the interface. The segregation was dominated by atomic-size and local hydrostatic-stress effects. The Cu atoms preferentially occupied prime diffusion-path sites at both grain boundaries. The Cu segregation increased the vacancy formation, and diffusion, activation energies at S = 11 grain boundaries, and therefore slowed the rate of atomic diffusion.

Atomistic Studies of Segregation and Diffusion in Al-Cu Grain Boundaries X.Y.Liu, W.Xu, S.M.Foiles, J.B.Adams: Applied Physics Letters, 1998, 72[13], 1578-80