The contribution of interstitials to this segregation process was investigated by using a new model. The latter considered 3 types of interstitial dumb-bell, their diffusion and conversion via interstitialcy migration, their recombination with a vacancy, and their vacancy diffusion via positional exchange with a lattice atom. An analysis of radiation-induced segregation kinetics in a Cu-Au alloy was used to check the model, and good agreement was obtained with experimental measurements. The present model was compared with the Wiedersich-Okamoto-Lam model; in which mixed dumb-bell movement was neglected. Effective diffusion coefficients were derived which incorporated the effect of the mixed dumb-bell into the Wiedersich-Okamoto-Lam model.

T.Hashimoto, Y.Isobe, N.Shigenaka: Materials Transactions, 1995, 36[5], 639-44