Percolation effects during interdiffusion in the Cu-NiAl system

Abstract The interdiffusion in Cu-(Ni-43 at.% Al) system was studied. It was shown that in the diffusion zone Cu atoms substitute mainly Al atoms and the diffusion problem can be treated as a quasibinary. The concentration dependencies of interdiffusion coefficient were determined in the temperature range of 923–1273 K. The rapid increase of interdiffusion coefficient in the narrow region of Cu concentrations was interpreted in terms of percolation model. Calculated percolation threshold for Cu atoms (6.06 at.%) agrees well with the experimental data.