The self-diffusion of 63Ni along boundaries in Ni-25.2Al was investigated by using radiotracer and serial sectioning techniques. By using the near-surface parts of the profiles, which reflected lattice diffusion, the volume diffusion coefficients were estimated. By using the bulk diffusion results, and by analyzing the tails of the measured profiles, grain-boundary diffusivities were calculated for 1273 to 1073K. It was found that these could be described by the relationship:

D (m3/s) = 1 x 10-12 exp[-195(kJ/mol)/RT]

N.P.Zulina, E.V.Bolberova, I.M.Razumovskii: Acta Materialia, 1996, 44[9], 3625-31