Considerable grain growth occurred in a nanostructured Cu sample produced by surface mechanical attrition treatment during isothermal annealing at 423K. The time-dependence of diffusion of 63Ni in the nanostructured Cu was investigated by the radiotracer technique. It was shown that the apparent interfacial diffusivity determined by taking into account the grain growth effects was higher by a factor of 10 than the value determined according to the model of stationary interfaces.

Effects of Grain Growth on Interface Diffusion in Nanostructured Cu. Z.B.Wang, K.Lu, G.Wilde, S.V.Divinski: Scripta Materialia, 2011, 64[11], 1055-8