Investigation Of Diffusion Behavior Of Solute Atoms In Nanocrystalline Copper

In this paper, nanocrystalline layer is obtained by SMAT on the surface of pure copper in order to investigate diffusion behavior of solute in it. By carbon ion implantation, painting Ag slurry and electric plating Ni into/on the surface of nanocrystalline copper, some stable diffusion sources are obtained, in which the atoms are interstitial or substitutional. The specimens treated are annealed at given temperatures for some time to study microstructures and concentration profiles of the solute by means of XRD, SEM, TEM, HRTEM and AES. The conclusions can be drawn as follows:(1) In the nanocrystalline materials, concentration and depth of carbon ion implantation are enhanced due to large amount of grain boundaries and vacancies contained, which carbon atoms will easily migrate and segregate along.(2) Amorphous carbon and carbon nano-onions are synthesized by carbon ion implantation into copper substrate heated at given temperatures, which is the result of electron beam irradiation. The fast diffusion possibly relates to the nanocrystalline structures and the irradiation induced injury by ion beams.(3) The nanosized grains still exist without obvious coarsening at 300°C. Diffusion phenomena on interface between Silver/Nickel layers, which are painted or electroplated on the surface of nanocrystalline copper respectively, and copper substrate is observed after annealed at lower temperatures. It...