Diffusion in the γ'-phase was investigated at 1423 to 1523K by using pseudo-binary diffusion couples. The cross interdiffusion coefficient, DAlRuNi, was independent of matrix ordering since it was qualitatively comparable with those in the γ'-Ni3Al and γ-Ni phases. The tracer diffusion coefficient of Ru in Ni3Al was estimated by extrapolation, and the activation energy was consistent with the site preference of the element. The diffusivity in the γ’ phase could be described by:

D(m2/s) = 1.3 x 10-3exp[-318.7(kJ/mol)/RT]

These results suggested that the diffusion of Ru in Ni3Al was governed mainly by diffusion in the Ni sub-lattice.

E.Mabruri, S.Sakurai, Y.Murata, T.Koyama, M.Morinaga: Materials Transactions, 2008, 49[6], 1441-5