Diffusion in this system was investigated at 1323 to 1523K via determination of the interdiffusion coefficients. The main interdiffusion coefficients of this

system were larger than the cross-interdiffusion coefficients; indicating that the influence of the concentration gradients of the elements generally still predominated. From the ratio of the cross-interdiffusion coefficient to the main one, |Dijk/Diik|, it was found that the effect of Co upon the diffusion of Re was more appreciable than that of Ru. From a comparison of diffusion in the binary Ni-Re and ternary Ni-Co-Re, it was clear that the presence of Co reduced Re diffusivity in Ni. The results thus revealed that an attractive force existed between Co and Re, and that the interatomic bonding of Co-Re seemed to be stronger than that of Ni-Re. The interdiffusion coefficients could be described by the Arrhenius expressions:

DCoCoNi(m2/s) = 3.45 x 10-5exp[-265.56(kJ/mol)/RT]

DRuRuNi(m2/s) = 5.99 x 10-5exp[-291.27(kJ/mol)/RT]

DCoRuNi(m2/s) = 8.59 x 10-8exp[-237.99(kJ/mol)/RT]

DRuCoNi(m2/s) = 2.62 x 10-5exp[-307.71(kJ/mol)/RT]

E.Mabruri, S.Sakurai, Y.Murata, T.Koyama, M.Morinaga: Materials Transactions, 2007, 48[10], 2718-23